Authors

Dr Keran Sundaraj MBBS MSc (Trauma) FRACS FAOA

Anterior cruciate ligament (ACL) reconstruction is a successful procedure in most patients with high satisfaction rates and a return to pre-injury activity levels. Despite this, rates of graft rupture/failure range from 10 to 20 %. 

Factors to consider in graft failure include:

• Position of the ACL sockets and tunnels

• The meniscus (shock-absorbers within the knee)

• The cartilage (lining of the bone within the joint)

• Posterior tibial slope (the sloping angle of the joint from the side)

• Patient factors - age, rehabilitation, return to sport

The position of your graft can be a significant factor in ACL re-injury. An overly 'vertical' graft may help with anterior-posterior movement (front to back) but will not control the knee as well in rotation. Conversely, an overly oblique graft may help with rotation, but the knee may have excessive anterior-posterior motion. When considering revision ACL surgery, the position of your original graft and tunnels is important in determining the method of revision surgery.

 Your original tunnels may be:

1. In the ideal position

2. Close to the ideal position, but could be improved.

3. Not in the ideal position.

Treatment is based on which of these scenarios is present.

1. For tunnels in the ideal position, one operation can be performed to rebore the tunnels and insert a new and larger graft.

2. For tunnels close to the ideal position, a two-stage operation may need to be performed. The first operation is to remove any hardware that may compromise future operations, remove the old ACL graft in the tunnels, rebore the tunnels and insert allograft bone (donated bone) to heal these holes. After 4 to 6 months, the bone has healed and makes for a new base to create tunnels with the ACL in an improved position.

3. For tunnels not in the ideal position, new tunnels can be drilled without disturbing the old holes. However, this is a rare situation as most tunnels will pass close to the ideal position and require a 2-stage procedure.

Other considerations for revision ACL reconstruction include addressing:

• Overall alignment with an osteotomy (realignment of the bone)

• Extra-articular procedures, such as reconstructing the anterolateral ligament, to further stabilise the knee joint from excessive rotation and translation.

These are rarely necessary but may be considered in special instances.

What to Discuss with Dr Sundaraj

• What type of operation will I require?

• What is the likely outcome from this treatment?

• How long can I expect off work?

• When can I start driving?

• When can I start physiotherapy?

• When do I need to come back?

As with all operations, if at any stage anything seems amiss, it is better to call for advice rather than wait and worry. A fever, redness or swelling around the line of the wound or an unexplained increase in pain should all be brought to the surgeon's attention. You can contact Dr Sundaraj by telephoning his staff during business hours or the Mater Hospital after hours. For any questions, please do not hesitate to contact our staff (02) 9437 5999 For after-hour assistance contact Mater Hospital (02) 9900 7300 Further information is available on our website