Safety evaluation of a laxity-minimizing suture at 5 days and 6 weeks after repair of a sheep infraspinatus tendon

Background: The ideal rotator cuff repair achieves high initial fixation strength and secure tendon-to-bone apposition until biological healing occurs. A suture that reacts to the local stress environment by minimizing suture laxity across the repair could theoretically maintain soft-tissue apposition to bone and therefore improve healing.

Methods: By use of an in vivo ovine shoulder model, the infraspinatus tendon was transected and then repaired with either a laxity-minimizing suture or a traditional high tensile suture. The purpose of this study was to evaluate both sutures' safety at 5 days and 6 weeks after repair.

Results: The macroscopic and microscopic analyses of the repair sites showed similar amounts of surgical trauma. There was no evidence of cheese wiring or tissue necrosis of the repaired tendons for either suture. There was no evidence of systematic toxicity in any animal. The maximum gap between cut edges of the tendon for repairs with the predicate suture was approximately twice the gap for the laxity-minimizing suture.

Conclusion: The laxity-minimizing suture was as safe at 5 days and 6 weeks as the predicate suture. Neither suture contributed to local tissue damage or particle generation leading to adverse systematic consequences. An additional observation was that the maximum gap between cut edges of the tendon for repairs with the predicate suture was approximately twice the gap for the laxity-minimizing suture.