脊柱侧后凸/后凸畸形SRS-Schwab四级截骨术后近端交界性后凸的危险因素分析

Risk factors for proximal junctional kyphosis after SRS-Schwab grade 4 osteotomy in patients with spine kyphoscoliosis/kyphosis

中文关键词:  脊柱侧后凸/后凸  SRS-Schwab四级截骨术  近端交界性后凸  危险因素

英文关键词:Kyphoscoliosis/Kyphosis  SRS-Schwab grade 4 osteotomy  Proximal junctional kyphosis  Risk factors

中文摘要:

  【摘要】 目的：探讨脊柱侧后凸/后凸畸形患者SRS-Schwab四级截骨术后发生近端交界性后凸（proximal junctional kyphosis，PJK）的相关危险因素。方法：回顾性分析2011年5月~2015年12月于我院行SRS-Schwab四级截骨手术且具有完整临床及影像学资料的46例脊柱侧后凸/后凸畸形患者，其中男性24例，女性22例，手术时年龄23.1±19.7岁。记录患者体重指数、融合节段、最上端固定椎（upper instrumented vertebra，UIV）位置及置钉密度等。测量术前、术后3个月及末次随访时的胸椎后凸角（thoracic kyphosis，TK）、腰椎前凸角（lumbar lordosis，LL）、骨盆入射角（pelvic incidence，PI）、局部后凸角（segmental kyphosis，SK）、主弯Cobb角（main curve，MC）、矢状面平衡（sagittal vertical axis，SVA）及近端交界角（proximal junctional angle，PJA）。根据患者术后是否发生PJK分为非PJK组和PJK组，采用t检验、χ2检验或Fisher精确检验对比两组临床资料及影像学参数，利用多因素Logistic回归分析确定PJK发生的危险因素。结果：46例患者术后随访24～63个月（36.9±13.4个月），其中11例（23.9%）发生PJK，以Ⅰ型PJK（8/11）最为常见，8例发生于术后6个月内。PJK组和非PJK组患者性别、年龄、随访时间、体重指数、融合节段、骨密度、置钉密度、UIV位置均无统计学差异（P>0.05）。PJK组患者术前TK＞40°（6/11）和SK矫正＞30°（7/11）的比例均高于非PJK组（P＜0.05）。两组患者间术前PJA、LL、MC、PI、SVA和术后及末次随访时TK、LL、MC、SK、PI、SVA改变均无统计学差异（P>0.05）。回归分析结果显示术后SK矫正＞30°（OR=7.000，95%CI=1.591-30.800，P=0.010）是PJK发生的独立危险因素。PJK组术前PJA为7.5°±3.0°，术后3个月为20.8°±4.1°，末次随访时为22.0°±4.5°，交界性后凸未见明显加重。结论：脊柱侧后凸/后凸畸形患者SRS-Schwab四级截骨术后PJK发生率为23.9%，其主要发生于术后6个月内，脊柱后凸畸形过度矫正是其独立危险因素。

英文摘要:

  【Abstract】 Objectives: To investigate the risk factors for proximal junctional kyphosis(PJK) in patients with kyphoscoliosis/kyphosis underwent SRS-Schwab grade 4 osteotomy. Methods: A retrospective review of 46 patients with spine kyphoscoliosis/kyphosis who underwent SRS-Schwab grade 4 osteotomy between May 2011 and December 2015 was performed, including 24 males and 22 females, with an average age of 23.1±19.7 years. Body mass index, fusion segment, upper instrumented vertebra(UIV) and implant density were recorded. The spine-pelvic parameters including thoracic kyphosis(TK), lumbar lordosis(LL), pelvic incidence(PI), segmental kyphosis(SK), main curve(MC), sagittal vertical axis(SVA) and proximal junctional angle(PJA) were measured pre- and post-operationally and at last follow up. Patients were divided into PJK group and non-PJK group. Comparison of clinical and radiographic data was conducted between the 2 groups by Student′s t-test and Chi-square test or Fisher′s exact test. Multivariate Logistic regression analysis was used to determine the risk factors of PJK. Results: The average follow-up period of 46 patients was 36.9±13.4 months, during which PJK occurred in 11 cases(23.8%). 8 patients developed PJK during the first six months after surgery and the most common type of PJK was type Ⅰ(8/11). There was no significant difference in gender, age, follow-up, body mass index, fusion segment, bone mineral density, implant density and UIV between two groups (all P>0.05). Compared with the non-PJK group, the PJK group showed higher rate of pre-operative TK>40° and SK improvement >30° (all P<0.05). No significant difference was detected between both groups in pre-operative PJA, LL, MC, PI, SVA, and TK, LL, MC, SK, PI, SVA changes after operation and at the last follow-up (all P>0.05). Logistic regression analysis showed that SK improvement >30° (OR=7.000, 95%CI=1.591-30.800, P=0.010) was independent risk factor associated with PJK. The average PJA increased from 7.5°±3.0° to 20.8°±4.1° at 3 months after surgery. At the final follow-up in PJK group, PJA averaged 22.0°±4.5° and no significant progression of PJA was observed. Conclusions: The incidence of PJK after SRS-Schwab grade 4 osteotomy in patients with spine kyphoscoliosis/kyphosis was 23.9%, which mainly occurred within 6 months, and over correction of kyphosis is one of the high risk factors.