Concomitant Treatment of High-Grade Cartilage Lesions Mitigates Risk of Meniscal Allograft Transplant Failure.

Purpose: To identify frequently studied significant preoperative risk factors for meniscal allograft transplantation (MAT) failure.

Methods: Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were used to conduct this systematic review. The database analysis was performed in May 2022 and included PubMed, Embrace, and Cochrane. Studies between January 1, 2000, and January 1, 2021, were reviewed with search terms, including "meniscal," "meniscus," "transplantation," "transplant," and "allograft." Twenty-one full-text manuscripts met inclusion criteria of studies assessing preoperative risk factors for MAT failure defined as either clinical failure (Lysholm <65) or surgical failure (revision, removal, or conversion to knee arthroplasty).

Results: In total, 21 studies were included, comprising 47.6% with Level of Evidence III and 52.4% with Level of Evidence IV. The analysis involved 2,533 patients, and the mean final follow-up ranged from 2.2 to 20.0 years. The presence of high-grade cartilage defects was the only factor found predictive of MAT surgical failure in the majority of studies in which it was analyzed (5/7 studies, 71.4%). Four of the 5 studies that found high-grade cartilage defects to be a predictor of MAT surgical failure did not treat all cartilage lesions, whereas the 2 studies that found high-grade cartilage defects an insignificant predictor of MAT surgical failure treated all defects at the time of MAT. For clinical failure, no risk factors were predictive of MAT failure in the majority of studies, although smoking and concomitant ligamentous or realignment procedures were significant in 1 study.

Conclusions: The presence of untreated high-grade cartilage appears to elevate the risk of surgical MAT failure; however, concomitant treatment of defects may mitigate their detrimental effect. There is no clear risk factor that consistently predicts clinical failure. Age, sex, body mass index, knee compartment, time from prior meniscectomy, femorotibial alignment (after correction), concomitant cartilage procedure, and laterality do not routinely influence MAT failure.

Level Of Evidence: Level IV, systematic review of Level III and IV studies.