Purpose: The goal of the study was to compare the primary fixation strength of transosseous suture, suture anchor, and hybrid repair techniques for rotator cuff repair.
Type of study: Animal model experiment.
Methods: Thirty-two sheep shoulders were divided into 4 homogeneous groups, according to bone density and tendon dimensions. Infraspinatus tendons were transected from their insertions and reattached using 4 different techniques. Group 1 was repaired with a single Mason-Allen stitch and 2 transosseous tunnels for each end of the suture, knotted on the lateral cortex of proximal humerus; group 2 was repaired with double Mason-Allen stitches and 2 transosseous tunnels; group 3 was repaired with 2 Corkscrews (Arthrex, Germany); and group 4 was repaired with 2 Corkscrews combined with a single Mason-Allen transosseous suture. All specimens were tested for their fixation strengths with a material testing system.
Results: The mode of failure in group 1 was mainly suture breakage. In groups 3 and 4, the tendons pulled out from the sutures. In group 2, sutures broke the bony bridge between the 2 tunnels. The mean load to failure value was 160.31 +/- 34.59 N in group 1, 199.36 +/- 11.73 N in group 2, 108.32 +/- 15.98 N in group 3, and 214.24 +/- 28.52 N in group 4. Anchor fixation was significantly weaker compared with other groups (P <.001). Combination of a transosseous suture and anchor fixation (group 4) was significantly stronger than the single transosseous suture (group 1) and double anchor techniques (group 3) (P <.001).
Conclusions: Hybrid technique was the strongest among the tested rotator cuff repair techniques. With the addition of one transosseous suture to two anchors, the strength of the repair could be doubled.