The anterior cruciate ligament (ACL) is an important ligament within the knee involved in its stability. ACL tears are one of the most common knee injuries seen, particularly in those sports that involve twisting movements of the knee. Unfortunately, ACL tears do not heal, often leading instead to instability of the knee. An ACL reconstruction is a surgical procedure to stabilize the knee by replacing (reconstructing) the torn ACL with another ligament graft. The graft is taken from tissues around the knee, such as the hamstring tendons or patella (knee cap) tendon. ACL reconstructions are performed arthroscopically (i.e., keyhole surgery). What are the symptoms of ACL injury? You may also feel your knees giving way. This is followed by sudden pain and swelling. It may be difficult to walk for several days. The acute symptoms of pain and swelling eventually resolve spontaneously. However, the knee ‘giving way’ or instability often persists when attempting to return to sporting activities. Other symptoms include loss of full range of motion of the knee joint, inability to fully straighten the knee, pain with walking and tenderness along the joint line. How do you diagnose ACL injury? A thorough examination of your knee can help in the diagnosis of ACL injury. X-rays are often normal or may show an associated fracture (broken bone) known as a “segond lesion” indicative of an ACL injury. MRI may be required if the diagnosis is unclear or if other soft tissue injuries are suspected, such as concomitant ligament injuries, meniscus or articular cartilage injuries. What is the treatment for ACL injuries? A torn ACL will not heal without surgery. However, not everyone requires surgery, and treatment is tailored to the patient’s individual needs. The less active patient may be able to return to a quieter lifestyle without surgery. Surgery is recommended if there are repeated episodes of instability as it can cause further damage to important structures in the knee, which may result in early arthritis. Patients wishing to return to sports involving cutting or pivoting movements (e.g., soccer, football, badminton, cricket etc.) or with physical jobs involving cutting or pivoting movements will require surgery to restore function and stability. Non-surgical treatment involves physical therapy and rehabilitation to strengthen the quadriceps and hamstrings muscles. Bracing may be required to protect your knee from instability. Rehabilitation and recovery after ACL reconstruction Physiotherapy is an integral part of the treatment and is recommended to start as early as possible. Preoperative physiotherapy is helpful to better prepare the knee for surgery. The early aim is to regain range of motion, reduce swelling and achieve full weight-bearing. Rehabilitation is supervised by a physiotherapist and will involve activities such as exercise bike riding, swimming, proprioceptive exercises and muscle strengthening. Cycling can begin at 2 months, jogging can generally begin at around 3 months. The graft is strong enough to allow sport at around 6 months; however, recreational athletes may take longer to return to sport, depending on their motivation levels and the time put into rehabilitation. At the National Sports Medicine Center, we have been performing ACL reconstruction surgeries for over a decade and we have helped many professional sportsmen and active individuals return to sport and an active life style.