The follow-up outcomes of more than 5 years after one-stage posterior correction of scoliosis with Chiari Ⅰ malformation and syringomyelia

English Keywords:Scoliosis  Chiari malformation  Syringomyelia  Surgical correction  Follow-up outcomes

English Abstract:

  【Abstract】 Objectives: To analyze the more than 5 years′ follow-up outcomes of scoliosis with Chiari Ⅰ malformation(CM1) and syringomyelia(SM) treated by one-stage spinal correction. Methods: A retrospective study was performed on 23 patients with CM1 and SM associated scoliosis treated from January 2007 to June 2015. The patients had complete clinical data and were followed up for more than 5 years after one-stage spinal correction. There were 19 males and 4 females with an average age of 16.0±5.9(range, 10-39) years old. The one-stage spinal correction was performed on all the patients, including 10 patients with posterior vertebral column resection (PVCR), 13 patients with simple spinal correction without shortening osteotomy. The spinal radiographs were obtained from all patients preoperatively, postoperatively and at final follow-up． Syringomyelia size and change were measured based on the results of MRI. According to full-spine standing radiographs, the spine sagittal and coronal correction rate were evaluated. According to the results of MRI, the average cervical syrinx tension ratio(CSTR) was used as an indicator of syrinx size and change, and a ≥20% decline was set as a boundary of syrinx improvement at the final follow-up. According to the degree of CSTR decline, all the cases were divided into two groups: with or without cervical SM improvement. And the cases were also divided into with or without PVCR based on whether the spinal shortening osteotomy was performed intraoperatively. Then gender, age at surgery, apical level, main scoliosis, kyphosis, deformity angular ratio (DAR), length of syrinx, average CSTR, preop traction, No. of fusion segments, coronal correction rate, sagittal correction rate, syrinx improvement, and period of the follow-up were compared separately. Differences between two groups were assessed by independent t test, and categorical variables were compared using Chi-square test. Results: The average follow-up period of all patients was 6.2±1.1 years(range, 5-9 years). The average scoliosis angle reduced from 77.1°±28.0° before surgery to 27.8°±18.4° after surgery and 29.5°±21.2° at the final follow-up, with a correction ?????慯湦搠?卣??慩獯獳潩捳椠慯瑦攠搨?猵挮漷沱椱漳献椰猩??眠桔楨捥栠?湶潥瑲?潧湥氠祫?慰捨桯楳敩癳攠獡?獧慬晥攠?獥灤極湣慥汤?捦潲牯牭攠挵琷椮漲溰?眳椱琮根澰甠瑴?渠攲甹爮漳沰澱朱椵挮愲沰?楡湦瑴敥牲瘠敳湵瑲楧潥湲??扡畮瑤?愳氲献漴?玱琱收愮搵榰氠祡?椠浦灩牮潡癬攠獦?慬湬摯?猭瑵慰戬椠汷楩穴敨猠?匠??楲湲?浣潴獩瑯?瀠慲瑡楴敥渠瑯獦?kyphosis of (48.4±22.6)%. At final follow-up, the spinal correction and fusion were satisfied, and no patient experienced deterioration of neurological function. In all patients, the improvement rate of CSTR was 47.8%. There were 11 patients in the syrinx improvement group and 12 patients in the without syrinx improvement group. Of patients with syrinx improvement, the mean age at surgery was bigger(18.6±7.5 years vs. 13.7±2.4 years, P=0.040), the frequency of undergoing PVCR was more (81.8% vs. 16.7%, P=0.012), and the number of fusion segments was bigger(14.2±0.9 vs. 12.3±2.9, P=0.044) than those in the group without syrinx improvement. However, there was no significant difference in gender, apical level, main scoliosis, kyphosis, DAR, length of syrinx, average CSTR, preop traction, coronal correction rate, sagittal correction rate, and the follow-up period(P>0.05). The patients who underwent PVCR had severer scoliosis (98.8°±13.8° vs. 60.5°±24.5°, P=0.000) and kyphosis(74.8°±37.5° vs 43.6°±18.6°, P=0.032), as well as greater coronal DAR(15.6°±4.2° per level vs. 10.2°±4.2° per level, P=0.006), sagittal DAR(12.0°±7.6° per level vs. 6.7°±3.9° per level, P=0.040) and total DAR (26.8°±11.4° per level vs. 15.3°±6.5° per level, P=0.006) than those without PVCR. There were more frequent uses of preoperative traction(70.0% vs. 23.1%, P=0.024), longer fusion segments (14.2±1.2 levels vs. 12.4±2.7 levels, P=0.045), and higher syrinx improvement rate (80.0% vs. 23.1%, P=0.007) in the patients with PVCR. However, there was no significant difference in gender, age at surgery, apical level, length of syrinx, averaging CSTR, coronal correction rate, sagittal correction rate, and the follow-up period(P>0.05). Conclusions: One-stage spinal correction can be another good choice in selected patients without preoperative clinically detectable neurologic deficit of