Older age and diabetes mellitus are negative prognostic factors for shoulder manipulation under ultrasound-guided cervical nerve root block for frozen shoulder: a retrospective cohort study.

BACKGROUND

Manipulation under ultrasound-guided cervical nerve root block (MUC) for frozen shoulder has successful clinical outcomes; however, some cases remain refractory. Therefore, we aimed to investigate the outcomes of MUC for frozen shoulder.

METHODS

We retrospectively reviewed 126 frozen shoulders in 113 patients who underwent MUC. We defined frozen shoulder as a limited shoulder range of motion (ROM) (passive forward flexion <120°, external rotation <30°, or internal rotation lower than L3). Patients who fulfilled any one of the criteria were considered to have frozen shoulder. The refractory group included patients who fulfilled any of the criteria for frozen shoulder at 12 months after MUC; those in the success group fulfilled none of the criteria. The ROM, Constant Shoulder score, and University of California, Los Angeles score were evaluated before and 12 months after MUC. Multiple logistic regression analysis was performed to identify risk factors.

RESULTS

Twelve months after MUC, both the success (n = 112 frozen shoulders in 100 patients) and refractory groups (n = 14 frozen shoulders in 13 patients) showed significantly improved ROM and functional scores. Although the groups did not differ significantly before MUC, the refractory group showed significantly inferior outcomes to the success group at 12 months after MUC. Age and the presence of diabetes mellitus (DM) were significantly higher in the refractory group than in the success group. Multiple logistic regression analysis revealed older age and the presence of DM as independent risk factors for refractory clinical outcomes. Receiver operating characteristic curve analysis showed that the cutoff value of age for refractory of MUC was 56 years.

CONCLUSION

Older age and the presence of DM are negative prognostic factors for MUC in frozen shoulder. This result may be useful when counseling patients with these conditions.