Biomechanical Comparison of Traditional and Locked Suture Configurations for Arthroscopic Repairs of the Rotator Cuff

Abstract

Background The optimal suture configuration for arthroscopic rotator cuff repairs is controversial. “Locked” suture configurations, which use a combination of simple and transverse suture loops, have demonstrated better fixation strength than have traditional simple and horizontal mattress techniques. Purpose To compare traditional arthroscopic suture configurations to locked arthroscopic configurations in ability to resist gap formation under cyclic loading. Study Design Controlled laboratory study. Methods Crescent-shaped defects were created at the infraspinatus tendon insertion in 32 bovine shoulders. Four arthroscopic suture configurations were tested (8 specimens in each group): simple (group 1), horizontal mattress (group 2), locked mattress (group 3), and locked inverted mattress (group 4). A metal corkscrew suture anchor doubly loaded with No. 2 Fiberwire suture was used for the repairs. A cyclic loading protocol with application of forces from 10 to 180 N for a maximum of 2500 cycles was used. The number of cycles required to form gaps of 5 mm and 10 mm was recorded. Results The locked mattress configuration (group 3) outperformed all other groups in resisting 5-mm gap formation (P <. 0001), requiring a mean of 628 cycles in comparison to 65, 193, and 197 cycles for groups 1, 2, and 4, respectively. Both locked configurations (groups 3 and 4) were superior to traditional simple and horizontal mattress configurations in resisting 10-mm gap formation. Conclusion The locked mattress suturing technique (group 3) provided the most secure tendon fixation of all arthroscopic configurations tested. Clinical Relevance The use of locked suture configurations for arthroscopic rotator cuff repairs may enhance tendon fixation and limit gap formation in the early postoperative period.