Purpose: Suture technique, suture material, and the number of strands all play critical roles in achieving optimal strength of flexor tendon repairs. We evaluated the contribution to the tensile strength of flexor tendon repair using the strongest suture material, Fiberwire, and the best surgical technique (locking configuration) using 2- and 4-strand core repair to see what factor played the most important role in tendon repair.
Methods: Human cadaver flexor tendons were harvested and repaired in a randomized fashion using locking configuration as derived from Pennington's report. Ten tendons per group were repaired using either 4-0 Fiberloop, 4-0 Fiberwire, or 2-0 Fiberwire. During load-to-failure testing, visible gap force and maximum tensile strength were statistically analyzed.
Results: All flexor tendon repairs failed by suture pullout. The 4-strand 4-0 Fiberwire double-Pennington repair was found to be significantly stronger than the 4-strand 4-0 Fiberloop single-Pennington repair. When the 2-strand repair (2-0 Fiberwire) was compared to the 4-strand single-Pennington repair (4-0 Fiberloop), there was no significant difference found.
Conclusions: The suture strand configuration rather than the strict number of strands or the strength of the suture material yielded the maximum tensile strength with reduced gapping at the repair site.