Bone mineral density differences between paraplegic and quadriplegic patients: a cross-sectional study

Abstract

Study design: This cross-sectional study was conducted by comparing bone mineral density (BMD) of paraplegic and quadriplegic patients. Objectives: The purpose of this study was to investigate the relationship between the bone mineral loss and injury level in spinal cord injury patients. Settings: Experiments were conducted at Yoneda Hospital and Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan. Methods: Lumbar spine (L2-4), proximal femur (femoral neck, trochanter region and Ward's triangle) and whole body BMD were measured in ten paraplegic and ten quadriplegic patients using dual-energy X-ray absorptiometry (DXA, HITACHI BMD-1X). Results: Signi®cant di erences were observed in the lumbar spine, trochanter region and upper extremities BMD between paraplegic and quadriplegic patients (P50.05, P50.05 and P50.01, respectively), but not in the femoral neck, Ward's triangle, head, pelvis, lower extremities or whole body BMD. Conclusion: These results suggest that the injury level in¯uences on the lumbar spine, upper extremities and trochanter region BMD. From a biomechanical standpoint, it is possible to explain that the di erences in mechanical loading exerted on bones also a ected the di erence of lumbar spine BMD in the two groups.

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

“…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.…”

“…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.…”

“…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.…”

“…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.…”

“…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.…”