The document summarizes the main anatomical structures of the knee, including bones (femur, patella, tibia, fibula), menisci, ligaments (ACL, PCL, MCL, LCL), bursae, fat pads, muscles and common injuries. It describes the key functions and attachments of the ligaments in stabilizing the knee joint. Common causes of ACL and PCL tears include twisting motions or dashboard injuries. The document also outlines rehabilitation approaches for knee injuries focusing on conditioning, mobilization and gradual return to activity.

1. The Knee and Related Structures

2. The Knee Bones Femur Patella Largest Sesamoid bone in human body Tibia Fibula Non-weight bearing bone Articulations Four Articulations Femur and Tibia Femur and Patella Femur and Fibula Tibia and Fibula

3. Meniscus Two oval fibrocartilages that sit in the tibia Semi-lunar (half moon shape) Stabilize the knee Especially the medial, when the knee is flexed at 90 degrees Medial C-shaped Attach to the tibia, joint capsule by the coronary ligament, and the semimenbranous muscle (hamstring) Lateral O-shaped Attached to the tibia, loosely to capsule, and popliteal tendon, and ligament of Wristberg Blood Supply Divided into 3 circumferential zones Red –Red Red-White White-White Avascular

4. 3 Zones of Meniscus

5. Stabilizing Ligaments Account for a considerable amount of knee stability Two ligamentous bands that cross one another within the joint capsule of the knee Anterior Cruciate Ligament (ACL) 3 twisted bands Prevents the femur from moving posteriorly weight bearing and anteriorly non-weight bearing. Stabilizes the tibia from excessive internal rotation (IR) Posterior Cruciate Ligament (PCL) Resists IR of the tibia Prevents hyperextension of the knee

6. ACL & PCL

7. Common Cause of ACL Tear

8. Common Cause of PCL Tear Situations in which the PCL can tear include - excessive hyperflexion (forced bending), eg falling onto the shin with a bent knee and foot pointed dashboard injury in a car - where the knee is bent to a right angle and a sudden force drives the tibia backwards

9. Medial Collateral Ligament Superficial ligament(MCL) is separate from the deeper capsular ligament. Attaches above the join line on the medial epicondyle of the femur and below on the tibia – Just beneath the attachment of the pesanserinus (hamstring tendons) Deep medial capsular ligaments Primary purpose are to attach the medial meniscus to the femur and to allow the tibia to move on the meniscus inferiorly Lateral Collateral Ligament Size of a pencil Attached to lateral epicondyle of the femur and to the head of the fibula. Taut during knee extension but relaxed during flexion

11. More Structures of the Knee Joint Capsule Knee joint is surrounded by the LARGEST joint capsule in the body. Contains: infrapatellar pouch, fat,pad, and bursae, MCL, and other ligaments. Divided into Four regions – are reinforced by other anatomical structures Posterolateral & medial Anterolater al & medial

12. Knee Musculature 13+ Muscles Movements of the Knee Knee Flexion & Extension External & Internal Rotation Bursae Reduce friction 2 dozen have been identified in the knee Fat Pads Several pads located around the knee Infrapatellar fat pad is the largest Nerve & Blood Supply

14. Specific Injuries Medial & Lateral Collateral Sprain Hit from opposite side of leg ACL & PCL Sprain ACL= lower leg is rotated while the foot is fixed (jumping) PCL=fall with full weight on the anterior aspect of the bent knee with the foot in plantar flexion (sliding) Meniscal Lesions Most common= weight bearing combined with a rotary force while running Patellar Conditions Patellar orientation predisposes you to have certain types of injuries Acute patellar subluxation or dislocation Chondromalacia Softening and deterioration of the articular cartilage on the back of the patella Three stages Patellofemoral Stress Syndrome Some lateral deviation of the patella as it tracks in the femoral groove

15. MCL & LCL Sprain

16. Meniscal Lesions

17. Patellar Tracking

18. Patellar Examination The Q-Angle Quadriceps angle Normal is 10’ Males / 15’ Females 20’ (+) predisposed to patellar subluxation/dislocation

19. Extensor Injuries Osgood-Schlatter Disease Pain at the attachment of the patellar tendon to the tibial tubercle Can lead to avulsion fracture Larsen-Johansson Disease Occurs at the inferior pole of the patella Excessive repeated strain on the patellar tendon Patellar Tendinitis (Jumper’s/Kicker’s Knee) Repetitive trauma Extreme tension on the knee extensor muscle complex Painful at patellar or quadriceps tendon Iliotibial Band Friction Syndrome (runner’s knee) General expression for many repetitive and overuse conditions Malalignment and structural assymetries of the foot and lower leg.

20. Extensor Injuries

21. Patellar tendonitis can be classified by the following techniques: Stage 0 - No Pain Stage 1 - Pain only after intense sports activity; no undue functional impairment Stage 2 - Pain at the beginning and after sports activity; still able to perform at a satisfactory level Stage 3 - Pain during sports activity; increasing difficulty in performing at a satisfactory level Stage 4 - Pain during sports activity; unable to participate in sport at a satisfactory level Stage 5 - Pain during daily activity; unable to participate in sport at any level

22. Knee Joint Rehabilitation General Body Conditioning Weight Bearing Knee-Joint Mobilization Flexibility Muscular Strength Neuromuscular Control Bracing / Taping Functional Progression Return to Activity