内固定方式对青少年特发性脊柱侧凸选择性胸椎融合矢状面重建的影响

目的 探讨胸弯型青少年特发性脊柱侧凸患者行后路选择性胸椎融合术时采用不同内固定方式对胸椎矢状面形态及远端腰椎代偿模式的影响.方法 行胸弯后路矫形内同定术且有2年以上(2～3年)完整随访资料的lenke 1、2型青少年特发性脊柱侧凸患者51例,按内固定方式分为A组(全钩组)、B组(钩钉混合组)和C组(全钉组).测量术前及术后随访的胸弯Cobb角、腰弯Cobb角、胸椎后凸角、腰椎前凸角、远端交界性后凸、胸腰段交界性后凸及C7铅垂线偏离S1后上缘的距离.结果 三组患者主弯矫正率均大于60%,继发弯也获得较满意的自发性矫正.三组患者术前及随访中腰椎前凸角、C7铅垂线偏离S1后上缘的距离均保持正常.随访2年时,A组远端交界性后凸、胸椎后凸角、胸腰段交界性后凸分别达3.6°、23.0°、6.4°,其中远端交界性后凸与术前比较差异有统计学意义(P<0.05).B组和C组各项指标与术前比较差异均无统计学意义.结论 全钩型同定可以获得良好的冠状面矫形,且在随访中能保持腰椎前凸和欠状面平衡.但钩的固定不如椎弓根螺钉牢固,全钩型固定患者胸椎后凸角有增大趋势,胸腰椎交界区有失代偿的可能.

The effect of instrumentation patterns on the sagittal reconstruction following selective posterior correction for thoracic adolescent idiopathic scoliosis

Objective To explore the effect of various instrumentation patterns on the sagittal re-construction with selective posterior fusion for thoracic adolescent idiopathic scoliosis (A1S). Methods Fifty-one AIS patients of Lenke 1A, IB, 1C and 2B who underwent selective posterior thoracic fusion in at least 24 months follow-up were evaluated. The patients were divided into three groups: Group A (all-hook system), Group B (hybrid system with upper thoracic hooks and lower pedicle screws), and Group C (all-screw sys-tem). The radiological parameters before and after surgery included thoracic and lumbar curve Cobb angle, thoracic kyphosis(TK), lumbar lordosis (LL), thoracolumbar junction kyphosis (T10-I2, TJK), distal junctional kyphosis (DJK), and sagittal vertical axis (SVA). Results Over 60% coronal correction of the primary curve and a satisfactory spontaneous correction of the secondary curve were achieved in three groups. There was no change of LL in three groups and SVA maintained in normal range before surgery and during follow-up peri-ods in all groups. However, in Group A, at the last phase of this research, DJK had a mean value of 3.6° of kyphosis compared with preoperative angle of -2.3° (P=0.037), which showed a lordosis loss of 5.9° in Group A. TK averaged 23.0° at the last phase compared with preoperative angle of 13.5° (P=0.072). TJK averaged 6.4° at the last phase compared with preoperative angle of -2.8° (P=0.070), and there was a lordosis loss of 9.2°. There were no obvious changes of TK, TJK and DJK in Group B and Group C during the whole follow-up. Conclusion Satisfactory correction on coronal plane, sagittal balance and lumbar lordosis could be maintained with selective thoracic all-hook instrumentation for thoracic AIS patients during follow-up. How-ever, the patients with all-hook system may develop thoracic kyphosis and sagittal junctional decompensation because of the instability of instrumentation.