Outcomes and Predictors of Revision Anterior Cruciate Ligament Reconstruction: An Evaluation of the Norwegian Knee Ligament Registry

OBJECTIVES: The Norwegian Ligament Registry (NKLR) provides an opportunity for quality surveillance and research. Intraoperative findings and outcome after revision anterior cruciate ligament reconstruction (RACLR) is not as well studied as after primary ACL reconstruction. There were two objectives of this study. First, to evaluate the Norwegian Knee Ligament Registry (NKLR) for the occurrence, failure rate, graft choice, patient demographic profile (gender, age, body mass index), sport at time of injury and associated pathology (cartilage injuries, meniscal tears, other ligament injuries) for revision anterior cruciate ligament reconstructions (RACLR). Second, to match compare RACLR patients to primary ACL reconstructions in order to define possible predictors for those patients who will require RACLR. METHODS: All patients identified in the NKLR from June 2004 until September 2016 that did not undergo cartilage restoration, meniscal transplant nor had a documented fracture at the primary reconstruction were included in the study. Revision rates at 1, 2 and 5 years were estimated with Kaplan-Meier analysis, and the estimated risk of RACLR based upon demographic and associated pathology was estimated with Cox regression analysis. RESULTS: 784 patients with an average age of 25.6 years (25.0-26.3) met the inclusion and exclusion criteria with 53.1% being male. 62.1% of revisions were performed with bone patellar bone (BPTB) autograft while 23% used hamstring autograft. Associated injuries of the menisci, cartilage, and other ligaments and the sport at the time of injury are listed (Table 1). 12.9% of RACLR patients went on to have a Re-revision ACLR at 5 years postop (Figure 1). Match comparisons of primary ACLR patients with RACLR demonstrated no significant difference in occurrence based upon age (<20, 20-30, and >30 years), graft choice (BPTB, Hamstring, Allograft, Bone Quadriceps Tendon (BQT)), cartilage injury (No injury, ICRS 1-2, ICRS 3-4), meniscal Injury, associated ligament injury, sport at time of injury or Body Mass Index (BMI). CONCLUSION: Based upon review of a large ligament reconstruction registry, one can expect that less than 13% of patients undergo a Re-revision ALCR following failure of a RALCR at 5 years. Match comparison of primary ACLR versus RACLR demonstrated no significant predictor of RACLR based upon age, graft choice, cartilage injury, meniscal injury, associated ligament injury, sport or BMI.