Different suture anchor fixation techniques affect contact properties in humeral greater tuberosity fracture: a biomechanical study

BACKGROUND: Suture anchor-based fixations of humeral greater tuberosity (GT) fractures have yielded good outcomes in both clinical and biomechanical studies. Be that as it may, the interface contact properties of these fixations have yet to be elaborated. In response, the contact characteristics of two double-row suture anchor fixations for the management of GT fracture were compared. METHODS: Two suture anchor-based fixation techniques, namely the Double-Row Suture Anchor Fixation (DR) and Suture-Bridge Technique (SB), were used to repair humeral GT fractures in 12 fresh-frozen human cadaveric shoulders. A Tekscan pressure sensor placed between the repaired tuberosity and humerus recorded continuous data points directly after repair and for 60 min at set time intervals. The constructs were then cyclically loaded until 100 N, and the shoulders tested at 0°, 30°, and 60° of abduction. Under an applied force, the contact pressure and contact area of the interface were determined. RESULTS: Although both fixation configurations showed decreased contact pressure and area over time, the SB group had higher contact pressure right after fixation and at all time points thereafter. In contrast, the DR group demonstrated significantly more contact pressure and area at each abduction position with the applied load. Nevertheless, contact pressure and area decreased in response to increasing abduction position for both fixation constructs. CONCLUSION: Findings suggest that despite the SB construct having superior interface contact immediately after fixation, the DR construct offered better contact performance at all abduction angles with applied force. LEVEL OF EVIDENCE: Basic Science, Biomechanics.