Gap formation in a transosseous rotator cuff repair as a function of bone quality

Abstract

Background: The transosseous approach has been well known for a long time as a valid repair approach. Over time, various criticisms have been raised over this technique principally classifiable in two main categories: technical difficulty and related reproducibility in an arthroscopic environment, and repair stability (in the suture-bone contact area). About cyclic performance, several authors have conceived test setups with the aim of simulating a real environment in dynamic load conditions. The aim of this study was to monitor gap formation in a cyclic test setup.

Methods: The performance (measured as gap formation) has been monitored as a function of bone density to verify the effect of the latter. The test blocks have been shaped using sawbones® test bricks (Malmo, Sweden) of different densities, and the following values have been tested: 10, 15, 20, 30 and 40pcf.

Findings: The comparison has been made between the two groups: traditional transosseous and new approach with an interposed device. Regarding the traditional transosseous approach in a 10-pcf environment, not even the first loading cycle was completed, the whole bone bridge was destroyed in the first loading ramp and no further loading capability was present in the repair. By increasing the block density, the surface damage in the suture-block contact decreased.

Interpretation: With this work, it has been demonstrated how the traditional transosseous approach is strongly influenced by the bone quality up to the point where, in certain conditions, a safe and reliable repair is not guaranteed.

Keywords: Biomechanics; Cyclic loading; Rotator cuff; Shoulder; Transosseous.