HOW DO WE TEAR THE ACL?
The ACL is commonly injured whilst playing ball sports or skiing. Whilst playing ball sports upon attempting a pivot, side step or landing from a jump, the knee gives way. The foot is planted on the ground and the rest of the body rotates about the knee creating the force required to snap the cruciate ligament. When rupturing the ACL patients frequently hear or feel a snap, a pop or a crack accompanied by pain. They fall to the ground, stop playing and come off the pitch. Swelling commonly occurs within the hour. Frequently pain is felt on the outer aspect of the knee. Occasionally the medial ligament of the knee joint (MCL) may also be disrupted resulting in severe pain and swelling at the medial aspect of the knee.
HOW DO WE DIAGNOSE AN ACL RUPTURE?
The majority of the ACL ruptures can be diagnosed by:
- Taking the relevant history from the patient.
This is the classical story that is given by the typical patient: “I twisted my knee with my foot on the ground or landed after a jump. I fell to the ground and felt the knee giving way. I felt a crack / pop or snap inside the knee with an intense pain. I couldn’t play on. My knee swelled up ’like a balloon’ immediately. When pain eventually settled I found it hard to bend my knee. Since then my knee gives way and I don’t fully trust it”
When hearing a similar story we should treat this as an ACL tear until proven otherwise.
- Doing a clinical examination of the knee.
The patients may present at a variable interval (days or weeks/moths) complaining of their knee giving way during simple activities. When presenting early, within days of injury the knee is often stiff, swollen and painful. In these cases the examination is difficult and signs may be subtle. When presenting late (weeks or months) following injury the knee is often pain free, has full range of motion, it may be slightly swollen (small effusion) and is loose when testing for the ACL.
Taking as history as outlined above is often sufficient to raise the suspicion of an ACL injury.
WHAT IMAGING IS REQUIRED WHEN SUSPECTING AN ACL TEAR?
When we suspect an ACL injury we should request an X-ray (Both AP and Lateral) and an MRI of the affected knee. The X-ray will show if there are any fractures caused by the injury involving the knee. The MRI will outline the anatomy of the ligaments, menisci and chondral surfaces. It will diagnose the ruptured ACL and the associated injuries when present.
WHAT IS THE BEST ADVICE TO SOMEONE WITH AN ACL TEAR?
If the patient is in the acute phase (i.e. the first week or two after the injury) and the knee is still swollen, he/she should follow the RICE treatment principle: Rest, Ice, Compression and Elevation. For pain control he should take Paracetamol up to eight tablets a day. In the majority of cases we should encourage weight-bearing and range of motion mobilisation with no brace as pain allows. Sometimes depending on the associated injuries a knee brace allowing range of motion exercises could help.
When suspecting or dealing with a confirmed ACL injury we should refer the patient for further evaluation and treatment to an Orthopaedic Surgeon with an interest and sub-specialised training (Fellowship) in Sports Knee surgery.
SHOULD EVERYBODY WITH AND ACL TEAR HAVE SURGERY?
No, not all patients with ACL rupture should have surgery. The patients, along with their Orthopaedic Surgeon, should decide during the consultation what is the best treatment for them.
The goal of treatment for anybody with an injured knee is to return to their desired level of activity without risk of further injury to the joint. Treatment may be surgical or non-surgical. Patients who have a ruptured ACL and are content with activities that require little in the way of side-stepping (i.e. running in straight lines, cycling and swimming) may opt for conservative treatment. Surgical treatment cannot guarantee that further injury to the joint will not occur.
Conservative treatment is by physical therapy aimed at reducing swelling, restoring the range of motion of the knee joint and rehabilitating the full muscle power. Intense proprioceptive training to develop the necessary protective reflexes is required to protect the joint for normal daily living activities. As the cruciate ligament controls the joint during changes of direction, it is important to alter your sports to the ones involving straight-line activity only. Social (non-competitive) sport may still be possible without instability as long as one does not change direction suddenly. Skiing is possible with conservative treatment. A brace and adherence to groomed runs may be required.
Those patients who wish to pursue competitive ball sports, or who are involved in an occupation that demands a stable knee are at risk of repeated injury resulting in tears to the menisci, damage to the articular surface leading to degenerative arthritis and further disability. In these patients, surgical reconstruction is recommended. Surgery is best carried out on a pain free, healthy joint with a full range of motion. This is achieved with a pre-habilitation program supervised by a Physiotherapist.
MY SURGICAL TREATMENT FOR PATIENTS WITH ACL TEAR?
All reconstructive procedures for the ACL require a graft. My reconstructive technique involves grafting the torn ACL with segments of the patient hamstring tendons. This technique uses specially designed screws allowing secure immediate fixation of the tendon within the joint allowing for a rapid, early rehabilitation. Stabilising the joint protects the menisci and thus it may reduce the chances of developing later osteoarthritic degenerative changes. Although ACL reconstruction surgery has a high probability of returning the knee joint to near normal stability and function, the end result for the patient depends largely upon a satisfactory rehabilitation and the presence of other damage within the joint. Advice will be given regarding the return to sporting activity, depending on the amount of joint damage found at the time of reconstructive surgery.