Prognostic factors of shoulder manipulation under ultrasound-guided cervical nerve root block for frozen shoulder for patient with diabetes mellitus: A retrospective cohort study

INTRODUCTION: Shoulder manipulation under ultrasound-guided cervical nerve root block (MUC) gives good clinical results in patients with frozen shoulder 1 week after the procedure. However, some patients are refractory to MUC. The present study was performed to investigate the prognostic factors of MUC for frozen shoulder. METHODS: We evaluated 73 frozen shoulders (70 patients) to investigate the prognostic factors of MUC. The patients' mean age was 56.6 years, and 60% were female. The mean duration of symptoms before MUC was 8.6 months. We assessed pain using a numeric rating scale (NRS), range of motion (ROM), and the American Shoulder and Elbow Surgeons (ASES) score before and 1 year after MUC. We compared patients with an ASES score of <80 (defined as a poor clinical result) with those with an ASES score of ≥80 (good clinical result). To identify the risk factors for a poor clinical result, multiple logistic regression analysis was performed using the following variables: age, sex, duration of symptoms before MUC, diabetes mellitus (DM), initial NRS score, and initial ROM. RESULTS: The initial NRS score and the prevalence of DM were significantly greater in the poor clinical results group. Multiple logistic regression analysis revealed that DM was the only independent risk factor for a poor clinical result after MUC (odds ratio, 51; 95% confidence interval, 10.9–237; p = .01). CONCLUSIONS: DM is a negative prognostic factor of MUC for frozen shoulder, and patients with DM should be informed of this before they undergo treatment for frozen shoulder.