Anterior Cruciate Ligament (ACL)
The anterior cruciate ligament (ACL) is the knee ligament that most commonly requires reconstruction. Since it is located within the knee joint, the ACL will not heal by itself. Furthermore, the knee commonly becomes very unstable following ACL injury. Recurrent knee instability may mean having to stop sports, and can also cause further injury within the knee, such as meniscal tears. While some people may accept instability and modify their lifestyle accordingly, most people will benefit from surgical reconstruction of the ACL.
ACL Reconstruction Surgery
Of the many ACL reconstruction techniques commonly used, my preference is to use two of the hamstring tendons as a single bundle four-strand autograft. This is probably the most common technique currently used around the world. By securing this graft to the femur with a small titanium button (called an endobutton) and to the tibia with the combination of a bone staple and a screw, a stable knee with a physiological range of motion can be reliably achieved. Although a small incision is required to harvest the hamstring graft, the majority of the operation is performed arthroscopically (keyhole surgery).
Following ACL Reconstruction Surgery
Click here for a copy of my recommended rehabilitation protocol following ACL reconstruction surgery.
The knee is immediately stable following surgery and you are encouraged to fully weight-bear as soon as possible – usually this is within a day or two of surgery. While I give most patients a splint to ensure that the ability to fully straighten the knee is maintained while adequate quadriceps strength is restored, most people require the splint for less than a week or two. The most important thing to remember following ACL reconstruction surgery is that although the graft is stable from the day of surgery and the knee feels good within a few weeks, the rehabilitation program takes many months; it is usually a year before you will have returned to competitive sports.
Posterior Cruciate Ligament (PCL)
Like the ACL, the posterior cruciate ligament (PCL) is located within the knee joint and will heal by itself. Unlike an ACL deficient knee, however, the knee is usually stable enough to participate in sports following PCL injury. Most people who rupture the PCL are able to return to sporting activities with a physiotherapy program directed at strengthening the hamstring and quadriceps muscles. A small portion of patients require PCL reconstruction surgery. My preference is to perform this surgery arthroscopically, in a similar manner to ACL reconstruction.
Medial Collateral Ligament (MCL)
The medial collateral ligament (MCL) is located outside the knee joint and has the capacity to heal without surgery. Most patients with an MCL injury can be managed with physiotherapy and an extended period of activity reduction (usually at least three months). Severe MCL injuries require surgery, which I usually perform as an open procedure using a hamstring tendon autograft.
Lateral Collateral Ligament (LCL) and Postero-Lateral Corner (PLC)
Although the lateral ligamentous structures of the lateral collateral ligament (LCL) and the postero-lateral corner (PLC) are located outside the knee joint, they are complex and often do not heal back to the correct location following injury. My preferred management of injuries to the LCL and PLC is direct repair with open surgery, performed within three weeks of the injury. If the injury is more than three weeks old, reconstruction surgery is usually required. Surgical reconstruction of these structures is unable to fully replicate their complex anatomy, and the results of delayed reconstruction are inferior to early direct repair.