TY - JOUR
T1 - Dual-energy X-ray absorptiometry overestimates bone mineral density of the lumbar spine in persons with spinal cord injury
AU - Bauman, W. A.
AU - Schwartz, E.
AU - Song, I. S.Y.
AU - Kirshblum, S.
AU - Cirnigliaro, C.
AU - Morrison, N.
AU - Spungen, A. M.
PY - 2009/8
Y1 - 2009/8
N2 - Background: Bone mineral density (BMD) of the lumbar spine (L-spine) has been reported to be normal or increased in persons with chronic spinal cord injury (SCI). Objective: To determine BMD of the L-spine by dual-energy X-ray absorptiometry (DXA) and quantitative computerized tomography (qCT) in men with chronic SCI compared with able-bodied controls. Design: Cross-sectional, comparative study. Setting: Clinical research unit, Veterans Affairs Medical Center, Bronx, NY, USA and Kessler Institute of Rehabilitation, West Orange, NJ, USA. Methods: Measurements of the L-spine were made in 20 men with SCI and compared with 15 able-bodied controls. The DXA images were acquired on a GE Lunar DPX-IQ. The qCT images of the L-spine were acquired on a Picker Q series computerized tomographic scanner. Results: The mean ages for the SCI and control groups were 44±13 vs 42±9 years, and the duration of injury of the group with SCI was 14±11 years. There were no significant differences between the SCI and control groups for L-spine DXA BMD (1.391±0.210 vs 1.315±0.178 g/m2) or for L-spine DXA T-score (1.471±1.794 vs 0.782±1.481). L-spine qCT BMD was significantly lower in the SCI compared with the control group (1.296±0.416 vs 1.572±0.382 g/m2, P=0.05); the T-score approached significance (-1.838±1.366 vs -0.963±1.227, P=0.059). Subjects with moderate degenerative joint disease (DJD) had significantly higher T-scores by DXA than those without or with mild DJD. Conclusion: Individuals with SCI who have moderate to severe DJD may have bone loss of the L-spine that may be underestimated by DXA, reducing awareness of the risk of fracture.
AB - Background: Bone mineral density (BMD) of the lumbar spine (L-spine) has been reported to be normal or increased in persons with chronic spinal cord injury (SCI). Objective: To determine BMD of the L-spine by dual-energy X-ray absorptiometry (DXA) and quantitative computerized tomography (qCT) in men with chronic SCI compared with able-bodied controls. Design: Cross-sectional, comparative study. Setting: Clinical research unit, Veterans Affairs Medical Center, Bronx, NY, USA and Kessler Institute of Rehabilitation, West Orange, NJ, USA. Methods: Measurements of the L-spine were made in 20 men with SCI and compared with 15 able-bodied controls. The DXA images were acquired on a GE Lunar DPX-IQ. The qCT images of the L-spine were acquired on a Picker Q series computerized tomographic scanner. Results: The mean ages for the SCI and control groups were 44±13 vs 42±9 years, and the duration of injury of the group with SCI was 14±11 years. There were no significant differences between the SCI and control groups for L-spine DXA BMD (1.391±0.210 vs 1.315±0.178 g/m2) or for L-spine DXA T-score (1.471±1.794 vs 0.782±1.481). L-spine qCT BMD was significantly lower in the SCI compared with the control group (1.296±0.416 vs 1.572±0.382 g/m2, P=0.05); the T-score approached significance (-1.838±1.366 vs -0.963±1.227, P=0.059). Subjects with moderate degenerative joint disease (DJD) had significantly higher T-scores by DXA than those without or with mild DJD. Conclusion: Individuals with SCI who have moderate to severe DJD may have bone loss of the L-spine that may be underestimated by DXA, reducing awareness of the risk of fracture.
KW - Bone mineral density
KW - Degenerative joint disease
KW - Dual-energy X-ray absorptiometry
KW - Quantitative computerized tomography
KW - Spinal cord injury
KW - Vertebral body
UR - http://www.scopus.com/inward/record.url?scp=68349106701&partnerID=8YFLogxK
U2 - 10.1038/sc.2008.169
DO - 10.1038/sc.2008.169
M3 - Article
C2 - 19153590
AN - SCOPUS:68349106701
SN - 1362-4393
VL - 47
SP - 628
EP - 633
JO - Spinal Cord
JF - Spinal Cord
IS - 8
ER -