The Applied Anatomy of the

Limbs

Presenter: Dr. D B Mwale

Moderator: Dr Munthali

Content

o Embryological Development

o Lower Limb

o Gross Anatomy

o Applied Anatomy

o Upper Limb

o Gross Anatomy

o Applied Anatomy

Frolich, Human Anatomy,UpprLimb

What is a limb? Ventral somatic outgrowth of outer tube

Bones (with bone, cartilage, marrow, NAV, etc.) Joints Muscle Nerves Vascular supply

No viscera--all innervation is somatic (motor or sensory) from ventral ramus of spinal nerve (except autonomics to blood vessels)

From paraxial mesoderm (i.e. somites): Dermatome gives rise to connective tissue of the dermis

Myotome gives rise to limb muscles

From lateral plate mesoderm: Bones of arm, forearm, hand, thigh, leg and foot

Blood vessels

Connective tissue (except for that of the dermis)

Peripheral nerve elements,are derived from neural crest

EMBRYOLOGY

initial growth and patterning of the limbs occurs during weeks 4 – 8.

Limb buds appear at about 4 weeks and much of the basic structures of the limbs (bones and muscle groups) are established by 8 weeks. After 8 weeks, the limb elements then just increase in size.

Disruption of growth and/or patterning can result in many possible defects:

Amelia: absence of an entire limb (e.g. early loss of Fgf signaling)

Meromelia: absence of part of a limb (e.g. later or partial loss of Fgfsignaling)

Phocomelia: short, poorly formed limb (e.g. partial loss of Fgf;

Adactyly: absence of digits (e.g. even later loss of Fgf)

Ectrodactyly: “Lobster-Claw” deformity (variant of adactyly –middle digit is lost)

Polydactyly: extra digits

Syndactyly: fusion of digits

Frolich, Human Anatomy,UpprLimb

Sensory from limb

(dermatomes/sensory skin

segments from spine)

Dermatomes extend over limbs

Twisted orientation reflects twisting of limb during development

Named nerves generally innervate skin over muscles that they innervate

Surface Anatomy

Gluteal region /

posterior pelvis

Iliac crest

Gluteus maximus

Cheeks

Natal/gluteal cleft

Vertical midline; “Crack”

Gluteal folds

Bottom of cheek;

“prominence”

Surface Anatomy

Anterior thigh and leg Palpate

Patella

Condyles of femur

Femoral Triangle Floor: pectineus, iliopsoas and

adductor longus muscles.

Roof : fascia lata

Boundaries:

Sartorius (lateral)

Adductor longus (medial)

Inguinal ligament (superior)

Contents:

Femoral artery, vein and nerve, lymph nodes

Surface Anatomy

Posterior leg Popliteal fossa

Diamond-shape fossabehind knee

Boundaries Biceps femoris (superior-

lateral)

Semitendinosis and semimembranosis(superior-medial)

Gastrocnemius heads (inferior)

Contents Popliteal artery and vein

Floor : posterior surface of the knee joint capsule, and

posterior surface of the femur. Roof : popliteal fascia and skin

Calcaneal (Achilles) tendon

Skeletal Composition

Bones of the Lower Limb

Function: Locomotion

Carry weight of entire erect body

Support

Points for muscular attachments

Components: Thigh

Femur

Knee Patella

Leg Tibia (medial)

Fibula (lateral)

Foot Tarsals (7)

Metatarsals (5)

Phalanges (14)

Thigh

Femur Largest, longest,

strongest bone in the body!!

Receives a lot of stress

Courses medially More in women!

Articulates with acetabulumproximally

Articulates with tibia and patella distally

Knee

Patella

Triangular sesamoid

bone

Protects knee joint

Improves leverage of

thigh muscles acting

across the knee

Contained within patellar

ligament

Leg

Tibia

Receives the weight of body from

femur and transmits to foot

Second to femur in size and

weight

Articulates with fibula proximally

and distally

Interosseous membrane

Fibula

Does NOT bear weight

Muscle attachment

Not part of knee joint

Stabilize ankle joint

Foot

Function: Supports the weight of the

body

Act as a lever to propel the body forward

Parts: Tarsals

Talus = ankle

Between tibia and fibula

Articulates with both

Calcaneus = heel

Attachment for Calcanealtendon

Carries talus

Navicular

Cuboid

Medial, lateral and intermediate cuneiforms

Metatarsals

Foot

3 arches Medial

Lateral

Transverse

Has tendons that run inferior to foot bones

Help support arches of foot

Function Recoil after stepping

Longitudinal

Joints of Lower Limb

Hip (femur + acetabulum) Ball + socket

Multiaxial

Synovial

Knee (femur + tibia) Hinge (modified)

Biaxial

Synovial

Contains menisci, bursa, many ligaments

Knee (femur + patella) Plane

Gliding of patella

Synovial

Joints of Lower Limb

Proximal Tibia + Fibula Plane, Gliding

Synovial

Distal Tibia + Fibula Slight “give” (synarthrosis)

Fibrous (syndesmosis)

Ankle (Tibia/Fibula + Talus) Hinge, Uniaxial

Synovial

Intertarsal & Tarsal-metatarsal Plane, synovial

Metatarsal-phalanges Condyloid, synovial

Interphalangeal Hinge, uniaxial

Muscles

Muscles of Thigh

& Hip Gluteals

Posterior pelvis

Extend thigh

Rotate thigh

Abducts thigh

Anterior Compartment Thigh Flexes thigh at hip

Extends leg at knee

Medial/Adductor Compartment Adducts thigh

Medially rotates thigh

Posterior Compartment Thigh Extends thigh

Flexes leg

Anterior

Compartment

Thigh Quadriceps femoris

Rectus femoris Origin – anterior inferior iliac

spine, margin of acetabulum Insertion – patella and tibial

tuberosity via the patellar ligament

Action – extends knee, flexes thigh

Vastus lateralis Vastus medialis Vastus intermedius

Origin - femur Insertion – patella and tibial

tuberosity via the patellar ligament

Action – extends knee

Sartorius Origin - anterior superior iliac

spine Insertion – medial tibia Action - flex, abduct, lat rotate

thigh; weak knee flexor

All above innervated by the femoral nerve!!!

Anterior

Compartment

Thigh

Iliopsoas

Origin - Ilia, sacrum,

lumbar vertebrae

Insertion – lesser

trochanter

Action – flexor of thigh

Innervation – femoral

nerve

AdductorsMEDIAL COMPARTMENT

Adductor longus Adductor brevis Adductor magnus

Origin – inferior pelvis Insertion - femur Action – adducts and medial rotates Innervation – Obturator nerve

Pectineus Origin - pubis Insertion – lesser trochanter Action – adducts, medial rotates Innervation – femoral, sometimes obturator

Gracilis Origin - pubis Insertion – medial tibia Action – adducts thigh, flex, medial, rotates

leg Innervation – Obturator nerve

innervated by the obturator nerve

Arterial supply is via the obturator artery.

Posterior Compartment –

Hamstring

Biceps femoris (2 heads)

Origin – ischial tuberosity, distal femur

Insertion - lateral tibia, head fibula

Action - thigh extension, knee flexion, lateral rotation

Semitendinosus

Semimembranosus

Origin - ischial tuberosity

Insertion - medial tibia

Action - thigh extension, knee flexion, medial rotation

Sciatic nerve innervates all of the above muscles!!!

Muscles of the Leg

o Anterior Compartmento Dorsiflex ankle, invert foot, extend

toeso Innervation: Deep fibular nerve

o Lateral Compartmento Plantarflex, evert footo Innervation: Superficial Fibular

nerve

o Posterior Compartment o Superficial and deep layerso Plantarflex foot, flex toeso Innervation: Tibial nerve

Anterior Compartment

Tibialis anterior

Origin - tibia

Insertion - tarsals

Action - dorsiflexion, foot inversion

Extensor digitorum longus

Origin – tibia and fibula

Insertion - phalanges

Action – toe extension

Extensor hallucis longus

Origin – fibula, interosseous

membrane

Insertion – big toe

Action - extend big toe, dorsiflex

foot All innervated by deep fibular nerve

Lateral Compartment

Fibularis (peroneus)

longus

Origin – lateral fibula

Insertion – 5th metatarsal,

tarsal

Action - plantarflex, evert

foot

Fibularis (peroneus) brevis

Origin – distal fibula

Insertion - proximal fifth

metatarsal

Action – same as above!!All innervated - superficial fibular nerve

Superficial Posterior

Compartment

Triceps surae

Gastrocnemius (2 heads)

Origin - medial and lateral condyles

of femur

Insertion - posterior calcaneus via

Achilles tendon

Soleus

Origin – tibia and fibula

Insertion – same as above

Action of both – plantarflex foot

Plantaris (variable)

Origin – posterior femur

Insertion – same as above!

Action – plantarflex foot, week knee

flexion

All innervated by the tibial nerve

Deep Posterior

Compartment Popliteus

Origin - lateral condyle femur

and lateral meniscus

Insertion – proximal tibia

Action – flex and medially rotate leg

Flexor digitorum longus Origin - tibia

Insertion - distal phalanges of toe 2-5

Action – plantarflex and invert foot, flex toe

Flexor hallucis longus Origin - fibula

Insertion - distal phalanx of hallux

Action - plantarflex and invert foot, flex toe

Tibialis posterior Origin – tibia, fibula, and interosseous

membrane

Insertion - tarsals and metatarsals

Action - plantarflex and invert footAll innervated by the tibial nerve

Innervation

Plexuses of the

Lower Limb

“Lumbosacral plexus”

Lumbar Plexus

Arises from L1-L4 with

contribution from T12.

Lies within the psoas major

muscle

Mostly anterior structures

Sacral Plexus

Arises from spinal nerve L4-

S4

Lies caudal to the lumbar

plexus

Mostly posterior structures

Lumbar Plexus

Femoral nerve Cutaneous branches

Thigh, leg, foot (e.g. saphenous nerve)

Motor branches Anterior thigh muscles (e.g. quadriceps,

sartorius, iliopsoas)

Obturator nerve Sensory

Skin medial thigh; hip, knee joints

Motor Adductor muscles

Lateral femoral cutaneous Sensory

Skin lateral thigh

Genitofemoral Sensory

Skin scrotum, labia major, anterior thigh

Motor Cremaster muscle

Sacral Plexus

Sciatic Motor:

Hamstring

Branches into: Tibial nerve

Cutaneous Posterior leg and sole of foot

Motor Posterior leg, foot

Common fibular (peroneal) nerve Cutaneous

Anterior and lateral leg, dorsum foot

Motor Lateral compartment, tibialis anterior,

toe extensors

Superior gluteal nerve Motor

Gluteus medius and minimus, tensor fasciae latae

Sacral Plexus (continued)

Inferior gluteal nerve Motor

Gluteus maximus

Posterior femoral cutaneous nerve Sensory

Inferior buttocks, posterior thigh, popliteal fossa

Pudendal nerve

Sensory

External genitalia, anus

Motor

Muscles of perineum

Vasculature

Arteries

Common iliac (from

aorta) branches into:

Internal iliac

Supplies pelvic organs

External iliac

Supplies lower limb

Arteries

Internal iliac branches into: Cranial and Caudal Gluteals

(Superior and Inferior)

Gluteals

Internal Pudendal

Perineum, external genitalia

Obturator

Adductor muscles

Other branches supply rectum, bladder, uterus, vagina, male reproductive glands

Arteries External iliac becomes…….

Femoral Once passes the inguinal ligament

Lower limb

Branches into Deep femoral Adductors, hamstrings, quadriceps

Branches into Medial/lateral femoral circumflex Head and neck of femur

Femoral becomes…… Popliteal (continuation of femoral)

Branches into: Geniculars

Knee

Splits into: Anterior Tibial

Anterior leg muscles, further branches to feet

Posterior Tibial Flexor muscles, plantar arch, branches

to toes

Veins Deep Veins: Mostly share names

of arteries Ultimately empty into Inferior Vena

Cava

Plantar

Tibial

Fibular

Popliteal

Femoral

External/internal iliac

Common iliac

Superficial Veins Dorsal venous arch (foot)

Great saphenous (empties into femoral)

Small saphenous (empties into popliteal)

Applying The Anatomy In The

Lower Limb

FEMUR

SURGICAL APPLICATION

Intracapsular fractures

Common in elderly

Damage medial femoral circumflex artery – avascular

necrosis of the femoral head

Femoral shaft fractures

Can damage the femoral artery and nerve

Sciatic Nerve Injuryo Penetrating wounds

o Fractures of the pelvis

o Dislocations of the hip joint

(posterior)Most frequently injured

during I.M. İnjections

oUse upper outer quad of buttock.

Most nerve lesions are incomplete –

Sciatica [Sciatic neuralgia]

Motor: Hamstring muscles paralyzed,

but weak flexion of the knee is possible

tnx to sartorius (femoral nerve) & gracilis

(obturator nerve).

All the muscles below the knee are

paralyzed, foot drop.

Sensory: Sensation is lost below the

knee, except for a narrow area down the

medial side of the lower part of the leg

and along the medial border of the foot

as far as the ball of the big toe, which is

supplied by the saphenous nerve

(femoral nerve).42

Femoral Hernia

bowel pushes into

the femoral canal,

underneath the inguinal

ligament.

It presents as a lump

situated inferolaterally

to the pubic tubercle.

common in women, due

to their wider bony

pelvis.

Rapid access to a large vein is needed

Femoral Vein Catheterization

Anatomy of the Procedure

1. The skin of the thigh below

the inguinal ligament is supplied

by the genitofemoral nerve; this

nerve isblocked with a local

anesthetic.

2. The femoral pulse is palpated

midway between the anterior

superior iliac spine and the

symphysis pubis, andthe femoral

vein lies immediately medial to it.

3. At a site about two

fingerbreadths below the

inguinal ligament, the needle is

inserted into the femoral vein.

44

LEG SURGICAL APPLICATION: Footdrop

It is most commonly seen when the common fibular nerve (from which the deep fibular nerve arises) is damaged.

Superficial course around fibular neck

Most injured nerve in the lower limb

The unopposed pull of the plantarflexormuscles produces permanent plantarflexion.

the patient can flick the foot outwards while walking – known as an ‘eversionflick‘.

A varicosed vein

Larger diameter than

normal, elongated &

tortuous

Commonly occurs in the

superficial veins of the

lower limb

Varicose Veins

Responsible for considerable discomfort and pain

Every time the patient exercises, high-pressure

venous blood escapes from the deep veins into

the superficial veins and produces a varicosity,

and gets worse by time.

46

Passengers who sit immobile for

hours on long-distance flights

are very prone to deep vein

thrombosis in the legs.

Preventative measures include

stretching of the legs every hour

to improve the venous

circulation.Prevention of deep vein

thrombosis associated with

flying

• Exercise the calf muscle foot

• Drink plenty of water to avoid a

lack of fluid in the body

(dehydration) muscles regularly

• Elastic compression stockings in

pts with risk factors.

Deep Vein Thrombosis & Long-DistanceAir Travel

47

SURGICAL APPLICATION

Trendelenberg Sign - This signifies that the

abductor muscles on the standing limb are greatly

weakened or paralysed. For example, if the left leg

was raised, and pelvic drop was observed on that

side, the abductor muscles on the right leg are the

cause.

During walking, a weakness in the abductor muscles

gives rise to a characteristic gait. As the pelvis drops

on one side, the trunk lurches to the opposite side, in

an effort to maintain a steady pelvic level. This is

called the Trendelenberg gait.

UPPER LIMB

Frolich, Human Anatomy,UpprLimb

Frolich, Human Anatomy,UpprLimb

Sensory territory of nerves

Brachial plexus serves to re-direct

spinal routes into named nerves

covering certain territory

Cutaneous branches of

medial cord/ulnar nerve

Frolich, Human Anatomy,UpprLimb

Upper Limb Skeleton

Scapula

Humerus

Radius, ulna

Carpals--proximal,

distal (x8)

Digits

Metacarpals (x5)

Phalanges (x14)

Upper Limb

Skeleton

A=Scaphoid B=Lunate C=Triquetrum

(Triangular)*Piramidal

D=Pisiform Distal:

E=Trapezium F=Trapezoid G=Capitat

e H=Hamate Others:

1=Radius 2=Ulna 3=Metacarpus

Frolich, Human

Anatomy,UpprLimb

Surface Anatomy of Upper Limb

Biceps + Triceps brachii

Olecrenon Process

Medial Epicondyle

Cubital Fossa

Anterior surface elbow

Contents

Median Cubital Vein

Brachial Artery

Median Nerve

Boundaries

Medial= Pronator teres

Lateral= Brachioradialis

Superior= Line between epicondyles

pg 786 + 784

Frolich, Human

Anatomy,UpprLimb

Surface Anatomy of

Upper Limb

Carpal Tunnel

Carpals concave anteriorly

Carpal ligament covers it

Contains: long tendons,

Median nerve

Inflammation of tendons =

compression of Median

nerve

Anatomical Snuffbox

Lateral = E.pollicis brevis

Medial = E. pollicis longus

Floor = scaphoid, styloid of

radius

Contains Radial Artery

(pulse)pg 306, 788

Frolich, Human Anatomy,UpprLimb

• If INSERTION on scapula = Move scapula– Rhomboids

– Trapezius

– Pectoralis Minor

– Serratus Ventralis

– Levator Scapulae

• If ORIGIN on scapula = Move Arm– Subscapularis

– Supraspinatus

– Infraspinatus

– Teres Minor

– Teres Major

– Latissimus Dorsi (partial O on scap)

– Coracobrachialis

pg 299

Rotator Cuff

Use location of Insertion to determine exact

movement!!

Frolich, Human Anatomy,UpprLimb

Axilla = Armpit

Region between arm and chest

Boundaries

Ventral - pectoral muscles

Dorsal = latissimus dorsi, teres major

subscapularis

Medial = serratus ventralis

Lateral = bicipital groove of humerus

Contents

Axillary lymph nodes, Axillary vessels n Brachial Plexus

Frolich, Human Anatomy,UpprLimb

POSTERIOR AND ANTERIOR COMPARTMENTS

Brachial Plexus

• Posterior Compartment—posterior cord

• Anterior compartment—medial, lateral cords

• Name of cord is relative to axillary artery

Parts of Brachial Plexus

Really Tired? Drink Coffee

Buddy!

R = ROOTS (ventral rami)

T = TRUNKS

D = DIVISIONS

C = CORDS

B = BRANCHES

Frolich, Human Anatomy,UpprLimb

ANTERIOR MUSCLES

M-C

Biceps

brachialis

Median

Forearm flexors

Thumb intrinsics (1M$

nerve)

Ulnar

Flexor carpi ulnaris

Hand intrinsics

POSTERIOR MUSCLES

Muscles (radial nerve)

Triceps

Anconeus

Brachioradialis

Carpal, digit extensors

Frolich, Human Anatomy,UpprLimb

Muscles and nerves by compartment

ANTERIOR POSTERIOR

NERVES M-C, ulnar,

median

Radial

MOVEMENT Flexion Extension

MUSCLES Biceps,

flexors

Triceps,

extensors

TWIST Flexors from

medial

epicondyle

Extensors from

lateral

epicondyle

FOREARM POSTERIOR

known as the extensor muscles.

all innervated by the radial nerve.

muscles divided into deep and superficial

compartments separated by a layer of fascia.

FOREARM POSTERIOR

Superficial muscles

Extensor Carpi Radialis Longus and Brevis,Extensor

Digitorum,Extensor Digiti Minimi and Extensor Carpi

Ulnaris

Deep Muscles

the supinator, abductor pollicis longus, extensor pollicis

brevis, extensor pollicis longus and extensor indicis.

With the exception of the supinator, these muscles act on

the thumb and the index finger

Frolich, Human Anatomy,UpprLimb

Posterior Compartment of Forearm

Extensor digitorum

Extensor carpi ulnarisExt Carpi Radialis Longus

Brachioradialis

Lateral Epicondyle

Posterior View

FOREARM- ANTERIOR Superficial Compartment

all originate from a common tendon - medial epicondyle of the humerus.

Flexor Carpi Ulnaris

attaches to the pisiform carpal bone., Flexion and adduction at the wrist, innervated by Ulnar nerve.

Palmaris Longus

attaches to the flexor retinaculum of the wrist; Flexion at the wrist; innervated by Median nerve.

Flexor Carpi Radialis

attaches to the base of metacarpals II and III; Flexion and abduction at the wrist; innervation by Median nerve.

Pronator Teres

attaches laterally to the mid-shaft of the radius; Pronation of the forearm, innervation by Median nerve.

FOREARM

Intermediate compartment

flexor digitorum superficialis

splits into four tendons and attach to the middle

phalanges of the four fingers.

Flexes the metacarpophalangeal joints and proximal

interphalangeal joints at the 4 fingers, and flexes at the

wrist.

Innervated by Median nerve.

FOREARM - ANTERIOR

Deep Compartment

Flexor Digitorum Profundus

flex the distal interphalangeal joints of the fingers, flexes

the metacarpophalangeal joints and the wrist.

Innervated by ulnar nerve (medial) and median nerve

(lateral)

Flexor Pollicis Longus

Flexes the interphalangeal joint and metacarpophalangeal

joint of the thumb; innervated by Median Nerve.

Pronator Quadratus

Pronates the forearm; Innervated by Median Nerve.

Frolich, Human Anatomy,UpprLimb

Anterior Compartment Forearm

Flexor Carpi Radialis

Flexor Retinaculum

Medial Epicondyle

Flexor Digitorum Superficialis is deep

to other flexors

pg 302

Flexor Carpi Ulnaris

Brachioradialis

Pronator Teres

Anterior View

Carpal Tunnel

Formed by the carpal bones and overlying flexor

retinaculum (attaches to the pisiform, hook of hamate,

the scaphoid and the trapezium bones).

Structures passing through:

Median nerve

Tendons of flexor digitorum superficialis/profundus

Flexor pollicis longus

Flexor carpi radialis (not in carpal tunnel)

Muscles of the Hand

Thenar muscles : abductor pollicis brevis, flexor pollicis brevis, opponens pollicis

and adductor pollicis.

All act on the thumb

Innervated by the median nerve

Hypothenar Muscles : Abductor digiti minimi, flexor digiti minimi and oppponens digiti

minimi.

Innervated by the ulnar nerve

All act on the small finger

Interosseous muscles: 8 muscles

Flex metacarpophalangeal joints and extension of interphalangeal joints

Adduction and Abduction of fingers, in relation to the middle finger

Muscles of the Hand

Frolich, Human Anatomy,UpprLimb

Routes of nerves (in human)

M-C: between biceps brachii and brachialis

Median: medial/posterior to biceps, branches into forearm flexors at elbow then to hand through carpal tunnel Recurrent median (1M$) superficial at wrist to thumb

over thenar emminence) deficit - ape’s hand

Ulnar: medial in arm, posterior to medial epicondle of humerus (funny bone) down medial forearm medial to carpal tunnel into palm

Radial: deep posterior arm around lateral epicondyle of humerus to forearm (deep and superficial branches)

Frolich, Human Anatomy,UpprLimb

Vascular supply

Subclavianaxillary

radial (same street, new

street sign every block)

Collateral circulation Posterior/anterior circumflex

humeral

Deep brachial a.

Radial a. (with median

n.) deep palmar arch

Ulnar a. (with ulnar n.)

superficial palmar

arch

APPLIED ANATOMY OF UPPER

LIMB

SCAPULAR

articulates with humerus at the glenohumeral joint,

and with clavicle at acromioclavicular joint.

SURGICAL APPLICATION

The long thoracic nerve innervates the serratus anterior,

which originates from ribs 2-8, and attaches the costal

face of the scapula, pulling it against the ribcage. Damage

to this nerve causes winging of the scapular

WINGING SCAPULAR

CLAVICLE

SURGICAL APPLICATION: Fracture of the Clavicle

Common fracture point is the junction of the medial 2/3

and lateral 1/3, due to fall on shoulder or outstretched

hand.

lateral end of the clavicle is displaced inferiorly by the

weight of the arm, and medially, by the pectoralis major.

The medial end is pulled superiorly, by the

sternocleidomastoid muscle.

The suprascapular nerves may be damaged, these

innervate the lateral rotators of the shoulder –

so unopposed medial rotation of the upper limb –

the ‘waiters tip’ position.

FRACTURE OF CLAVICLE

WAITER’S TIP

HUMERUS

SURGICAL APPLICATION: Surgical Neck Fracture

This is a frequent site of fracture, this occurs by falling on an outstretched hand.

May result in damage to axillary nerve and posterior circumflex artery.

Damage to the axillary nerve will result in paralysis to the deltoid and and teres minor muscles; the patient will not be able to abduct their arm loss of sensation of the skin over the deltoid (regimental badge area).

SURGICAL NECK FRACTURE

HUMERUS

SURGICAL APPLICATION: Mid-shaft Fracture

A mid-shaft fracture could damage the radial

nerve and profunda brachii artery – in radial groove.

The radial nerve innervates the extensors of the

wrist. This results in unopposed flexion of the wrist -

‘wrist drop’.

sensory loss over the dorsal surface of the hand,

and the proximal ends of the lateral 3 and a half

fingers dorsally.

WRIST DROP

HUMERUS

SURGICAL APPLICATION: Distal Humeral Fracture

A supraepicondylar fracture - interference to the blood supply of the forearm from

the brachial artery - Volkmann’s ischaemiccontracture – uncontrolled flexion of the hand, as flexors muscles become fibrotic and short.

damage to the medial, ulnar or radial nerves.

A medial epicondyle fracture could damage the ulnar nerve - ulnar claw is the result.

SUPRAEPICONDYLAR FRACTURE

CLAW HAND

SURGICAL APPLICATION – Common

Fractures of the Ulna

The interosseous membrane transmits force from

one bone to the other, thus, fractures of both the

forearm bones are not uncommon.

There are two classical fractures:

Monteggia’s Fracture – The proximal shaft of ulna

is fractured, and the head of the radius dislocates

anteriorly at the elbow.

Galeazzi’s Fracture – A fracture to the distal radius,

with the ulna head dislocating at the distal radio-

ulnar joint.

Monteggia’s Fracture

SURGICAL APPLICATION: Common

Fractures of the Radius

Colles’ Fracture – The most common type of radial

fracture. A fall onto an outstretched hand causing a

fracture of the distal radius, with posterior

displacement of wrist - ‘dinner fork deformity’.

Smith’s Fracture – A fracture caused by falling onto

the back of the hand. It is the opposite of a Colles’

fracture, as the distal fragment is now placed

anteriorly.

COLLE’S FRACTURE

SURGICAL APPLICATION: Fractures of the

Carpal Bones

The two carpal bones that are most commonly

fractured are the scaphoid and lunate.

Scaphoid fracture

tenderness in the anatomical snuffbox

cut off the blood supply to the proximal part of the bone ,

causing avascular necrosis.

lunate fracture

occurs when falling on a outstretched hand

can be associated with some median nerve damage.

CARPAL TUNNEL

Clinical Relevance: Carpal Tunnel Syndrome

Compression of the median nerve

The typical signs of carpal tunnel syndrome are pins

and needles in the sensory distribution of the

median nerve and weakness of thenar muscles.

It can be treated by cutting into the flexor

retinaculum, relieving the pressure.