Bone mineralization in the distal forearm of hemiplegic patients.

Bone mineral content was measured by single photon absorptiometry using a modified bone densitometer (Packard) with 125I as the source. In 42 hemiplegic subjects, matched for sex and age, the bone density was compared bilaterally on the radius and ulna 2 cm and 4 cm above the wrist. The nonparalyzed side served as a control for the paralyzed side. The results indicate a consistent, general loss of bone mineral on the paralyzed side compared with the nonparalyzed side. The extent of demineralization in females was greater than in male subjects. Right-dominant left-paralyzed patients showed a greater loss of bone density than right-dominant right-paralyzed subjects. The absorption ratio of the paralyzed vs the nonparalyzed sides revealed that there was a 5.3% and 7.4% decrease in the average bone density at 4 and 2 cm above the wrist, respectively. There was a progressive loss of bone mineral content relative to time after the onset of paralysis, amounting to an average of 6.4% approximately three months after the onset of injury. It was estimated that before the onset of paralysis there was an excess of bone mineral on the dominant vs the nondominant side of +5.4% and +3.2% for males and females, respectively.