HSS 2104 Lecture Notes - Lecture 4: Femoral Head, Transverse Plane, Osteoarthritis
Document Summary
The knee: largest joint in body, modified hinge joint, two joint structure tibiofemoral and patellofemoral joints, transmits loads, essential to motion, vulnerable to injuries. Structures of knee: bones levers for movement, weight bearing, ligaments structural strength and integrity, menisci/cartilage eliminate bone to bone contact; shock absorbers. Rotational facilitation: patella impact protection, improves effect of quads. Screw-home mechanism: external rotation of tibia during knee extension and internal rotation during knee flexion, medial femoral condyle is 1. 7 cm longer, locks joint in place at full extension by screwing bones together. Joint reaction forces: 2 factors influence magnitude of joint forces in dynamic situation. Acl knee injuries: most common of cruciate ligament injuries, amplified if contact occurs simultaneously on lateral aspect of knee. Other knee injuries: o"donoghue"s triad acl, mcl, & medial meniscus sustain damage, meniscus injury. Damage from combo of flexion-rotation or extension-rotation during weight bearing. Rapid extension of knee causing tear to medial meniscus.