Lenke 1A型青少年特发性脊柱侧凸患者胸弯融合术后附加现象的原因分析

Risk factors for distal adding-on phenomenon in type Lenke 1A scoliosis

中文关键词:  青少年特发性脊柱侧凸  Lenke 1A型  内固定  附加现象  并发症

英文关键词:Adolescent idiopathic scoliosis  Lenke 1A  Internal fixation  Adding-on  Complication

中文摘要:

  【摘要】 目的：分析Lenke 1A型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）患者胸弯融合术后发生远端附加现象的原因，探讨远端固定椎（lowest instrumented vertebra，LIV）的选择方法。方法：2007年1月~2010年12月，对54例Lenke 1A型AIS患者采用后路椎弓根螺钉系统矫形固定，女43例，男11例，平均年龄14.4岁。平均随访3.2年，在末次随访时的站立位全脊柱正位X线片上观察融合远端附加现象，主胸弯下端椎（lowest end vertebra，LEV）向远端移动且Cobb角增加5°以上或LIV远端椎间隙成角5°以上为发生远端附加现象。将发生远端附加现象可能的相关因素进行统计学分析。结果：54例患者中有12例（22.2%）发生远端附加现象，纳入病例组；未发生附加现象的42例患者纳入对照组。单因素变量分析发现两组间存在统计学差异的因素包括：术前LIV偏离骶骨中线（center sacral vertical line，CSVL）距离、LIV与LEV相距节段数、LIV与中立椎（neutral vertebra，NV）相距节段数、LIV与稳定椎（stable vertebra，SV）相距节段数以及Risser征；多变量Logistic回归分析显示术前LIV偏距超过10mm、未固定到NV（NV-LIV＞0）、Risser征2级以下是发生远端附加现象的独立危险因素。结论：远端固定椎选择不当和骨骼发育程度低是术后发生附加现象的重要原因；固定到NV是最佳选择，当选择NV-1作为LIV时，术前LIV偏离CSVL的距离超过10mm容易发生附加现象。

英文摘要:

  【Abstract】 Objectives: To investigate the risk factors associated with postoperative distal adding-on phenomenon in type Lenke 1A scoliosis, and the optimal strategy for the choice of the lowest instrumented vertebrae(LIV). Methods: 54 patients(43 females, 11 males, average 14.4 years old) with type Lenke 1A scoliosis undergoing posterior pedicle screw instrumentation alone in our department between January 2007 and December 2010 were retrospectively reviewed. The adding-on phenomenon was defined as progressive increase in the number of vertebrae within the primary curve and combined with either an increase in the Cobb angle of at least 5° or an increase of more than 5° in the angulation of the first disc below LIV at final follow-up. Potential related parameters were investigated statistically to determine the risk factors. Results: After a mean follow-up of 3.2 years, distal adding-on was observed in 12 of 54 patients(22.2%), while the other 42 cases were defined as control group. The risk factors including preoperative LIV deviation from CSVL, Risser grade, difference in levels of LIV with the lowest end vertebra(LEV), neutral vertebra(NV) and stable vertebra(SV) were significantly associated with adding-on phenomenon. Multivariate Logistic regression revealed the preoperative LIV deviation from CSVL＞10mm and the difference in levels between LIV and NV(NV-LIV＞0), and Risser grade＜Ⅱ played as independent predictive roles. Conclusions: Inappropriate selection of LIV and skeletal immatureness tend to result in postoperative distal adding-on. Based on our study, choosing NV as LIV may be the optimal strategy. If so, the vertebra deviation from CSVL less than 10mm preoperatively should be considered carefully, otherwise the adding-on phenomenon may occur.