Anterior Cruciate Ligament Injury
The anterior and posterior cruciate ligaments are important stabilisers of the knee joint to allow movement. The Anterior Cruciate Ligament (ACL) is commonly injured during sporting activities. It is usually a result of a twisting injury and some patient may be able to feel a 'pop' sound in the knee as the ligament ruptures. This is usually followed by immediate knee swelling. ACL injury generally prevents any further participation in the sport due to pain. Following injury, the patient may feel as if the knee is giving way which can lead to hesitation in running and jogging.
Doctors initially treat this by immobilising the knee in a splint (a device to restrict movement in the affected area) after applying a compression bandage. Patients will also be prescribed ice therapy, pain killers and provided with crutches for support. Physical therapy will be recommended to regain movement of the knee.
- X-rays are generally not helpful in diagnosis unless the injury is at the ends of the ligament when there is a possibility of it pulling a chip of bone with it.
- An MRI scan helps confirm the diagnosis and also helps to diagnose injury to other structures in the knee joint.
Physical therapy will be started to strengthen the muscles around the knee joint which may help stabilise the joint. Younger and more active individuals may be recommended surgery in the form of ACL reconstruction. Studies have shown that the ACL does not heal simply by repairing the torn ends together.
Surgery is commonly performed by key-hole surgery called arthroscopy, which is a non invasive surgery but can also be done by an open technique. Reconstruction is generally performed by substituting the ACL with another tendon which may either by taken from the patient himself/herself or from other sources. These tendons used for the reconstruction generally have a minor function and does not cause further problems for the patient. The most commonly used grafts are the bone-patellar graft, tendon-bone graft and the hamstring tendon grafts which involve borrowing tendons from different parts from the knee. The torn ACL is first excised and bony tunnels are created in the upper tibia and lower femur which are the bones which constitute the knee joint and at places where the native ACL was attached. The tendon graft is then passed through these tunnels and secured at either end with suitable implants.