Association of Subacromial Bursa Characteristics With Preoperative Nocturnal Pain and the Efficacy of Surgical Treatment for Pain Relief: A Prospective Cohort Study

Background: Nocturnal pain is a common symptom in patients with subacromial bursitis (SAB), yet its underlying determinants and optimal management remain unclear. Purpose: To evaluate the impact of bursal pathological and morphological features on nocturnal pain and the effectiveness of arthroscopic bursectomy. Study Design: Cohort Study; Level of evidence, 2. Methods: A total of 130 patients were initially enrolled for arthroscopic surgery between January and July 2025. Five patients were lost to follow-up, leaving 125 patients for analysis. Preoperative baseline characteristics and intraoperative bursal features—including morphological classifications (filamentous, reticular, septate, and fullness type) and pathological types (hyperemic and fibrofatty)—were recorded. Nocturnal pain was assessed using the visual analog scale preoperatively and at 4 and 12 weeks postoperatively. Data were analyzed using Friedman and Gamma regression tests. Results: Nocturnal pain declined substantially after arthroscopic bursectomy, with clear improvements from preoperative assessment to 4 and 12 weeks postoperatively. Fullness-type bursal morphology was associated with significantly greater pain burden, showing a 22% increase compared with the filamentous reference type, whereas reticular and septate morphologies did not differ significantly. Pathological findings were strongly related to symptom severity. Compared with patients exhibiting no pathological features, those with “both positive” pathology reported 29% higher pain scores, followed by fibrofatty (16% higher) and hyperemic pathology (13% higher). No meaningful associations were observed for patient age, sex, or body mass index. Conclusion: Hyperemic, fibrofatty, and “both positive” pathological features, as well as fullness-type bursal morphology, are strongly associated with higher nocturnal pain in patients with SAB. Arthroscopic bursectomy yields rapid and sustained symptom relief, supporting its role as an effective treatment option for patients who do not respond to conservative management.