Clinical Outcomes of Medial Meniscal Allograft Transplantation With or Without High Tibial Osteotomy: A Case-Control Study Up to 8 Years of Follow-up

Background: Satisfactory clinical results of meniscal allograft transplantation (MAT) have been reported in recent years. However, it remains unclear whether the clinical outcomes of MAT when combined with an osteotomy are inferior to those of isolated MAT. Purpose: To compare the survival rates and clinical outcomes of patients who received isolated medial MAT with those of patients undergoing medial MAT combined with high tibial osteotomy (HTO). Study Design: Cohort study; Level of evidence, 3. Methods: A total of 55 patients underwent arthroscopic medial MAT using the soft tissue technique and HTO (mean age, 41.3 +/- 10.4 years; 9 female); after fuzzy case-control matching on demographics, 55 controls who underwent isolated medial MAT were also included. Survival analyses were performed using the Kaplan-Meier method with surgical failure, clinical failure (Lysholm score, <65), and reoperation as endpoints. Subjective clinical scores were collected preoperatively and at the final follow-up. Results: The mean follow-up time was 5.4 years, up to 8 years. All outcomes significantly improved at the last follow-up (P < .001). No differences were identified between MAT and MAT + HTO groups preoperatively and at the last follow-up (P > .05). At the final follow-up, 8 of 55 (14.5%) of the MAT + HTO patients and 9 of 55 (16.4%) of the MAT patients had a Lysholm score <65 (P = .885). Overall, 90% of the patients declared they would repeat the surgery regardless of the combined procedure. Surgical failure was identified in 6 of 110 (5.5%) patients: 5 of 55 (9.1%) in the MAT + HTO group and 1 of 55 (1.8%) in the MAT group (P = .093). Clinical failure was identified in 19 of 110 (17.3%) patients: 11 of 55 (20%) in the MAT + HTO group and 8 of 55 (14.5%) in the MAT group (P = .447). A significantly lower survivorship from surgical failure was identified in the MAT + HTO group (hazard ratio, 5.1; P = .049), while no differences in survivorship from reoperation and clinical failure were identified (P > .05). Conclusion: Patients undergoing medial MAT + HTO showed similar clinical results to patients undergoing isolated medial MAT at midterm follow-up, and thus a surgically addressed malalignment does not represent a contraindication for medial MAT. However, the need for a concomitant HTO is associated with a slightly higher failure rate over time.