knee joint and muscles of leg
DESCRIPTION
Knee joint and Muscles of Leg. Dr. Sama ul Haque. Objectives. Name and identify the bony features of the tibia and fibula. Know the type and formation of knee joint. Explain the stability factors of the knee joint. Identify the muscles that act at the knee joint. - PowerPoint PPT PresentationTRANSCRIPT
Knee joint and
Muscles of Leg
Dr. Sama ul Haque
Name and identify the bony features of the tibia and
fibula.
Know the type and formation of knee joint.
Explain the stability factors of the knee joint.
Identify the muscles that act at the knee joint.
Know the locking and unlocking mechanism of the knee
joint.
Understand the functions of the Popliteus and Iliotiabial
tract.
Identify the neurovasculature behind the knee (popliteal
fossa) and in the leg.
Enlist the contents of the muscular compartments of the
leg.
Identify the muscles of the leg in terms of their origin,
insertion, nerve supply and actions.
Enlist the muscles causing plantar flexion, dorsiflexion,
eversion, inversion, flexion of digits and extension of
digits.
Tibia: Condyles Tibial tuberosity
Tibia and fibulaare united by aninterosseous Membrane.[Proximal and distal tibio-fibular joints]
The fibula is not part of the knee joint.
Anterior.Sagittal section thru knee
Patella articulateswith the femur.
interosseous membrane
Head of Fibula
During the entirerange of kneeflexion, the patellaonly articulates with the femur.
KNEE.
Modified hinge jt.-flexion / extension (some rotation)
Superior view of tibial surface.
Medial and lateral articularsurfaces, separated by an intercondylar eminence.
Medial and lateral Meniscii:
Fibrocartilage shock-absorbersthat sit on surface of tibial condyles and deepen the articular surface.
Anterior and posterior Cruciate ligaments (ACL, PCL):-hold femur and tibia together-stabilize knee joint
lateral articular surface
medial articular surface
intercondylar eminence
lateral meniscus PCL medial meniscus
ACL
Tibial Condyles Tibial Condyles
Medial and lateralfemoral condyleshave same shape as correspondingtibial condyles:
Medial – elongatedLateral – circular
Meniscii:Each is attached to tibia at their ends (horns).
Femur
Anterior Cruciate Ligament:- Weaker of the two, slack when knee is flexed & tightens in extension.- Prevents hyperextension.
Posterior Cruciate Ligament:- Tightens during flexion of knee joint
Stabilization of themedial knee:
Tibial collateralligament.
A flat strap whichis attached to the medial aspect of tibia and medial femoral epicondyle.
Its deeper fibres areattached to themedial meniscus.
tibial collateral ligament
Retinacularfibres
Joint capsule
Pes anserinus: Common insertion ofSartorius, gracilis, semitendinosus
Stabilization of thelateral knee:
Fibular collateral ligament - a cord which is attached to the head of the fibula and the lateral epicondyle of the femur.
*Its deep fibers are not attached to the meniscus.
fibular collateral ligament
Ilio-tibial band
Biceps femoris
Head of fibula
» Remember the 3 C’s:» -cartilage» -cruciates» -collaterals
Unhappy triad - common associated injury to:ACL (anterior cruciate ligament) MCL (Medial / tibial collateral ligament)medial meniscus
Fibrous capsule of the KNEE (anterior):
Stabilized by: Extensor Retinacula
- Derived from insertionsof vastus lateralis andvastis medialis into patellaand into sides of patellarligament.
extensor retinacula
Vastuslateralis
Vastus medialis
Anterior knee in extension
PatellarLigament
Fibrous capsule of the KNEE (posterior):
Thickened by ligaments:
-Arcuate popliteal ligament (arching over popliteus muscle)
-Oblique popliteal ligament (from tendon of insertion of semimembranosus m.)
arcuate popliteal ligament
oblique popliteal ligament
Tendon ofSemimembranosus
Popliteus
Posterior knee in extension
suprapatellar bursa
prepatellar bursa
infrapatellar bursae
Sagittal section shows: - Suprapatellar bursa (extension of synovium under tendon of quadriceps femoris)
Subcutaneous bursae:- Prepatellar, - Infrapatellar (2): (superficial & deep to patellar ligament).
Bursae of Knee Joint:
Popliteal fossaDiamond-shaped regionPosterior to knee-semimembranosus / semitendinosus-biceps femoris-medial & lateral heads of gastrocnemius.
Contents:-popliteal vessels (from femoral vessels)-Tibial and Common fibular (peroneal) divisions of the sciatic nerve.
Superficial:-Small saphenous vein draining into popliteal vein
Popliteal Fossa
Muscles that act on the knee (modified hinge joint):Main movement = flexion / extension
Flexion – mainly hamstrings (+ Sartorius, gracilis, gastrocnemius)
Extension – mainly quadriceps (+ tensor fascia lata)
Rotation (possible when the knee is partially flexed, or in the final stage of extension):
[here defined as rotation of tibia with respect to the femur]
Medial rotation – semitendinosus, semimembranosuspopliteus (extended knee)
Lateral rotation – biceps femoris
LEG.
Tibia and fibula:
-held together by an interosseus membrane.
-anterior border of tibia is subcutaneus from the tibial condyles to its distal end. [Shin]
-only the distal ¼ of fibula is subcutaneus
The distal ends are held together to formthe proximal articular surface of ankle.
Each ends subcutaneusly as a Malleolus(medial – tibial and lateral - fibular).
Proximal and distal tibio-fibular joints
interosseous membrane
Lateralmalleolus
Medialmalleolus
Mid-shaft cross-section of leg:
Functional compartments.
Fascial compartments:-anterior-lateral-posterior (superficial & deep)
anterior compartment (dorsiflexion, extension of digits)
lateral Compartment(eversion)
deep posterior compartment(plantarflexion)
superficial posterior compartment (inversion, flexion of digits)
Plantarflexion / dorsiflexion: (ankle joint)Flexion / extension: (digits) Inversion / eversion: Complex twisting
movement at transverse tarsal and subtalar joints. [inter-tarsal joints]
Anterior compartment of leg:
-tibialis anterior-extensor hallucis longus-extensor digitorum longus (fibularis tertius)
All supplied by the deepfibular (peroneal) nerve.
Hallux = big toe [hallucis]
Tendons are bound down byextensor retinaculum as theycross the ankle jt.
Function: -dorsiflexion (ankle) -extension (digits) -inversion
tibialis anterior
extensor digitorum longus
extensor hallucis longus
extensor retinaculum
extensor digitorum longus
extensor hallucis longus
TibialisAnterior
Deep dissectionAnterior view:
Note vulnerability of common fibular nerve as it winds aroundthe neck of fibula.
Superficial Fibular n.
Common Fibular n.
Deep Fibular n.
DROP FOOT??????
Lateral compartment of leg:
- Fibularis (peroneus) longus- Fibularis (peroneus) brevis
-both supplied by the superficial fibular (peroneal) nerve.
Tendons are bound down byfibular retinaculum as theypass behind the lateral malleolus.
Functions: - eversion- plantarflexion
Fibularis longus
Fibularis brevis
peroneal retinaculum
Fibularis tertius
FIBULARIS=PERONEUS
Posterior compartment of leg:
Superficial
medial & lateral heads of gastrocnemius
Insert into calcaneus (heel)
Function –plantar flexion
Innervated by Tibial nerve.
gastrocnemius
Achilles tendon(calcaneal tendon)
plantaris
soleus
Deeper dissection of superficial posterior compartment:
- medial & lateral heads of gastrocnemius- soleus- (plantaris)
Common tendon: Calcaneal (achilles) tendon- insert into calcaneus (heel)
Function – plantar flexion
Innervated by Tibial nerve.
Posterior (deep) compartment of leg:
-Tibialis posterior-Flexor digitorum longus-Flexor hallucis longus
Tendons are bound down by flexor retinaculum as they pass into foot behind the medial malleolus.
Functions: -plantarflexion-flexion-inversion
Innervated by Tibial nerve.
flexor hallucis longus
tibialis posterior
flexor digitorum longus
flexor retinaculum
Blood supply to the lower limb:
Thigh:-Femoral artery and branches: (profunda, medial & lateral circumflex)
Behind knee:-Popliteal artery
Leg:-divides into anterior and posterior tibial arteries.to supply these compartments.
The posterior tibial artery gives offthe fibular (peroneal) arteryto supply the lateral compartment.
popliteal a.
posterior tibial a.
anterior tibial a.
fibular artery
Anterior PosteriorAnterior, lateral, medial thigh ( lumbar plexus). - branches of femoral n. - lateral femoral cutaneous n.)
Posterior thigh – from sacral plexus.
Anteromedial leg – branch of femoral n. (Saphenous nerve).
Posterolateral leg – from Sciatic n. (Sural nerve).Anterior leg:- From Sciatic n. (Superficial fibular n.)
saphenousnerve
Post. femoral cutaneous n.
sural nerve
Cutaneus innervation of thigh and leg:
L4S1
Great Saphenous
vein:
Drains into femoral vein in femoral
triangle
Small Saphenous
vein:Drains into
popliteal vein
Superficial drainage of the lower limb
Varicose veins
Thank you