Peripheral quantitative computed tomography and blood biomarkers in children with spinal cord disorders.

Study design: Cross-sectional study OBJECTIVES: Spinal cord disorders (SCD) in children are uncommon, but for those affected the musculoskeletal effects can be severe. Little is known about bone health and pediatric SCD experiences in Australia. We aimed to describe bone and muscle development following pediatric SCD.

Setting: The Royal Children's Hospital, Melbourne, Australia METHODS: Ten participants with SCD were recruited and underwent peripheral quantitative computed tomography (pQCT) scans and blood tests to observe bone health biochemistry.

Results: Z-scores (mean ± SD) for trabecular density at the 4% tibial site were lower in non-weightbearing children compared to weightbearing children (-6.5 ± 1.5 vs. -2.4 ± 1.5, Total cohort: -5.0 ± 2.6). At the 66% site, muscle cross-sectional area (-4.7 ± 2.2 vs. -1.1 ± 1.7, Total cohort: -3.1 ± 2.7), strength strain index (-3.4 ± 1.3 vs. -1.0 ± 0.4, Total cohort: -2.5 ± 1.6) and total bone cross-sectional area (-2.4 ± 0.8 vs. 0.4 ± 1.7, Total cohort: -1.2 ± 1.9) were also lower in non-weightbearing children. Radial Z-scores revealed reduced total bone area at the 4% site (-3.5 ± 2.1) and strength strain index at the 65% site (-1.3 ± 1.8) in all participants. Serum testing revealed alkaline phosphatase was reduced in three participants, one of whom was also deficient in phosphate and 25-Hydroxyvitamin D.

Conclusions: Weightbearing status influenced multiple outcomes including trabecular density, muscle cross-sectional area and bone strength in the tibia.