reviSiOn anTeriOr cruciaTe ligaMenT recOnSTrucTiOn : preOperaTive planning and Technical cOnSideraTiOnS

Thomas J. Gill, MD ABSTRACT Revision anterior cruciate ligament (ACL) reconstruction poses a challenging situation for the surgeon. First and foremost, a diagnosis as to why the index reconstruction failed must be made – was this simply the result of a new trauma, or were there technical, diagnostic, or biological considerations associated with the index surgery that predisposed it to failure. From a surgical standpoint, a successful revision requires selection of an appropriate graft, a detailed surgical plan with regards to tunnel management, graft fixation, and treatment of associated injuries, as well as postoperative rehabilitation. This presentation is meant to concentrate on the technical aspects of revision ACL surgery. We detail our approach to revising a failed primary ACL reconstruction and discuss several of the technical challenges faced in the revision setting. INTRODUCTION It has been estimated that more than 100,000 anterior cruciate ligament (ACL) injuries occur annually in the United States with over half of these patients opting for surgical reconstruction. The goals of surgery are a stable knee with full painless motion that can withstand the stresses of sporting activities and prevent further damage to other intra-articular structures. Good to excellent subjective results following primary ACL reconstruction can be expected in the majority of patients, and more than half will return to their pre-injury level of athletic participation2, 6. Even with good to excellent subjective outcomes, previous biomechanical studies suggest that ACL reconstruction does not restore normal in vivo kinematics or forces across the ACL graft7, 9. Those patients that return to high-risk activities, such as sports that involve rapid deceleration and cutting maneuvers (football, basketball, soccer, and skiing), will be at higher risk for failure. As the number of primary ACL reconstructions increases, naturally so does the number of failures and thus the necessity for revision procedures. When compared to primary ACL reconstruction, an inferior outcome can often be expected with a revision procedure. Clinical failures have been noted to occur in up to 35% of patients4, 5, 8 with return to pre-injury level of activity being as low as 54% of patients11. Even though the clinical results are often inferior, there is considerable evidence to suggest that knee stability comparable to a primary reconstruction can be achieved in the revision setting1, 3, 10, 12. To achieve optimum results though, well-executed preoperative planning and surgical technique are critical. In this article, we detail our preferred treatment plan and discuss the technical considerations of revision surgery. PREOPERATIVE PLANNING When approaching a revision ACL reconstruction, it is especially important to create a detailed surgical plan. First, anatomic factors that might affect the outcome of the revision should be assessed. This includes the mechanical axis, associated ligamentous instabilities if any, and associated meniscus or articular cartilage damage. From a technical perspective, the operative plan should address “tunnel management,” which type of graft should be used, as well as the method of fixation. Tunnel management should include an assessment of the position and quality of the tibial and femoral tunnels as well as noting any osteolysis or presence of hardware. The preoperative work-up should include preoperative standing radiographs (Figure 1) and the previous operative note. Preoperative radiographs are useful to assess for tunnel position and widening. aMOn T. ferry, Md, SaMuel K. van de velde, Md, guOan li, phd, peTer aSniS, Md, berTraM zarinS, Md, ThOMaS J. gill, Md MassacHusetts General Hospital reviSiOn anTeriOr cruciaTe ligaMenT recOnSTrucTiOn: preOperaTive planning and Technical cOnSideraTiOnS