Outcomes and Risk Factors of Rerevision Anterior Cruciate Ligament Reconstruction: A Systematic Review

Purpose The purpose of this study was to systematically review the literature on rerevision anterior cruciate ligament (ACL) reconstruction, focusing on patient outcomes. The secondary aims of this study were to (1) identify risk factors that contribute to multiple ACL reconstruction failures (defined as a complete tear of a revision ACL graft with knee instability) and (2) assess concomitant knee injuries, such as articular cartilage and menisci lesions. Methods A systematic review of the literature was performed. Inclusion criteria were as follows: outcomes of rerevision ACL reconstruction, English language, minimum of 2 years of follow-up, and human studies. We excluded cadaveric studies, animal studies, basic science articles, editorial articles, surgical technique descriptions, surveys, and rerevision ACL articles in which rerevision reconstruction subgroups were not reported independently of first-time ACL revision groups. Results Six studies met the inclusion criteria and were considered for review. One was a case-control study (Level III evidence), and 5 studies were case series (Level IV evidence). Compared with preoperative scores, patient outcomes improved after rerevision ACL reconstruction. However, more meniscal and cartilage pathologies were present in rerevision cases compared with after primary and revision ACL reconstruction. Conclusions Although rerevision ACL reconstruction can restore stability and improve functional outcomes compared with the preoperative state, outcomes remained inferior when compared with primary ACL reconstructions, particularly regarding a patient's ability to return to his or her preinjury level of activity. Additional factors that place increased stress on the ACL graft, such as increased posterior tibial sagittal plane slope or undiagnosed concomitant ligament injuries, should be investigated, especially in atraumatic failures. If present, operative treatment of these factors should be considered. Level of Evidence Level IV, systematic review of Level III and IV studies.