Background Surgical management of cervical kyphosis in patients with NF-1 is a challenging task. Presently, anterior-only (AO), posterior-only (PO) and combined anterior-posterior (AP) spinal fusion are common surgical strategies. However, the choice of surgical strategy and application of Halo traction remain controversial. Few studies have shown and recommended posterior-only approach for cervical kyphosis correction in patients with NF-1. The aim of this study is to evaluate the safety and the effectiveness of Continuous-Incremental-Heavy Halo Traction (CIH-HT) combined with posterior-only approach for treatment of cervical kyphosis with NF-1. Methods 19 patients with severe cervical kyphosis due to NF-1 were reviewed retrospectively between January 2010 and April 2017. All the cases underwent CIH-HT combined with posterior instrumentation and fusion surgery. Correction result, neurologic status and complications were analyzed. Results In this study, cervical kyphosis Cobb angle decreased from initial 63.0 ± 21.0 degrees to postoperative 10.8 ± 4.0 degrees(P＜0.01),with total correction rate of 92%, which consist of 44% from CIH-HT and 48% from surgical correction. JOA scores were improved from preoperative 13.6±1.6 to postoperative 16.0±1.0(P＜0.01). Neurological status was also improved. There was no correction loss and the neurological status was stable in mean 3.7 years follow-up. The incidence of complications was 36.8% (7/19). Six patients underwent local complications and one patient underwent a second surgery. Conclusion CIH-HT combined PO approach is safe and effective method for cervical kyphosis correction in patients with NF-1. A satisfied correction result, and successful bone fusion can be achieved via this procedure, even improvement of neurological deficits can also be obtained. Our study suggested that CIH-HT combined PO approach is another consideration for cervical kyphosis correction in patients with NF-1. Key words : Neurofibromatosis-1; Cervical kyphosis; Continuous-Incremental-Heavy Halo Traction; posterior-only approach;

Background ： 1/3rd-2/3rd of the remaining vertebral height can hold and withstand the standard pedicle screws; some surgeons have adopted affected vertebral fixation to avoid the complications of both long and short segment fixation during surgical correction of lumbar tuberculosis (TB).This study aimed to compare efficacy of mono-segment-fixation versus the short-segment fixation methods with the use of titanium mesh-cage (TMCs) and interbody fusion in the treatment of mono-segmental lumbar spinal TB via single stage posterior-only approach. Methods ： A retrospective review was done among 34 lumbar spinal TB patients. These patients underwent debridement, interbody fusion with (TMCs) by either Mono-segment fixation or short-segment fixation methods. Eighteen patients underwent mono-segment fixation method, group (A). While 16 patients underwent short-segment fixation method, group (B). Fusion, deformity correction, and decompression were done within the affected segment in group (A), while for group (B) fusion extended one level above and below the affected vertebrae . Operation time, intra-operative blood loss, degree of deformity correction and neurological functions were analyzed. Results: Comparing group (A) vs (B), average operation time in minutes (mins) for group A was 144.2±16.5, group B was 170.3 ± 25.0 (P=0.001). Average intraoperative blood loss in milliliter (mls) was 502.8±151.9 for group (A) and 742.5±143.2 for group (B) (p ˂0.05). The mean cobb’s angle between group A versus group B; preoperative was 23.8 ± 6.5 0 vs 22.2±9.2 0 (p=0.6), immediate post operatively was 8.0±3.5 0 vs 8.3±5.7 0 (p=0.847) and at final follow-up was 8.9±3.1 0 vs 9.2 ± 5.9 0 (p=0.866) respectively. Correction rate between group (A) vs group (B) was 15.7±3.8 0 vs 13.9±5.5 0 (p=0.285) and loss of correction was 1.2±0.7 0 vs 1.1±0.7 (p=0.817) respectively. No significant differences in neurological recovery between the two groups were founds. Conclusion: Under precise conditions: mono-segment fixation method, debridement, interbody fusion with TMCs, and posterior instrumentation can effectively reconstruct the spine, maintain stability and correct kyphosis deformity similar to short-segment fixation method. Also, it can relieve pain and improve neurological symptoms. When used in combination with anti-TB chemotherapy in the treatment of mono-segmental lumbar TB via a single-stage posterior-only approach.