Halo Gravity Traction Can Mitigate Preoperative Risk Factors and Early Surgical Complications in Complex Spine Deformity.

ABSTRACT

STUDY DESIGN: Retrospective review of prospective cohort. OBJECTIVE: We sought to examine the role of halo gravity traction (HGT) in reducing preoperative surgical risk. SUMMARY OF BACKGROUND DATA The impact of HGT on procedure choice, preoperative risk factors, and surgical complications has not been previously described. METHODS: Patients treated with HGT before primary surgery were included. The FOCOS Score (FS) was used to quantify operative risk. FS was calculated using patient-factors (ASIA, body mass index, etiology), procedure-factors (PcF; osteotomy planned, number of levels fused, etc.), and curve magnitude (CM). Scores ranged from 0 to 100 with higher scores indicating increased risk. FS was calculated before and after HGT to see how changes in FS affected complication rates. RESULTS: A total of 96 patients were included. Halo-related complications occurred in 34% of patients but revision was required in only 8.3%. Average FS improved by 18 points after HGT. CM, PcF, and patient-factors all improved (P < 0.05). The greatest changes were in CM and PcF. The planned rate of three-column osteotomies dropped from 91% to 38% after HGT. FS (area under the curve [AUC] 0.68, P = 0.023) and change in FS (AUC 0.781, P < 0.001) was successfully able to predict the rate of surgical complications. A preoperative FS of 74 was identified as a cut-off for a higher rate of surgical complications (sensitivity 58.8%, specificity 74.7%). Patients with a reduction in FS <  = 10pts were five times more likely to have a complication (relative risk 5.2, 95% confidence interval 1.9-14.6, P < 0.001). A multivariate regression showed that change in FS was an independent predictor of complication rates (P < 0.05). CONCLUSION: FS can successfully predict surgical risk in pediatric patients with complex spinal deformity. Preoperative HGT can reduce FS and surgical risk by improving CM, lowering three-column osteotomies use, and improving body mass index. A reduction in FS after HGT predicts a lower rate of surgical complications. LEVEL OF EVIDENCE 3.