Protocol for a Retrospective Comparative Study to Determine the Effect of Two Different Biocomposite Suture Anchors on the Occurrence of Bony Ingrowth and Implant Reabsorption Following Arthroscopic Rotator Cuff Repair

INTRODUCTION: Surgical treatment of rotator cuff tears commonly entails reattachment of the ruptured tendon to its bony insertion using suture anchors. Suture anchor design has evolved from solid metal anchors to vented biocomposite anchors with potentially biologic consequences. Few studies have investigated the differences between different modern anchor design and materials, making it difficult to justify their use or cost. OBJECTIVE: To compare the rate of bony ingrowth and implant resorption between a coil-type open-architecture biocomposite suture anchor and a vented screw-type biocomposite suture anchor, used for arthroscopic double-row rotator cuff repair. METHODS AND ANALYSIS: In this retrospective comparative study, a consecutive series of patients who undergo a double row rotator cuff repair using a coil-type open architecture biocomposite suture anchor in the medial row and a vented screw-type biocomposite suture anchor in the lateral row will be included. A sample size calculation demonstrated that 16 participants are required in each group. Primary outcome measures will be bony ingrowth and reabsorption of the suture anchor as measured on computed tomography (CT). Secondary outcomes will include patient reported outcome measures (The American Shoulder and Elbow Surgeons score and The Western Ontario Rotator Cuff questionnaire), range of motion, postoperative tendon integrity, and cyst formation. HIGHLIGHTS: Open-architecture suture anchors facilitate the release of marrow constituents. The rate of bony ingrowth for coil- and screw-type anchors will be assessed. The difference in functional outcome between the two anchors will be assessed.