TIBIAL BONE-DENSITY LOSS IN SPINAL-CORD INJURED PATIENTS - EFFECTS OFFES EXERCISE

A group of 37 spinal cord injured (SCI) patients underwent bone densit y measurements at the distal and proximal end of the tibia by a specia l computed tomography scanner, the OsteoQuant(R). Fifteen of these pat ients had follow-up measurements while enrolled in a lower-limb exerci se training program with functional electrical stimulation (FES). The pre-exercise measurements revealed a strong correlation (0.88 less-tha n-or-equal-to r less-than-or-equal-to 0.90) of trabecular, subcortical , and cortical bone density between the distal and proximal ends of th e tibia. The expected bone density loss during the first two years pos t injury (as calculated from the regression lines of bone density vs. time post injury) amounted to 51.5% for trabecular, 44.2% for subcorti cal, and 32.7% for cortical bone. No major bone density loss was calcu lated after 7 years post injury. Analysis of the bone density data dur ing the FES exercise program revealed various degrees of loss. However , the rate of bone loss for this FES exercise group was less than expe cted from the regression lines. The reduction of bone loss was between 0.2 and 3.3% per year, and was significant (p < 0.05) for all bone pa rameters at the distal end and for trabecular bone density at the prox imal end of the tibia. These bone density measurements revealed a pote ntially positive effect of FES exercise intervention for the rehabilit ation of SCI patients.