Knee Ms. Bowman

Bones Femur Tibia Patella Fibula

Bony Landmarks

Joints These are the two main joints in the knee. Tibiofemoral-the articulation of the tibia and femur Modified Hinge joint Patellofemoral-the articulation of the patella and the femur The patella moves within a groove (or track) on the femur. These are the two main joints in the knee.

Patella Lives inside the patellar tendon Moves along groove of femur Quadriceps tendon superior Patellar tendon inferior Attaches to tibial tuberosity Moves along groove of femur Articular cartilage on back

Menisci These two fibrocartilaginous discs lay on top of the tibia and cushion the articulation of the femur on the tibia. They serve as shock absorbers. Increase stability of knee Medial meniscus- more ‘C’ shaped Lateral meniscus-more ‘O’ shaped

Menisci Superficial edge of the menisci is vascularizaed Deep portion of the menisci is avascular

Ligaments ACL-anterior cruciate ligament Located on inside of knee Helps to prevent anterior translation of the tibia Runs from medial aspect of antero- medial meniscus to the lateral condyle of the femur

Ligaments PCL-posterior cruciate ligament Located on the inside of the knee Helps to prevent posterior translation of the tibia Runs from the postero- medial aspect of the lateral meniscus to the medial condyle of the femur

Ligaments MCL-medial collateral ligament Located on the medial aspect of knee Runs from the medial condyle of the femur to the medial condyle of the tibia Resists valgus forces

Ligaments LCL- lateral collateral ligament Located on the lateral aspect of the knee Runs from the medial condyle of the femur to the head of the fibula Resists varus forces

MUSCLES

Hamstrings Origin- ischial tuberosity, proximal posterior femur Insertion- semimembranosis:posterior medial condyle of femur; semitendinosus: proximal medial surface of shaft of tibia; biceps femoris: head of fibula, lateral condyle of tiboa Action- knee flexion, hip extension

Gracilis Origin- distal margin of pubic bone Insertion- proximal medial surface of shaft of tibia Action- adducts hip, flexes knee

Sartorius Origin- anterior superior iliac spine Insertion- proximal medial tibia Action- flexes hip, externally rotates hip, abducts hip, flexes knee,

Quadriceps Origin-rectus femoris: front part of ilium vastus group: proximal shaft of femur Insertion- patella via patellar tendon Action- extends knee, flexes hip

Gastrocnemius Origin-lower posterior surface of femur above medial condyle, lateral condyle and lower posterior surface of femur Insertion-posterior surface of calcaneus via Achilles tendon Action- knee flexion, plantarflexion

Popliteus Origin-lateral surface of lateral condyle of femur Insertion-superior part of posterior surface of tibia Action-externally rotates femur when foot is planted, internally rotates tibia when non-weight bearing, “unlocks” extended knee to initiate flexion