The role of teriparatide in tuberosity healing after reverse shoulder arthroplasty in complex proximal humeral fragility fracture

Abstract

Introduction: Tuberosity healing is known to be one of the factors that increase functional outcome in Reverse Total Shoulder Arthroplasty (rTSA). In fragility fractures, tuberosity healing is difficult to be achieved. The fragment stability and bone-forming agent application become strategies to overcome this problem. The purpose of this study was to evaluate the benefit of teriparatide application to promote tuberosity union in rTSA on four-part proximal humeral fractures to achieve better functional outcome. Methods: A retrospective study of a prospectively collected shoulder arthroplasty medical record was performed. Eleven patients were included in this analysis and consisted of two groups, teriparatide and no-teriparatide groups. Patients were evaluated on the range of motions and clinical outcome using the American Shoulder Elbow Surgeon (ASES) Shoulder Score and X-ray to determine tuberosity union. The group differences were analyzed by t -test or Mann–Whitney U test with SPSS version 20.0 for Windows. Results: The statistical analysis revealed no significant differences in mean age in both the groups. There were significant differences between teriparatide and no-teriparatide groups in external rotation (29.5° vs. 7.5°; p = 0.004), external rotation in 90° abduction (55° vs. 12.5°; p < 0.020), forward flexion (120° vs. 105°; p = 0.002) range of motions, and ASES (84.5 vs. 74.6; p = 0.019). We found clinical difference between teriparatide and no-teriparatide groups in time to achieve the initial callus (33 ± 18.3 days vs. 150 ± 42.4 days) and tuberosity consolidation (165.8 ± 70.3 days vs. 315 ± 106.1 days). Conclusions: Teriparatide administration supports tuberosity repair results in a high tuberosity healing rate with restoration of external rotation after rTSA in acute complex proximal humeral fractures.