Efficacy analysis of preoperative traction combined with posterior approach one-stage osteotomy correction in treating severe scoliosis accompanied with syringomyelia

English Keywords:Scoliosis  Syringomyelia  Traction  Surgical correction

English Abstract:

  【Abstract】 Objectives: To analyze the effects of preoperative traction and surgical osteotomy correction in patients with severe scoliosis(SS) accompanied by syringomyelia(SM), and explore the safety and efficacy of one-stage posterior osteotomy surgery following preoperative traction in treating patients with SS accompanied with SM(SS-SM). Methods: A retrospective study was conducted on 40 cases of SS-SM patients who underwent one-stage posterior osteotomy surgery following preoperative traction in our department from January 2007 to October 2023. There were 19 males and 21 females, aged 11 to 41 years(18.28±6.66 years). All the patients had no history of neurosurgical operational treatment and underwent full-spine X-rays, CT, and MRI examinations before surgery to measure the major curve angle on coronal plane, kyphosis angle on sagittal plane, length of SM, to evaluate whether combined with Chiari malformation, and to calculate the size of SM(maximal syrinx/cord ratio, S/C) and deformity angular ratio(DAR). During traction and after operation, full-spine X-rays were re-examined in a timely manner to assess the correction conditions of deformity. According to whether SM was accompanied with Chiari Ⅰ malformation(CMⅠ), the patients were divided into the CMⅠ-related SM group(CS group) and the idiopathic SM group(IS group); According to the size of SM, the patients were also divided into the big syrinx group(BS group, S/C>0.6) and the little syrinx group(LS group, S/C≤0.6). The contribution rates of preoperative traction and surgery to correction were statistically analyzed and compared between different groups(CS group vs IS group, BS group vs LS group). Results: The S/C ratio of SM in 40 patients was 0.59±0.18, with a length of 9.43±5.50 segments. Preoperative skull-femoral traction(SFT) was performed in 36 cases, and halo-gravity traction(HGT) in 4 cases. During traction, 5 cases experienced temporary local numbness, 2 cases had temporary local muscle weakness, and 5 cases developed traction nail tract infections. Low-grade osteotomy was performed in 29 cases(72.5%), and high-grade osteotomy with spinal shortening and fusion was performed in 11 cases(27.5%), with an average of 13.48±1.34 fusion segments. Postoperative complications included local trunk numbness in 2 cases, pulmonary infection in 4 cases, and superficial wound infection in 3 cases, with no motor dysfunction observed. The coronal main curve angle, sagittal kyphosis angle, and total DAR(T-DAR) before operation were 104.80°±18.58°, 66.57°±31.21° and 25.73°±8.30°/segment, respectively, which were 65.55°±19.00°, 44.95°±23.32° and 16.73°±7.24°/segment, respectively after traction. After correction operation, the scoliosis and kyphosis angles were 37.78°±14.91° and 29.95°±14.14°, respectively, with a main curve flexibility of (20.79±11.02)%. The total correction rates for coronal scoliosis and sagittal kyphosis were (64.44±9.44)% and (51.74±18.40)%, respectively. The average contribution rates of traction and surgery to the correction of coronal scoliosis and sagittal kyphosis were (59.90±17.67)% and (40.10±17.67)%, and (59.21±27.51)% and (40.79±27.51)%, respectively. There were no significant differences in the total correction rates of scoliosis and kyphosis, or the contribution rates of traction and surgery to the correction of scoliosis and kyphosis between the CS and IS groups, and between the BS and LS groups. Preoperative traction improved the DAR by more than 34% and achieved a correction contribution rate of over 50%. The proportion of males was higher in the CS group, while the proportion of females was higher in the IS group(P=0.027). There were no statistical differences between the CS and IS groups in terms of age, preoperative main curve Cobb angle and flexibility, spinal kyphosis angle, DAR value, S/C ratio and SM length, traction improvement effect, total postoperative correction rate, number of fusion segments, osteotomy grade, blood loss, operational duration, or the contribution rates of traction and surgery to spinal correction(P>0.05). The average S/C ratio in the BS group was significantly higher than that in the LS group(0.74 vs 0.45, P<0.001), the number of fusion segments was lower in the BS group than in the LS group(13.00 vs 13.90, P=0.031), and the proportion of high-grade osteotomy was higher in the BS group than in the LS group(8/19 vs 3/21, P=0.049). There were no statistical differences between the BS and LS groups in terms of age, preoperative main curve Cobb angle and flexibility, spinal kyphosis angle, DAR value, SM length, traction improvement effect, total postoperative correction rate, blood loss, operational duration, or the contribution rates of traction and surgery to spinal correction(P>0.05). Conclusions: Preoperative traction can improve spinal deformity to a certain extent, reducing the difficulty of intraoperative correction and risks of neurological injury. For SS-SM patients, regardless of whether they are accompanied with CMⅠ or the size of SM, preoperative traction can contribute more than half of the deformity correction rate for coronal scoliosis and sagittal kyphosis. One-stage posterior osteotomy correction surgery following preoperative traction is a safe and effective treatment strategy for SS-SM patients who have not undergone preventive neurosurgical intervention.