Compression Suture Staple Repair of Simulated Gluteus Medius Partial Tendon Tears Provides Increased Contact Pressure Compared With Stepwise Bridged Repair.

Purpose: To examine the contact mechanics of 2 different suture anchor configuration constructs for gluteus medius repair in partial-thickness tears and to define an optimal distance for anchor placement in a biomechanical model. Methods: Trochanteric bone was simulated using polyurethane foam blocks, and a polyurethane rubber was used as a surrogate for the gluteus medius tendon tissue. As the rubber remained partially attached to the foam, this design simulated a partial-thickness tear without any retraction of the tendon tissue. A pressure sensor was used to collect contact data. Repairs were performed with knotless suture anchors. Three different 2-anchor repair interval distances (10, 15, and 20 mm) were first tested to define the optimal distance for anchor placement. We then performed 2 different 3-anchor repairs (stepwise bridged and compression suture staple) using the optimal distance. Pressure data were collected and compared between 3-anchor groups. Results: Results from the 2-anchor interval distance testing showed an overall significant effect for contact force ( Conclusions: In this biomechanical study, the compression suture staple technique exerted more pressure than the stepwise bridged repair technique at time 0 with no cyclic loading. Additionally, 15 mm had the greatest contact pressure of those examined for anchor placement using knotless suture anchors for these repairs. Clinical Relevance: By studying the contact mechanics of different suture anchor configurations, we determined which setup may provide better compression of the tendon onto the bone.