歐陽品教授 12/01/2015 Lower Limb 4: Leg and Knee Joint The leg or crus can be divided into 4 regions : by the anterior and posterior intermuscular septa

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1 歐陽品教授 12/01/2015 Lower Limb 4: Leg and Knee Joint The leg or crus can be divided into 4 regions : by the anterior and posterior intermuscular septa as well as interosseous membrane 1. medial surface of tibia: subcutaneous 2. anterior crural region (anterior compartment) 3. fibular region (lateral compartment) 4. posterior crural region (posterior compartment)

2 Bones of the leg Tibia : shin bone, 2 nd largest bone in the body Medial and lateral condyles Tibial plateau Intercondylar tubercles Tibial tuberosity 3 borders : anterior, medial and lateral -lateral border (interossuous border, gives attachment to interosseous membrane) fibular notch

3 3 surfaces; medial, lateral and posterior medial surface medial mallelous tibial collateral ligament (medial ligament of the knee) tendons of pes anserinus (goose s feet) : tripods (semitendinous, sartorius, gracilis) great saphenous vein lateral surface origin of tibialis anterior m. Posterior surface soleal line

4 Fibula : a main function is to provide attachments for 9 muscles, 8 of which pull inferiorly, carry no weight to the ground

5 Fibula Peroneal (fibular) surface : for peroneal (fibular) muscles flexor (posterior) surface : for soleus, flexor hallucis longus and tibialis posterior m. anterior surface : for extensors of toes. fibular collateral ligament lateral malleolus malleolar fossa tibiofibular syndesmosis: contain interosseous membrane

6 Anterior crural region and dorsum of foot Muscles : all innervated by deep fibular n. tibialis anterior : strongest dorsiflexor origin: lateral surface of tibia insertion : medial surfaces of 1st metatarsal and 1st cuneiform extensor digitorum longus origin : anterior surface of fibula insertion : distal 2 phalanges of the lateral 4 toes

7 extensor hallucis longus : dorsiflexor origin : lower anterior surface of fibula insertion : base of the distal phalange of the great toe peroneus (fibularis) tertius: unique to man, part of extensor digitorum longus insertion : dorsum of the 4 or 5th metatarsal

8 extensor digitoum brevis (dorsum of foot): contain extensor hallucis brevis m. origin : anterior part of calcaneus insertion : base of proximal phalanges of medial 4 toes

9 Arteries anterior tibial a. anterior tibial recurrent a. medial and lateral malleolar a. dorsalis pedis a.; comparable to radial a. in the hand, a major source of blood supply to the forefoot, forming deep plantar arch with lateral plantar a. medial and lateral tarsal a. arcuate a. dorsal metatarsal a. dorsal digital a.

10 Deep fibular n.: accompanies anterior tibial a., lesion causes inability to dorsiflex (footdrop) dorsal digital n. (cutaneous); supply opposed surfaces of great toe and its neighbour

11 Retinacula superior extensor retinaculum : attaches to tibial inferior extensor retinaculum : attaches to superior surface of calcaneus, form a strong loop around the tendons of fibularis tertius and extensor digitorum longus m.

12 Peroneal (fibular) region Muscles : all innervated by superficial fibular n. peroneal (fibularis) brevis insertion : base of 5th metatarsal peroneal (fibularis) longus insertion : under groove of cuboid, to lateral side of 1st metatarsal and 1st cunefrom * both tendons pass beneath lateral malleolus and cross calcaneofibular lig.

13 Superior and inferior fibular retinacula Superficial fibular n. dorsal digital n. (cutaneous) : to all toes, except adjacent sides of 1st and 2nd (deep peroneal n.) and the lateral side of the 5th (sural n.)

14 Posterior crural region Muscles: all innervated by tibial n.,divided by transverse intermuscular septum to superficial and deep subcompartment superficial group: plantarflexors gastrocnemius : origin from medial and lateral epicondyles of femur insertion : tendo calcaneus soleus : origin from soleal line of tibia and posterior surface of fibula insertion : tendo calcaneus *both muscles make up the three-headed triceps surae plantaris : origin rom near lateral head of gastrocnemius insertion : tendo calcaneus

15 deep group popliteus : origin from lateral epicondyle of femus insertion : posterior surface of tibia tibialis posterior : origin from interosseous membrane insertion : navicular tuberosity flexor digitorum longus : origin from posterior surface of tibia * both 2 tendons pass beneath medial malleolus flexor hallucis longus : origin from posterior surface of fibula and interosseous membrane, tendon runs between two seasmoid bones in the tendons of flexor hallucis brevis m.

16 Tibial n.: accompanies posterior tibial a. medial and lateral plantar n. medial calcanean n. Arteries and veins posterior tibial a. medial and lateral plantar a. fibular a. lateral calcanean a. small saphenous vein circumflex fibular a.

17 Surface Anatomy of the Leg

18 Knee joint : largest and most superficial joint Knee joint consists of 3 articulation: medial and lateral femorotibial articulation and femoropatellar articulation The most important muscle in stabilizing the knee joint is quadriceps femoris m.

19 arcuate popliteal ligament Joint capsule of the knee joint: consists of an external fibrous layer and internal synovial membrane Extracapsular ligaments: 1. Patellar ligament 2. fibular collateral ligament 3. Tibial collateral ligament 4. oblique popliteal ligament; a recurrent expansion of the tendon of semimembranosus m. 5. arcuate popliteal ligament; arises from posterior fibular head over the tendon of popliteal m.

20 Alar fold Articular cavity of the knee joint infrapatellar synovial fold; a vertical fold of synovial membrane, subdivides the articular cavity into right and left femorotibial articular cavities alar fold; covers the inner surface of fat pad on each side of patellar ligament Suprapateallar bursa: knee joint cavity extend deep to the vastus intermdeius m. Subpopliteal bursa

21 Intra-articular ligaments: 1. Cruciate ligaments: maintain contact with femoral and tibial articular surfaces during knee flexion anterior cruciate lig. (prevent knee joint hyperextension) posterior cruciate lig. (prevent knee joint hyperflexion)

22 2. medial and lateral menisci: deepen the articular surface and function as shock absorbent Transverse ligaments of knee: joins anterior edge of menisci Posterior meniscofemoral ligament: joins lateral meniscus to post. cruciate lig. 3. popliteal tendon : unlock the knee by popliteal muscle so that flexion of knee can occur

23 Movements of the knee joint Quardriceps femoris m. Hamstrings Semitendinosus m. Biceps femoris m. Semimembanosus m.

24 Locking of the knee

25 Tibiofibular joints 1. Superior tibiofibular joint 2. Tibiofibular syndesmosis: compound fibrous joint, union of tibia and fibula by means of interosseous membrane and anterior, interosseous and posterior tibiofibular ligaments