2014-09-01, Rosso, Claudio, Müller, Sebastian, Buckland, Daniel M., Schwenk, Tanja, Zimmermann, Simon, de Wild, Michael, Valderrabano, Victor

All-inside arthroscopic meniscal repairs are favored by most clinicians because of their lower complication rate and decreased morbidity compared with inside-out techniques. Until now, only 1000 cycles have been used for biomechanical testing. Hypothesis: All-inside meniscal repairs will show inferior biomechanical response to cyclic loading (up to 100,000 cycles) and load-to-failure testing compared with inside-out suture controls. Study Design: Controlled laboratory study. Methods: Bucket-handle tears in 72 porcine menisci were repaired using the Omnispan and Fast-Fix 360 (all-inside devices) and Orthocord 2-0 and Ultrabraid 2-0 sutures (matched controls). Initial displacement, displacement after cyclic loading (100, 500, 1000, 2000, 5000, 10,000, and 100,000 cycles) between 5 and 20 N, ultimate load to failure, and mode of failure were recorded, as well as stiffness. Results: Initial displacement and displacement after cyclic loading were not different between the groups. The Omnispan repair demonstrated the highest load-to-failure force (mean 6 SD, 151.3 6 21.5 N) and was significantly stronger than all the other constructs (Orthocord 2-0, 105.5 6 20.4 N; Ultrabraid 2-0, 93.4 6 22.5 N; Fast-Fix 360, 76.6 6 14.2 N) (P \ .0001 for all). The Orthocord vertical inside-out mattress repair was significantly stronger than the Fast-Fix 360 repair (P = .003). The Omnispan (30.8 6 3.5 N/mm) showed significantly higher stiffness compared with the Ultrabraid 2-0 (22.9 6 6.9 N/mm, P \ .0001) and Fast-Fix 360 (23.7 6 3.9 N/mm, P = .001). The predominant mode of failure was suture failure. Conclusion: All-inside meniscal devices show comparable biomechanical properties compared with inside-out suture repair in cyclic loading, even after 100,000 cycles. Clinical Relevance: Eight to 10 weeks of rehabilitation might not pose a problem for all repairs in this worst-case scenario.