Halo Gravity Traction Is Associated with Reduced Bone Mineral Density of Patients with Severe Kyphoscoliosis.

Background. Halo gravity traction (HGT) is one of the most commonly used perioperative techniques for the treatment of severe kyphoscoliosis. This study was to explore the influence of HGT on the BMD of these patients. Methods. Patients with severe kyphoscoliosis treated by preoperative HGT for at least 2 months were included. Patients' BMD were assessed by dual-energy X-ray absorptiometry at lumbar spine (LS, L2-L4) and femur neck (FN) of the nondominant side. The weight and duration of traction, as well as baseline characteristics, were recorded. Results. Twenty patients were recruited. The average traction duration was 77.9 ± 13.0 days while the mean traction weight was 39.9% ± 11.1% of total body weight. Remarkable decrease of BMD was observed at LS of 17 (85%) patients and at FN of 18 (90%) patients. After HGT, 75% of patients were found to have osteoporosis, the incidence of which was significantly higher than that before HGT (35%). The correlation analysis revealed BMD reduction was only significantly correlated with the traction duration. Conclusions. The current study showed that preoperative HGT can have obvious impact on the BMD. The BMD reduction is associated with traction duration, suggesting that long traction duration may bring more bone mineral loss.