Adhesive Capsulitis of the Shoulder (Frozen Shoulder) Produces Bone Loss in the Affected Humerus, but Long-Term Bony Recovery Is Good

The objective of the study was to assess the short- and long-term effects of adhesive capsulitis (frozen shoulder) on the bone mineral density (BMD) of the affected extremity. BMD and clinical status of 22 patients (group A) with active-phase unilateral adhesive capsulitis and of 31 patients (group B) with a previous adhesive capsulitis (average 9 years before the examination) were determined. BMD was measured from the proximal humerus, humeral shaft, radial shaft, ulnar shaft, and distal forearm of both upper extremities using dual-energy X-ray absorptiometry (DXA). In group A, the mean BMD of the affected extremity, as compared with that of the unaffected side, was significantly lower in the proximal humerus (−5.6%; p = 0.001) and humeral shaft (−3.0%; p = 0.008). The radial shaft, ulnar shaft, and distal forearm showed no significant side-to-side differences. In contrast, in group B, the affected-to-unaffected side BMD differences were small and statistically insignificant. Compared with the 31 patients in group B, the relative side-to-side BMD difference of the 22 patients with active-phase disease (group A) was significantly lower in the proximal humerus (−5.6% vs. −1.5%, p = 0.009). In the other sites, groups A and B showed no significant differences. In conclusion, this study indicates that adhesive capsulitis of the shoulder results in significant bone loss in the humerus of the affected extremity, but in the long term, capsulitis-induced bone loss shows good recovery.