Mid-to long-term clinical outcomes and graft survival rates of arthroscopic meniscal allograft transplantation in young adults: a meta-analysis

Meniscal deficiency is associated with early osteoarthritis, knee pain, and functional impairment. Meniscal allograft transplantation (MAT) is commonly performed in young patients with symptomatic meniscal deficiency; however, the available evidence regarding mid- to long-term outcomes remains limited. This study aimed to systematically review and meta-analyze graft survival rates and clinical outcomes after MAT in patients aged ≤ 45 years, focusing on mid-term (5–10 years) and long-term (≥ 10 years) follow-up. A systematic literature search was performed to identify eligible studies published up to December 31, 2025. Clinical outcomes and graft survival rates after MAT in patients aged ≤ 45 years were analyzed. Changes in functional scores before and after surgery were evaluated, and pooled graft survival rates were calculated for mid-term (5–10 years) and long-term (≥ 10 years) follow-up. Subgroup analyses were performed according to graft location, preservation method, and fixation technique. Publication bias and sensitivity analyses were also assessed. Eighteen studies involving 1050 knees were included. The pooled long-term graft survival rate was 78%, with substantial heterogeneity (I² = 86.93%, p < 0.001), whereas the pooled mid-term graft survival rate was 89% with low heterogeneity (I² = 4.59%, p = 0.40). No significant differences in graft survival were observed according to meniscal compartment, graft preservation method, or fixation technique, and all subgroup analyses showed no detectable heterogeneity (I² = 0.00%). Egger’s test showed no significant evidence of publication bias ( p = 0.795), and sensitivity analyses indicated that the pooled results were stable. Postoperative Lysholm, KOOS, and IKDC scores significantly improved, whereas VAS pain scores significantly decreased. No significant change was observed in Tegner scores. In patients aged ≤ 45 years, MAT was associated with improved patient-reported outcomes and favorable mid-term graft survival. However, the long-term graft survival estimate should be interpreted cautiously because of substantial variability among studies. Graft location, preservation method, and fixation technique were not associated with significant differences in mid- to long-term graft survival.