Five-year longitudinal bone evaluations in individuals with chronic complete spinal cord injury

Area of Science:

• Orthopedics
• Neurology
• Bone Metabolism

Background:

• Existing knowledge on spinal cord injury (SCI) bone changes relies heavily on cross-sectional studies, yielding controversial findings.
• Longitudinal data, especially long-term chronic studies, are scarce, limiting understanding of bone variations over time post-SCI.

Purpose of the Study:

• To investigate chronic longitudinal bone variations in individuals with complete spinal cord injury (SCI).
• To provide a clearer perception of bone density changes over an extended period following complete SCI.

Main Methods:

• Dual-energy X-ray absorptiometry (DXA) was used to assess bone status in 31 individuals with chronic, complete SCI.
• Measurements were taken at two time points, with an average interval of approximately 5 years.
• Primary analyses focused on male participants due to a small sample size of women (n=4).

Main Results:

• Significant increases in spine and hip bone mineral density (BMD) Z-scores were observed (P < 0.0001).
• Knee BMD and lower extremity bone mineral showed significant decreases, though increases were noted in a subset of participants.
• Individuals with tetraplegia exhibited significantly lower bone values and different change patterns compared to those with paraplegia (P < 0.0001).

Conclusions:

• Chronic complete SCI does not invariably lead to bone mineral density (BMD) loss; BMD gain can occur.
• The impact of SCI on BMD is site-specific and influenced by sex and level of injury.
• Findings have implications for the assessment and treatment of bone health in SCI populations.