KNEE JOINT (1).pptx ....................

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1. Knee joint By: Kikatoli Zhimomi Department of anatomy

2. KNEE JOINT : It is largest and most complex joint of the body Fusion of three joints namely - Lateral femorotibial joint Medial femorotibial joint Femoropatellar joint

3. TYPE : Condylar synovial joint Two condylar joints b/w tibia and femur One saddle joint b/w femur and patella

4. ARTICULAR SURFACES : Formed by – Condyles of femur Patella Condyles of tibia Femoral condyles articulates with tibial condyle below & behind and patella in front

5. LIGAMENTS : Supported by following ligaments – Capsular ligament Ligamentum patellae Tibial collateral ligament Fibular collateral ligament Oblique popliteal ligament Arcuate popliteal ligament Medial & lateral menisci Anterior & posterior cruciate ligaments Coronary ligament Transverse ligament

6. 1. Fibrous capsule : Femoral attachment – Anteriorly - deficient Posteriorly - attached to intercondylar line Laterally - encloses origin of popliteus

7. Tibial attachment - Anteriorly - descends along the margins of condyles to tibial tuberosity Posteriorly - attached to intercondylar eminence Posterolaterally - a gap for passage for tendon of popliteus muscle

8. Coronary ligament: These are parts of capsule that provide attachment to peripheral margins of medial and lateral menisci.

9. 2. Ligamentum patellae : Derived from the tendon of quadriceps femoris Extends from the apex of patella to the upper part of the tubercle of tibia When the knee joint is locked at the end of extension, all ligaments are taut except the ligamentum patellae

10. 3. Tibial collateral ligament : Consist of superficial and deep part Both part are attached above to the medial epicondyle of femur The superficial part extends downward and forward as a flattened band. Attached to the medial condyle and upper part of medial border of shaft of tibia . The deep part blends with capsule and is attached to medial condyle of tibia

11. 4. Fibular collateral ligament : Extends from lateral epicondyle of femur to the head of fibula close to its styloid process.

12. 5. Oblique popliteal ligament : Derived from the insertion of semimembranosus Extends from the posterior surface of medial condyle of tibia to the lateral part of intercondylar line of femur

13. 6. Arcuate popliteal ligament : It forms a Y-shaped band Stem is fixed to the styloid process of head of fibula Posterior band is attached to the lateral condyle of tibia Anterior band is attached to the lateral condyle of femur

14. 7. Cruciate ligaments : These are very thick and strong fibrous bands, to maintain antero-posterior stability of knee joint. ACL : Begins from anterior part of intercondylar area of tibia and gets attached to the posterior part of the medial surface of lateral condyle of femur. PCL : Begins from posterior part of intercondylar area of tibia and gets attached to the anterior part of the lateral surface of medial condyle of femur.

15. 8. Medial and lateral menisci : They are composed of fibro-cartilage Shaped like crescents. Medial menisci : Semicircular, Wider behind than infront . Lateral menisci : Circular.

16. FUNCTIONS OF MENISCI : They increase the concavity of tibial condyles for the better adaptation with femoral condyles Menisci act as shock absorber They help in lubricating the joint cavity.

17. 10. Transverse ligament : It connect the anterior horn of medial meniscus to the anterior margin of lateral meniscus

18. SYNOVIAL MEMBRANE : The synovial membrane lines the joint and produces synovial fluid to cushion the movement of the joint.

19. BURSAE : A bursa is a fluid-filled structure that is present between the skin and tendon or tendon and bone. The main function of a bursa is to reduce friction between adjacent moving structures.

20. Anteriorly: Subcutaneous pre - patellar Subcutaneous infra- patellar bursa Deep infra-patellar bursa Supra-patellar bursa

21. Laterally : Between lateral head of gastrocnemius & the capsule Between tendon of biceps femoris & fibular collateral ligament Between fibular collateral ligament & tendon of popliteus muscle Between tendon of popliteus & lateral condyle of tibia.

22. Medially: Medial head of gastrocnemius & the capsule Superficial part of tibial collateral ligament, sartorius, gracilis and semitendinosus Superficial & deep part of tibial collateral ligament Semi- membranosus & medial condyle of tibia.

23. RELATIONS OF KNEE JOINT : Anteriorly : Quadriceps femoris Antero-medially : Medial patellar retinaculum Antero-laterally : Lateral patellar retinaculum & iliotibial tract Postero -medially : Sartorius, gracilis , semimembranosus & semitendinosus Postero -laterally : Tendon of biceps femoris & common peroneal nerve Posteriorly : Popliteal vessels, tibial nerve, both head of gastrocnemius & plantaris

24. BLOOD SUPPLY : Descending genicular branch of femoral artery Descending branch of lateral circumflex femoral artery Genicular branches of popliteal artery Recurrent branches of anterior tibial artery Circumflex fibular branch of posterior tibial artery

25. NERVE SUPPLY : From femoral nerve: Nerve to the vasti Three from the tibial nerve: Superior medial Genicular Inferior medial genicular Middle genicular nerve Three from the common peroneal nerve: Superior lateral Genicular Inferior lateral genicular Recurrent genicular nerve

26. MOVEMENTS AT THE KNEE JOINT : Active movements performed at the knee joint are: Extension: Extension or straightening continues until leg & thigh are in the same vertical lines Extension is produced by Quadriceps femoris & assisted by tensor fascia latae

27. Flexion: Prime movers: semimembranosus, semitendinosus, biceps femoris Initiated by popliteus Assisted by, sartorius, gracilis , both head of gastrocnemius & plantaris Medial rotation: Semimembranosus, semitendinosus, popliteus, sartorius & gracilis Lateral rotation: Biceps femoris

28. LOCKING & UNLOCKING OF THE KNEE JOINT : Locking is a mechanism that allows the knee to remain in the position of full extension as in standing without much muscular effort. Locking occurs as a result of medial rotation of the femur during last stage of extension. Locking is produced by Quadriceps femoris ( Vastus medialis part ) Unlocking occurs as a result of lateral rotation of the femur during initial stage of flexion. Unlocking is produced by Popliteal muscle.

29. APPLIED ASPECT : Injuries to menisci : Most injured structures of the knee are tibial collateral ligament, the medial menisci & ACL. Lateral aspect of the knee when the foot is on the ground may sprain the tibial collateral ligament, the attached medial menisci may also be torn. Injuries to the menisci commonly occur in the flexed knee as a result of forcible rotation or abduction.

30. Inflammation of bursa- Housemaids knee - Subcutaneous pre-patellar bursa Clergyman's knee - Subcutaneous infra patellar bursa Osteoarthritis of knee joint Fracture of patella is a frequent problem