In vitro analysis of rotator cuff repairs: a comparison of arthroscopically inserted tacks or anchors with open transosseous repairs.

PURPOSE: The purpose of this study was to employ a cyclic loading protocol to compare rotator cuff repair strengths of arthroscopically inserted cuff tacks and suture anchors with the traditional open transosseous suture repair.

TYPE OF STUDY: In vitro cadaveric analysis.

METHODS: Full-thickness 1 x 3-cm rotator cuff defects were created in 25 fresh-frozen cadaveric shoulders, and were randomized to 1 of 4 repair groups: (1) open repair with transosseous sutures, (2) arthroscopic repair with 2 singly loaded suture anchors, (3) arthroscopic repair with 2 doubly loaded suture anchors, and (4) arthroscopic repair with cuff tacks. All repairs were cyclically loaded from 10 to 180 N, and the numbers of cycles to 50% (5-mm gap) and 100% (10-mm gap) failure were recorded.

RESULTS: The number of cycles to 100% failure was significantly higher for the arthroscopic doubly loaded suture anchor repairs when compared with the (1) open transosseous suture repair (P = .009), (2) arthroscopic cuff tack repair (P = .003), and (3) arthroscopic singly loaded suture anchor repair (P = .02). Additionally, the number of cycles to 50% failure was significantly higher for all anchors versus open or tack repair (P = .03 for both).

CONCLUSIONS: Immediate postoperative fixation of rotator cuff repairs with doubly loaded suture anchors was more stable than that provided by the open transosseous suture repairs, arthroscopic singly loaded suture anchors, or cuff tacks. However, additional evaluation is needed to examine the effects on the sustained strength of the repair throughout the healing process.

CLINICAL RELEVANCE: These in vitro results indicate that superior immediate postoperative fixation of rotator cuff repairs may be achieved with the doubly loaded suture anchors. However, additional evaluation is needed to examine the effects on the sustained strength of the repair throughout the healing process.