Poster 371: A Comparison of Fresh-frozen Tendon versus Fresh Meniscus Allograft Transplantation for Acetabular Labrum Reconstruction

OBJECTIVES: To document indications, surgical technique, and outcomes for acetabular labrum reconstruction in the initial series of cases using fresh meniscus allograft transplantation in comparison to a contemporaneous cohort of cases using fresh-frozen tendon allografts. The study was designed to test the hypothesis that patients undergoing labral reconstructions using fresh meniscus allograft transplantation would have better short-term outcomes compared to those using fresh-frozen tendon allografts based on patient-reported measures of pain and function. METHODS: With IRB approval and documented informed consent, patients were prospectively enrolled into a dedicated registry designed to follow outcomes after allograft transplant surgeries in the hip. Included patients underwent acetabular labral reconstruction for irreparable acetabular labral insufficiency between November 2015 and June of 2021 with at least 1-year of follow-up available. Cohort assignment was defined based on type of allograft used for acetabular labrum reconstruction, as follows: Fresh meniscus allograft transplant (MAT) utilized to reconstruct the acetabular labrum; Frozen tendon allograft transplant (TAT) utilized to reconstruct the acetabular labrum. Patient reported outcome measures were collected pre-operatively and at regular intervals after surgery (6 weeks, 3 months, 6 months, and then yearly). Visual analog scale for pain (VAS), Hip disability and Osteoarthritis (HOOS) junior, and Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function scores were collected via electronic data capture. Patient electronic medical records were used to obtain patient demographic, operative, complications, and re-operations data. Treatment failures were defined as any revision surgery involving the hip joint or total hip arthroplasty (THA). Patients were considered successful when they were recorded as having returned to functional activities without revision or arthroplasty at final follow-up at least one year post-operatively. Initial success rate was calculated using the formula: 100% - (%revision + %THA). Final follow up was defined at 1 year (Range = 12-81 mos; mean 34.5 mos). Fisher exact tests were used to assess for significant differences in proportions. t-Tests or rank sum tests were used to assess for significant differences between cohorts at each time point. Repeated measures analysis of variance was used to assess for significant differences within cohorts over time. Significance was set at P<0.05. RESULTS: A total of 27 patients (12 male, 15 female) were included for analysis. Mean age was 30.7 ± 9.2 years (range: 18-48) and mean body mass index (BMI) was 27.1 ± 5.4 kg/m2 (range: 20.1-44.0). Initial success rate for the entire group of 27 patients was 88.9%. Initial success rate in the TAT cohort was 80% with one patient undergoing THA at 4 months after transplantation. Initial success rate in the MAT cohort was 90.1% with two patients undergoing THA at 9 and 38 months after transplantation. Initial treatment success rates were not significantly different between cohorts (p=0.47). Treatment failure was significantly associated with concurrent femoral head OCA transplantation (p=.029, OR = 19.9). For the MAT cohort, clinically meaningful and statistically significant improvements in HOOS JR (p=.004, p=.023), VAS pain (p<.001, p=.<.001), and PROMIS PF (p=.044, p=.035) scores were noted at 1-year and final follow-up. For the TAT cohort, clinically meaningful improvements in HOOS JR and VAS pain scores were noted at 1-year but were not sustained at final follow-up. CONCLUSIONS: These data support consideration for use of fresh meniscus allografts as an option for acetabular labrum reconstruction when indicated. MAT for acetabular labrum reconstruction was associated with better short-term patient reported scores and success rate when compared to TAT, which may be related to biologic and biomechanical differences in graft types and transplantation techniques. However, only concurrent femoral head OCA transplantation was associated with a significantly higher treatment failure rate.