Bone Mineral Density and Indexes of Bone Metabolism in Spinal Cord Injury

Abstract

We evaluated the pattern of osteoporosis after spinal cord injury, determined the time-frame of the changes, and elucidated the relationship among parathyroid hormone levels, biochemical markers of bone formation, and the pattern of bone mass loss. We included 176 subjects with spinal cord injury and 62 subjects without spinal cord injury as controls in the study. Bone mineral density of the spine and the proximal femur was measured. The participants' age, level of injury, and length of time since injury were compared with the nonspinal cord-injured controls and with each other. Serum levels of calcium, calcitonin, biochemical markers of bone formation, and parathyroid hormone were determined. Our results revealed that bone mineral density of the proximal femur declined and reached fracture threshold at one to five years after injury. The decline was detected at 12 months after injury in all age groups. Spinal bone mineral density neither declined significantly nor reached fracture threshold. Parathyroid hormone levels declined before the end of the first year postinjury and increased at one to nine years postinjury in the 20- to 39-year age group. The increase correlated with the initial decline of bone mineral density of the proximal femur. Our studies in spinal cord-injured subjects revealed a pattern of osteoporosis similar to age and parathyroid dysfunction-related osteoporosis. No other correlation was detected between indexes of bone metabolism and bone mineral density measurements.

Intensive exercise may preserve bone mass of the upper limbs in spinal cord injured males but does not retard demineralisation of the lower body

“…Our bone mass ®ndings at these sites concur with those of others. 6,13,14,37 This may attest to the homogeneity of the study populations. That is, demineralisation of the sublesional areas is consistent in SCI whether their lesions result in tetraplegia or paraplegia and are complete or incomplete, however the extent of the loss may vary.…”

“…Tetraplegics demonstrate an initial post injury loss before attaining a BMD plateau, whereas paraplegics do not show any initial loss. 37,40 No signi®cant di erences have been found between tetraplegic and paraplegic SCI for BMD at the lumbar spine once this bone mass plateau has been reached. 37,40 The BMD of the lumbar spine was similar for both the tetraplegics and paraplegics in our study, and concurs with ®ndings by Szollar et al 37 but is contrary to those of Tsuzuku et al 14 The DOI of the two groups in the study by Tsuzuku et al 14 and ours may explain this di erence.…”

Energy expenditure during walking with weight-bearing control (WBC) orthosis in thoracic level of paraplegic patients

“…To this end, those on the upper and left side of the figure can be It is well known that paraplegic patients have significantly reduced V O 2 peak values as a consequence of the reduction in the daily activity levels. 19 In addition, the isolation of the upright standing and walking should lead to various secondary disorders, for example, the decrement of the bone mineral density 20,21 and malfunction of the peripheral circulation in paralyzed areas. 22 Although there is little agreement of the effect on the above point, there is no doubt that some purposeful effects should be offered by orthotic gait.…”

Implantable FES system for upright mobility and bladder and bowel function for individuals with spinal cord injury

“…Individuals with SCI have been shown to have decreased bone density, [7][8][9][10] and fractures are known as a risk for individuals with SCI who choose upright mobility. It is unlikely that the use of the FES itself contributed to the stress fracture sustained by subject 2 due to his report of greater impact on that leg prior to developing spasticity.…”