In the early days of cruciate reconstructive surgery, the critical contribution of rehabilitation was not fully appreciated. Now we better understand that the rehabilitation protocol and its timing can make or break the success of ACL graft surgery.
Contributing factors to graft failure during rehabilitation include -
Inappropriate speed of rehabilitation
In the 1970s, when cruciate ligament surgery was maturing, surgeons believed that it was necessary to protect the graft in the first 8-10 weeks via the use of splints or casts. But we found that this approach frequently led to inability to regain a full range of motion, especially full extension due to tightening of the capsular structures behind the knee. Failure to regain the last few degrees of extension may result in graft shortening.
Now, rehabilitation focuses on immediately moving the knee the day after surgery, with the patient regaining full flexion and extension by the 4-6 week. At all times, consideration is given to the type of graft and fixation, and exercises progress according to the anticipated phase of graft revascularisation and ligamentisation. If the rehabilitation is too quick or aggressive, the graft may fail or the joint space may become inflamed and trigger arthrofibrosis.
Failure to recognise early arthrofibrosis
Arthrofibrosis is abnormal scarring within the knee joint cavity and the soft tissue structures around the knee.
If the knee becomes inflamed and regaining range of motion is slower than expected, it is important that the rehabilitation team keep in mind the possibility that adhesions and scar tissue may be forming within the joint cavity. In the early stages of rehabilitation, it is usually possible to arrest this process by appropriate intervention. My previous set of tutorials on arthrofibrosis goes into the subject in some depth.