特发性胸椎侧凸选择性融合术后远端叠加现象

Distal adding-on phenomenon after selective fusion for idiopathic thoracic scoliosis

中文关键词:  特发性脊柱侧凸  选择性融合  主胸弯  叠加现象

英文关键词:Idiopathic scoliosis  Selective fusion  Main thoracic curve  Adding-on

中文摘要:

  【摘要】 目的：探讨主胸弯型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）单次前或后路胸弯融合术后远端叠加现象的发生率，并对其影响因素进行分析。方法：回顾性分析110例行单次前或后路主胸弯融合术的主胸弯型（Lenke 1A型）AIS患者。其中男20例，女90例；年龄10～18岁，平均14.2±2.0岁；主胸弯Cobb角40°～80°，平均为48.2°±7.8°。所有患者在术前、术后及术后随访时均摄站立位全脊柱正侧位X线片。测量侧凸Cobb角，记录患者的年龄、Risser征、Y软骨形态、手术方式、稳定椎及融合节段，统计术后远端叠加现象的发生率，分析其影响因素。结果：随访时间为12～46个月，平均21±5个月。术后Cobb角平均为16.7°±6.1°，末次随访时Cobb角平均为22.0°±8.5°。共有19例出现远端叠加现象，发生率为17.3%。与非叠加组相比，叠加组患者的Risser征较低（2.1±1.4∶3.1±1.3，P=0.002），月经来潮后时间较短（11.2±14.2∶21.9±18.9个月，P=0.002），代偿性腰弯柔软度较高[（97.0±9.1）%∶（90.5±15.5）%，P=0.017]，远端融合椎（LIV）的位置约高出0.8个椎体。关于叠加现象发生率，低Risser征患者高于高Risser征患者，Y软骨开放组高于Y软骨闭合组，月经初潮未至和来潮小于1年组高于月经来潮大于1年组，腰弯高柔软度组高于低柔软度组，LIV高位置组[相对于稳定椎（SV）]高于低位置组。经过Logistic回归分析，LIV-SV≤-2、Y软骨开放和腰弯高柔软度是术后发生远端叠加现象的三个独立的危险因素。结论：部分主胸弯型AIS患者前或后路矫形术后可发生远端叠加现象。LIV的选择、患者的生长发育成熟度和代偿性腰弯的柔软度是影响远端叠加现象的重要因素。

英文摘要:

  【Abstract】 Objectives: To investigate the prevalence of distal adding-on phenomenon after selective fusion in adolescent idiopathic scoliosis(AIS) patients having a main thoracic curve, and to determine its risk factors.Methods: This study retrospectively recruited 110 AIS patients having a main thoracic curve(Lenke type 1A), who underwent one-stage anterior or posterior selective fusion surgery. There were 20 boys and 90 girls, with a mean age of(14.2±2.0) year and a mean thoracic curve of 48.2°±7.8°. All the patients took the standing long-cassette anteroposterior radiographs of spine before surgery, immediately after surgery and at postoperative follow-up. The gender, chronologic age, Risser sign, operative approach, position of stable vertebra(SV) and lowest instrumented vertebra(LIV) and fusion levels were recorded. Cobb angles were measured at initial visit and every time of follow-up after surgery. Then the incidence of distal adding-on phenomenon was calculated, and the risk factors were analyzed. Results: The thoracic curve of the cohort averaged 16.7°±6.1° immediately after surgery and 22.0°±8.5° at final follow-up, respectively. The mean follow-up was 21±5 months. At final follow-up, distal adding-on was observed in 19 patients(17.3%). Compared with the patients without distal adding-on, those with distal adding-on had lower Risser grade (2.1±1.4 versus 3.1±1.3, P=0.002), fewer months since menarche (11.2±14.2 months versus 21.9±18.9 months, P=0.002), more flexible in the compensatory lumbar hemicurve[(97.0±9.1)% versus (90.5±15.5)%, P=0.017], and higher LIV position relative to SV(1.5 vertebrae versus 0.7 vertebra, P=0.003). The incidence of distal adding-on was higher in patients who had lower Risser grade, open triradiate cartilages, or more flexible lumbar hemicurve, or who were at pre-menarche or less than 1 year since menarche, or who were treated with higher location of LIV in relation to SV. According to the results of Logistic regression, LIV-SV≤-2, open triradiate cartilage and more flexible lumbar hemicurve were the independent risk factors contributing to distal adding-on. Conclusions: Selective fusion for thoracic scoliosis has a risk of distal adding-on phenomenon, in which the selection of LIV together with the maturity of growth and the flexibility of the lumbar hemicurve are involved.