Meniscal Allograft Transplantation: The Effect of Cartilage Status on Survivorship and Clinical Outcome

Purpose To evaluate the survivorship of meniscal allograft transplantations (MATs), their clinical outcomes, and to compare the effect of perioperative cartilage status on survivorship. Method A consecutive series of MATs with a minimum postsurgical time of 4 years were included from a prospectively collected database from 2001 to 2015. Mechanical failure was defined as transplant removal or knee arthroplasty. The effect of peri-operative cartilage status on survivorship was analyzed using a Kaplan-Meier analysis. Also, pre- and postoperative outcome scores were evaluated. The clinical outcome tools used were the Lysholm Knee Scoring Scale, Tegner Activity Level Scale, Oxford Knee Score (OKS) and International Knee Documentation Committee (IKDC) subjective knee form. Results The mean (±SD) postsurgical follow-up (n = 45 MATs, 43 knees) was 8.6 ± 3.4 years. Among the 45 MATs, 31 had an Outerbridge Cartilage Score (OCS) of 3 to 4. Eight transplants (17.7%) failed at an average of 6.1 ± 4.4 years postoperatively, and all occurred in patients with an OCS of 3 to 4. Functional outcomes showed significant improvement in the Lysholm by 17.7 points (95% confidence interval [CI], 8.5-26.9, P P  = .031), and IKDC scores by 15.6 (CI, 6-25.2, P  = .001). However, the Tegner score improvement by 0.6 was not statistically significant (CI, 0.3545-1.6212, P  = .2). In a subanalysis, the OCS 3-4 group had a significant improvement in all the clinical outcomes except the Tegner score. In the OCS 0-2 group, the Lysholm and Tegner significantly improved, whereas the improvement in the OKS and IKDC was not significant. Conclusions MAT is a viable and effective surgical option for the painful meniscus-deficient knee, with good survivorship and functional outcomes in the medium to long term. Mechanical failure is associated with advanced OCS. Patients with minimal cartilage damage have improved MAT survivorship but both groups benefit clinically. Level of Evidence Level IV, case series.