Outcome comparison of meniscal allograft transplantation (MAT) and meniscal scaffold implantation (MSI): A systematic review

Background: Although numerous studies have reported successful clinical outcomes of Meniscal allograft transplantation (MAT) or Meniscal scaffold implantation (MSI), the difference between the outcome of MAT and MSI remains unclear. Purpose: To compare the overall outcomes and survival rates of MAT and MSI, aiming to provide comprehensive evidence for determining the optimal treatment strategy for meniscal defects. Methods: A systematic review was performed via a comprehensive search of PubMed, Embase, and the Cochrane Library. Studies of MAT or MSI were included according to the inclusion and exclusion criteria. The Lysholm score was chosen as the primary outcome measure, while secondary outcomes encompassed Patient-reported Outcome Measures (PROMs), Return to Sports (RTS) rates, survival rates, and complication rates. The outcomes were stratified into two groups: MAT group and MSI group, followed by statistical comparison (P<0.05). The quality of the included studies was assessed by the Cochrane Risk of Bias 2 (RoB2) assessment tool for randomized controlled trials (RCTs) and the Coleman Methodology Score (CMS) for non-randomized controlled trials. Results: A total of 3932 patients (2859 MAT, 1073 MSI) in 83 studies (51 MAT, 32 MSI) had the overall significant improvement in all clinical scores. The group MSI had higher Lysholm score of both preoperative (P=0.002) and postoperative (P<0.001) than group MAT; however, the mean improvements were similar between the two groups (P=0.105). Additionally, MSI had higher improvements of IKDC (P<0.001), KOOS symptom (P=0.010), KOOS pain (P=0.036), and KOOS ADL (P=0.004) than MAT. Interestingly, MAT had higher preoperative (P=0.018) and less postoperative VAS pain (P=0.006), which was more improved in MAT (P<0.001). Compared with MAT, MSI had higher 10-year survival rate (P=0.034), similar mid-term survival rate MAT (P=0.964), and lower complication rate (P<0.001). Conclusion: Both MAT and MSI could have good clinical outcomes after surgery with the similar improvement in Lysholm score. MSI had higher 10-year survival rate and less complications than MAT. Level of Evidence: IV, systematic review.