Anterior Cruciate Ligament Reconstruction
The anterior cruciate ligament (ACL) links the tibia, the shinbone, to the femur, the thigh bone, and is commonly ruptured by twisting injuries in sport. Typically, the knee will give way and there may be a popping sensation.
The diagnosis depends on a clinical examination at which time the laxity of the ligament can be assessed, possibly through an MRI scan, to see if the cartilage is also damaged. It is often difficult to examine a knee soon after the initial injury as it is swollen and painful. In this case, it is usual to arrange for an MRI scan and physiotherapy whilst the knee settles down. After a few weeks, it is easier to examine the knee to confirm diagnosis.
The ACL reconstruction surgery is an arthroscopic procedure in which the damaged ACL is removed and replaced with a graft of the patient's own tissue. The surgeons within the Orthopaedic Centre of Excellence use a hamstring graft, using two tendons from the inside of the knee. Despite the loss of the tendons, the hamstring strength will usually return almost to normal after rehabilitation.
Patients usually remain in hospital for one night post-operatively. An outpatient physiotherapy rehabilitation programme will begin five days post discharge and is split into three phases of three months.
During the first three months, patients will regain a full range of movement mainly performing 'closed chain exercises'. These are exercises with the foot on the floor or a pedal of a stationary bike so as not to stress the healing graft. After three months, the graft has healed strongly to the bone in the tunnels either side of the knee joint.
The second three months sees the start of 'open chain exercises' such as jogging in a straight line and progressing to shuttle runs in the gym. Patients will also do 'proprioception' exercises to train the muscles to respond quickly.
The final phase involves specific sport training. This should remain gentle e.g. avoid tackling in football games, so as not to inhibit the rehabilitation.
After nine months, the rehabilitation is complete and patients can return to their chosen sport without restrictions.