Impacts of Ultra-early Hyperbaric Oxygen Therapy on Bone Mass of Rats With Complete Spinal Cord Transection.

STUDY DESIGN Seventy-five SD rats were randomly assigned to four groups: sham-operated group (Sham, n = 15), complete spinal cord transection (CSCT, n = 20) group, hyperbaric oxygenation group 1 (HBO1, n = 20), and hyperbaric oxygenation group 2 (HBO2, n = 20). OBJECTIVE The aim of this study was to analyze the impacts of ultra-early hyperbaric oxygen therapy on bone mass of rats with CSCT. SUMMARY OF BACKGROUND DATA Treatment of patients with complete SCI is still an unresolved medical issue and needs to be further investigated. Studies on changes in bone mass as well as osteoporosis prevention after SCI have important clinical significance. METHODS Rats in the sham group only underwent T10 laminectomy, without damaging the spinal cord. Rats in CSCT, HBO1, and HBO2 groups underwent T10 laminectomy and spinal cord transection at T10 level. Rats in HBO1 and HBO2 groups received three courses of hyperbaric oxygen therapy with 10 days per course starting at 3 and 12 hours after spinal cord injury, respectively. The femoral biomechanical characteristics, the bone calcium, and the bone hydroxyproline (B-HYP) contents were determined. Morphology of the femur bone trabecula and the bone collagen were observed by HE staining and by masson triad color staining, respectively. RESULTS After 6 weeks of treatment, rats in the CSCT group showed significant decreases in femur structural and material mechanics parameters, calcium and B-HYP contents, (P < 0.01), as well as sparse, fractured, malaligned trabecular bone and collagen compared with rats in the sham group. After treatments, compared with rats in the CSCT and HBO2 groups, rats in HBO1 group showed enhancement in femur structural and material mechanics parameters, calcium and B-HYP contents, (P < 0.05), as well as trabecular bone and collagen with better continuity and neater arrangement. CONCLUSION Ultra-early HBO therapy can significantly improve bone mass in CSCT rats. LEVEL OF EVIDENCE N/A.