强直性脊柱炎胸腰椎后凸畸形经椎弓根椎体截骨术后机械并发症与GAP评分的相关性及其危险因素分析

Correlations of the mechanical complications following pedicle subtraction osteotomy in ankylosing spondylitis related-thoracolumbar kyphosis with global alignment and proportion score and analysis of its risk factors

中文关键词:  强直性脊柱炎  胸腰椎后凸畸形  GAP评分  经椎弓根椎体截骨术  机械并发症

英文关键词:Ankylosing spondylitis  Thoracolumbar kyphosis  Global alignment and proportion  Pedicle subtraction osteotomy  Mechanical complication

中文摘要:

  【摘要】 目的：探讨强直性脊柱炎（ankylosing spondylitis，AS）胸腰椎后凸畸形经椎弓根椎体截骨术（pedicle subtraction osteotomy，PSO）术后机械并发症与GAP（global alignment and proportion）评分的相关性，并分析其危险因素。方法：回顾性分析2010年1月~2019年6月在我院行单节段PSO且随访超过2年的AS胸腰椎后凸畸形患者。在术前、术后站立位全脊柱侧位X线片上测量矢状面平衡（sagittal vertical axis，SVA）、骨盆投射角（pelvic incidence，PI）、骶骨倾斜角（sacral slope，SS）、腰椎前凸角（lumbar lordosis，LL）、下腰椎前凸角（lower lumbar lordosis，LLL）、整体倾斜（global tilt，GT），计算GAP评分。根据患者GAP评分分为3组：矢状面协调组（GAP评分0～2分）、中等不协调组（GAP评分3～6分）、严重不协调组（GAP评分7～13分），记录随访过程中发生的机械并发症，包括近端交界性后凸/失败（proximal junctional kyphosis/failure，PJK/PJF）、远端交界性后凸/失败（distal junctional kyphosis/failure，DJK/DJF）、断棒，比较不同组之间机械并发症的发生率。记录患者年龄、性别、融合节段、后凸分型、骨密度（bone mineral density，BMD）、身体质量指数（body mass index，BMI）、截骨水平，并通过单因素和多因素Logistic回归分析AS患者PSO术后机械并发症的危险因素。结果：共纳入163例患者，其中男性145例，女性18例，年龄35.8±10.0岁（17～63岁），术后随访38.6±16.9个月（24~96个月），26例发生机械并发症，其中断棒16例，PJK 10例。矢状面协调组、中等不协调组、严重不协调组机械并发症发生率分别为19.2%（5/26）、16.1%（9/56）和14.8%（12/81），三组之间无统计学差异（χ2=0.287，P=0.866）。单因素分析结果表明，年龄（P=0.036）和BMI（P＜0.001）与术后机械并发症的发生相关。多因素Logistic回归分析结果表明，年龄（P=0.046）和BMI（P＜0.001）为AS胸腰椎后凸畸形患者PSO术后机械并发症的独立危险因素。结论：AS胸腰椎后凸畸形患者PSO术后机械并发症的发生风险与GAP评分无明显相关性，与年龄和BMI有相关性。

英文摘要:

  【Abstract】 Objectives: To investigate the correlations between the mechanical complications after pedicle subtraction osteotomy(PSO) in ankylosing spondylitis(AS) patients with thoracolumbar kyphosis and global alignment and proportion(GAP) score and analyze the risk factors for such mechanical complications. Methods: AS patients with thoracolumbar kyphosis who underwent single-level PSO between January 2010 and June 2019 and were followed up for 2 years and above were analyzed retrospectively. Radiographic parameters including sagittal vertical axis(SVA), pelvic incidence(PI), sacral slope(SS), lumbar lordosis(LL), lower lumbar lordosis(LLL), and global tilt(GT) were measured on lateral full-spine X-rays preoperatively and postoperatively to calculate the GAP score. The patients were divided into 3 groups: proportion group(GAP score 0-2), moderate disproportion group(GAP score 3-6), and severe disproportion group(GAP score 7-13). All the mechanical complications during follow-up were documented including proximal junctional kyphosis/failure(PJK/PJF), distal junctional kyphosis/failure(DJK/DJF), and rod fracture, and the incidences of the mechanical complications were compared between the 3 groups. The age, gender, fusion levels, classification of kyphosis, bone mineral density(BMD), body mass index(BMI), and the level of osteotomy were also collected. Univariate analysis and multivariate logistic regression analysis were used to determine the risk factors for mechanical complications in AS patients following PSO. Results: 163 patients were included, including 145 males and 18 females, with a mean age of 35.8±10.0 years(range, 17 to 63 years) and the follow-up period was 38.6±16.9 months. A total of 26 patients had mechanical complications during follow-up containing rod fracture(n=16) and PJK(n=10). The incidences were 19.2%(5/26), 16.1%(9/56) and 14.8%(12/81) in proportion group, moderate disproportion group and severe disproportion group, respectively( χ2=0.287, P=0.866). Univariate analysis showed that age(P=0.036) and BMI(P<0.001) were associated with postoperative mechanical complications. Multivariate logistic regression analysis showed that age(P=0.046) and BMI(P<0.001) were the independent risk factor for mechanical complications in AS patients with thoracolumbar kyphosis following PSO. Conclusions: The mechanical complications following PSO in AS patients with thoracolumbar kyphosis have no obvious correlations with GAP score, while they were correlated with age and BMI.