Background

Meniscus allograft transplantation (MAT) is an important treatment option for young patients with deficient menisci; however, there lacks a consensus on the optimal method of allograft fixation.

Methods

Single-arm meta-analysis of studies reporting graft failure, reoperations and other clinical outcomes following MAT was performed. Studies were stratified by method of fixation, namely suture-only, bone plug and bone bridge techniques. Proportionate rates of failure and reoperation for each fixation technique were pooled with a generalized linear mixed effects model, following which, reconstruction of relative risks with confidence intervals was performed using the Katz-logarithmic method.

Results

A total of 2604 patients underwent MATs. Graft failure rates were noted to be 6.2% (CI: 3.2% to 11.6%) for bone plug fixated allografts, 6.9% (CI: 4.5% to 10.3%) for suture-only fixation, and 9.3% (CI: 6.2% to 13.9%) for the bone bridge group. Transplanted menisci secured using bone plugs as compared to bone bridges displayed a lower risk of graft failure (RR = 0.97; 95% CI: 0.94-0.99; p=0.02), however, risks of failure were neither significantly different when comparing bone bridge to suture fixation (RR = 1.02; 95% CI: 0.99-1.06; p=0.12), nor between bone plug and suture fixation methods (RR = 0.99; 95% CI: 0.96-1.02; p=0.64). Meta-regression was performed for studies reporting failure in the suture-only fixation group, with failure rates being regressed against the meniscus laterality. Patients receiving a medial meniscus allograft transplant, secured by suture fixation, was associated with an increased risk of graft failure (ß = 3.01; SE = 1.27; p=0.02). In terms of the risk of reoperation following MAT procedures, allografts secured using bone plugs were at a lower risk of requiring reoperations as compared to those secured using sutures (RR = 0.91; 95% CI: 0.87-0.95; p<0.0001), while those fixated using bone bridges were observed to have a higher risk of necessitating reoperations when compared to allografts fixated using either sutures (RR = 1.28; 95% CI: 1.19-1.38; p<0.001), or bone plugs (RR = 1.41; 95% CI: 1.32-1.51; p<0.0001).

Conclusion

Transplanted meniscal allografts secured using bone plugs show a lower risk of graft failure as compared to the bone bridge technique, as well as lower risks of needing reoperations than both bone bridge, and suture-only fixation. Hence, with these risk estimates, a case can be made for the use of bone-plug techniques when securing meniscal allograft transplants.