Osteoporosis after spinal cord injury

Abstract

Immobilisation secondary to spinal cord injury (SCI) is associated with marked and rapid atrophy of trabecular bone. The purpose of this study was to evaluate bone mineral density (BMD) in both the upper and lower extremities following SCI sustained for various lengths of time and to correlate the BMD to the level of the lesion, time from injury, spasticity and serum calcium, phosphorus and alkaline phosphatase (ALP) levels. A study was undertaken in 41 SCI patients with a mean age of 35.8+12.7 years. A signi®cant di erence in BMD between upper and lower extremities of the paraplegics were found. BMD of upper and lower extremities were similar in tetraplegies. The BMD values were signi®cantly di erent when the upper extremity scores of paraplegics and tetraplegics were compared but BMD scores of the lower extremities were similar in the two groups. The decrease in BMD was less in the spastic patients when compared to the¯accid group. There was a positive correlation between time from injury and the degree of BMD de®cit in the paralysed areas. In the whole group of patients a signi®cant positive correlation was found between the duration of SCI and serum ALP levels.

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

“…5,6 A signi®cant di erence in arm bone mass between tetraplegic and paraplegic SCI has been reported by others. 5,6,13,14,33 We did not ®nd any substantial di erence in arm BMC and BMD between our two SCI groups, nor were there di erences noted when each SCI group was compared with the control population. A contributing factor to our disparity with the aforementioned studies may have been the inability to detect any signi®cant di erences in arm bone mass between our SCI participants with incomplete and complete lesions.…”

“…The level of the lesion and thus the extent of impairment of motor and sensory function is one, with tetraplegics (impairment of arms, trunk and legs 32 ) being more likely to lose bone mass throughout the skeleton than paraplegics (lower body segment paralysis 32 ). 5,6,13,14 In addition, bone mass loss may be greater in SCI individuals with complete lesions (absence of sensory or motor function below the neurological level, including the lowest sacral segment 32 ) than those SCI who sustain incomplete lesions (partial preservation of motor and/or sensory function below the neurological level, including the lowest sacral segment 32 ). 5,6 A signi®cant di erence in arm bone mass between tetraplegic and paraplegic SCI has been reported by others.…”

“…5,6,13,14 In addition, bone mass loss may be greater in SCI individuals with complete lesions (absence of sensory or motor function below the neurological level, including the lowest sacral segment 32 ) than those SCI who sustain incomplete lesions (partial preservation of motor and/or sensory function below the neurological level, including the lowest sacral segment 32 ). 5,6 A signi®cant di erence in arm bone mass between tetraplegic and paraplegic SCI has been reported by others. 5,6,13,14,33 We did not ®nd any substantial di erence in arm BMC and BMD between our two SCI groups, nor were there di erences noted when each SCI group was compared with the control population.…”

“…In spinal cord injured (SCI) however, demineralisation is also in¯uenced by the level and completeness of the spinal cord lesion, and duration of injury (DOI). 5,13,14 In the able-bodied population, exercise has been shown to have an osteogenic in¯uence, with the greatest bone mass preservation or increase at sites which are loaded intermittently. 15 ± 18 Morel et al 15 found arm BMD to be greatest in sportsmen involved in rugby, ®ghting sports, basketball, volleyball, handball and bodybuilding, and the increased bone mass in the dominant arm of tennis players is well documented.…”

Long-term changes in the tibia and radius bone mineral density following spinal cord injury

“…Some prior crosssectional studies have not demonstrated bone loss ongoing with chronic immobilization, 1,9,10 whereas several other studies suggest the opposite. 11,[28][29][30] These results underpin the need for more longitudinal data, as in this study, for determination of true changes with time for individuals with a newly acquired SCI.…”