Knee joint (2.6)

Bursae

Fluid filled sacs that reduce friction and cushion joints

Meniscus

Fibrocartilage pad located between the femur and tibia; acts as a shock absorber, and stabilizes the joint

Medial collateral ligament (MCL)

Attached to the medial meniscus, femur, and tibia. Prevents excessive separation of the inside of knee joint. Injury to the ligament is caused by impact from outside the knee.

Lateral collateral ligament (LCL)

Attached to the lateral meniscus, femur, and tibia. Prevents force coming from inside the knee. Injury to the ligament is caused by sudden force to the outside of the knee or twisting of the knee

Anterior cruciate ligament (ACL)

Avascular ligament attatched to the femur and tibia. Prevents excessive anterior translation of the tibia. Injuries are caused when the tibia slides to far forward, this can occur due to planting and cutting, straight-leg landing, one-step-stop landing with the knee hyperextended, and pivoting followed by a sudden deacceleration.

Posterior cruciate ligament (PCL)

Thick ligament attatched to the fibia and tibia. Prevents excessive posterior translation of the tibia. Injuries are commonly caused by "blows" to the lateral side of the knee.

Unhappy triad

ACL, MCL, medial meniscus are all dammaged simultaneously. Often occurs when lateral force is applied when foot is planted.

Patellofemoral syndrome (PFS)

The gradual onset of anterior knee pain or pain around the patella. Usually affects adolescents or young adults, and women are often affected more than men. Pain is a result of increase or misdirected forces between the kneecap and the femur

Osteoarthritis

Degenerative joint disease in which the synovial cartilage surrounding a joint degrades and bone spurs start to form, makin it painful for one to flex the joint