Effect of Acupuncture at Myofascial Trigger Points Combined with Injection on Pain and Shoulder Function in Patients with Periarthritis of the Shoulder: A Retrospective Cohort Study

Objective: This study aimed to observe the clinical efficacy of acupuncture at myofascial trigger points (MTrPs) combined with periarticular shoulder injection (PSI) in the treatment of periarthritis of the shoulder (PS) and to evaluate its effects on pain relief and functional recovery. Methods: A retrospective analysis was conducted on 75 patients diagnosed with PS at our hospital from January 2024 to December 2025. Patients were divided into two groups based on treatment received: the observation group ( n = 38) received acupuncture at MTrPs combined with PSI, and the control group ( n = 37) received PSI alone. Both groups underwent a 4-week treatment course. Outcome measures included the visual analog scale (VAS) for pain, Constant–Murley shoulder score (CMS) for functional assessment, and shoulder range of motion (ROM) in flexion, abduction, and external rotation. Measurements were taken at baseline, 2 weeks, 4 weeks, and 3 months posttreatment. Adverse events were recorded. Results: Both groups showed significant improvements in all outcome measures compared to baseline ( P < 0.05). The observation group demonstrated superior outcomes compared to the control group at 4 weeks and 3 months posttreatment. At 3-month follow-up, VAS scores were 1.8 ± 0.7 in the observation group versus 2.6 ± 0.9 in the control group ( P < 0.001); CMS scores were 86.4 ± 7.2 versus 78.5 ± 8.1 ( P < 0.001). ROM improvements were significantly greater in the observation group for all measured directions ( P < 0.05). The total effective rate was 94.7% in the observation group and 83.8% in the control group ( P < 0.05). No serious adverse events were reported. Conclusion: In this retrospective cohort study, acupuncture at MTrPs combined with PSI was associated with greater pain relief and functional improvement compared to injection alone, with a favorable safety profile. These findings suggest a potential synergistic benefit that warrants confirmation in randomized controlled trials.