Evaluation and treatment of recurrent instability after anterior cruciate ligament reconstruction.

Revision ACL surgery has become increasingly common. Successful revision surgery requires a thorough preoperative evaluation, including a detailed history and a physical and radiographic examination. Preoperative planning is imperative for a successful outcome, as it limits the potential for repeating the errors that led to the failure of the primary procedure. This begins with a determination of the mechanism of failure. Often, a primary as well as a secondary cause of failure can be identified. Determination of the etiology of failure is the first step in a carefully constructed treatment plan, which includes the type of revision and skin incision, graft and hardware removal, tunnel placement, graft selection and fixation, and the rehabilitation protocol. The preoperative plan should have enough flexibility to accommodate unanticipated findings in the operating room. Finally, the importance of counseling the patient preoperatively regarding potential results must be emphasized. Given the complexity of revision ACL reconstruction, the patient's expectations must be adjusted to realistically match the potential for success. The goal of successful revision surgery may be only to return the patient to activities of daily living or work, especially if there is evidence of degenerative joint disease. With proper planning and attention to detail, revision ACL surgery can provide a satisfying solution to difficult cases of knee instability.