Longitudinal study of bone mineral content in the lumbar spine, the forearm and the lower extremities after spinal cord injury

Abstract

Bone mineral content (BMC) of the lumbar spine, femoral neck and shaft, and proximal tibia was measured by dual photon absorptiometry in six men and two women after traumatic spinal cord injuries. In six of these patients, BMC of the distal forearm was measured as well. The patients were 18-49 years old at injury and had complete motor lesions from C7 to L1. All but one had some spasticity, and they all used a wheelchair. The initial BMC measurements were carried out from 9-167 days (median 43) post-injury and followed up by 5-13 (median 8) measurements up to 31-53 months (median 41) after the injury. BMC of the lumbar spine and distal forearm remained nearly unchanged in the whole period, and the measurements were within the normal range, except for the lumbar spine when Harrington rods in the scanned area induced high BMC values. In the lower extremities the BMC decreased after injury. New steady-state levels for BMC were reached at 2 years post-injury for the proximal tibia and the femoral neck at 40-50% and 60-70% respectively of normal values. For the femoral shaft the decrease in BMC was more slow and it seems that a steady-state was not reached within our observation period for several of the patients. This longitudinal study indicates, in agreement with a previous cross-sectional study, that normal muscle function and load bearing is necessary to prevent bone loss.

Effect of weight-bearing activities on bone mineral density in spinal cord injured patients during the period of the first two years

“…8 A number of studies have been conducted on weightbearing effects on bone mass at different skeletal sites. [9][10][11][12][13][14] Some studies 15,16 have shown the influence of passive weight-bearing on BMD, but these findings were not confirmed by other researchers. [17][18][19][20] The aim of the study was to assess bone loss in persons with SCI and its dependence on weight-bearing activity (passive standing) during the first 2 years post injury.…”

“…BieringFSorensen et al reported 50% BMD decrease in paralyzed extremities during 3 years longitudinal study. 14 Leg BMD of our patients reduced by 34% per 2 years, on average. Such difference may be due to the longer duration of SCI and to the method of BMD evaluationFin the aforementioned study BMD was evaluated by age-matched BMD (Z-score) and in our study datum-level was the first BMD result, accomplished on average in 11 weeks after SCI.…”

Challenges, concerns and common problems: physiological consequences of spinal cord injury and microgravity

“…Skeletal unloading in astronauts can result in a loss of as much as 1-2% per month of BMD. 89,95 On the Mir yearlong mission, bone measurements of astronauts showed a 10% reduction of lumbar vertebrae as compared with preflight. 76 Consequently, on an approximately 3-year manned mission to Mars, it is anticipated that astronauts could have significant BMD loss in select locations.…”

Frequency and age effects of secondary health conditions in individuals with spinal cord injury: a scoping review

“…[96][97][98] Course: leg BMD decreases more over time more in non-standing individuals (24%) than in standing individuals; differences became significant by the second year post injury; 38 BMD appears to achieve a steady state at 2 years post injury. 99 Obesity and high body mass index (BMI) Age: age assoc w/fatigue (older 4younger). 60,104 Duration: duration assoc w/fatigue (more duration 4less duration).…”