Sublesional spinal vertebral bone mineral density correlates with neurological level and body mass index in individuals with chronic complete spinal cord injuries

• Published in: Spine (Philadelphia, Pa. 1976) Pa. 1976), 2010-04, Vol.35 (9), p.958-962
• Main Authors: Wang, Yi-Chian, Wang, Yen-Ho, Ting-Fang Shih, Tiffany, Pan, Shin-Liang, Huang, Tien-Shang
• Format: Article
• Language: English
• Subjects: Activities of Daily Living; Adolescent; Adult; Body Mass Index; Bone Density - physiology; Cervical Vertebrae - diagnostic imaging; Cross-Sectional Studies; Humans; Lumbar Vertebrae - diagnostic imaging; Male; Middle Aged; Patient Selection; Radiography; Regression Analysis; Spinal Cord Injuries - diagnostic imaging; Thoracic Vertebrae - diagnostic imaging; Weight-Bearing
• ISSN: 0362-2436; 1528-1159
• DOI: 10.1097/BRS.0b013e3181bc9dc9

A cross-sectional study. Our aim was to find out the factors influencing the bone mineral density (BMD) change of sublesional spinal vertebrae in spinal cord injury (SCI) individuals. In individuals with SCI, the BMD of sublesional extremities dramatically decreases to fracture threshold because of unloading. In contrast, the BMD of sublesional spinal vertebrae is reported to be preserved. The etiology of the discrepancy is unknown. This study was performed in a university tertiary referral medical center. A total of 62 men with traumatic and neurologically complete SCI attending a special SCI clinic attached to the medical center from 2000 to 2003. Participants were prescreened using lumbosacral roentgenography to rule out heterotopic ossification and early-onset spinal degeneration. The BMD was then evaluated with dual energy radiograph absorptiometry at the thoracic spine and lumbar spine, using anteroposterior and lateral scout images. The mean age was 27.3 +/- 8.3 years and mean injury duration was 11.7 +/- 6.8 years. Lumbar spine BMD did not increase or decrease significantly after SCI. Lumbar spine BMD correlated significantly with body mass index. Thoracic and lumbar spine BMDs were significantly higher if the injury level was below T6. There were no correlations with postinjury duration, age of the subject, or level of physical activity. In men with chronic complete SCI, the long-term sublesional spinal vertebrae BMDs are significantly lower if injury levels are at T6 or above, suggesting the role of neurologic control on bone metabolism.