Revision anterior cruciate ligament surgery.

The importance of the anterior cruciate ligament (ACL) to the maintenance of normal knee function is now well accepted. 94 An untreated ACL tear can lead to recurrent giving-way episodes, damage to the menisci and articular cartilage, with progression to osteoarthritis in some patients. 9 , 38 , 41 , 42 , 91 , 94 , 106 , 141 The poor long-term results of nonoperative treatment, primary repair, and extra-articular reconstruction have led to intra-articular ACL reconstruction becoming the surgical procedure of choice for an athletically active patient with a functionally unstable knee. * Reconstruction of the ACL is one of the most commonly performed orthopedic operations. According to the National Center of Health Statistics, in 1991 approximately 63,000 ACL reconstructions were performed in the United States. By current industry estimates, over 100,000 ACL reconstructions are performed annually in the United States. The success rate of primary ACL reconstruction has been reported to range from 75% to 93%, good or excellent results with respect to relief of giving-way symptoms, restoration of functional stability, and return to normal or near normal activity levels † Given the reported success rates, a significant number of patients who undergo ACL reconstruction may have a less than satisfactory outcome. What qualifies as a unsatisfactory result or “failure” after ACL reconstruction, however, has not been well defined or agreed on. Johnson and Fu 69 have defined a failed ACL reconstruction as a knee that demonstrates recurrent pathologic laxity that was present prior to surgery, or a stable knee that has a range of motion from 10 to 120 degrees of flexion that is stiff and painful even with activities of daily living. Although graft failure is the most common cause of failed ACL surgery, it is important to keep in mind that non–graft-related conditions may also result in persistent complaints and an unsatisfactory outcome. Failed ACL surgery can be classified into one of the following four categories with the potential for overlap among the categories in some cases 69 : 1 Loss of motion or arthrofibrosis 2 Extensor mechanism dysfunction 3 Arthritis 4 Recurrent patholaxity (graft failure) It is important to characterize and categorize properly the residual complaints following the original ACL reconstruction in order to prevent a second ligament operation directed at improving anterior laxity of the knee from being performed, only to result in the patient continuing to experience the original non–graft-related complaints. Given today's emphasis on maintaining fitness and the participation of all age groups in physical activities that place the ACL at risk for injury, the number of primary ACL reconstructions performed can be expected to continue to increase. Although surgical and rehabilitation advancements have improved the success rate of primary ACL reconstruction, the increasing number of primary reconstructions being performed can be expected to lead to an increasing number of patients with the potential need for revision ACL surgery. 44 , 47 , 59 , 60 , 120 , 132 , 134 , 136 In general, the results of revision ACL reconstruction do not appear to be as favorable as those of primary reconstructions. * The success rate of revision ACL reconstruction is determined by many factors including the origin of the primary failure, the preoperative laxity of the knee, the status of the secondary restraints, menisci and articular cartilage, and patient motivation and compliance. † In order to maximize the success of revision ACL surgery, a methodic and organized approach is required. This article reviews the etiology of failed ACL surgery, discusses preoperative evaluation and planning, and reviews some of the technical considerations of revision ACL surgery.