UPPER EXTREMITIES BONE DENSITY AFTER SPINAL CORD INJURY MEASURED BY HIGHLY SENSITIVE PERIPHERAL QUANTITATIVE COMPUTED TOMOGRAPHY 632

Loss of bone mineral density after spinal cord injury (SCI) is known as disuse osteoporosis. This is caused by immobilization and is associated with rapid loss of trabecular bone. Four spinal cord injured male patients (age 27 to 55) underwent cortical and trabecular bone density measurements at the distal end of the radius and ulna of the non-dominant arm by highly sensitive peripheral quantitative computed tomography (pQCT; reproducibility in mixed collectives 0.3%). The level of their medullary lesion was between C4 and T11. Bone density was measured 5, 10, 15, 20, and 25 weeks after SCI. During this time, three patients took actively part in a rehabilitation program(occupational therapy, weight training for upper body, standing), while one patient was completely immobilized. The cortical bone density of radius and ulna did not change (± 0.5% of the first measurement) after 25 weeks in all four individuals. After the same time, the trabecular bone mass of ulna and radius changed only sightly in the three active patients (± 1.5% and ± 2.5%, respectively). However, in the immobilized patient the trabecular bone density decreased linearly by 44% in radius and by 5.5% in ulna. These results suggest that active participation in a rehabilitation program probably prevents a decrease in trabecular bone mineral density in upper extremities in SCI patients.