Background: In our previous study, iatrogenic capsular tears, bone bruises of the humeral head, and labral tears were detected on magnetic resonance imaging (MRI) performed 1 week after manipulation following ultrasound-guided cervical nerve root block in patients with frozen shoulder 6 months after manipulation.
Methods: We studied 25 patients with frozen shoulder. MRI was performed before, 1 week after, and 6 months after manipulation. On the basis of the course of MRI findings over a period of 6 months, the patients were divided into 2 groups: those with MRI findings of bone bruises, capsular tears, and/or labral tears (19 patients) and those with no MRI findings (6 patients). The clinical outcomes of the 2 groups at 6 months after manipulation were compared using the Wilcoxon matched-pairs test, the Mann-Whitney test, and the Fisher exact probability test for statistical analysis.
Results: At 1 week after manipulation, 96% of patients had capsular tears, 40% had bone bruises, and 20% had labral tears; these percentages had decreased at 6 months after manipulation to 4%, 20%, and 8%, respectively. No significant differences in clinical outcomes were noted between patients with residual MRI findings 6 months after manipulation and those without any MRI findings.
Conclusion: Most of the iatrogenic capsular tears, bone bruises, and labral tears detected 1 week after manipulation had disappeared 6 months later. Residual MRI findings 6 months after manipulation had no significant correlation with clinical symptoms.
Keywords: Frozen shoulder; MRI findings; bone bruise; capsular tear; labral tear; manipulation.