4Tibiofemoral JointModified hinge joint allowing some lateral and rotational motions to occur as well.Lateral epicondyle is larger than medial.Because of size difference there is a screwing home mechanism to bring the knee into full extension.
5Menisci Semilunar fibrocartilage (half moon shapes) Attach to the superior plateaus of the tibia.Absorption and dissipation of forceLubricationMedial meniscus is semicircular and attaches to the medial collateral ligamentLateral meniscus is almost a complete circle and attaches to the posterior cruciate ligament
6BursaeSuprapatellar bursa, lies between the femur and quadriceps femoris tendonSubpopliteal bursa, lies between the femur and the popliteal muscleSemimembranosus bursa, lies between the medial head of the gastrocnemius and the semimembranosus tendon.Prepatellar bursa, lies between the skin and the anterior surface of the patella
7Bursae continuedSuperficial infrapatellar bursa is located between the skin and the patellar tendon.Deep infrapatellar bursa is located between the tibial tubercle and the infrapatellar tendon.
8LigamentsAnterior Cruciate Ligament (ACL), attaches anteriorly on the tibia, and to the posterior surface of the lateral femoral condyle.Prevents:Anterior translation of the tibia on a fixed femurPosterior translation of the femur on a fixed tibiaInternal and external rotation of the tibia on the femurHyperextension of the tibia
9Ligaments continuedPosterior Cruciate Ligament (PCL), attaches posteriorly to the tibia, and to the anterior surface of the lateral medial condyle of the femur.Prevents:Posterior displacement of the tibia on a fixed femur.
10Ligaments continuedMedial collateral ligament (MCL) connects from the medial condyle of the femur to the medial tibia through the medial meniscus.Prevents:Medially directed shear forces (valgus)Rotational forces
11Ligaments continuedLateral collateral ligament (LCL) connects from the lateral condyle of the femur to the head of the fibula.Prevents:Laterally directed shear forces (Varus)External rotation of the tibia
12Ligaments continuedArcuate-popliteal complex composed of the semimembranosus tendon and the popliteal ligament connects the lateral condyle of the femur to the head of the fibula.Prevents:Anterior displacement of the tibia relative to the femur.Hyperextension of the kneeHyperflexion of the knee
13Patellofemoral jointTriangular bone (Patella) rests between the femoral condyle to form the patellofemoral joint.Three distinct facetsIncreases angle of pull on the patellar tendonGlides between the femoral Trochlear groove
14Patellofemoral joint cont. Greatest compressive forces occur when the knee is in 30 deg. Of flexion.Patellar positioning is maintained by:Lateral retinaculumMedial retinaculumMedial patellofemoral ligamentLateral patellofemoral ligament
17KinematicsFlexion primarily carried out by the hamstrings assisted by gastroc, popliteus, gracilis, and sartorius.Secondary responsibility of these muscles is to rotate the tibiaExtension primarily carried out by the quadriceps group.
18ContusionsFat Pad ContusionPeroneal Nerve Contusion
19Bursitis Prepatellar Deep infrapatellar bursitis Pes anserine bursitis Tibial collateral bursitis