Poster 330: Graft Selection and Lateral Augmentation in Revision ACL Reconstruction: Experience of a Large Tertiary Academic Center

Abstract

Objectives: Primary purpose of this study was to assess failure rates in revision ACL reconstruction and to determine the influence of graft selection and lateral augmentation procedures. A secondary purpose was to identify a subset of patients for whom reconstruction with allograft yields equivalent failure rates to autograft. Methods: This was a retrospective study at a tertiary academic medical center. The electronic medical record was queried for current procedural terminology codes for ACL reconstructions (29888) from June 2011 – October 2022. Data was reviewed to ensure that only revision ACL reconstructions were included. Demographic information including age, gender, and BMI were obtained from the EMR query as well. Graft types used and lateral augmentation procedures performed were identified through manual review of operative notes. Failure rates were recorded based on documentation of ACL graft re-tear in the database. Results: Three-hundred thirty patients who underwent revision ACL reconstruction at our institution were included in the final analysis. Patients were 30.2% female with a mean age of 31.9 years (SD 10.5). Mean follow up was 21.7 months (SD 25.8). Overall re-tear rate at final follow up was 6.7%. Lateral augmentation procedures were performed in 42.1% of patients (48.2% anterolateral ligament reconstruction [ALL], 51.8% lateral extraarticular tenodesis [LET]). The most common graft types were bone patella bone (BTB) allograft (40.3%) and BTB autograft (36.1%). Other graft types included quadriceps tendon autograft (6.4%), hamstring tendon allograft (5.2%), hamstring tendon autograft (4.5%), tibialis anterior allograft (4.2%), Graftlink allograft (1.5%), quadriceps tendon allograft (1.5%), and Achilles tendon allograft (0.3%). Age, gender, and BMI were not significantly different between patients who retore their ACL graft vs. those who did not (p> .05). Patients who underwent a LET procedure had significantly lower failure rates (0%) than those who underwent an ALL reconstruction (10.4%) or no lateral augmentation procedure (7.9%), (p=.029). Failure rates for the three most common grafts used are shown in Figure 1. The rate of re-tear was significantly higher in patients who underwent reconstruction with allograft as compared to autograft (10.3% vs. 2.6%, p=.007). When only patients above 40 years of age were analyzed (n=67), the rate of re-tear was not significantly different in patients who underwent reconstruction with allograft as compared to autograft (8.8% vs. 10.0%, p=.999). There was a higher proportion of patients over 40 with allograft who underwent LET (22.8% vs. 10.0%), but this was not statistically significant (p=.675). Among patients under 40 who underwent reconstruction with allograft, a lower proportion of patients who had a re-tear underwent LET than those who did not re-tear (0% vs. 16.3%), but this was not statistically significant (p=.210). Conclusions: Overall re-tear rates were higher in patients who underwent revision ACL reconstruction with allograft. However, in older patients who may be less active, re-tear rates were comparable for allograft and autograft. Additionally, patients who underwent lateral extraarticular tenodesis had lower re-tear rates. Careful consideration of patient demographics and clinical characteristics is necessary for graft selection and indication for lateral augmentation in revision ACL reconstruction.