Medial and Lateral Meniscus Allograft Transplantation Showed No Difference With Respect to Graft Survivorship and Clinical Outcomes: A Comparative Analysis With a Minimum 2-Year Follow-Up

Purpose To compare the differences with respect to clinical and graft survivorship and patient-reported outcomes (PROs) between lateral (LMAT) and medial (MMAT) meniscus allograft transplantation. Methods Patients having a primary MAT between 1998 and 2016 were enrolled. The inclusion criteria were (1) patients who had a minimum 2-year follow-up and (2) patients who had magnetic resonance imaging (MRI) >2 years after surgery. Knees with localized grade 4 articular cartilage lesions >3 cm2 at the time of MAT were excluded. Clinical failure was defined as follows: modified Lysholm score 50% of the graft, meniscectomy to the meniscocapsular junction zone, conversion to revision MAT, or realignment osteotomy or arthroplasty. Graft failure was defined as follows: tears involving >50% of the graft or unhealed peripheral rim observed on MRI. Kaplan–Meier survival analysis with log-rank test was used to compare survivorship between LMAT and MMAT. Patient-reported outcomes were compared based on the Hospital for Special Surgery, modified Lysholm, and International Knee Documentation Committee subjective scores collected preoperatively and at the final follow-up. Results A total of 299 knees (249 LMAT, 50 MMAT, mean age 33.0 ± 9.8 years) were included. Twenty clinical [2 MMAT (4.0%), 18 LMAT (7.2%)] and 24 graft [2 MMAT (4.0%), 22 LMAT (8.8%)] failures were identified. The mean clinical follow-up period was 63.1 ± 43.1 months (range 2 to 248), and MRI follow-up period was 62.6 ± 43.8 months (range 2 to 248). No significant differences in clinical and graft survivorship were found between the LMAT and MMAT groups (P = .481, P = .271, respectively). PROs preoperatively and at last follow-up also showed no significant difference between the groups. Conclusion No significant differences in clinical survivorship, graft survivorship, and PROs were found between the LMAT and MMAT groups. Level of evidence Level III, retrospective comparative study.