Does the Injection Environment of Intra-Articular and Radiofrequency Procedures Affect Treatment Response in Patients with Frozen Shoulder? A Retrospective Study

Aim: This study aims to investigate the effects of intra-articular injection and suprascapular nerve pulsed radiofrequency (PRF) procedures on clinical, psychological, and functional outcomes in patients with frozen shoulder based on the treatment setting (operating room vs. outpatient clinic). Materials and Methods: Data from 40 patients diagnosed with frozen shoulder were retrospectively reviewed. Procedures were performed under fluoroscopy in the operating room or ultrasonography in the outpatient clinic. Before treatment and at 1 and 3 months after treatment, patients were evaluated using the Numerical Rating Scale (NRS), Shoulder Pain and Disability Index (SPADI), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), and Central Sensitization Inventory (CSI). Patient satisfaction was also recorded. Statistical analyses included repeated measures ANOVA, t-tests, Pearson correlation, and regression modeling. Results: All scores significantly improved over time in both groups (p < 0.001). However, improvements in NRS, SPADI, BAI, and PSQI were greater in the operating room group (p < 0.05). No significant differences were found in BDI and CSI scores. Regression analysis showed that higher initial depression scores and female gender were linked to less reduction in pain. Patient satisfaction was also higher in the operating room group. Discussion: Although both settings provided clinical benefit, procedures performed with sedation and fluoroscopic guidance in the operating room led to more pronounced improvements in pain, function, anxiety, and sleep. These results indicate that setting and psychosocial factors such as depression and gender may influence treatment outcomes.