The anterior cruciate ligament (ACL) is vital to normal knee stability and function. It acts as one of the main restraining ligaments in the knee and primarily controls rotation and twisting movements.
Injury to the ACL commonly occurs during sporting activities and because the ligament rarely heals, recurrent episodes of giving way and instability can develop. Importantly, secondary damage to the menisci (load absorbers) or articular cartilage (joint surfaces) can then occur.
Diagnosis of an ACL injury is made on history, clinical examination and MRI scan. The diagnosis is unfortunately often missed or delayed as a torn ACL is not visible on a plain x-ray which patients may have initially in the casualty department or through their GP.