Anterior Cruciate Ligament Reconstruction: Surgical Management and Postoperative Rehabilitation Considerations

INTRODUCTION Surgical techniques for anterior cruciate ligament (ACL) reconstruction have progressed in the past 20 to 30 years. In the 1970s, ACL reconstructions were done through large arthrotomies, using non-anatomic, extra-articular reconstructions, with long postoperative periods of immobilization.1,2 In the 1980s, large arthrotomies were replaced by arthroscopic, anatomic, intra-articular reconstructions. Arthroscopy eliminated the need for prolonged postoperative immobilization, and accelerated rehabilitation protocols were established. In the 1990s, the rehabilitation protocols were advanced further to allow athletes an early return to sports.2 Today, while there is less variability in the surgical techniques used, there remains variability in the types of surgical grafts used. The most commonly used grafts for ACL reconstruction are the bonepatellar-tendon-bone autograft, semitendinosus autograft, and the semitendinosus/ gracilis autografts and allografts.3,4 The success of a patient’s recovery who has undergone an ACL reconstruction is predicated on several factors including surgical technique, graft selection, prevention of postoperative complications, patient compliance, and postoperative rehabilitation.4,5 The postoperative rehabilitation regimen must be guided by principles such as the early return of knee range of motion (ROM), especially extension, while obtaining and maintaining a relatively stable physiological state of the knee joint (homeostasis). Strengthening, proprioception exercises, and early weight bearing have also become guiding principles.2 The purpose of this paper is to outline current surgical and postoperative factors that should be considered when establishing the rehabilitation program for a patient following ACL reconstruction. BASIC ANATOMY AND FUNCTION The ACL restrains anterior translation of the tibia, and prevents tibial rotation and varus/valgus stresses to the knee. Participating in sports and activities in which pivoting occurs where the foot is planted, the knee is flexed, and a change in direction is needed puts one at a higher risk for an ACL injury. Basketball, skiing, and football are examples of sports in which a high number of ACL injuries occur.6 The ACL is also very susceptible to injury in contact sports. It can be damaged along with the medial collateral ligament when there is an associated valgus stress. A force that results in the tibia being driven forward, the femur being driven backward, or in the knee joint being severely hyperextended may also result in damage to the ACL. The ACL does not heal well without surgery.7 This is most likely due to the amount of force involved in the injury, the lack of blood supply to the ligament, and its intraarticular location. However, about onethird of all patients can expect a fair to good outcome without surgery.8 Typically, these patients who do well without surgery are older or less active, and modify their activity level following injury, including avoiding pivoting sports/activities. Generally, younger and/or active individuals do not do well with nonoperative treatment. This is due to the expectation of continuing to participate in sports that require high levels of pivoting. Active patients with an ACL deficiency are at risk for reinjury, including meniscal tears and/or articular damage, leading to subsequent degenerative changes in the knee. Patients who opt for surgical reconstruction of the ACL can expect restored stability of the knee and return to preinjury levels of activity.9 Over the past 20 years, advances have been made with respect to graft choice and fixation, and perioperative management, including rehabilitation. These advances have led to increased functional outcomes and early return to activity.10