Pre-operative halo-gravity traction in the treatment of complex spinal deformities: What do we know so far?: A systematic review

Spinal deformity surgeries are complex procedures associated with a high risk of complications. Halo-gravity traction (HGT) is a useful option that provides a gradual traction force to aid in deformity correction. Though its benefits are well-acknowledged, there still exist major ambiguities regarding its role in the management of complex spinal deformities. We performed a systematic review of the electronic databases including EMBASE, MEDLINE, PubMed, and Cochrane on November 12, 2021 to identify relevant articles on HGT; to analyze the existing literature on pre-operative HGT; and to compare the existing protocols for HGT in spinal deformity patients, its varied effects on the radiological parameters and general health status of the patients, and its associated complications. Among the 284 articles available in the literature, 34 articles were finally included and a total of 1151 patients [mean age, 14.6 years] were analyzed. Mean pre-traction coronal Cobb angle of 107° (72°-140.7°) was reduced by 24.8% [to a mean of 80.5° (42°-120.2°)] following HGT. Mean pre- and post-traction sagittal Cobb angles were 88° (56°-134.7°) and 65.4° (36°-113°; a reduction by 25.7%), respectively. Following HGT, mean body weight and body mass index (BMI) of patients improved by 7.2% and 9.1%, respectively. Mean improvement in forced vital capacity and forced expiratory volume has been reported to be 14.5% and 13.9%, respectively. Pre-operative HGT is a useful option in the treatment of spinal deformities. It aids in reducing curve magnitude and provides optimal time for improving general condition (pulmonary and nutritional status) of patients pre-operatively. It is a safe procedure with 2.1% neurological and 11.6% non-neurological complication rates.