That’s torn it
Knee ligament injuries always increase during the ski season, and an ACL tear is one of the most common.
At this time of year, knee ligament injuries tend to flood orthopaedic clinics as people return from the ski slopes.
The most common ligament injury in the knee is a tear of the anterior cruciate ligament or ACL. These tears often occur in association with other injuries around the knee, including meniscal cartilage injuries, articular cartilage damage and other ligament injuries. ACL injuries, usually caused by a sudden twisting or an impact to the knee, are also common in other sports such as football or rugby.
ACL tears in skiing typically occur as a result of a bad fall where the knee is wrenched, often with a tearing or popping sensation. The knee will normally swell up rapidly as it bleeds internally, and most patients are unable to ski down. Patients are usually assessed by a local doctor – most of whom are skilled at diagnosing this injury clinically – and X-rays are taken to exclude any bony injury. Patients are normally fitted with a brace and advised to return to the UK to see a relevant specialist.
An MRI scan is performed to confirm the diagnosis and looks for other pathology. The anterior cruciate ligament is vital in providing stability in the knee – without it, the knee is liable to give way. Sometimes, an anterior cruciate ligament rupture can be treated with physiotherapy alone to overcome its absence by improving strength and joint position sense in the muscles that surround the knee. Most younger, sporty or active patients, though, do require an ACL reconstruction and the results of these are good, with around 90% either returning to their pre-injury activity levels or nearly so.
The surgery to reconstruct the ACL is quite routine. It is unusual to be able to simply repair the torn ligament – it most often needs to be replaced with a ligament graft, using either the hamstring tendons or patellar tendon.
An important new development in this surgery has been that of the Arthrex internal brace, which protects the reconstructed ligament, acting as a sort of artificial “safety belt” alongside or within the reconstructed ligament.
The surgery involves very precisely replacing the torn anterior cruciate ligament with either hamstring tendon grafts or patellar tendon grafts in exactly the right anatomic position and tensioning. The surgery takes approximately one hour under a general anaesthetic. Patients are normally discharged the day after surgery and then undergo an extensive and very important post-operative rehabilitation programme.