后路半椎体切除长节段骨盆固定治疗成人先天性腰骶部半椎体

Pelvic fixation for posterior lumbosacral hemivertebra resection and long fusion in adult spinal deformity

目的评估成人先天性腰骶部半椎体(lumbosacral hemivertebra,LSHV)行后路半椎体(hemivertebra,HV)切除长节段固定远端是否需要骨盆固定。方法回顾性分析2005年4月至2019年8月接受后路HV切除长节段固定的成人LSHV患者32例,男12例,女20例;年龄(32.9±8.8)岁(范围21~44岁)。根据冠状面平衡(Coronal balance distance,CBD)分型:A型(术前CBD≤30 mm)15例,B型(术前CBD>30 mm且C7铅垂线向凹侧偏移)1例,C型(术前CBD>30 mm且C7铅垂线向凸侧偏移)16例。根据远端内固定模式分为骨盆固定(pelvic fixation,PF)组(PF组),即远端固定至髂骨或骶髂骨;非骨盆固定(non-pelvic fixation,NPF)组(NPF组),即远端固定至L5或S1。主要观察指标为全脊柱正、侧位X线片评估原发弯和代偿弯Cobb角、CBD改善,同时评估术后CBD分型的转变。结果32例患者术后均获得随访,随访时间为(3.9±2.6)年(范围2~11年)。术前PF组和NPF组原发弯Cobb角分别为42.6°±13.5°和41.3°±10.9°,术后矫正至13.1°±5.4°和17.7°±5.8°,末次随访时13.4°±5.1°和18.5°±6.7°,差异均有统计学意义(FPF组=32.58,FNPF组=28.64,均P<0.001),术后改善率分别为69.3%±11.8%和57.6%±10.3%(t=2.14,P=0.012)。两组代偿弯Cobb角分别由术前54.9°±14.8°和46.8°±13.6°,术后矫正至17.3°±9.6°和15.4°±8.4°,末次随访时18.5°±8.8°和17.6°±9.5°,差异均有统计学意义(FPF组=42.97,FNPF组=38.56,均P<0.001),术后改善率分别为68.4%±16.7%和67.2%±14.9%(t=0.17,P=0.849)。PF组患者原发弯和代偿弯Cobb角矫正率类似(69.3%±11.8%vs.68.4%±16.7%,t=0.15,P=0.837),而NPF组患者代偿弯Cobb角的矫正率明显高于原发弯,差异有统计学意义(67.2±14.9%vs.57.6±10.3%,t=2.13,P=0.013)。PF组和NPF组CBD分别由术前(33.3±11.2)mm和(28.8±8.1)mm,术后矫正至(18.5±3.5)mm和(27.1±6.8)mm,而末次随访时CBD均较术后无明显变化(FPF组=41.61,P<0.001;FNPF组=0.38,P=0.896);术后和末次随访时PF组CBD均优于NPF组,差异均有统计学意义(t术后=3.23,P=0.002;t末次=2.94,P=0.008)。术后12例患者出现冠状面失代偿(12/32,37.5%),均为NPF组患者。两组冠状面失代偿发生率的差异有统计意义(0vs.50%,χ^(2)=6.40,P=0.014)。PF组6例术前C型患者术后CBD均恢复正常(100%),而NFP组10例C型患者中4例(40%)恢复正常,差异有统计学意义(χ^(2)=5.76,P=0.034)。结论成人先天性腰骶部半椎体(LSHV)行后路半椎体切除长节段固定术后具有较高的冠状面失代偿发生率(12/32,37.5%),注重原发弯与代偿弯矫正率的匹配度对重建冠状面平衡有重要意义,骨盆固定有助于C型患者重建冠状面平衡。

Objective To evaluate whether pelvic fixation is needed in patients undergoing posterior lumbosacral hemivertebra(LSHV)resection and long fusion.Methods All 32 adult spinal deformity patients with posterior hemivertebra(HV)resection and long segment fixation treated from April 2005 to August 2019 were analyzed retrospectively,including 12 males and 20 females with a mean age of 32.9±8.8 years.According to the state of coronal balance distance(CBD),there were 15 cases of type A(preoperative CBD≤30 mm),1 case of type B(preoperative CBD>30 mm and C7 plumb line offset to the concave side),and 16 cases of type C(preoperative CBD>30 mm and C7 plumb line offset to the convex side).The clinical and imaging data before operation,immediately after operation and at the last follow-up were collected,and the short-term and long-term complications related to operation were recorded.The improvement of Cobb angle and coronal balance of primary curve and compensatory curve were evaluated on the whole spine frontal and lateral X-ray films,and the change of coronal balance type after operation was evaluated.According to the mode of distal internal fixation,the patients were divided into two groups:PF group(pelvic fixation):distal fixation to iliac or sacroiliac;NPF group(non-pelvic fixation):distal fixation to L 5 or S1.Results All 32 patients were followed up with an average time of 3.9±2.6 years(range 2-11 years).The Cobb angle of primary curve in PF and NPF groups were 42.6°±13.5°and 41.3°±10.9°respectively before operation,and corrected to 13.1°±5.4°and 17.7°±5.8°respectively after operation.It maintained at 13.4°±5.1°and 18.5°±6.7°in the two groups at the last follow-up,respectively(FPF=32.58,FNPF=28.64,P<0.001).The correction rates were 69.3%±11.8%and 57.6%±10.3%,respectively(t=2.14,P=0.012).The compensatory curves of in the two groups were corrected from 54.9°±14.8°and 46.8°±13.6°before operation to 17.3°±9.6°and 15.4°±8.4°after operation.It also maintained at 18.5°±8.8°and 17.6°±9.5°in the two groups at the last follow-up,respectively(FPF=42.97,FNPF=38.56,P<0.001).The correction rates were 68.4%±16.7%and 67.2%±14.9%,respectively(t=0.17,P=0.849)in the two groups.In PF group,the primary and compensatory curve were similar(69.3%±11.8%vs.68.4%±16.7%,t=0.15,P=0.837),while the correction rate of compensatory curve in NPF group was significantly higher than that of the primary curve(67.2%±14.9%vs.57.6%±10.3%,t=2.13,P=0.013).Coronal decompensation occurred in 12 patients(12/32,37.5%).The CBD in PF and NPF groups was corrected from 33.3±11.2 mm and 28.8±8.1 mm preoperatively to 18.5±3.5 mm and 27.1±6.8 mm postoperatively,respectively,and it showed no significant change at the last follow-up(FPF=41.61,P<0.001;FNPF=0.38,P=0.896).While the CBD in PF group was significantly better than that in NPF group(t=3.23,P=0.002;t=2.94,P=0.008).The incidence of coronal decompensation in PF group was 0%,which was significantly lower than 50%(12/24)in NPF group(χ^(2)=6.40,P=0.014).In addition,6 cases in PF group were type C coronal decompensation before operation,and the coronal balance was corrected to type A after surgery(100%).Among 10 patients with type C coronal decompensation in NFP,4(40%)patients returned to type A after operation,and the difference was statistically significant(6/6 vs.4/10,χ^(2)=5.76,P=0.034).Conclusion Coronal decompensation(12/32,37.5%)is not rare in patients after posterior LSHV resection and long fusion.Attention should be paid to the match of the corrections between lumbosacral deformity and compensatory curve,which is of great significance in coronal balance reconstruction.Pelvic fixation is helpful to reduce the incidence of postoperative coronal decompensation,especially for the type C patients.