Preoperative thoracic kyphosis influences clinical outcomes and joint range of motion after reverse shoulder arthroplasty: A retrospective study from the FP-UCBM shoulder study group

Background This study explores the relationship between thoracic sagittal kyphotic alignment, quantified by the Cobb angle, and postoperative shoulder function, specifically assessing whether the presence and severity of thoracic kyphosis influence clinical outcomes and range of motion (ROM) in patients undergoing reverse shoulder arthroplasty (rTSA). Methods A retrospective review was conducted on 110 patients who underwent rTSA from 2020 to 2022 at a single institution. Sagittal kyphosis was quantified on preoperative chest radiographs. Clinical outcomes were measured using the visual analog scale (VAS), constant score (CS), simple shoulder test, Single Assessment Numeric Evaluation (SANE) score, and pre- and postoperative ROM. Patients were separated into three groups based on Cobb angle severity (0–36°, 37–46°, ≥47°) and followed for a minimum follow-up of 2 years. A p-value <0.05 was considered statistically significant. Results Patients with a Cobb angle ≥47° exhibited a significant reduction in flexion (132.7° vs 149.4° for Cobb ≤36°; p = 0.031) and abduction (122.9° vs 142.1°; p = 0.035). This group also showed lower mean CSs (75.1 vs 83.3; p = 0.048). No significant differences were observed among groups in SANE or VAS pain scores. Conclusion Greater thoracic kyphosis is associated with reduced functional outcomes and diminished flexion and abduction following rTSA. These findings suggest that sagittal spinal alignment may influence postoperative shoulder performance. Level of evidence Retrospective Cohort Comparison III.