Tendon Stapler Device Versus Traditional Suture Repair for Flexor Tendon Injuries: A Biomechanical Comparison

BACKGROUND: Flexor tendon injuries remain a challenge for hand surgeons. The constraints of the pulley system with the need for a strong repair require a delicate balance. Suture repair has been the gold standard. The 4-strand locked cruciate stitch is the technique of choice for many. This can be laborious and technically difficult. Tendon stapler devices (TSDs) aim to provide fast, strong, low-profile repairs. Industry data have shown stronger TSD repairs compared with suture repair techniques. We aim to further explore the relative strengths of TSD and 4-strand locked cruciate repairs in cadavers. METHODS: Twenty-four flexor tendons were used for 12 suture repairs and 12 TSD repairs. Four-strand locked cruciate repairs used 3-0 braided composite suture. The TSD repairs used CoNextions devices. Specimens were analyzed on a uniaxial load frame and distracted at 0.5 mm/s. Tension was recorded at 100 Hz. A camera system measured reference point positions at 10 Hz. Maximum tension and tension at 2-mm gap formation were recorded. Independent t-tests were used to compare groups, with significance noted by P < .05. RESULTS: Load to failure for the staple group and suture group were 70.6 ± 20.5 N and 49.9 ± 14.1 N, respectively. Load to 2-mm gap for the staple group and the suture group were 57.5 ± 21.1 N and 38.6 ± 13.7 N, respectively. Mean load to failure and load to 2-mm gap were significantly greater in the TSD group. CONCLUSIONS: In this study, TSD repairs were stronger than the 4-strand locked cruciate suture repair. Further clinical studies and cost analyses are necessary to support their widespread use.