The anterior cruciate ligament (ACL) connects the tibia to the femur. It is often injured in sports that require pivoting movements and change of direction. Symptoms of an ACL tear are a sudden pain, pop sound and feeling of instability in the knee joint. People who sustain this injury have often swelling below the knee cap and are unable to weight bear on the affected leg. Surgery is often needed to repair the ligament, although some people are able to recover with conservative treatment.

The medial collateral ligament connects the medial side of the tibia to the femur. An inward knee sprain can cause trauma to this structure. Because of the vascularity of this tissue, MCL can often recover without surgery over a period of 6 weeks to 3 months, depending on the severity of the injury. 

Meniscus tear. The meniscii are two c-shaped structures made up of cartilage positioned between the tibia and the femur. They act as shock absorber for the knee joint. Meniscus tear can be caused either by aging or trauma. Tears caused by aging ( degenerative tear) are very common and they may not cause any symptoms. Traumatic tears are often sustained during sports and are more problematic. Depending on the location and severity of the tear, they may require surgery and a period of rehabilitation.

Iliotibial band (ITB) syndrome presents with pain and tenderness on touch of the lateral aspect of the knee. It is caused by repetitive rubbing of the ITB tendon against the knee bone. It is common in long distance runners. Treatment involves physiotherapy modalities to reduce pain and a strengthening program to increase the capacity of the ITB to sustain long periods of running.