Evaluation of Suture Abrasion Against Rotator Cuff Tendon and Proximal Humerus Bone

Abstract

This study evaluates the abrasion properties of different suture materials through the rotator cuff tendon and proximal humerus tuberosity bone. Three types of sutures were compared: monofilament polypropylene, braided polyester, and braided polyblend polyester with a polyethylene core. For soft-tissue testing, the suture was passed through the infraspinatus tendons of 11 cadaveric shoulders. The suture was cycled with a fixed load, and the migration of the suture as it cut through the tissue was measured at intervals of 5 cycles, for a total of 50 cycles. For tuberosity testing, the sutures were passed through a transosseous tunnel created in the lesser tuberosity, and the suture was cycled with a fixed load until suture failure occurred. On soft-tissue testing, the monofilament suture showed the least amount of abrasion, followed by the braided polyblend and then the braided polyester suture (cutting rate of 0.06 +/- 0.11 mm/cycle, 0.99 +/- 0.44 mm/cycle, and 1.75 +/- 0.91 mm/cycle, respectively; P < .0001). On tuberosity testing, suture breakage for the braided polyblend suture occurred at 501.3 +/- 220.4 cycles. The braided polyester and monofilament sutures broke after 256.6 +/- 120.9 and 193.5 +/- 144.8 cycles, respectively. The difference between cycles to failure of the polyblend and latter 2 sutures was statistically significant (P < .0001). This study shows increased abrasion properties for braided sutures compared with monofilament sutures, as well as different abrasion properties among different types of braided sutures. Furthermore, the braided polyblend suture showed significantly increased cycles before suture failure through a transosseous tunnel. Although development of new suture materials has increased their failure strength, further advancements in suture material design should focus on decreasing soft-tissue abrasion properties and increasing strength to suture failure when cycled through bone.