The significance of preoperative radiographic measurements on patient-reported outcome following anatomic total shoulder arthroplasty

Abstract

Background: Limited data exist on the impact of radiographic measurements in patient-reported outcomes after anatomic total shoulder arthroplasty (aTSA). The aim of this study was to investigate the association between outcomes following aTSA and the patient's preoperative and postoperative radiographic parameters, including the greater tuberosity angle (GTA), the acromiohumeral center edge angle (ACEA), and the critical shoulder angle (CSA). Methods: This retrospective study involves patients who underwent primary aTSA with a minimum 2-year follow-up. Patients were identified through data stored in a prospectively collected database at our institution. Patients completed American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores preoperatively and at 2-year follow-up. Before and after surgery, all radiographic parameters were also assessed by 2 independent reviewers using radiographs. Data were analyzed as continuous measurements and in groupings based on radiographic parameters (67° for GTA, 18° for ACEA, and 30° for CSA measurement). Correlations between significant parameters and clinical outcomes were calculated using the Pearson correlation coefficient. Significance was defined as P < .05. Results: A total of 86 patients were included. Preoperatively, the GTA measurement (67.3° ± 4.7°) was significantly more than postoperative (62.5° ± 6.3°, P < .001). The higher preoperative GTA group (GTA ≥ 67°) had a significantly better postoperative ASES score, 92.1 ± 8.9, compared to the lower group (GTA < 67°), 81.7 ± 16.2, P < .001. Furthermore, a positive significant correlation existed between preoperative GTA values and postoperative ASES scores (r = 0.32, P = .003) with better outcomes associated with higher preoperative GTA values. No difference existed in the postoperative patient-reported outcomes based on postoperative GTA, preoperative and postoperative ACEA, and CSA parameters. Conclusion: Our study identified a significant association at short-term follow-up between preoperative GTA measurements and clinical outcomes in patients who underwent aTSA. Consequently, GTA values may be helpful when making preoperative assessments and discussing postoperative outcome following aTSA.