In Vitro Analysis of Rotator Cuff Repairs: A Comparison of Arthroscopically Inserted Tacks or Anchors With Open Transosseous Repairs Anikar Chhabra, M.D., Vipool K. Goradia, M.D., Eric I. Francke, M.D., Geoffrey S. Baer, M.D., Tim Monahan, M.D., Alex J. Kline, B.S., and Mark D. Miller, M.D. 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  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) arthro- scopic 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). Addition- ally, 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. Key Words: Rotator cuff tears—Absorbable anchors—Absorbable tacks—Cyclic loading—Cadaveric model. T raditionally, the gold standard for rotator cuff repairs has been the open transosseous suture repair. More recently, arthroscopic and arthroscopi- cally assisted mini-open techniques of rotator cuff repair have become more popular. Accompanying this increase in popularity, several new arthroscopic rota- tor cuff repair devices have been designed and mar- keted. Since the introduction of the suture anchor in 1985 by Goble et al., 1 numerous permutations of the device have been developed. Among the most widely used rotator cuff repair devices currently available are cuff tacks and suture anchors. Ideally, these devices should be easy to insert, provide strength of repair equivalent to the open transosseous repair, and maintain repair strength throughout the healing process. 2 Many studies have looked at the initial ultimate tensile strength of rotator cuff repairs using suture anchors 3-6 as well as anchor pull-out strength. 3-8 More From the Department of Orthopaedics, The University of Virginia (A.C., E.I.F., G.S.B., A.J.K., M.D.M.), Charlottesville; and Orthopaedic Research of Virginia (V.K.G., T.M.), Richmond, Virginia, U.S.A. Address correspondence and reprint requests to Mark D. Miller, M.D., Department of Orthopaedic Surgery, University of Virginia, McCue Center, Box 800753, Emmet St and Massie Rd, Charlottesville, VA 22903-0753, U.S.A. E-mail: mdm3p@ virginia.edu © 2005 by the Arthroscopy Association of North America 0749-8063/05/2103-3971$30.00/0 doi:10.1016/j.arthro.2004.11.018 323 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 21, No 3 (March), 2005: pp 323-327