A rotator cuff rupture produces permanent osteoporosis in the affected extremity, but not in those with whom shoulder function has returned to normal.

Abstract

Areal bone mineral density (BMD) and clinical status of 34 men treated surgically 9 years earlier for a rotator cuff rupture of the dominant side shoulder were determined. The BMD was measured at the lumbar spine (L2-L4) and the proximal humerus, humeral shaft, radial shaft, ulnar shaft, distal forearm, and hand of both extremities using a dual-energy X-ray absorptiometric (DXA) scanner. Thirty-four age-, height-, weight-, and profession-matched normal men (controls) were also measured. The patients' mean side-to-side BMD difference (dominant minus nondominant/nondominant x 100%) was significantly lower in the proximal humerus (patients -3.5% vs. controls +2.4%, p = 0.0002), humeral shaft (-2.6% vs. +1.6%, p = 0.0005), radial shaft (-0.4% vs. +1.9%, p = 0.0311), distal forearm (-0.2% vs. +2.4%, p = 0.0158), and hand (+2.3% vs. +4.0%, p = 0.0047). In the ulnar shaft, this difference was almost the same in the patients (-0.2%) and controls (+0.2%) (NS). Also, the lumbar spine BMD did not differ significantly between these groups (mean +/- SD = 1.098 +/- 0.148 g/cm2 in patients vs. 1.066 +/- 0.156 g/cm2 in controls). In patients, the relative BMDs of the injured extremity did not significantly associate with the size of the rupture; time delay between the injury and the surgery; type of surgery and postoperative treatment; postoperative immobilization time; follow-up time; patient's age, muscle strength or pain assessment; and subjective assessment of shoulder function. However, they strongly associated with the objective assessment of the shoulder function: the better the observed function of the shoulder, the less bone loss caused by the injury.(ABSTRACT TRUNCATED AT 250 WORDS)