Presentation on theme: "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."— Presentation transcript:
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 fibula are united by an interosseous Membrane. [Proximal and distal tibio-fibular joints] The fibula is not part of the knee joint. Anterior. Sagittal section thru knee Patella articulates with the femur. interosseous membrane Head of Fibula
During the entire range of knee flexion, the patella only articulates with the femur. KNEE. Modified hinge jt. -flexion / extension (some rotation)
Superior view of tibial surface. Medial and lateral articular surfaces, separated by an intercondylar eminence. Medial and lateral Meniscii: Fibrocartilage shock-absorbers that 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
Medial and lateral femoral condyles have same shape as corresponding tibial condyles: Medial – elongated Lateral – 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 the medial knee: Tibial collateral ligament. A flat strap which is attached to the medial aspect of tibia and medial femoral epicondyle. Its deeper fibres are attached to the medial meniscus. tibial collateral ligament Retinacular fibres Joint capsule Pes anserinus: Common insertion of Sartorius, gracilis, semitendinosus
Stabilization of the lateral 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
Fibrous capsule of the KNEE (anterior): Stabilized by: Extensor Retinacula - Derived from insertions of vastus lateralis and vastis medialis into patella and into sides of patellar ligament. extensor retinacula Vastus lateralis Vastus medialis Anterior knee in extension Patellar Ligament
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 of Semimembranosus 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 fossa Diamond-shaped region Posterior 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, semimembranosus popliteus (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 form the proximal articular surface of ankle. Each ends subcutaneusly as a Malleolus (medial – tibial and lateral - fibular). Proximal and distal tibio-fibular joints interosseous membrane Lateral malleolus Medial malleolus
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 deep fibular (peroneal) nerve. Hallux = big toe [hallucis] Tendons are bound down by extensor retinaculum as they cross 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 Tibialis Anterior Deep dissection Anterior view: Note vulnerability of common fibular nerve as it winds around the 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 by fibular retinaculum as they pass 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 off the fibular (peroneal) artery to supply the lateral compartment. popliteal a. posterior tibial a. anterior tibial a. fibular artery
AnteriorPosterior Anterior, 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.) saphenous nerve Post. femoral cutaneous n. sural nerve Cutaneus innervation of thigh and leg: L4 S1
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