anil - limbs

Anatomy of the LimbsLCRS Year 2

Anil Chopra

ContentsLimbs 1a - Bone Growth, organisation and repair...................................................1Limbs 1b - Overview of Anatomy of Upper and Lower Limbs...............................6Limbs 2 – Shoulder and Arm....................................................................................10Limbs 3 – Elbow, Forearm and Wrist......................................................................24Limbs 4 – Hand..........................................................................................................33Limbs 5 – Brachial Plexus.........................................................................................42Limbs 6 - Hip, Buttock and Thigh............................................................................44Limbs 7 – Knee, Popliteal Fossa, Leg and Foot.......................................................58Limbs 8 - Lower limb Nerves and Vessels...............................................................74

Limbs 1a - Bone Growth, organisation and repairAnil Chopra

1 Outline the process of longitudinal growth of long bones making appropriate use of the following terms: cartilage model; primary ossification centre; diaphysis; secondary ossification centre; epiphysis; epiphyseal plate; calcification; vascularisation; ossification

2 Suggest possible advantages of epiphyseal growth over simple appositional growth at the bone extremities.

3 Suggest reasonable dates for the appearance of primary and secondary centres of ossification for long bones.

4 Recognise ossification centres in radiographs of growing limbs and use this information to estimate the age of a child.

5 Explain how bones grow in diameter and are remodelled.6 Describe the sequence of events in the repair of a fracture.7 List the main risk factors for fracture of the femoral neck.8 Identify anatomical and other factors that may compromise satisfactory repair of

fractures of the femoral neck.9 Explain the principles of management of simple fractures of limb bones.10 List the main dangers of limb fractures and of their mismanagement.

Functions of Bone:- support- storage of minerals- protection- levers for movement- site of blood cell production

Types of Bone:Woven – immature, in growing skeletons or in fractures. Weaker and more flexible than lamellar bone.Lamellar - mature, in normal skeletons. There are two types (usually arranged as layers – compact on the outside and cancellous on the inside):

- Cortical (compact): 80% of skeleton, high resistance to torsion and bending. Normally on the outside of the lamellar bone. Here the functional unit is the Haversian system, which has osteocytes round the outside and a Haversian canal on the inside. They are arranged into concentric layers of matrix called lamellae.

- Cancellous (trabecular): less dense, spicules of marrow in between; has high turnover rate. Normally on the inside of the lamellar bone. There are no lamellae in cancellous bone, only a network of rods called trabeculae.

Adaptability in Bone: Can grow without compromising its support functions – redundancy Increases or decreases bulk and density in response to pattern of use Can alter its shape both internally and externally in response to the pattern of use

– remodelling Can repair when fractured

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Cells in BoneOsteocytes: mature bone cells that lie within a lacunae (each lacunae contains one osteocyte). The lacunae are connected by canaliculi. Their role is to maintain bone matrix and repair bone. When bone is damaged, osteocytes are no longer bound to the lacunae and so they differentiate into osteoblasts and osteoprogenitor cells.

Osteoblasts: produce bone matrix. They eventually become osteocytes.

Osteoprogenitor cells: stem cells that differentiate into osteoblasts. Involved in fracture and repair.

Osteoclasts: (giant cells) remove bone matrix. They are derived from monocytes. This results in a constant turnover of bone matrix with the osteoblasts producing bone and the osteoclasts removing bone. This is known as remodelling and occurs as a result of different physical stresses put on the bone. Around 20% of the adult skeleton is remodelled each year.

Bone MatrixThe combination of substances in the bone matrix gives bone its mechanical properties. It consists of:

Collagen fibres: strong, flexible, good at resisting tension, twisting, bending, and provide a lattice for the hydroxyapatite crystals. They are not good for resisting compression.

Inorganic Ions: mainly calcium phosphate, calcium hydroxyapatite, and calcium hydroxide. The calcium phosphate crystals are hard but inflexible and brittle but good at resisting compression.

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PeriosteumThe periosteum is a thin layer of dense, irregular connective tissue membrane that covers the outer surface of a bone in all places except at joints. The outer layer is fibrous and the inner layer is cellular. Its job is to protect the bone from the surrounding tissues and also allows blood vessels and nerves into the bone. It is also very important for growth and repair.

EndosteumThe endosteum is a thin layer of connective tissue which lines the surface of the bony tissue that forms the medullary cavity (or marrow cavity) of long bones. It is very active in bone growth and repair.

Blood Supply in Bones

Periostial Arteries: enter bone via the periosteum. Stripping the periostium in a fracture can result in disruption of the blood supply from the bone and can also lead to bone infection and death.

Nutrient Arteries: enters near the middle of the bone, passing obliquely through the cortical bone and supplies the cancellous bone.

Metaphyseal and epiphyseal arteries: supply the ends of the bones. These are only present in a growing skeleton.

Nerve Supply to Bones

The periosteum that surrounds bone is richly innervated with sensory (pain and proprioception) fibres. The blood vessels going to bone also have sympathetic supply.

Growth of BonesBones grow from the 6th week of foetal life until 25 years of age. They grow via two different processes:

Intramembranous Ossification

This forms directly from the mesenchyme, an embryonic connective tissue. It occurs mainly in bones that are directly beneath the skin e.g. skull, mandible and clavicle. It occurs as follows: Mesenchymal cells produce bone matrix (osteoid) containing collagen. Osteoid becomes mineralised with calcium salts. Cells in the mesenchyme differentiate into osteoblasts. These produce more matrix. Some osteoblasts get trapped in lacunae and become osteocytes. Blood vessels grow and maintain blood metabolism. This forms cancellous bone The cancellous bone eventually remodels into cortical bone. Periosteum forms around the bone and traps the surface layer of osteoblasts

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http://en.wikipedia.org/wiki/Bone

http://en.wikipedia.org/wiki/Medullary_cavity

http://en.wikipedia.org/wiki/Connective_tissue

http://en.wikipedia.org/wiki/Bone

http://en.wikipedia.org/wiki/Membrane

http://en.wikipedia.org/wiki/Connective_tissue

Endrochondral Ossification

Most long bones ossify in this way and it involves the mesenchymal cells forming cartilage and then the cartilage ossifying. This allows them to support large forces while growing: Mesenchymal cells differentiate into chondroblasts (cells which form cartilage). These chondroblasts make cartilage models of the bone which expand by

expansion of the cartilage matrix. In the middle of the bone the chondrocytes die as the cartilage is increasingly

calcified and capillaries from the periosteum penetrate to the centre forming a periosteal bud.

This differentiates into osteoblasts and forms a primary ossification centre. This grows outwards forming a diaphysis. Appositional growth increases the

diameter of the diaphysis. Secondary ossification centres form at the epiphyses (ends) of the bone, usually

around 2 years after birth. The area between the diaphysis and the epiphyses is the epiphyseal plate.

The bone grows by adding at each epiphysis and only stops when the epiphyses meet the diaphysis.

This growth stops at puberty (increased hormone levels stop growth)

NB: calcification is not the same as ossification, ossification is vascular, calcification is not.

Growth in bone diameter: Apposition – addition to the exterior of the periosteum Osteoblasts and osteoclasts produce ridges and grooves on bone surface Blood vessels align in grooves Osteoblasts build new osteons around blood vessels Osteoclasts remove bone from endosteal surface

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Fracture Repair

1) When bones are damaged, the vessels rupture producing a vessel haematoma.2) Active osteoblasts and osteoprogenitor cells migrate toward the fracture.3) They form a type bone and cartilage called external callus which bridges the

ends of the bones and internal callus which forms between the bone ends. 4) Chondrocytes produce cartilage, which is calcified to woven bone and then

cancellous bone, which eventually remodels into cortical bone (via osteoblasts and osteoclasts).

Bone Remodelling: Bone is not dead, it is continually remodelling Process of remodelling mirrors bone growth and repair after fracture It is affected by physical stresses placed on the bone and metabolic and hormonal

factors 20% of the adult skeleton is remodelled every year

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Limbs 1b - Overview of Anatomy of Upper and Lower LimbsAnil Chopra

1 Explain briefly the embryological development of the limbs2 Outline briefly the similarities and differences in the upper and lower limbs3 Explain briefly the difference between the segmental and peripheral nerve supply

of a limb4 Describe the essential structure of the upper and lower limbs, noting the

compartmentalised nature of the limbs and their neurovascular supply5 Outline the muscular compartments of the upper limb6 Describe the neurovascular patterns of the upper limb7 Outline the muscular compartments of the lower limb8 Describe the neurovascular patterns of the lower limb9 Explain the neurological components of neurological supply to a limb: motor,

sensory, reflex, autonomic and trophic10 Describe a method whereby the neurological features of nerve injury can be

evaluated using the pattern described above.

Embryology of the LimbsThe limbs grow out of the trunk along with the nerves that are going to supply them (C5-T1 for the arms and L2-S2 for the legs). The upper limbs do not rotate. The lower limbs however undergoes extension and internal rotation.Upper limb – flexors are anterior extensors are posterior Lower Limb – Extensors are anterior Flexors are posteriorThe limbs pick up their nerve supply before rotation

Compartments of the LimbsMuscles in the same compartment tend to perform the same role and have similar blood and nerve supplies.Upper Limb:1. Pectoral girdle muscles (chest)2. Intrinsic shoulder muscles3. Anterior upper arm muscles - flexors4. Posterior upper arm muscles - extensors5. Anterior forearm muscles - flexors6. Posterior forearm muscles - extensors7. Intrinsic hand musclesLower Limb:1. Hip abductors2. Hip extensors3. Hip flexors4. Anterior thigh muscles - extensors5. Medial thigh muscles

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6. Posterior thigh muscles - flexors7. Anterior leg muscles - extensors8. Lateral leg muscles9. Posterior leg muscles - flexors10. Intrinsic foot muscles

Blood Supply to the Limbs

Upper Limb: Aorta Subclavian artery Axillary artery (as it passes into the limb) – has many branches. Brachial artery (as it enters the upper arm) – this then splits into the:

o Ulnar artery Common interosseous artery

Anterior interosseous artery Posterior interosseous artery

o Radial arteryo Anastomosis

Palmar carpal arch Dorsal palmar arch Metacarpal arteries Digital arteries

Veins generally follow the arteries There are 2 systems: superficial and deep

o Superficial system = cephalic and basilic vein which arise from the dorsal venous arch on the back of the hand

o The basilic vein runs on the medial (ulnar) aspect of the forearm and passes deep halfway to form the axillary vein

o The cephalic vein runs superficially on the lateral (radial) aspect of the forearm and upper arm and passes deep at the level of the shoulder to form the axillary vein

o Deep forearm veins pass from the forearm and drain into the basilic vein Venae comitantes pass alongside the brachial artery in the upper arm and drain

into the axillary artery The axillary vein passes from the upper arm into the axilla being a continuation of

the basilic vein where the cephalic and vena comitantes drain into it→ subclavian vein

During cold weather venous drainage is through deep veins During hot weather venous drainage is through superficial veins

Lower Limb: Common iliac arteries

o Internal iliac arteryo External iliac artery Femoral artery

Profunda femoris arteryo Superficial femoral arteryo Popliteal artery

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Posterior tibial artery Anterior tibial artery Peroneal artery

o Plantar arch In the leg there are also superficial and deep venous systems Deep veins in the calf form the popliteal vein at the back of the knee → forms the

superficial femoral vein which runs alongside the superficial femoral artery → joined by the venae comitantes to form the femoral vein → passes beneath the inguinal ligament to form the external iliac vein → inferior vena cave

Superficial veins start as the dorsal venous arch → long saphenous vein arises from the medial aspect of the dorsum of the foot just anterior to the medial malleolus and runs up the medial sside of the limb, joining the femoral vein in the groin. The short saphenous vein arises from the lateral aspect of the dorsal venous arch, runs up the back of the leg and joins the popliteal vein in the back of the knee

Nervous Organisation of the LimbsThe innervation from the limbs comes from spinal nerves:o C5 – T1 for the armso L2 – S2 for the legsNerves form plexi of which in the:

Upper limb: anterior division supply the flexors and the posterior division supply to the extensors

Lower limb: posterior division supply the flexors and the anterior division supply the extensors

Segmental Innervation- Muscles are generally supplied by two adjacent segments of the spinal cord.- Muscles with the same action share the same nerve supply.- Opposing muscles are usually supplied by nerves two segments above or

below.- The more distal (outward) the joint in the limb, the more caudal (lower) the

spinal segment controlling that.

The Upper LimbThe Upper Limb

Shoulder

Abduction C5Adduction C678

External Rotation C5Internal Roatation C678

Elbow Flexion C56Extension C78

Forearm Supination C6Pronation C78

Wrist Flexion C67Extension C67

Long tendons to hand Flexion C78Extension C78

Intrinsic hand muscles T1

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The Lower Limb

Lower LimbHip Knee Ankle

L2 FlexionL3 ExtensionL4 Extension Dorsa FlexionL5 FlexionS1 Planta FlexionS2

Sensory Segmental SupplyEach segmental spinal nerve supplies sensation to a strip of skin. These do generally overlap – so when a single dermatome is lost it is not generally noticed.

C4 – infraclavicular regionC5 – lateral armC6 – lateral forearm and thumbC7 – middle fingerC8 – little finger and medial forearmT1 – medial armT2 – axilla and trunkT4 – nippleT10 – umbilicusT12 – lower abdomenL1 – suprapubic regionL3 – front of the thigh (L3 to knee)L4 – front of leg (L4 to floor)L5 – dorsum of great toeS1 – lateral aspect of footS2-S4 – perineum and perianal region

Segmental Reflexes: Either stretch reflexes or deep tendon reflexes and are monosynaptic Two main reflex arcs in the upper limb:

Biceps jerk (C6) Triceps jerk (C7)

Two main reflexes in the lower limb: Knee jerk (L3) Ankle Jerk (S1)

Autonomic segmental supply to the limbs:Sympathetic supply via T2-T6 for upper limbs and T11-L2

for lower limbsNo significant parasympathetic outflow to the limbs

Peripheral Nerve Supply to the Limbs:Peripheral innervation of the upper limb is derived from the

brachial plexus which is from the anterior rami of C5-T1 of the spinal nerves

Peripheral innervation of the lower limbs is from the lumbro-sacral plexus which is derived from the anterior rami of L2-S2

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Most peripheral nerves are mixed, containing motor and sensory fibres.

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Limbs 2 – Shoulder and ArmAnil Chopra

1. Name the bones and joints of the upper limb from the shoulder girdle to the elbow.

2. Demonstrate the main movements of the shoulder girdle, shoulder joint and elbow

3. Identify in a living subject and in appropriate imaging;a. the clavicle and its sternoclavicular and acromioclavicular jointsb. the lateral and medial borders and inferior angle of the scapula, the

scapular spine, acromion process, coracoid process and glenoid fossa4. Name and demonstrate the position, main attachments and actions of;

a. pectoralis majorb. latissimus dorsic. trapeziusd. serratus anteriore. teres majorf. deltoid

5. List the spinal nerve roots supplying the upper limb6. Demonstrate the position and boundaries of the axilla7. Understand the general arrangement of the brachial plexus. 8. Demonstrate how the major nerves and vessels of the upper limb reach and

enter the axilla9. Explain the significance of the term “synovial ball-and-socket joint” using the

shoulder joint as an example10. Summarise the main factors stabilising the shoulder joint11. Explain how the stability of the shoulder joint fails in dislocation12. Discuss the difference between acromioclavicular dislocation and shoulder

joint dislocation13. Explain the risk to the axillary nerve in shoulder dislocation and the likely

consequences of injury to this nerve and demonstrate how the function of this nerve can be assessed

14. Describe the rotator cuff arrangement of muscles and tendons and explain why the rotator cuff is important in shoulder function and is clinically a common site of pathology. Outline the importance of imaging of the shoulder in rotator cuff problems. Describe clinical testing of the rotator cuff

15. Explain the anatomical basis of frozen shoulder. 16. Outline the main areas supplied by important branches of

the subclavian and axillary arteries and explain the importance of the anastomosis among these branches

17. Explain what is meant by winging of the scapula and its anatomical basis.

Bones of the Region

Clavicle: the collarbone. The clavicle is the only bony attachment between the trunk and the upper limb. It is palpable along its entire length and is an S-shaped contour. The acromial end is flat,

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whereas the sternal end is more robust and quadrangular in shape. The acromial end has a small oval facet on its surface for articulation with the medial end of the acromion of the scapula. The sternal end has a larger facet for articulation with the manubrium of the sternum. The inferior surface of the lateral third of the clavicle possesses a tuberosity containing the conoid tubercule and trapezoid line. It is the first bone to ossify in utero and does so by intramembranous ossification. Scapula: a large flat triangular bone with:

three angles (lateral, superior, and inferior); three borders (superior, lateral, and medial); two surfaces (costal and posterior); and three processes (acromion, spine, and coracoid process)

- The lateral angle is marked by the glenoid cavity (articulates with the head of the humerus – glenohumeral joint).

- The large triangular shaped roughening (the infraglenoid tubercule) inferior to the glenoid cavity is the site of attachment for the long head of the triceps brachii.

- The supraglenoid tubercule is the site of attachment of the long head of the biceps.

- The prominent spine divides up the posterior surface (into infraspinous and supraspinous).

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- The acromion (Greek = acromius meaning summit) is an anterolateral projection of the spine articulates with the clavicle.

- The lateral border is thick and strong as it is used for muscle attachments. - The superior border is marked on its lateral end by:

o Coracoid process: look like structureo Suprascapular notch

NB: the spine and coracoid process are easily palpable

Proximal Humerus: the hind bone of the arm. The head is a half-spherical shape and projects medially and somewhat superiorly to articulate with the much smaller glenoid cavity of the scapula.

There are 2 tubercles (greater and lesser) that are prominent landmarks for attachment sites for rotator cuff muscles:Greater Tubercle:- Supraspinatus- Infraspinatus- Teres minorLesser tubercle:- Subscapularis.

It is important to note the surgical neck because the neck is weaker than the proximal regions of the bone, fractures are common there. The associated axillary nerve and posterior circumflex humeral artery can be damaged by fractures here.

JointsSternoclavicular: this is the only real bony joint between the upper limb and the rest of the body. This is between the medial end of the clavicle and the clavicular notch on the manubrium of the sternum and the first costal cartilage. It is synovial and is held in place by 4 ligaments.

- anterior sternoclavicular ligament - posterior sternoclavicular ligament - interclavicular ligament- costoclavicular ligament

These ligaments make it particularly strong joint. It allows for movement of the clavicle mainly in the anteroposterior and vertical planes although some rotation occurs.

It is surrounded by a joint capsule and articular disc and can be damaged resulting in sternoclavicular subluxation and dislocation.

Acromioclavicular: small synovial joint between the acromion of the scapula and the acromial end of the clavicle. It is held together by:

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- acromioclavicular ligament – minor dislocations occur when this ligament is torn

- coracoclavicular ligament – important as is provides most of the weightbearing support for the upper limb on the clavicle and maintaining the position of the clavicle on the acromion. Major dislocations occur if this ligament if torn.

- coraco-acromial ligament

It allows for movement in the anteroposterior and vertical planes together with some axial rotation.This is often injured by falls onto an outstretched hand (ligaments are torn).

Glenohumeral: the shoulder joint. It is a synovial “ball and socket” joint between humerus and glenoid process of the scapula. It allows for great mobility at the expense of stability (any stability comes from the ligaments rather than the articulation itself) . It is very shallow and the head of the humerus lies in the glenoid labrum which is a fibrocartalaginous collar which attaches to the margin of the fossa.

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The capsule of the glenohumeral joint can protrude through the holes in the fibrous membrane that surrounds the joint forming bursae (a fluid filled sac):

- the subacromial bursa (between the humeral head and the acromial process – often a site of pathology for shoulder interference)

- the subtendinous bursa of subscapularis (between the subscapularis muscle and the fibrous membrane)

- the synovial sheath that extends along down the long head of the biceps brachii.

The coraco-acromial arch lies above the shoulder joint and stops the humerus rising superiorly against the acromion. It is held in place by the rotator cuff muscles and stabilised by a number of ligaments:

Gleno-humeral ligaments – strengthen the anterior portion of the shoulder capsule Coraco-humeral ligament – strengthens the capsule superiorly Transverse humeral ligament – holds the tendon of the long head of biceps in the inter-tubercular groove

Scapulo-thoracic: movements of the scapulo-thoracic joints are important and occur mainly when the arm is abducted more than 90°. It is a theoretical concept but allows for certain sorts of movement. The main movements are:

Elevation and depression of the scapula Protraction of the scapula – forward and lateral movement against the chest wall Retraction – backward and medial movement against the chest wall Rotation of the scapula

Muscles of the Region Muscle Origin Insertion Innervation FunctionAnterior Pectoral MusclesPectoralis major Clavicular head-anterior

surface of medial half of clavicle; sternocostal head-anterior surface of sternum; first seven costal cartilages; sternal end of sixth rib; aponeurosis of external oblique

Lateral lip of inter-tubercular sulcus of humerus

Medial and lateral pectoral nerves; clavicular head [C5,C6]; sternocostal head [C6,C7,C8,T1]

Flexion, adduction, and medial rotation of arm at gleno-humeral joint;.clavicular head-flexion of extended arm; sternocostal head- extension of flexed arm

Subclavius First rib at junction between rib and costal cartilage

Groove on inferior surface of middle one-third of clavicle

Nerve to subclavius [C5,C6]

Pulls tip of shoulder down; pulls clavicle medially to stabilize sternoclavicular joint

Pectoralis minor Anterior surfaces and superior borders of ribs III to V; and from deep fascia overlying the related intercostal spaces

Coracoid process of scapula (medial border and upper surface)

Medial pectoral nerve [C6,C7,C8]

Pulls tip of shoulder down; protracts scapula

Serratus anterior Lateral surfaces of upper 8-9 ribs and deep fascia overlying the related

Costal surface of medial border of scapula

Long thoracic nerve [C5,C6,C7]

Protraction and rotation of the scapula; keeps medial border and inferior angle

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intercostal spaces of scapula opposed to thoracic wall

Posterior Pectoral MusclesLevator scapulae

Transverse processes of CI and CII vertebrae and posterior tubercles of transverse processes of CIII and CIV vertebrae

Posterior surface of medial border of scapula from superior angle to root of spine of the scapula

Branches directly from anterior rami of C3 and C4 spinal nerves and by branches [C5] from the dorsal scapular nerve

Elevates the scapula

Latissimus dorsi Spinous processes of lower six thoracic vertebrae and related inter-spinous ligaments; via the thoracolumbar fascia to the spinous processes of the lumbar vertebrae, related interspinous ligaments, and iliac crest; lower 3-4 ribs

Floor of intertubercular sulcus

Thoracodorsal nerve [C6,C7,8]

Adduction, medial rotation, and extension of the arm at the glenohumeral joint

Rhomboid minor

Lower end of ligamentum nuchae and spinous processes of CVII and TI vertebrae

Posterior surface of medial border of scapula at the root of the spine of the scapula

Dorsal scapular nerve [C4,C5]

Elevates and retracts the scapula

Rhomboid major

Spinous processes of TII-TV vertebrae and intervening supraspinous ligaments

Posterior surface of medial border of scapula from the root of the spine of the scapula to the inferior angle

Dorsal scapular nerve [C4,C5]

Elevates and retracts the scapula

Trapezius Superior nuchal line, external occipital protuberance, medial margin of the ligamentum nuchae, spinous processes of CVII to TXII and the related supraspinous ligaments

Superior edge of the crest of the spine of the scapula, acromion, posterior border of lateral one-third of clavicle

Motor spinal part of accessory nerve (CN XI). Sensory (proprioception) anterior rami of C3 and C4

Powerful elevator of the scapula; rotates the scapula during abduction of humerus above horizontal; middle fibers retract scapula; lower fibers depress scapula

Intrinsic Shoulder MusclesSupraspinatus Medial two-thirds of the

supra-spinous fossa of the scapula and the deep fascia that covers the muscle

Most superior facet on the greater tubercle of the humerus

Suprascapular nerve [C5,C6]

Rotator cuff muscle; initiation of abduction of arm to 15° at gleno-humeral joint

Infraspinatus Medial two-thirds of the infra-spinous fossa of the scapula and the deep fascia that covers the muscle

Middle facet on posterior surface of the greater tubercle of the humerus

Suprascapular nerve [C5,C6]

Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint

Teres minor Upper two-thirds of a Inferior facet on the Axillary nerve Rotator cuff muscle;

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flattened strip of bone on the posterior surface of the scapula immediately adjacent to the lateral border of the scapula

posterior surface of the greater tubercle of the humerus

[C5,6] lateral rotation of arm at the glenohumeral joint

Teres major Elongate oval area on the posterior surface of the inferior angle of the scapula

Medial lip of the intertubercular sulcus on the anterior surface of the humerus

Inferior subscapular nerve [C5 to C7]

Medial rotation and extension of the arm at the glenohumeral joint

Subscapularis Medial two-thirds of subscapular fossa

Lesser tubercle of humerus

Upper and lower subscapular nerves [C5,C6(C7)]

Rotator cuff muscle; medial rotation of the arm at the gleno-humeral joint

Deltoid Inferior edge of the crest of the spine of the scapula, lateral margin of the acromion, anterior border of lateral one-third of clavicle

Deltoid tuberosity of humerus

Axillary nerve [C5,C6]

Major abductor of arm (abducts arm beyond initial 15° done by supraspinatus); clavicular fibers assist in flexing the arm; posterior fibers assist in extending the arm

Anterior Compartment of Upper Arm Biceps brachii Long head-supraglenoid

tubercle of scapula; short head- apex of coracoid process

Tuberosity of radius Musculocutaneous nerve [C5,C6]

Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at the glenohumeral joint

Coracobrachialis

Apex of coracoid process Linear roughening on mid-shaft of humerus on medial side

Musculocutaneous nerve [C5,C6,C7]

Flexor of the arm at the glenohumeral joint; adducts arm

Brachialis Anterior aspect of humerus (medial and lateral surfaces) and adjacent intermuscular septae

Tuberosity of the ulna

Musculocutaneous nerve [C5,C6]; (small contribution by the radial nerve [C7] to lateral part of muscle)

Powerful flexor of the forearm at the elbow joint

Posterior Compartment of the Upper ArmLong head of triceps brachii

Infraglenoid tubercle on scapula

Common tendon of insertion with medial and lateral heads on the olecranon process of ulna

Radial nerve [C6,C7,C8]

Extension of the forearm at the elbow joint; accessory adductor and extensor of the arm at the glenohumeral joint

Triceps brachii Long head-infraglenoid Olecranon Radial nerve Extension of the forearm at

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(and anconeus) tubercle of scapula; medial head-posterior suface of humerus; lateral head-posterior surface of humerus

[C6,C7,C8] the elbow joint. Long head can also extend and adduct the arm at the shoulder joint

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Movements of the Arm

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Movements of the Joints and muscles creating them

Shoulder Joint: Flexion:

Clavicular head of pectoralis major Anterior fibres of deltoid Coraco-brachialis Biceps

Extension – Latissimus dorsi Abduction:

Supraspinatus (first 30 degrees) Central fibres of deltoid (after 30 degrees)

Adduction: Pectoralis major Latissimus dorsi

Internal rotation – subscapularis External rotation – infraspinatus Circumduction – a combination of all movements

Muscles involved in preventing shoulder dislocation: Rotator cuff muscles – depress the humeral head into the glenoid Deltoid Coraco-brachialis Short and long heads of biceps

The scapulo-thoracic joint: Elevation – superior trapezius, levator scapulae, rhomboids Depression – inferior trapezius, pectoralis minor, serratus anterior Protraction – pectoralis minor, serratus anterior Retraction – rhomboids, middle trapezius, latissimus dorsi Rotation – elevation and depression of the glenoid fossa: Elevation – superior trapezius, inferior trapezius, serratus anterior Depression – pectoralis minor, latissimus dorsi, rhomboids and levator scapulae

The Elbow Joint: Flexion – biceps, brachialis, brachioradialis (pronator teres) Extension – triceps (anconeus)

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The Axilla

A gateway for nerves and vessels into the upper limb Shaped like a pyramid:

Base – skin, subcutaneous tissue and a facia extending from arm to chest Apex lies between the 1st rib, the clavicle and the superior border of the subscapularis muscle Anterior wall – formed by pec major and minor Posterior wall – formed by scapula and subscapularis superiorly and teres minor and latissimus dorsi inferiorly Medial wall – formed by chest wall (1st to 4th ribs) and serratus anterior Lateral wall – formed by humerus

Contents: Arteries – axillary and its branches Veins – axillary and tributaries Lymphatic vessels and lymph nodes – axillary lymph nodes particularly important Nerves – brachial plexus

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Vessels of the Region

Subclavian Artery: arises from brachiocephalic artery (right side) or the aortic arch (left side). Runs in the root of the neck where it becomes the axillary.

Axillary Artery: the subclavian artery becomes the axillary artery as it enters the axilla (as it comes over the margin of rib 1). This is split into 3 parts and numerous branches come off this:- first part is proximal to the pec

major- second part is posterior to pec major- third part is distal to pec majorIt supplies the walls of the axilla and associated regions.

Brachial Artery: the axillary artery becomes the brachial artery as soon as it passes the teres major muscle. It is found in the anterior compartment on the medial side. It passes down the arm laterally and crosses anterior to the elbow joint. It gives off a brach that supplies the posterior compartment of the arm (the profunda brachii artery). The brachial artery gives off a number of other branches and divides at the elbow to form the radial and ulnar arteries.

Axillary Vein: this deep vein is formed by two superficial veins, the basilic vein and the cephalic vein. The cephalic and basilic veins are the superficial veins of the forearm. The cephalic passes on the lateral aspect pf the arm and terminates by passing deep in the delto-pectoral triangle to join the axillary vein. The basilic vein passes on the medial side of the arm and passes deep halfway up to form the axillary vein along with the venae comitantes of the brachial artery

The axillary vein receives many tributaries such as the brachial veins, and the venae comitantes of the brachial artery. The typical site for peripheral venous access is the cephalic vein.

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At the first rib the axillary vein becomes the subclavian vein.

NervesAll the nerves that supply the shoulder and arm arise from the brachial plexus. All of which arise from the rami of C5-T1 spinal nerves. It consists of:1. Long Thoracic Nerve – supplies serratus anterior: NB – if this is damaged in

any way, then the serratus anterior muscle is unable to pull the scapula against and over the thoracic wall. This results in winging of the scapula if the patient pushes against something. Normal elevation of the arm is also no longer possible.

2. Suprascapular Nerve – supplies supraspinatus and infraspinatus3. Lateral pectoral nerve – supplies pectoralis major4. Thoraco-dorsal nerve – latissimus dorsi.5. The axillary nerve – supplies teres minor and then the deltoid as well as an

area of skin over the deltoid.6. The musculo-cutaneous nerve (C567) is the nerve of the anterior

compartment of the upper arm (coraco-brachialis, brachialis and biceps). It continues as the lateral cutaneous nerve of the forearm. It lies close to the subscapularis tendon anterior to the shoulder and can be damaged at the time of surgery to the front of the shoulder. It also supplies sensory innervation to the skin on the lateral surface of the forearm.

7. The ulnar nerve (C8T1) is one of the nerves that supplies the anterior compartment of the forearm but is mainly the nerve of the hand. It enters the arm with the median nerve and passes medial to the axillary artery. It lies posterior to the medial epicondyle of the elbow and can be damaged there.

8. The median nerve (C678T1) is one of the nerves that supply the anterior compartment of the forearm and hand. It enters the arm from the axilla at the inferior margin of the teres major muscle and passes vertically through the upper arm via the anterior compartment. At the level of the elbow it lies alongside the brachial artery and can be damaged there at the time of elbow fractures or dislocations.

9. The radial nerve (C5678T1) supplies the posterior compartment of the upper arm and forearm. It originates from the posterior cord of the brachial plexus and enters the arm by crossing the inferior margin of the teres major. It lies on the

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humerus in the radial groove and can be damaged there. Just above the level of the elbow it divides into the superficial radial nerve (sensory) and the posterior interosseous nerve (motor).

Lymphatics

The hand is drained by the superficial lymphatics which run alongside the basilic (medially) and cephalic (laterally) veins

Elbow is drained by the cubital lymph nodes. Delto-pectoral nodes run alongside the cephalic vein. Deep lymphatics run alongside the deep veins.

All of these lymph nodes in the arm drain toward the axillary nodes. These are very important as they also drain the breast (breast cancer). There are 5 groups of axillary nodes:

- humeral (lateral) nodes- pectoral (anterior) nodes- subscapular (posterior) nodes- central nodes- apical nodes

The nodes are important in breast cancer as are the site of lymph drainage from the breast as well.

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Limbs 3 – Elbow, Forearm and WristAnil Chopra

1. Name the bones and joints of the upper limb from the elbow to the wrist2. Demonstrate and explain the anatomical basis of elbow flexion and extension,,

pronation and supination of the hand and the movements of the wrist3. Demonstrate in a living subject the elbow the medial epicondyle, the

olecranon process and the lateral epicondyle; the radius and ulna; the wrist joint

4. Demonstrate the courses of the major nerves through the region and also to point out where the nerves might be vulnerable to injury;

5. Demonstrate the courses of the brachial, radial and ulnar arteries from the axilla to the hand

6. Demonstrate the pulses associated with the brachial, radial and ulnar arteries7. Demonstrate and name the main veins of the upper limb8. Demonstrate clinical testing of the muscles, tendon, nerves and vessels in the

forearm9. Discuss a supracondylar fracture of the humerus and explain why this

common injury can cause significant vascular and neurological complications and how may it be treated

10. Describe a Colles fracture, and explain why it is so common?

Bones of the Region

Distal end of Humerus: articulates with the radius and ulna. The distal end of the humerus has a number of articulations with the bones and ligaments it is attached to, including: Condyle: consists of the capitulum (articulates with the

radius) and the trochlea (articulates with the ulna). Epicondyles: consist of the medial and lateral

epicondyles. Both are palpable either side of the elbow. The ulnar nerve can be palpated on the posterior surface of the medial epicondyle.

Fossae: consist of the radial, coronoid and olecranon and are the sites into which projections slide as the forearm moves.

The joint itself is in contact with 4 nerves that can be damaged during fracture or dislocation:

- Axillary nerve – surgical neck of humerus- Radial nerve – radial groove- Ulnar nerve – posterior to medial epicondyle- Median nerve – anterior to distal humerus

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Radius: at its proximal end, the radius articulates with the capitulum of the humerus and the radial notch at the proximal end of the ulna. The radius rotates around the ulna The radial tuberosity is a roughened surface on the medial end

of the radius and attaches with the biceps tendon. At its distal end, it has the ulnar notch (articulates with the

ulna), the styloid process, the facets for its articulation with the scaphoid and lunate bones.

This is frequently fracture (Colles’ fracture) and is caused by falling onto outstretched hands.

Ulna: the main function of the ulna is to stabilise the arm. At its proximal end, the ulna has a large projection known as the

olecranon (the bony part of the elbow), the trochlear notch (which articulates with the trochlea of the humerus), the radial notch (articulates with radius) tuberosity of the ulna (attaches to the brachialis) and the attachment of the anconeus on the posterior side.

At its distal end, it has an ulnar styloid process (on the medial aspect).

Its main movement is extension and flexion of the elbow.

Carpal Bones: consists 8 bones, split into a proximal and distal row:(Some lovers try positions that they can’t handle) Proximal

o Scaphoido Lunateo Triquetrumo Pisiform

Distal

o Trapezium

o Trapezoid

o Capitateo Hamate

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Joints of the RegionElbow JointThe elbow joint is a synovial hinge joint between the ulna and the humerus. It involves 3 articulations sharing a common synovial cavity

(covered in hyaline cartilage). The main articular joint is between the trochlear notch of the

ulna and the trochlea. The distal humerus articulates with the ulna via the trochlea

whilst the radius articulates with the humerus via the capitulum

The joint capsule is reinforced by fat pads which move out of the way as the elbow flexes and extends.

The anular ligament of the radius cuffs the head of the radius into the ulna, and the joint is held together using the ulnar and radial collateral ligaments.

The carrying angle is the angle between the axis of the humerus and the axis of the ulna and radius.

There is a large bursa over the olecranon at the back of the elbow – the olecranon bursa. This frequently becomes inflamed.

Radio-Ulnar Joint At the proximal end the head of the radius sits in the radial notch of

the ulna and is able to rotate in supination and pronation. It is held in place by the anular ligament of the radius.

The radius and ulna are held together along their shafts by the interosseous membrane.

At the distal end, the ulnar notch of the radius is able to rotate around and over to the top of the head of the ulna in supination and pronation. Within the distal radio-ulnar joint is an articular disc called the triangular fibro-cartilage, which is commonly injured

Supination: supinator & bicepsPronation: pronator quadratus & pronator teres

Wrist JointThe bones that articulate with the distal ends of the radius and ulna are the scaphoid, lunate and triquetrum. Because the radial styloid process extends further than the ulnar styloid process, the wrist can be adducted more than it can be abducted. The ligaments of note here are the:

The ulnar collateral ligament The radial collateral ligament The palmar radio-carpal ligaments The dorsal radio-carpel ligaments The inter-carpel ligaments

The radio-carpel and inter-carpel ligaments are clinically important as are often injured The wrist joint allows flexion and extension. The midcarpal and carpo-metacarpal also allow flexion and extensionIntercarpal Joints Contribute to positioning of the hand.

Muscles of the Region Muscle Origin Insertion Innervation FunctionAnterior SuperficialFlexor carpi ulnaris

Humeral head-medial epicondyle of humerus; ulnar head-olecranon and posterior border of ulna

Pisiform bone, and then via pisohamate and pisometacarpal ligaments into the hamate and base of metacarpal V

Ulnar nerve [C7,C8, T1]

Flexes and adducts the wrist joint

Palmaris longus

Medial epicondyle of humerus

Palmar aponeurosis of hand

Median nerve [C7,C8]

Flexes wrist joint; because the palmar aponeurosis anchors skin of the hand, contraction of the muscle resists shearing forces when gripping

Flexor carpi radialis

Medial epicondyle of humerus

Base of metacarpals II and III


Pronation

Pronator teres Humeral head-medial epicondyle and adjacent supraepicondylar ridge; ulnar head-medial side of coronoid process

Roughening on lateral surface, mid-shaft, of radius


Flexes and abducts the wrist

Flexor digitorum superficialis

Humero-ulnar head-medial epicondyle of humerus and adjacent margin of coronoid process; radial head- oblique line of radius

Four tendons, which attach to the palmar surfaces of the middle phalanges of the index, middle, ring, and little fingers

Median nerve [C8,T1]

Flexes proximal interphalangeal joints of the index, middle, ring, and little fingers; can also flex metacarpophalangeal joints of the same fingers and the wrist joint

Anterior DeepFlexor digitorum profundus

Anterior and medial surfaces of ulna and anterior medial half of interosseous membrane

Four tendons, which attach to the palmar surfaces of the distal phalanges of the index, middle, ring, and little fingers

Lateral half by median nerve (anterior interosseous nerve); medial half by ulnar nerve [C8,T1]

Flexes distal interphalangeal joints of the index, middle, ring, and little fingers; can also flex metacarpophalangeal joints of the same fingers and the wrist joint

Flexor pollicis longus

Anterior surface of radius and radial half of inter-

Palmar surface of base of distal phalanx of thumb

Median nerve (anterior interosseous

Flexes interphalangeal joint of the thumb; can also flex metacarpo-

osseous membrane

nerve) [C7,C8]

phalangeal joint of the thumb

Pronator quadratus

Linear ridge on distal anterior surface of ulna

Distal anterior surface of radius

Median nerve (anterior interosseous nerve) [C7,C8]

Pronation

Posterior SuperficialBrachioradialis

Proximal part of lateral supraepicondylar ridge of humerus and adjacent inter-muscular septum

Lateral surface of distal end of radius

Radial nerve [C5,C6] before division into superficial and deep branches

Accessory flexor of elbow joint when forearm is mid-pronated

Extensor carpi radialis longus

Distal part of lateral supraepicondylar ridge of humerus and adjacent intermuscular septum

Dorsal surface of base of metacarpal II

Radial nerve [C6,C7] before division into superficial and deep branches

Extends and abducts the wrist

Extensor carpi radialis brevis

Lateral epicondyle of humerus and adjacent intermuscular septum

Dorsal surface of base of metacarpals II and III

Deep branch of radial nerve [C7,C8] before penetrating supinator muscle

Extends and abducts the wrist

Extensor digitorum

Lateral epicondyle of humerus and adjacent intermuscular septum and deep fascia

Four tendons, which insert via 'extensor hoods' into the dorsal aspects of the bases of the

Posterior interosseous nerve [C7,C8]

Extends the index, middle, ring, and little fingers; can also extend the wrist

Extensor digiti minimi

Lateral epicondyle of humerus and adjacent intermuscular septum together with extensor digitorum

Dorsal hood of the little finger


Extends the little finger

Extensor carpi ulnaris

Lateral epicondyle of humerus and posterior border of ulna

Tubercle on the base of the medial side of metacarpal V


Extends and adducts the wrist

Anconeus Lateral epicondyle of humerus

Olecranon and proximal posterior surface of ulna

Radial nerve [C6 to C8] (via branch to medial head of triceps

Abduction of the ulna in pronation; accessory extensor of the elbow joint

brachii)Posterior DeepSupinator Superficial part-

lateral epicondyle of humerus, radial collateral and anular ligaments; deep part-supinator crest of the ulna

Lateral surface of radius superior to the anterior oblique line


Supination

Abductor pollicis longus

Posterior surfaces of ulna and radius (distal to the attachments of supinator and anconeus), and intervening interosseous membrane

Lateral side of base of metacarpal I


Abducts carpometacarpal joint of thumb; accessory extensor of the thumb

Extensor pollicis brevis

Posterior surface of radius (distal to abductor pollicis longus) and the adjacent interosseous membrane

Dorsal surface of base of proximal phalanx of the thumb


Extends metacarpophalangeal joint of the thumb; can also extend the carpometacarpal joint of the thumb

Extensor pollicis longus

Posterior surface of ulna (distal to the abductor pollicis longus) and the adjacent interosseous membrane

Dorsal surface of base of distal phalanx of thumb


Extends interphalangeal joint of the thumb; can also extend carpometacarpal and metacarpophalangeal joints of the thumb

Extensor indicis

Posterior surface of ulna (distal to extensor pollicis longus) and adjacent interosseous membrane

Extensor hood of index finger


Extends index finger


Radial Artery: a branch of the brachial artery. That passes into along the forearm and into the hand in the dorsolateral part. It supplies mainly the arteries of the thumb and lateral index finger. In the forearm it has 3 main branches: Radial recurrent artery – forms an anastomotic network

of vessels around the elbow. Palmar carpal branch – supplies carpal bones and joints Superficial palmar branch – supplies the muscles at the

base of the thumb.A radial pulse can be felt just proximal to the thumb on the anterior side of the wrist.

Ulnar Artery: another branch of the brachial artery that passes down the medial side of the arm. It passes into the forearm to supply the medial three and a half fingers. It also has many branches in the forearm: Ulnar recurrent artery : split into anterior and posterior to

join the anastomotic network of vessels around the elbow.

Common interosseous artery : which divides intoo Anterior interosseous artery : passes anteriorly

along the interosseous membrane to supply the deep muscles of the forearm.

o Posterior interosseous artery : passes dorsally to supply the posterior compartment of the forearm.

Carpal arteries : supply the wrist.An ulnar pulse can be felt on medial side of the forearm just proximal to the hand.

Generally veins surround the arteries and drain into the brachial veins of the arm in the cubital fossa.

Nerves of the Region

Median Nerve: innervates the muscles in the anterior compartment of the forearm except the flexor carpi ulnaris (FCU) and index and middle fingers of the flexor digitorum profundus (FDP). It passes distally down the forearm and through the carpal tunnel. It has two major branches: Anterior interosseous nerve : innervates the muscles in

the deep layer of the forearm. Palmar branch : innervates skin over the base and central

palm.Ulnar Nerve: mainly supplies the hand although in the forearm it supplies the flexor carpi ulnaris (FCU) and ring and little fingers of the flexor digitorum profundus (FDP). It passes into hand superficial to the flexor retinaculum, not through the carpal tunnel. It also has 3 major branches:

Muscular branches to the FCU and half of FDP. Palmar branch to supply the skin on the medial side of the palm. Dorsal branch to supply skin on the posterior side of the hand and the skin of one

and a half digits.

Radial Nerve: this bifurcates into a 2 branches on the lateral part of the cubital fossa: Superficial branch is sensory and supplies the dorsolateral surface of the hand. Deep branch is motor and supplies muscles in the posterior part of the forearm.

Limbs 4 – HandAnil Chopra

1. Name the bones and joints of the wrist and hand2. Name and demonstrate the movements of the wrist and hand3. Distinguish between the power and precision grips4. Outline the main neuromuscular mechanisms underlying each type of grip5. Summarise in simple terms the overall pattern of motor and sensory segmental

nerve distribution to the limb6. Explain (in principle only) the role of the brachial plexus7. Explain the main motor and sensory deficits associated with carpal tunnel

syndrome, ulnar nerve injury near the elbow, radial nerve injury in the spiral groove, injury to the lower segments of the brachial plexus

8. Outline the functional deficits caused by the common injuries of the flexor and extensor tendons

9. Outline the mallet finger deformity10. Identify and summarise the functions of the carpal bones11. Describe how fractures of the scaphoid occur and explain why such injuries are

important12. Discuss the clinical term, trigger finger13. Describe gamekeeper’s thumb (skier’s thumb) and its anatomical basis.

Bones of the Region

The Carpel Bones: Proximal row (lateral to medial)=

Scaphoid – forms the wrist joint Lunate – forms the wrist joint Triquetrum – forms the wrist joint Pisiform – a sesimoid bone (develops in the tendon when it rubs forming a synovial joint (also seen in patella) is formed from FCU (flexor carpi ulnaris)

Distal row (lateral to medial) = Trapezium – supports the thumb by forming a saddle joint with it Trapezoid – supports the index finger Capitate – supports the middle finger. Acts like a keystone in supporting the carpus Hamate – supports the ring and little finger

The radius articulates with the scaphoid, lunate and triquetrum to form the wrist joint The ulna does not articulate with the carpus except via the triangular fibrocartilage which extends from the distal radius to ulna The scaphoid has a clinically important blood supply – blood vessels tend to pass from distal to proximal but can be interrupted by a fracture of the waist of the bone causing the proximal end to undergo avascular necrosis

Metacarpals: 5 metacarpals, (the thumb is number I) consisting of a base, shaft and head.

Phalanges: each finger has 3 (proximal, middle and distal) the thumb has 2 (proximal and distal).

Joints of the Region

The distal radio-ulna joint: A pivot joint that allows the radius to move around the ulna in rotation Within the joint is an articular disc = triangular fibro-cartilgae which is commonly injured, the disc also allows the ulna to indirectly articular with the carpal bones

The wrist joint: A synovial joint between the distal radius and its associated triangular fibrocartilage and the proximal row of the carpal bones (scaphoid, lunate and triquetrum, but not pisiform) Ligaments supporting the joint include:

The ulnar collateral ligament The radial collateral ligament The palmar radio-carpal ligaments The dorsal radio-carpel ligaments The inter-carpel ligaments

The radio-carpel and inter-carpel ligaments are clinically important as are often injured The wrist joint allows flexion and extension. The midcarpal and carpo-metacarpal also allow flexion and extension Radial and ulna deviation also occurs at the wrist joint

The intercarpal joints: Joints between the proximal row of carpal bones Joints between the distal row of carpal bones Joints between the proximal and distal row of carpal bones – the midcarpal joint Main movements occurring at the carpal joints is gliding, augmenting the movement occurring at the wrist joint, especially flexion and radial deviation of the wrist

Carpometacarpal joints There are 5 joints between the carpal and metacarpal bones. The saddle joint between metacarpal I and the trapezium (the CMC of the thumb) is much more mobile than those of the fingers and often becomes arthritic. The other CMC’s are between trapezoid, capitate and hamate with the metacarpals of the digits. The CMC’s of the middle finger are very rigid, that of ring finger less rigid and that of the little finger very mobile There are also intermetacarpal joints (IMC) between the metacarpals at their bases

Metacarpopharyngeal Joints Metacarpophalangeal joints (MCP’s) are condylar synovial joints between the metacarpal heads and proximal phalanges They allow for the following movements:

Flexion and extension Abduction and adduction

The interphalangeal joints (IP’s) are hinge synovial joints which allow for flexion and extension

There is a proximal IP and distal IP in each digit – the thumb only has one IP The collateral radial and collateral ulna ligaments hold the IP’s and MCP’s together The ulnar collateral ligament in the thumb is particular important as it is often damaged skiing The volar plate is an important structure on the anterior surface of the proximal interphalangeal plate. It is a dense condensation of fibrous tissue formed by the collateral ligaments at the front of the proximal IP joint

The Carpal TunnelThe carpal tunnel is formed anteriorly at the wrist by the deep arch of carpal bones. Contents: Median nerve 4 heads of tendons of flexor digitorum profundus 4 heads of the tendons of flexor digitorum superficialis tendon of flexor pollicis flongus

Carpal Tunnel Syndrome: the entrapment syndrome caused by pressure on the median nerve. Can be caused by swelling of tendons and formation of cysts in the carpal joints (e.g. rheumatoid arthritis). Symptoms include “pins-and-needles” in the muscles in the median nerve region, weakness, loss of muscle bulk of the thenar muscles.

The fascia of the palm: Anatomically continuous with the fascia of the forearm Palmar fascia lies in the palm – condensations (speciliasations) form the palmer

apponeurosis and the digital fibrous sheaths The palmer apponeurosis

Well defined and overlies the long flexor tendons. The proximal end is continuous with the flexor retinaculum and the palmaris

longus tendon. The distal end forms 4 bands which is continuous with the fibrous digital

sheaths of each finger The fibrous digital sheaths:

Are tubes which contain flexor tendons and their sheaths The space between the palmar apponeurosis and the bones of the hands is

separated into compartments by extensions of the fascia called septa A medial septum (to the little finger metacarpal) and a lateral septum (middle

finger metacarpal) divides the space into the hypothenar compartment, central compartment and thenar compartment (thenar closet to thumb, hypothenar closest to little finger)

Beneath the thenar compartment is the 4th compartment = adductor compartment which contains adductor pollicis

Intrinsic Muscles of the Hand

Thenar muscles: these consist of the abductor pollicis brevis flexor pollicis brevis opponens pollicisThese are all innervated by the median nerve and are responsible for opposition of the thumb.

Hypothenar muscles: these consist of opponens digiti minimi abductor digiti minimi flexor digiti minimi. They are innervated by the deep branch of the ulnar nerve.

Dorsal interossei: originate on the dorsal sides of the metacarpals and insert in the proximal phalanges. They are responsible for abduction of the fingers (away from the middle) and are innervated by the deep branch of the ulnar nerve.

Palmar interossei: these originate from the palmar metacarpals and insert in the phalanges. They are responsible for adduction of the fingers (toward the middle) and are innervated by the deep branch of the ulnar nerve.

Adductor pollicis: responsible for the adduction of the thumb and innervated by the deep branch of the ulnar nerve.

Lumbricals: these cause the flexion of the metacarpophalangeal joints when the interphalangeal joints are extended (pointing). They are innervated by the deep branch of the ulnar nerve.

Types of Grip: Power Grip (e.g. holding a rod)

long flexors of the fingers and thumb intrinsic muscles of the palm extensors of the wrist joint

Precision Grip (e.g. buttoning a shirt) the wrist and fingers are held rigidly by the long flexors and extensors the intrinsic muscles of the hand carry out the fine movements needed.

TENDINOUS ANATOMY OF THE REGION:

Anterior tendinous anatomy of the hand:» The fibrous digital sheath is a condenstation/specialisation of the palmar fascia» These sheaths extend from the level of the metacarpal head to the base of the

distal phalanx in each digit» Together with the underlying bone form the osseo-fibrous tunnels through which

the long flexor tendons and associated synovial sheaths run» Parts of the fibrous digital sheath forms condensations = pulleys which allow for

more functional use» These are called the annular and cruciform pulleys» Just after the wrist joint the tendons of FDP (flexor digitorum profundus) and FDS

(flexor digitorum superficialis) pass deep to the flexor retinaculum and enter a common synovial sheath

» Tendons then pass to the respective digit via a digital synovial sheath which is contained within the fibrous digital sheath

» At the base of the proximal phalanx FDS splits around FDP – FDS attaches to the anterior surface of the middle phalanx, FDP to the distal phalanx

» Flexor pollicis longus (the long thumb flexor) has its own synovial sheath at the flexor retinaculum – runs to the distal phalanx of thumb

Posterior tendinous anatomy:» All the extensor tendons are held to the back of the wrist by the extensor

retinaculum» Synovial tendon sheaths that surround the tendons allow for free movement» On the back of the hand the long extensor tendons are joined by bands called

inter-tendinous bands which prevent the free movement of one tendon independently to the others

» At the level of the metacarpals the long extensor tendons flatten to form extensor expansions which form a hood on the back of the digit

» The lumbricals and interossei attach to the extensor expansions» Extensor digitorum extends to the MCP and IP joints. It also plays a part in

extension of the wrist


Ulnar artery: passes in the anterior compartment of the forearm along the ulna and enter the hand on the medial side of the wrist (not through the carpal tunnel). The vessel lies between the palmaris brevis and the flexor retinaculum and is lateral to the ulnar nerve and the pisiform bone. Distally, the ulnar artery is medial to the hook of the hamate bone and then swings laterally across the palm, forming the superficial palmar arch, which is superficial to the long flexor tendons of the digits and just deep to the palmar aponeurosis. On the lateral side of the palm, the arch communicates with a palmar branch of the radial artery. Branches from the superficial palmar arch include:

a palmar digital artery to the medial side of the little finger; three large, common palmar digital arteries, which ultimately provide the

principal blood supply to the lateral side of the little finger, both sides of the ring and middle fingers, and the medial side of the index finger -they are joined by palmar metacarpal arteries from the deep palmar arch before bifurcating into the proper palmar digital arteries, which enter the fingers

Radial Artery: curves around the lateral side of the wrist and passes over the floor of the anatomical snuffbox and straight into the back of hand (not through the carpal tunnel). It passes between the two heads of the first dorsal interosseous muscle and then between the two heads of the adductor pollicis to access the deep plane of the palm and form the deep palmar arch. It splits to from the deep and superficial palmar arches before it reaches the thumb. It supplies the radial half of the index finger and the thumb.

Cephalic Vein: originates form the lateral side of the dorsal venous network and passes over the anatomical snuffbox into the forearm.

Basilic vein: originates on the medial side of the dorsal venous network and passes into the Dorsomedial aspect of the forearm.


Ulnar Nerve: (C8 T1) the ulnar nerve enters the hand lateral to the Pisiform and dorsomedially to the ulnar artery. It divides into deep and superficial branches. The superficial branch supplies the Palmaris brevis, and is sensory for the skin of the little and half of the ring finger. The deep branch supplies all the intrinsic hand muscles except for the thenar muscles thus making it the main nerve for fine movements.

Injury to the ulnar nerve causes clawing of the hand. This is because of the inhibition of intrinsic muscles of the hand.

Median nerve: (C678 T1) the median nerve enters the hand by passing through the carpal tunnel and dividing into a recurrent branch and digital branches. The digital branches are sensory for the thumb, index, middle and half of the ring finger. The recurrent branch provides motor innervation for the thenar muscles and the first and second lumbricals.

NB: Median nerve also supplies the anterior compartment of the forearm except the flexi carpi ulnaris and the ulnar portion of ht flexor digitorum profundus.

Radial Nerve: (C5678 T1) only the superficial branch of the radial nerve enters the hand and it does so by passing over the anatomical snuffbox. Its function is only to innervate skin on the dorsal aspect of the hand. Injury to the radial nerve results in wrist drop.

NB: Posterior inersseous nerve is a direct continuation of the radial nerve and passes between the heads of supinator to supply the extensor compartment of the forearm.

Limbs 5 – Brachial PlexusAnil Chopra1. Summarise in simple terms the overall patterns of motor and sensory segmental

nerve distribution to the limb2. Explain (in outline only) the role of the brachial plexus3. Demonstrate where the axillary, radial, median and ulnar nerves nerves are

vulnerable to injury4. Explain the main motor and sensory deficits associated with carpal tunnel

syndrome, ulnar nerve injury near the elbow, radial nerve injury in the spiral groove, axillary nerve injury and injury to the roots of the brachial plexus

Brachial PlexusArise from cervical spinal cords C5 – T1 in the neck. Patients however can have pre-fixed or post-fixed brachial plexi (e.g. C4-C8 or C6-T2).

Reasons for Brachial Plexus:- Limbs are so important that we can’t have one muscle supplied by one

segement in case of leision. The same applies for sensory terms.- Developmental: muscles more distal are innervated by spinal segments lower

down the spinal cord.- Nerves grow out in order down the spinal cord, but not all of the muscle can

be supplied by one nerve, when one nerve finishes, the next nerve “mops up” the rest of the muscle.

C5 & 6 join together to form upper trunk of brachial plexus.C7 is on its own and forms the middle trunk of brachial plexusC8 & T1 join together to form the upper trunk of the brachial plexus.

• C3-C7 supply shoulder girdle muscles• C5-C6 supply shoulder joint muscles and elbow flexors• C7-C8 supply elbow joint extensors• C6-C8 supply wrist and coarse hand muscles• C8-T1 supply small muscles of hand (fine movements)

Injuries to the Axillary Nerve

Posterior Cord: splits into axillary nerve (motor to teres minor and deltoid). Most commonly injured through dislocations of the shoulder as it wraps around the proximal head of the humerus. Will not be able to abduct the shoulder and causes wasting of the deltoid muscle. Can be tested by testing sense in the “badge area”.

Other is radial nerve. Particularly damaged through fractures of the humerus. Results in “wrist drop”, loss of power grip.

Musculocutaneous nerve: use left hand when unscrewing. Injury caused by surgery. Supplies biceps, brachialis and sensory innervation to skin.

Ulnar nerve: Part of the medial cord, it is most susceptible to fractures when it passes posterior to the epicondyle of the humerus at the elbow. Injury here results in clawing

of the hand, but not as much as if it is injured at the wrist because the flexors to the median 2 digits are lost as well.

Median Nerve: loss of fine motor skills of the hand due to loss of flexion of the fingers – no innervation to the anterior forearm muscles.

Lower Root InjuriesPathways affected:Roots C8 and T1 form the lower trunk of the plexusThe anterior division of this trunk forms the ulnar nerve and the cutaneous nerve of the arm and forearm and contributes to the median nerveThe posterior division contributes to the posterior cord, through which it reaches the radial nerve

Segmental innervation:Motor: Effects are on the most distal parts – especially the handSensory: the dermatomes of C8 and T1 cover the medial aspect of the limb between axilla and wrist.

Sensory effects:Sensation is altered or lost on the medial aspect of the arm and forearm and possibly the little finger, but is retained in the rest of the hand (mainly C7)

Motor effects:Most important is the total loss of intrinsic hand muscles and therefore loss of precision movements. The long extensors and flexors continue but, in the absence of functional fine control from the intrinsic muscles, they tend to hold the hand in a rather immobile, clawed position

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Limbs 6 - Hip, Buttock and ThighAnil Chopra

1. Identify the bones and joints of the lumbo-sacral region, hip joint and femur2. Find the following landmarks in the living subject: the mid-inguinal point, the

anterior superior iliac spine, the symphysis pubis and the pubic tubercle, the greater trochanter, the medial and lateral femoral epicondyles

3. Demonstrate the following prime movers and muscle groups and the main movements associated with them;

a. gluteus maximusb. hip abductorsc. ilio-psoasd. hip adductorse. the hamstringsf. quadriceps femorisg. the sartorius

2. Assign muscle groups to the following nerves: the gluteal nerve, the femoral nerve, the obturaor nerve, the sciatic nerve in the thigh

3. Describe a hamstring injury in sportspersons 4. Trace the routes of the femoral artery and the profunda femoris artery5. Demonstrate the femoral pulse and explain its significance6. Discuss femoral neck fractures. 7. Explain the difference between intracapsular fractures and extracaspsular fractures

of the femoral neck and their clinical importance8. Describe the Trendelenberg test9. Briefly describe the principles behind total hip replacement.

Bones of the Region

PelvisIlium: this forms the fan shaped part of the body pelvis. The top of it is the iliac crest ending anteriorly at the ACIS – anterior superior iliac spine (at L5) and posteriorly at the posterosuperior iliac spine.

Ischial Tuberosity: associated with the attachments for the hamstring muscles. Pokes out postero-inferiorly from the acetabulum.

Acetabulum: the large cup-shaped space associated with articulation with the head of the femur. Pubic Bone: the external surface of the ischiopubic ramus anterior to the ischial tuberosity. It provides attachments for the adductor muscles in the medial compartment of the thigh. NB:All the bones of the pelvis are fused.

Sacrum: See spinal anatomy. It articulates with the hip-bone at the sacro-iliac joint.

Femur: consists of the head, neck and two trochanters proximally. The proximal head of the femur inserts into the acetabulum. The neck of the femur is a cylindrical strut that connects the head to the shaft. The upper part of the shaft bears the lesser trochanter (attachment for psoas major and iliacus) and the greater trochanter (attachment for the obturator externus, gluteus medius and minimus) which are jointed by the intertrochanteric line and intertrochanteric crest posteriorly. There is a line on the shaft of the femur running posteriorly called the linea aspera.

Fractures of the neck of the femur can cause disruptions to a number of hip vessels and result in necrosis of the femoral head.

Joints of the Region

Sacro-iliac joint: articulation is fixed.Hip joint: a synovial articulation between the head of the femur and the acetabulum. It is a ball and socket joint and is designed for stability and weightbearing at the expense of flexibility. This is achieved by the acetabulum wrapping almost entirely round the hemisphere of the femoral head. The femoral head is held in place by a number of ligaments

o Iliofemoral ligament: anterior to the hip jointo Pubofemoral ligament: anteroinferior to the hip jointo Ischiofemoral ligament: posterior aspect of hip joint

- Around the rim of the acetabulum is a rim of tissue called the acetabular labrum- Within the acetabulum is also the transverse acetabular ligament- The capsule of the joint extends down the femur – extends further anteriorly than

posteriorly- The capsule contains the important blood supply for the head- Fractures are either intracapsular or extracapsular- Important ligaments at the hip joint:

o Ilio-femoral ligamento Pubo-femoral ligamento Ischio-femoral ligamento Ligament of the head of the

femur- The blood supply of the joint is derived

from the medial and lateral circumflex arteries mainly

- Insignificant blood supply for the adult, but significant in the child is provided by the artery of the head of the femur

- Circumflex vessels easily damaged in intracapsular fractures of proximal femur leading to avascular necrosis

Foramina of the Hip and Lower Limb

The gluteal region:» Contains important ligaments which connect the bones of the region and provides

passageway for nerves and vessels» The greater sciatic notch and the lesser sciatic notch are converted into the

greater sciatic foramen and lesser sciatic foramen by the sacrotuberous ligament and sacro-spinous ligament

» Greater sciatic foramen – structures passing from pelvis to lower limb (including sciatic nerve)

» Lesser sciatic foramen – structures passing from pelvis to perineum

The femoral triangle:Borders:

Superior – inguinal ligament Medial – adductor longus Lateral - sartorius

It contains the femoral nerve, femoral artery and femoral vein (lateral to medial). The femoral sheath encloses the artery and vein but not the nerve. Medially the sheath forms the femoral canal.

The adductor canal: Extends on the medial aspect of the thigh from the apex of the femoral triangle Transmits the superficial femoral artery and vein and the saphenous nerve Formed by:

Anteriorly – vastus medialis Posteriorly – adductor longus and mangus Medially – sartorius

Muscles of the Region

Gluteal – extensors and abductors of the hipGluteus minimus

External surface of ilium between inferior and anterior gluteal lines

Linear facet on the antero-lateral aspect of the greater trochanter

Superior gluteal nerve (L4,L5,S1)

Abducts femur at hip joint; holds pelvis secure over stance leg and prevents pelvic drop on the opposite swing side during walking; medially rotates thigh

Gluteus medius

External surface of ilium between anterior and posterior gluteal lines

Elongate facet on the lateral surface of the greater trochanter

Superior gluteal nerve (L4,L5,S1)

Abducts femur at hip joint; holds pelvis secure over stance leg and prevents pelvic drop on the opposite swing side during walking; medially rotates thigh

Gluteus maximus

Fascia covering gluteus medius, external surface of ilium behind posterior gluteal line, fascia of erector spinae, dorsal surface of lower sacrum, lateral margin of coccyx, external surface of sacrotuberous ligament

Posterior aspect of iliotibial tract of fascia lata and gluteal tuberosity of proximal femur

Inferior gluteal nerve (L5,S1,S2)

Powerful extensor of flexed femur at hip joint; lateral stabilizer of hip joint and knee joint; laterally rotates and abducts thigh

Short External Rotators of the HipTensor fasciae latae

Lateral aspect of crest of ilium between anterior superior iliac spine and tubercle of the crest

Iliotibial tract of fascia lata Superior gluteal nerve (L4,L5,S1)

Stabilizes the knee in extension

Piriformis Anterior surface of sacrum between anterior sacral foramina

Medial side of superior border of greater trochanter of femur

Branches from (S1,S2)

Laterally rotates the extended femur at hip joint; abducts flexed femur at hip joint

Obturator internus

Anterolateral wall of true pelvis; deep surface of obturator membrane and surrounding bone

Medial side of greater trochanter of femur

Nerve to obturator internus (L5,S1)


Gemellus superior

External surface of ischial spine

Along length of superior surface of the obturator internus tendon and into the medial side of greater trochanter of femur with obturator internus tendon

Nerve to obturator internus (L5,S1)

Laterally rotates the extended femur at hip joint; abduction of flexed femur at hip joint

Gemellus inferior

Upper aspect of ischial tuberosity

Along length of inferior surface of the obturator internus tendon and into the medial side of greater trochanter of femur with obturator internus tendon

Nerve to quadratus femoris (L5,S1)


Quadratus femoris

Lateral aspect of the ischium just anterior to the ischial tuberosity

Quadrate tubercle on the intertrochanteric crest of the proximal femur

Nerve to quadratus femoris (L5,S1)

Laterally rotates femur at hip joint

Anterior Thigh – Hip flexors and Knee extensorsPsoas major Posterior abdominal wall (lumbar transverse

processes, intervertebral discs, and adjacent bodies from TXII to LV and tendinous arches between these points)

Lesser trochanter of femur

Anterior rami L1,L2,L3

Flexes the thigh at the hip joint

Iliacus Posterior abdominal wall (iliac fossa) Lesser trochanter of femur

Femoral nerve [L2,L3]

Flexes the thigh at the hip joint

Vastus medialis

Femur-medial part of intertrochanteric line, pectineal line, medial lip of the linea aspera, medial supracondylar line

Quadriceps femoris tendon and medial border of patella

Femoral nerve [L2,L3,L4]

Extends the leg at the knee joint

Vastus intermedius

Femur-upper two-thirds of anterior and lateral surfaces

Quadriceps femoris tendon and lateral margin of patella



Vastus lateralis

Femur-lateral part of intertrochanteric line, margin of greater trochanter, lateral margin of gluteal tuberosity, lateral lip of the linea aspera

Quadriceps femoris tendon



Rectus femoris

Straight head originates from the anterior inferior iliac spine; reflected head originates from the ilium just superior to the acetabulum

Quadriceps femoris tendon


Flexes the thigh at the hip joint and extends the leg at the knee joint

Sartorius Anterior superior iliac spine Anterior surface of tibia just inferomedial to tibial tuberosity


Flexes the thigh at the hip joint and flexes the leg at the knee joint

Medial Compartment – hip adductorsGracilis A line on the external surfaces

of the body of the pubis, the inferior pubic ramus, and the ramus of the ischium

Medial surface of proximal shaft of the tibia

Obturator nerve [L2,L3]

Adducts thigh at hip joint and flexes leg at knee joint

Pectineus Pectineal line and adjacent bone of pelvis

Oblique line extending from base of lesser trochanter to linea aspera on posterior surface of proximal femur


Adducts and flexes thigh at hip joint

Adductor longus

External surface of body of pubis (triangular depression inferior to pubic crest and lateral to pubic symphysis)

Linea aspera on middle one-third of shaft of femur

Obturator nerve (anterior division) [L2,L3,L4]

Adducts and medially rotates thigh at hip joint

Adductor brevis

External surface of body of pubis and inferior pubic ramus

Posterior surface of proximal femur and upper one-third of linea aspera

Obturator nerve[L2,L3]

Adducts thigh at hip joint

Adductor magnus

Adductor part-ischiopubic ramus

Posterior surface of proximal femur, linea aspera, medial supracondylar line

Obturator nerve [L2,L3,L4]

Adducts and medially rotates thigh at hip joint

Hamstring part-ischial tuberosity

Adductor tubercle and supracondylar line

Sciatic nerve (tibial division) [L2,L3,L4]

Obturator externus

External surface of obturator membrane and adjacent bone

Trochanteric fossa Obturator nerve (posterior division) [L3,L4]

Posterior Compartment – hip extensors and knee flexorsBiceps femoris Long head-inferomedial part

of the upper area of the ischial tuberosity; short head-lateral lip of linea aspera

Head of fibula Sciatic nerve [L5 to S2]

Flexes leg at knee joint; extends and laterally rotates thigh at hip joint and laterally rotates leg at knee joint

Semitendinosus Inferomedial part of the upper area of the ischial tuberosity

Medial surface of proximal tibia

Sciatic nerve [L5 to S2]

Flexes leg at knee joint and extends thigh at hip joint; medially rotates the thigh at the hip joint and leg at the knee joint

Semimembranosus

Superolateral impression on the ischial tuberosity

Groove and adjacent bone on medial and posterior surface of medial tibial condyle

Sciatic nerve [L5,S1,S2]

Flexes leg at knee joint and extends thigh at hip joint; medially rotates thigh at the hip joint and leg at the knee joint


External Iliac Artery: passes from the pelvis beneath the inguinal ligament into the femoral triangle to become the femoral artery.

Femoral Artery: this is the major artery that supplies the lower limb. It is a continuation of the external iliac artery. It gives rise to the profunda femoris artery, which itself gives rise to the circumflex vessels which supply the muscles of the thigh.

» Palpable at the mid-inguinal point (half-way between the anterior superior iliac spine and pubic symphysis)

» It is lateral to the femoral vein and medial to femoral nerveAt the knee it becomes the popliteal artery

Gluteal Arteries: there are 2 main gluteal arteries, the superior and inferior. They originate in the pelvic cavity and are branches of the internal iliac artery. They supply the gluteal regions.

Obturator Artery: another branch of the internal iliac artery, it supplies the medial compartment of the thigh.

Femoral Vein: this is the main deep vein draining the lower limb. The deep veins of the thigh drain into the popliteal vein which becomes the femoral vein. It becomes the external iliac vein when it crosses the inguinal ligament, which itself joins the internal iliac vein to form the common iliac vein.

Saphenous Veins: these are the main superficial veins of the lower limb. All the superficial veins drain into these including the venae comitantes of the profunda femoris vein. They join the femoral vein at the saphenofemoral junction. There are 2, the great (long) saphenous vein and the small saphenous vein. The LSV pierces the fascia of the thigh to join the deep system at the femoral triangle. There is an important valve at the sapheno-femoral junction which prevent blood passing from deep to superficial – incompetence causes varicose veins.

Varicose veins - a condition caused by incompetence of valves in the veins. This causes blood to pile up in the lower veins. It can increase the risk of deep vein thrombosis, is unsightly, causes an increase in pressure and hence can damage capillaries thus producing a brown pigmentation of the skin and venous eczema. Also increases risk of skin ulcers.

Lymphatics of the region» Lymph drainage follows the superficial

and deep systems» Superficial system runs with long and short

saphenous veins and has superficial inguinal lymph nodes in the groin

» These drain into the inguinal lymph nodes and external iliac lymph nodes

» The deep system drains alongside the deep veins to the deep inguinal lymph nodes which drain to the external iliac lymph nodes


Motor segmental supply:» Hip flexors – L23» Hip extensors – L45» Knee extensors – L34» Knee flexors – L5 S1

The nerves of the lower limb all originate from the lumbosacral plexus. There are a number of nerves that emerge:

Femoral Nerve: leaves the abdomen by passing under the inguinal ligament and into the femoral triangle. It innervates all the muscles on the anterior compartment of the thigh as well as the skin of the anterior aspect of the thigh, the medial side of the leg and the medial side of the foot. It arises from spinal levels L3 and L4.

Sciatic Nerve: the largest nerve in the body, and carries contributions from L4 – S3. It enters the leg through the greater sciatic foramen and passes through the gluteal region. Passes through buttock and divides at an inconsistent level on the posterior aspect of the thigh into the tibial nerve and common peroneal nerve. It innervates the posterior compartment of the thigh, as well as all the muscles of the leg and foot, and the skin on the lateral side of the leg and the lateral sole of the foot. If the buttock is divided into quadrants the nerve lies in the inferior and medial – therefore injections always given in the superior and lateral compartments.

Obturator Nerve: this also originates from L2 to L4, but descends along the posterior abdominal wall and enters the thigh through the obturator canal. It innervates the medial compartment of the thigh and the skin on the medial and upper thigh.

Gluteal Nerves: there are 2 nerves that supply the gluteal region, the superior gluteal nerve supplies the gluteus minimus and medius, and the inferior gluteal nerve supplies the gluteus maximus.

Trendelenberg Test Important test of hip abductor function = Trendelenberg Test

Stand on one leg The contralateral pelvis should rise as a result of the abductor muscles (gluteus medius and minimus) If dips = positive test. Patients with a positive test waddle when they walk

True leg length = the measurement between the medial malleolus of the ankle and the anterior superior iliac spine ( a fixed bony part of the pelvis) Apparent leg length = measurement between the medial malleolus and the xiphisternum

Hip FracturesThere are four types of “hip fracture”The differences between them are important because each is treated differently. Femoral head fracture denotes a fracture involving the femoral head. This is

usually the result of high energy trauma and a dislocation of the hip joint often accompanies this fracture.

Femoral neck fracture (sometimes Neck of Femur (NOF), subcapital, or intracapsular fracture) denotes a fracture adjacent to the femoral head in the neck between the head and the greater trochanter. These fractures have a propensity to damage the blood supply to the femoral head, potentially causing avascular necrosis.

Intertrochanteric fracture denotes a break in which the fracture line is between the greater and lesser trochanter on the intertrochanteric line. It is the most common type of 'hip fracture' and prognosis for bony healing is generally good if the patient is otherwise healthy.

Subtrochanteric fracture actually involves the shaft of the femur immediately below the lesser trochanter and may extend down the shaft of the femur.

http://en.wikipedia.org/wiki/Femur

http://en.wikipedia.org/wiki/Intertrochanteric_line

http://en.wikipedia.org/wiki/Avascular_necrosis

http://en.wikipedia.org/wiki/Avascular_necrosis

Limbs 7 – Knee, Popliteal Fossa, Leg and FootAnil Chopra1. Identify the bones and joints of the entire lower limb2. Find the following landmarks in the living subject;

a. the medial and lateral femoral epicondylesb. the patella and the patellar ligamentc. the head of the fibulad. the medial and lateral malleolie. the navicular tuberosityf. the base of the fifth metatarsalg. the head of the first metatarsal

3. Demonstrate the following prime movers and muscle groups and the main movements associated with them;

a. the gastrocnemius-soleus (the superficial flexor compartment of the leg)

b. the deep flexor compartment of the legc. the peroneal compartment of the legd. the extensor compartment of the leg

4. Assign muscle groups to the following nerves;a. the sciatic nerve in the thighb. the tibial nervec. the common peroneal nerve

5. Trace the routes of the femoral artery, the profunda femoris artery, the anterior tibial artery and the posterior tibial artery

6. Demonstrate the femoral pulse, the popliteal pulse, the posterior tibial pulse and the dorsalis pedis artery and explain their significance

7. Briefly explain the operation of total knee replacement and potential damage during the operation

8. Describe arthroscopy of the knee joint9. Discuss the common injury of anterior cruciate ligament rupture. 10. Discuss Achilles Tendon Ruptures and their anatomical bases11. Discuss the clinical entity of compartment syndrome and explain its anatomical

basis.

Bones of the Region

Distal Femur: the course of the femur is oblique, resulting in the knee being closer to the midline under the body’s centre of gravity. The shaft of the femur is triangular and has smooth surfaces. The distal end of the femur has 2 epicondyles, lateral and medial in between which is the intercondylar fossa. In here the medial epicondyle attaches to the posterior cruciate ligament and the lateral epicondyle to the anterior cruciate ligament.

Tibia: tibia is medial and the larger of the 2 bones that make up the leg and the only one that articulates with the femur. At its proximal end it flattens into a transverse plane used for weight bearing. It has 2 condyles, lateral and medial – thick horizontal parts of the bone attached to the top of the shaft (the parts in between them known as the intercondylar eminence). There are 6 facets for the attachment of ligaments and menisci (moon shaped cartilaginous tissues):

- medial meniscus – attaches both anteriorly and posterior

- anterior cruciate ligament- lateral meniscus – attaches both anteriorly

and posteriorly- posterior cruciate ligament

The distal end of the tibia is shaped like a rectangular box with a bony protuberance on the medial side – the medial malleolus, the inferior of which articulates with the talus (a tarsal bone). On its lateral side it contains a deep triangular notch (the fibular notch) to which the distal head of the fibula is anchored by a thickened part of the interosseous membrane.

Fibula: the most lateral bone of the leg and is not involved at the knee joint. Its head is an expansion at its proximal end and contains attachments for the biceps femoris and the collateral ligament. It has a facet for articulation with the lateral condyle of the tibia and a process sticking out of the top called the styloid process.

The fibula is narrower than the tibia as it is not involved in weight bearing. The distal end of the tibia expands to form the lateral malleolus. It articulates with the lateral surface of the talus hence forming the lateral part of the ankle.

Patella: also known as the “knee cap”, the patella is a sesamoid bone (formed within a tendon) and is an attachment for the quadriceps tendon and the patellar ligament. It is triangular in shape and sits anterior to the distal end of the femur.

The FootTarsal Bones: the tarsal bones are split into 2 main groups, the proximal group consists Talus – a snail shaped bone that articulates with the tibia and fibula. It has a

rounded head, which projects forward onto a short broad neck. The head is domed anteriorly – the talar dome, which articulates with navicular bone. At its posterior end, it has a groove for the attachment of the flexor hallucis longus.

Calcaneus – an irregular shaped bone that sits underneath the talus and forms the heel of the foot. It has articulations for attachment of the calcaneal tendon (Achilles’ tendon) on its posterior surface. On its medial surface it contains the sustentaculum tali – a shelf of bone projecting medially and supporting the posterior part of the talus. The plantar surface of the bone contains the calcaneal tuberosity.

The intermediate tarsal bone is the: Navicular: a boat shaped bone on the medial side of the foot. It articulates with

the talus and has a rounded tuberosity which is an attachment site for the tibialis posterior tendon.

The distal group contains: Cuboid: in front of the caclaneus. Cuneiforms: there are 3 cuneiforms, lateral, intermediate and medial, they are in

front of the navicular bone and behind the metatarsals.

Metatarsals: the metatarsals articulate with the tarsals and the proximal phalanges. They consists of base, shaft, head and neck. N.B. – the tuberosity on the base of the 5th

which articulates with the cuboid

Phalanges: there are 3 phalanges for each toe: proximal, middle and distal apart from the great toe (big toe) which has 2 – a proximal and distal)

The Popliteal Fossa – the gateway to the lower limb. It is a diamond shaped fossa on the back of the knee formed by:

Superolaterally – biceps femoris Superomedially – semimembranosus Inferolaterally – lateral head of gastrocnemius Inferomedially – medial head of gastrocnemius Posteriorly – skin and fascia Anteriorly – the femur

The contents of the popliteal fossa are: Popliteal artery Popliteal vein The tibial and common peroneal nerves – the tibial nerve runs straight, the peroneal nerve runs to the side before running round the neck of the fibula Short saphenous vein Popliteal lymph nodes

Joints of the RegionKnee joint: the largest synovial joint in the body. It consists of the articulation between the femur and the tibia (weight bearing) and the articulation between the patella and the femur. There are 3 main compartments to the knee: the medial compartment, lateral compartment and patello-femoral compartment. The distal femur:

Articular condyles – articulate with the tibia, medial is bigger than lateral The patella articulates anteriorly The linea aspera provides the attachment for vastus and biceps femoris

Proximal tibia: The articular surfaces receive the femoral condyles Intercondylar eminence provides attachment for cruciate ligaments and menisci Tibial tuberosity provides attachment for the patellar ligament

Proximal fibula: The head articulates with the tibia

Patella – a sesimoid bone in the tendon of quadriceps femoris

It is held in place by the two menisci one on each side between the femoral condyles. The medial and lateral menisci form partial cushions between tibia and femur and are attached to the intercondylar eminence of the tibia. The medial meniscus is commonly injured in twisting, more commonly than lateral

It is essentially a hinge joint which involves flexion and extension. It can also when the joint is extended to assist with standing. It contains a number of different ligaments:- Patellar ligament: attaches from patella to tibial tuberosity- Collateral ligaments: stabilise the hinge-like motion of the knee; there are 2, a

fibular collateral ligament which attaches from the lateral femoral epicondyle to the lateral fibular head; and the tibial cruciate ligament which attaches from the medial femoral epicondyle to the medial condyle of the tibia.

o The medial collateral is a broad flat thickening of the knee capsule and is attached to the medical meniscus. Prevents knee abduction

o Lateral collateral is a cord like ligament and is not attached to either the knee capsule or lateral meniscus. Prevents knee adduction

- Cruciate ligaments: there are 2; anterior and posterior, both attach from the intercondylar area at the back of the tibia, to the intercondylar area of the femur.

o Anterior cruciate is attached to the intercondylar area of tibia and passes upwards, backwards and laterally. Limits anterior movement of the tibia on the femur (or posterior movement of the femur on the tibia). We can live without it

o Posterior cruciate is attached to the posterior intercondylar area of the tibia and lateral meniscus. It passes upwards, forwards and medially. It prevents posterior movement of the tibia on the femur and vice verse. It takes the weight of the body when the knees are bent – so it is important

-

Bursae around the knee: - bags of synovial membrane and fluid found between tendons or muscles and skin

Pre-patellar bursa

Pre-patellar tendon bursa Popliteal bursa (Baker’s cyst)

Interosseous Membrane: this is a tough fibrous membrane that connects the tibia and fibula. It has two apertures, one at the proximal end for the anterior tibial vessels and one at the distal end for the fibular artery. There are also two tibiofibular ligaments at the distal end of the two bones, anterior and posterior

Ankle Joint: A hinge synovial joint between the medial malleolus of the tibia, lateral malleolus of the fibula and talar dome of the talus that only plantarflexion or dorsiflexion. The joint is stabilised by the medial and lateral ligaments:

- The lateral ligament complex – calcaneofibular, anterior talofibular and posterior talofibular. The anterior talofibular ligament most often sprained

- The medial or deltoid ligament of the ankle – from the medial malleolus the medial ligament spreads out as a triangle. The superficial part goes and down and

back to the tail of the calcaneus, the deep part goes backwards and downwards along the entire length od the sustentaculum tali

The articular surface of the talus is wider at the front than the back so in dorsiflexion the joint is more stable than in plantar flexion. Eversion and Inversion do not occur at the ankle joint but at the sub-talus joint

Intertarsal Joints: these joints are used in eversion or inversion of the foot, (rocking the sole of the foot) and supination and pronation (rotating the foot). The foot is divided into the hind foot, mid foot and fore foot The sub-talar joint consists of:

o The talo-calcaneal joint – anterior to the head of the taluso The talo-navicular jointo The calcaneo-cuboid joint – a separate joint cavity but a functional unit

with the talo-calcaneal joint The mid-tarsal joint consists of joints between the midtrasal bones and the

metatarsals

Tarsometatarsal joints: limited sliding movement

Metatarsophalangeal joints: allow extension, flexion, adduction, abduction, rotation and circum duction of the toes.

Interphalangeal joints: held in place by collateral ligaments.

Muscles of the RegionSuperficial Posterior Compartment – plantar flexors (foot down)

Muscle Origin Insertion Innervation FunctionGastrocnemius

Medial head-posterior surface of distal femur just superior to medial condyle; lateral head-upper posterolateral surface of lateral femoral condyle

Via calcaneal tendon, to posterior surface of calcaneus

Tibial nerve [S1,S2]

Plantarflexes foot and flexes knee

Plantaris Inferior part of lateral supracondylar line of femur and oblique popliteal ligament of knee



Plantarflexes foot and flexes knee

Soleus Soleal line and medial border of tibia; posterior aspect of fibular head and adjacent surfaces of neck and proximal shaft; tendinous arch between tibial and fibular attachments



Plantarflexes the foot

NB: Gastrocnemius is superficial to soleus (the main two muscles), they come together to form the Achilles heel

Deep Posterior CompartmentMuscle Origin Insertion Innervation FunctionPopliteus Posterior surface of proximal tibia Lateral femoral condyle Tibial nerve

[L4 to S1]Unlocks knee joint (laterally rotates femur on fixed tibia)

Flexor hallucis longus

Posterior surface of fibula and adjacent interosseous membrane

Plantar surface of distal phalanx of great toe


Flexes great toe

Flexor digitorum longus

Medial side of posterior surface of the tibia

Plantar surfaces of bases of distal phalanges of the lateral four toes


Flexes lateral four toes

Tibialis posterior

Posterior surfaces of interosseous membrane and adjacent regions of tibia and fibula

Mainly to tuberosity of navicular and adjacent region of medial cuneiform

Tibial nerve [L4,L5]

Inversion and plantarflexion of foot; support of medial arch of foot during walking

Lateral Compartment – ankle evertors (sole of foot away from midline)Muscle Origin Insertion Innervation FunctionFibularis longus

Upper lateral surface of fibula, head of fibula and lateral tibial condyle

Undersurface of lateral sides of distal end of medial cuneiform and base of metatarsal I

Superficial fibular nerve [L5,S1,S2]

Eversion and plantarflexion of foot; supports arches of foot

Fibularis brevis

Lower two-thirds of lateral surface of shaft of fibula

Lateral tubercle at base of metatarsal V

Superficial fibular nerve [L5,S1,S2]

Eversion of foot

Muscle Origin Insertion Innervation FunctionTibialis anterior

Lateral surface of tibia and adjacent interosseous membrane

Medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of metatarsal I

Deep fibular nerve [L4,L5]

Dorsiflexion of foot at ankle joint; inversion of foot; dynamic support of medial arch of foot

Extensor hallucis longus

Middle one-half of medial surface of fibula and adjacent surface of interosseous membrane

Dorsal surface of base of distal phalanx of great toe

Deep fibular nerve [L5,S1]

Extension of great toe and dorsiflexion of foot

Extensor digitorum longus

Proximal one-half of medial surface of fibula and related surface of lateral tibial condyle

Via dorsal digital expansions into bases of distal and middle phalanges of lateral four toes


Extension of lateral four toes and dorsiflexion of foot

Fibularis tertius

Distal part of medial surface of fibula

Dorsomedial surface of base of metatarsal V


Dorsiflexion and eversion of foot

Anterior Compartment – plantar flexors (foot up)

Intrinsic Foot MusclesDorsal Aspect of the Foot

Muscle Origin Insertion Innervation FunctionExtensor digitorum brevis

Superolateral surface of the calcaneus

Base of proximal phalanx of great toe and lateral sides of the tendons of extensor digitorum longus of toes II to IV

Deep fibular nerve [S1,S2]

Extension of metatarsophalangeal joint of great toe and flexion of toes II to IV

Sole of Foot First Layer

Muscle Origin Insertion Innervation FunctionAbductor hallucis

Medial process of calcaneal tuberosity Medial side of base of proximal phalanx of great toe

Medial plantar nerve from the tibial nerve [S2,S3]

Abducts and flexes great toe at metatarsophalangeal joint

Flexor digitorum brevis

Medial process of calcaneal tuberosity and plantar aponeurosis

Sides of plantar surface of middle phalanges of lateral four toes

Medial plantar nerve from the tibial nerve [S2,S3]

Flexes lateral four toes at proximal interphalangeal joint

Abductor digiti minimi

Lateral and medial processes of calcaneal tuberosity, and band of connective tissue connecting calcaneus with base of metatarsal V

Lateral side of base of proximal phalanx of little toe

Lateral plantar nerve from tibial nerve [S2,S3]

Abducts little toe at the metatarsophalangeal joint

Second LayerMuscle Origin Insertion Innervation FunctionQuadratus plantae

Medial surface of calcaneus and lateral process of calcaneal tuberosity

Lateral side of tendon of flexor digitorum longus in proximal sole of the foot

Lateral plantar nerve from tibial nerve [S1 to S3]

Assists flexor digitorum longus tendon in flexing toes II to V

Lumbricals First lumbrical-medial side of tendon of flexor digitorum longus associated with toe II; second, third, and fourth lumbricals-adjacent surfaces of adjacent tendons of flexor digitorum longus

Medial free margins of extensor hoods of toes II to V

First lumbrical-medial plantar nerve from the tibial nerve; second, third, and fourth lumbricals-lateral plantar nerve from the tibial nerve [S2,S3]

Flexion of metatarsophalangeal joint and extension of interphalangeal joints

Third layerMuscle Origin Insertion Innervation FunctionFlexor hallucis brevis

Plantar surface of cuboid and lateral cuneiform; tendon of tibialis posterior

Lateral and medial sides of base of proximal phalanx of the great toe


Flexes metatar-sophalangeal joint of the great toe

Adductor hallucis

Transverse head-ligaments associated with metatarsophalangeal joints of lateral three toes; oblique head-bases of metatarsals II to IV and from sheath covering fibularis longus

Lateral side of base of proximal phalanx of great toe


Adducts great toe at metatarsopha-langeal joint

Flexor digiti minimi brevis

Base of metatarsal V and related sheath of fibularis longus tendon

Lateral side of base of proximal phalanx of little toe


Flexes little toe at metatarsophalangeal joint

Fourth layer

Muscle Origin Insertion Innervation FunctionDorsal interossei

Sides of adjacent metatarsals

Dorsal expansions and bases of proximal phalanges of toes II to IV

Lateral plantar nerve from tibial nerve; first and second dorsal interossei also innervated by deep fibular nerve [S2,S3]

Abduction of toes II to IV at metatarsophalangeal joints; resist extension of metatarsophalangeal joints and flexion of interphalangeal joints

Plantar interossei

Medial sides of metatarsals of toes III toV

Dorsal expansions and bases of proximal phalanges of toes III to V


Adduction of toes III to V at metatarsophalangeal joints; resist extension of the metatarsophalangeal joints and flexion of the interphalangeal joints


Popliteal artery: this is the major blood supply to the leg and foot and enters the posterior compartment of the leg from the popliteal fossa. It becomes the popliteal artery from the femoral artery and has 3 major branches.

Peroneal artery: which runs in lateral compartment of the leg

Anterior tibial artery: passes forward thorough the aperture of the interosseous membrane and supplies the anterior compartment of the leg. In the foot is forms the dorsalis pedis artery.

Posterior tibial artery: descends through the deep region of the posterior compartment. It supplies both the lateral and posterior compartments of the leg. It splits in just inferior to the knee into the:

- circumflex fibular artery - anastomosis with vessels surrounding the knee

- fibular artery – supplies the posterior compartment of the leg, it also sends of a perforating branch which anastomosis with a branch of the anterior tibial artery.

The posterior tibial artery enters the foot through the tarsal tunnel. This is a palpable spot because the artery is not covered by very much. It bifurcates into lateral and medial plantar arteries. The lateral plantar artery forms the deep plantar arch. These go on to supply the plantar side of the toes.

Dorsalis Pedis: a continuation of the anterior tibial artery. It enters the foot after passing the ankle joint. It passes inferiorly into the deep plantar arch between the first and second metatarsal. Its pulse is palpable on the dorsal surface of the foot in between the metatarsals of the first and second toe.

Deep Veins: the deep veins of the leg generally follow the arteries and eventually drain in to the great and small saphenous vein which drains into the femoral vein. They consists of the:posterior tibial veins, dorsal digital veins, popliteal vein and the perforating veins through which blood passes from superficial to deep. The deep system forms a powerful muscle pump in the calf

Dorsal Venous Arch: connect the great and small saphenous veins in the foot. From the medial aspect of the dorsal venous arch runs the

long saphenous vein – lies 2cm above and 2cm medial to medial malleolus. It runs in the medial aspect of the leg, behind the knee and empties into the femoral vein at the sapheno-femoral junction in the groin. In the leg it anastomoses freely with the short saphenous vein and has connecting veins to the deep system

From the lateral aspect of the dorsal venous arch runs the short saphenous vein. It runs posterior to the lateral maleolus, up the back of the calf and drains into the deep system and popliteal vein in the popliteal fossa


Segmental motor supply: Hip flexors – L23 Hip extensors – L45 Knee extension – L34 Knee flexion – L5S1 Ankle dorsiflexion – L45 Ankle plantaflexion – S12 Think patterns in walking – walking starts at the top and passes down the lumbro-sacral region

Segmental Sensory Supply: Regular dermatomal supply L3 to knee, L4 to floor L5 to the dorsum of the great toe S1 to lateral side of foot S1 to sole of foot

Tibial Nerve: this is the nerve that mainly associated with the posterior compartment of the leg. It is a branch of the sciatic nerve which descends in to the posterior compartment from the popliteal fossa. It also supplies the skin on the lower posterolateral surface of the leg and the lateral side of the foot and little toe.

When it reaches the foot is splits into a - medial plantar nerve which is sensory for the sole of the foot- lateral plantar nerve which supplies motor fibres to the intrinsic muscles of

the sole – the plantar flexors.

Superficial Fibular Nerve: this supplies the lateral compartment of the leg and originates as one of the two branches from the common fibular nerve (originating from the sciatic nerve).

Deep fibular nerve: this supplies the anterior compartment of the leg and continues onto the foot where it innervates the dorsal flexors of the foot.

GaitGait can be divided into the swing phase and stance phase.

The swing phase = 1/3 of cycle, the stance phase 2/3

Limbs 8 - Lower limb Nerves and VesselsAnil Chopra

1. Summarise and demonstrate the arterial supply and venous drainage of the lower limb

2. Review the techniques of palpation of the femoral, popliteal, posterior tibial and dorsalis pedis arteries

3. Explain the likely causes and consequences of embolism in the lower limb4. Explain the term intermittent claudication5. Explain the causes and likely consequences of compartment syndromes, giving

appropriate examples6. Explain the mechanism for venous return from the lower limb in terms of

superficial and deep veins, perforators, valves and the muscle pump7. Explain how varicose veins arise in the lower limbs and how they may lead to

venous circulatory incompetence8. Describe the common sites and causes of deep venous thrombosis and outline its

possible consequences9. Discuss the anatomical basis of canulation of the femoral vein and arterial access

to the femoral artery in the groin.10.Describe how to perform a cut-down of the long saphenous vein at the ankle,

including its anatomical landmarks and clinical importance

Neuroanatomy of the Lower LimbThere are 2 types of nerve distribution, both of which can be damaged:Segmental: part of the spinal cord that can be damaged by lesionsPeripheral: part of the separate peripheral nerves themselves which can be damaged by surgery, laceration, limb injury.

The lower limb undergoes extension and internal rotation, therefore the extensor muscles are anterior and the flexor muscles are posterior:

HIP KNEE ANKLE

L2} FLEXL3} L3}

EXTENDL4} L4} L4} EXTEND D-FLEXL5} L5} L5}

FLEXS1} S1}

P-FLEXS2}

The segmental dermatomes are as follows:L3 – front of the thigh (“L3 to the knee”)L4 – front of the leg (“L4 to the floor”)L5 – dorsum of the great toe

S1 – lateral aspect of the footS2-4 – perineum and perianal region

There are 2 main reflex arcs in the knee that are controlled by segemental neves:- Knee jerk: L3- Ankle jerk: S1

The different peripheral nerves all arise from the lumbosacral plexus:- The iliohypogastric and ilio-inguinal nerves (L1)- The genitofemoral nerve (L1L2)- The lateral cutaneous nerve of the thigh (L2L3)- The femoral nerve (L2L3L4, posterior divisions)- The obturator nerve (L2L3L4, anterior divisions)- The lumbosacral trunk (L4L5) – feeds the sacral plexus- The Sciatic Nerve (L4L5S1S2S3)- The nerve to piriformis (S1S2)- The posterior cutanous nerve of the thigh (S1S2S3)- The pelvic splanchnic nerves (S2S3S4) – parasympathetic- The pudendal nerve (S2S3S4)- The nerve to nerve to obturator internus (L5S1S2)- The superior gluteal nerve (L4L5S1)- The inferior gluteal nerve (L5S1S2)

Clinical Neurological Problems with Lower Limb

Injury to the Femoral NerveThe femoral nerve is relatively superficial in the groin but is rarely damaged except by doctors (iatrogenic injuries). The commonest injury today is via traction injuries during hip replacements, and also at laparoscopic repair of inguinal hernias. It can also be damaged during erroneous attempted cannulations of the femoral artery or femoral vein.

The Lateral Cutanous Nerve of the thighThis superficial nerve passes 2cm medial to the anterior superior iliac spine at the level of the inguinal ligament. It can be compressed at this level causing meralgia paraesthetica.

The obturator nerveThe obturator nerve is rarely damaged. Beware pain in the distribution of the obturator nerve as it can be indicative of malignant disease in the pelvis.

Injury to the superior gluteal nerveThe superior gluteal nerve supplies the gluteus medius and gluteus minimus muscles. If this nerve is damaged, the result is a Tredelenberg gait, where the pelvis lurches during gait.

The commonest injury today to the superior gluteal nerve is at hip replacement. The nerve lies approximately 5cm proximal to the tip of

the greater trochanter, and approaches to the hip joint should not extend more than 5cm from the tip of the greater trochanter.

Injury to the sciatic nerve The commonest cause today of injury to the sciatic nerve is after hip replacement.

The common peroneal division is far more vulnerable than the tibial division. Can result in the flaccid paralysis of hamstrings, paralysis of all muscles below the

knee and loss of most sensation below the knee. To avoid damage to the sciatic nerve, always give an intramuscular injection in

the upper outer quadrant of the buttock. Keep away from the lower inner quadrant, which is where the nerve is most likely to be situated.

Other causes of damage are trauma (e.g. hip dislocations or acetabular fractures) and pelvic disease.

Injury to the common peroneal nerveAs well as being damaged at the level of the hip, the common peroneal nerve is highly vulnerable to damage at the level of the fibular neck, around which the nerve winds.Results in paralysis of extensor and peroneal compartment of leg results in foot drop accompanied by loss of sensation over most of antero-lateral leg and dorsum of foot.Causes of damage are trauma, knee replacement and external pressure e.g. from plasters or during surgical procedures.

Injury to the saphenous nerveInjury to this nerve is surprisingly common.The nerve can be damaged at the medial malleolus (e.g. after varicose vein surgery or cut down) or at the level of the knee (e.g. ACL surgery).

Compression of the spinal roots Often results after lumbar disc injury – pain is felt down route of affected nerve. L4 or L5 is common leading to sciatica

Anaesthetic Nerve BlocksNerve blocks can be utilised by anaesthetists to aid or substitute general anaesthesia during surgery.Examples include femoral nerve blocks, sciatic nerve blocks, ankle blocks or blocks of the lateral cutaneous nerve of the thigh. Knowledge of peripheral anatomy allows the anaesthetist to localise the best place to insert local anaesthetic and also to predict the level and extent of anaesthesia provided.

Vascular Problems with the Lower Limb

Femoral hernias Pass into the femoral canal which is medial to the femoral vein in the femoral sheath

Cannulation of the femoral artery and veinThe femoral artery and vein can be easily exposed and cannulated at the groin e.g. for cardiac arteriography (artery) or for resuscitation (vein).

Cut-down at the medial malleolus of the long saphenous vein.In the shocked patient, venous cannulation may not be easy or possible.

The anatomical surface marking of the long saphenous vein at the ankle (2cm above and proximal to the tip of the medial malleolus) makes it an excellent site to perform a “cut-down”.

A small incision can be made at the ankle and a venous cannula placed under direct vision into the vein for resuscitation.

The concept of arterial embolismAcute arterial embolism can be caused by sudden occlusion of an atheroclerotic vessel or by thrombus from atrial fibrillation. If a vessel is suddenly occluded with no time for a collateral circulation to develop, the consequences can be severe. For example if an arterial clot forms in the popliteal artery, there may be no time for a collateral circulation to develop and the leg may become ischaemic and require amputation if the lesion is no cleared within a few hours.

Intermittent claudication is a condition where there is a gradual occlusion of arteries within the limb, usually atherosclerotic. The muscles supplied distal to the occlusion become deprived of blood on exercise so that there is a limited walking distance before pain occurs, most commonly in the calf, but sometimes in the thigh or buttock.

Compartment syndromeCompartment syndromes can occur anywhere in the leg but are most common in the true leg itself.

There are three compartments in the leg, the anterior, posterior and lateral compartments. Each compartment is bound by a very tight fascia, which only let the enclosed muscles swell to a certain degree before resisting any further expansion and then increase the pressure in the muscle itself.

If the pressure in the muscle increases too far, the arterial supply and venous return of the muscle in that compartment is cut off, resulting in muscle death, with resulting loss of movement and contractures in the limb.

There are clinical syndromes where muscle swelling causes such damage, and these are termed compartment syndromes.

Acute compartment syndrome occurs after trauma to a limb, e.g. fractures, muscle damage. Unless the fascia is released urgently by a fasciotomy the muscle will die with disastrous consequences. Note that the arterial pulse is not lost in acute compartment syndromes. The tissue pressure is only 25mmHg and pressure need only to rise to 50-60mmHg to cause a compartment syndrome. The diastolic blood pressure is 80mmHg and the systolic 120mmHg!

Chronic compartment syndrome occurs in athletes where the muscles swells during exercise and causes activity-related pain. Elective fasciotomy can relieve the pain of this condition.

Varicose veins and deep venous insufficiencyAs explained above, the superficial veins in the limb have valves which prevent backflow of blood. However, as well as this, the deep veins and the perforating veins also have valves. Probably the most important valve is at the sapheno-femoral junction in the groin. If this valve is incompetent, then blood can easily flow back into the superficial venous system, causing varicose veins. Most operations for varicose veins involve tying off the sapheno-femoral junction.Varicose veins are dilated and tortuous superficial veins. They can be painful, causing an aching discomfort on standing. However, they are also pathological in that the increased pressure within the superficial venous system can cause increased pressure in the superficial circulation, causing skin changes (lipodermatosclerosis) and often skin ulcers. Most skin ulcers are due to venous insufficiency of this type.

Deep venous thrombosisBlood can clot (thrombose) in the superficial and deep veins of the lower limb. When it occurs in the deep veins, this is termed deep venous thrombosis (DVT).

DVT is often “silent” but may present with pain and swelling in the calf or the proximal thigh. A distal DVT occurs in the calf whilst a proximal DVT extends into the thigh and pelvis. A proximal DVT is very dangerous, as there is a high risk of propagation of the clot into the lungs.

DVT is very important clinically. It can occur idiopathically (i.e. without an obvious cause) but is often associated with immobility, trauma, surgery within the abdomen, pelvis or limbs, obesity, malignancy, pregnancy or with the use of the oral contrceptive pill. DVT has two main consequences;

a. the clot may propagate into the pulmonary circulation, causing a pulmonary embolus (PE). A PE may be fatal and for this reason DVT’s are usually treated by anticoagulation to prevent this complication occurring.

b. The clot in the deep veins may cause increased back pressure in the deep veins, causing venous insufficiency and leg ulcers (the post-phlebitic syndrome)

The superficial veins may also clot or become inflamed/infected. This causes superficial thrombophlebitis. This is not so dangerous as DVT but can be very painful. The treatment is usually symptomatic (analgesia, rest, ice etc) rather than with anticoagulation.The superficial veins as grafts in elective surgeryThe saphenous veins are often used in cardiac and vascular surgery as grafts to replace arteries. Obviously the veins need to be orientated correctly due to the valves present within them.

As there is such an excellent anastomosis in the leg, the removal of the superficial veins rarely causes a problem.

Femoral TriangleThe femoral triangle is outlined by;» Superiorly – the inguinal ligament» Medially – by the adductor longus» Laterally – by the sartoriusThe femoral triangle contains the femoral nerve, artery and vein, which are arranged as follows, from lateral to medial; Femoral Nerve Femoral Artery Femoral VeinThe femoral sheath encloses the femoral artery and vein (but not the femoral nerve). A portion of it medially forms the femoral canal.

Lower Limb Pulses

anil - limbs

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