Background: All-inside meniscal repairs are performed with increasing frequency because of the availability of newly developed devices. A comparison of their biomechanical characteristics may aid physicians in selecting a method of meniscal repair.
Hypothesis: All-inside meniscal repairs will be superior to their inside-out controls in response to cyclic loading and load-to-failure testing.
Study design: Controlled laboratory study.
Methods: Sixty-six bucket-handle tears in matched porcine menisci were repaired using the Ultra FasT-Fix, Meniscal Cinch, Ultrabraid No. 0, and FiberWire 2-0 sutures. Initial displacement, cyclic loading (100, 300, and 500 cycles), and load-to-failure testing were performed. The displacement, response to cyclic loading, and mode of failure were recorded. The stiffness was calculated.
Results: The Meniscal Cinch demonstrated a significantly higher initial displacement than the other methods tested (P = .04). No significant difference was found among the methods in response to cyclic loading. The inside-out FiberWire repair demonstrated the highest load to failure (120.8 ± 23.5 N) and was significantly higher than both the Meniscal Cinch (64.8 ± 24.1 N, P < .001) and the Ultra FasT-Fix (88.3 ± 14.3 N, P = .002). It was not significantly higher than the inside-out Ultrabraid suture repair (98.8 ± 29.2 N). The inside-out FiberWire repair had the highest stiffness (28.7 ± 7.8 N/mm). It was significantly higher than the Meniscal Cinch (18.0 ± 8.8 N/mm, P = .01). The most common mode of failure in all methods was suture failure.
Conclusion: An inside-out suture repair affords surgeons the best overall biomechanical characteristics of the devices tested (initial displacement, response to cyclic loading, and load to failure). For an all-inside repair, the Ultra FasT-Fix reproduces the characteristics of its matched inside-out suture repair more closely than the Meniscal Cinch.
Clinical relevance: Inside-out sutures and all-inside devices have similar responses to cyclic loading.