Arthroscopic rotator cuff repair: a biomechanical comparison of the suture-bridge technique vs. a new transosseous technique using SutureButtons(®).

BACKGROUND: The suture-bridge technique using anchors as established transosseous-equivalent technique in arthroscopic rotator cuff repair was compared to a modified transosseous technique suitable for arthroscopic cuff repair.

METHODS: In 10 fresh-frozen matched pairs of human cadaveric shoulders (mean age 67.1, SD 8.5 years), two different surgical techniques of cuff repair were tested: Group 1, using the suture-bridge technique with suture anchors, and Group 2, using two transosseous tunnels with SutureButtons(®). Lateral row fixation was performed in both groups using knotless implants. Cyclic displacement to gap formation of 2 and 5mm, linear stiffness, yield load, ultimate load, and mode of failure were recorded.

FINDINGS: Gap formation at the tendon-to-bone interface of 2mm occurred after a mean of 219.5 (SD 590.7) cycles in Group 1 and after 750.0 (SD 1566.1) cycles in Group 2. Gap formation of 5mm occurred after 2331.6 (SD 2033.9) cycles (Group 1) and 2364.5 (SD 1994.2) cycles (Group 2), respectively. The yield and ultimate loads were 316.9 (SD 114.1)N and 375.9 (SD 131.2)N in Group 1, and 311.0 (SD 97.2)N and 363.8 (SD 107.6)N in Group 2, respectively. The linear stiffness was 40.3 (SD 10.4)N/mm in Group 1, and 41.6 (SD 13.2)N/mm in Group 2. There were no statistically significant intergroup differences.

INTERPRETATION: The new transosseous technique using SutureButtons(®) achieves equivalent biomechanical properties to the established suture-bridge technique using anchors. A tendentially reduced primary gap formation may be of importance for repair healing during the early phase of rehabilitation.