Improved Rotator Cuff Footprint Contact Characteristics With an Augmented Repair Construct Using Lateral Edge Fixation.

BACKGROUND

The transosseous-equivalent (TOE) rotator cuff repair construct has become the gold standard for the repair of medium and large rotator cuff tears. Repair failure, however, continues to be a problem. One contributing factor may be the inability of the TOE repair to replicate the native footprint contact characteristics during shoulder movement, especially in rotation. This results in higher strain across the repair, which leads to gapping and predisposes the construct to failure. In an effort to better reproduce the native compression forces throughout the footprint, an augmented TOE construct supplemented with lateral edge fixation is proposed, and the contact characteristics were compared with those of the gold standard TOE construct.

HYPOTHESIS: The augmented TOE repair will demonstrate improved footprint contact characteristics when compared with the classic TOE repair.

STUDY

DESIGN

Controlled laboratory study.

METHODS

Ten fresh-frozen cadaveric shoulders underwent supraspinatus repair using both the classic TOE double-row construct and the augmented TOE repair. For the augmented repair, 2 luggage tag sutures were used to secure the lateral edge and incorporated into the lateral row anchors. A Tekscan pressure sensor (Tekscan Inc) placed under the repaired tendon was used to collect footprint contact area, force, peak pressure, and contact pressure data for each construct.

RESULTS

The augmented construct demonstrated significantly greater contact forces (average difference, 4.9 N) and significantly greater contact pressures (average difference, 23.1 kPa) at all degrees of abduction and all degrees of rotation. At 30° of internal and 30° of external rotation at both 0° and 30° of shoulder abduction, the augmented construct demonstrated significantly greater peak contact pressures.

CONCLUSION

The augmented construct showed superior contact characteristics when compared with the classic TOE technique. The addition of lateral edge fixation to the classic TOE repair significantly improves bone-tendon contact characteristics with minimal additional surgical effort.

CLINICAL RELEVANCE: The results of this study indicate that lateral augmentation of the classic TOE repair produces a biomechanically superior construct that may optimize tendon healing.