Knee_joint.pptx

ANATOMY OF KNEE JOINT BY DR. MUSLIM A. ABBAS ORTHOPAEDIC SURGEON M.B.CH.B. F.I.C.M.S WASIT COLLEGE OF MEDICINE  KNEE JOINT Largest synovial joint Diarthrodial joint Articulation: 1- Round condyles of the femur and tibial plateaus and mensci 2. gliding j...

ANATOMY OF KNEE JOINT BY DR. MUSLIM A. ABBAS ORTHOPAEDIC SURGEON M.B.CH.B. F.I.C.M.S WASIT COLLEGE OF MEDICINE  KNEE JOINT Largest synovial joint Diarthrodial joint Articulation: 1- Round condyles of the femur and tibial plateaus and mensci 2. gliding joint between the patella and the patellar surface of the femur Synovial hinge joint apsule and Synovium attached to the margins of the articular surfaces and surrounds the sides and posterior aspect of the joint. Synovial Membrane: lines the capsule and attaches to the margins of the articular surfaces  Bursae Related to Knee Joint Anterior Bursae  The suprapatellar bursa.  The prepatellar bursa  The superficial infrapatellar bursa.  The deep infrapatellar bursa. Posterior Bursae  The popliteal bursa  The semimembranosus bursa Ligaments of the Knee Extracapsular Ligaments The lateral collateral ligament: Attachment : from the lateral epicondyle of the femur and attaches distally to the head of the fibula. Function :  Resists varus angulation  Provide restraint to axial rotation. The Medial Collateral lig.: Attachment : medial epicondyle of the femur and attaches distally to the medial condyle of the tibia Function :  Resists valgus angulation  Provide restraint to axial rotation.  Ligaments of the Knee Extra-capsular The ligamentum patellae attaches above to the lower border of the patella and below to the tuberosity of the tibia. The oblique popliteal ligament is a tendinous expansion derived from the semimembranosus muscle.  Intracapsular igaments of the Knee Anterior Cruciate Ligament (ACL)  Bundles: Anteromedial band (AM) and posterolateral band (PL)  Attachment: ant. Intercondylar area of the tibia and the medial surface of the lateral femoral condyle  Function: restraining anterior tibial translation and rotational stability  Intracapsular igaments of the Knee Posterior Cruciate Ligament Attachment: attaches to the posterior intercondylar of the tibia to the anterior part of the lateral surface of the medial femoral condyle. Bundles : Anterolateral (AL) and Posteromedial (PM) Function: Prevent posterior tibial translation in relation to femur  Intracapsular igaments of the Knee Menis ci  C-shaped sheets of fibrocartilage  Medial and lateral menisci connected by transverse lig. of the knee  The Medial M. is attached to capsule while the L.M. is moe mobile  Function:  Deepen the articular surfaces of the tibial condyles  Serve as cushions between the two bones  Distribute forces transmitted through the joint. Knee Movement  Main movement :  Flexion by the Hamstring muscles = 145 – 160 degree  Extension by Quadriceps M. = 0-5 degree  Minor movement:  Internal rotation by Popliteus and semi tendinosis = 10 deg  External Rotation by Biceps femoris = 10 deg  STABILITY OF THE KNEE JOINT Bony Factors Ligamentous factors Muscular factors Special situations  MUSCULAR FACTORS Vitally important – Vasti – Medialis (VMO)– important for patella stability – Ilio-tibial band – stabilizes the slightly flexed knee (varus)  Knee locking  During the last 30 degrees of knee extension, the tibia ext. rotate and the femur must internally rotate.  As the length of the medial femoral condyle is longer than the length of the lateral condyle.  At terminal extension, the knee joint is slightly hyperextended and stabilized with the tightening of the cruciate and collateral lig aments.  This is Called Screw Home Clinical Points Ligaments tear of the knee ACL Tear :  Falling in Flexion and Valgus  Clinically : Pain , immediate swelling and giving away  Drawer test +ve  Rx = Reconstruction Clinical Points PCL tear When tibia subjected to direct blow ant. To post. Post drawer test +ve with Sag sign Rx = mainly conservative  Clinical Points LCL Tear  Varus force may lead to partial or complete tear MCL  Valgus force ( partial or complete Clinical Points Meniscal Injury  Most common knee injury  A twisting injury with the foot anchor on the ground  MM more common than LM injuries Thank You