老年陈旧性症状性骨质疏松性胸腰椎骨折后路长节段内固定术后近端交界性后凸的危险因素

目的探讨后路长节段内固定治疗老年Ⅳ型陈旧性症状性骨质疏松性胸腰椎骨折(CSOTLF)后近端交界性后凸(PJK)发生的相关危险因素。方法采用病例对照研究分析2013年1月至2018年6月西安交通大学附属红会医院收治的95例老年Ⅳ型CSOTLF患者临床资料,其中男32例,女63例;年龄60~85岁(67.4±6.5)岁]。损伤节段:T1117例,T1237例,L130例,L211例。患者均接受后路长节段内固定术治疗。按照术后是否发生PJK,将患者分为PJK组(30例)和非PJK组(65例)。采用单因素分析患者性别、年龄、体重指数(BMI)、骨密度(BMD)、吸烟史、致伤原因、合并症、损伤节段、美国脊髓损伤协会(ASIA)分级及受伤至手术时间等一般资料;交界性后凸角(PJA)、矢状垂直偏移(SVA)、骨盆入射角-腰椎前凸角差值(PI-LL)、骨盆倾斜角(PT)及骶骨倾斜角(SS)等术前影像学资料;后方韧带复合体(PLC)损伤、近端固定椎(UIV)位置、远端固定椎(LIV)位置、固定节段数等手术基本资料与术后PJK发生的相关性。采用多因素Logistic回归分析与术后PJK发生的独立危险因素。结果单因素分析结果显示,年龄、BMI、BMD、术前PJA、术前SVA、术前PI-LL、PLC损伤、UIV位置、LIV位置、固定节段数与术后PJK发生有一定的相关性(P均<0.05),而性别、吸烟史、致伤原因、合并症、损伤节段、ASIA分级、受伤至手术时间、术前PT、术前SS与术后PJK发生不相关(P均>0.05)。多因素Logistic回归分析结果表明,年龄≥70岁(OR=32.28,95%CI 3.83~272.29,P<0.01)、BMI>28.0 kg/m2(OR=7.88,95%CI 1.63~37.99,P<0.01)、BMD T值<-3.5 SD(OR=20.84,95%CI 2.36~183.93,P<0.01)、术前PI-LL>20°(OR=13.30,95%CI 1.54~113.87,P<0.05)及PLC损伤(OR=13.98,95%CI 1.37~142.34,P<0.05)与术后PJK发生显著相关。结论年龄≥70岁、BMI>28.0 kg/m2、BMD T值<-3.5 SD、术前PI-LL>20°及PLC损伤是老年Ⅳ型CSOTLF患者行后路长节段内固定术后PJK发生的独立危险因素。术中应重视软组织保护和脊柱矢状位平衡恢复,术后应注意控制体重及抗骨质疏松治疗。

Risk factors for proximal junctional kyphosis after posterior long-segment internal fixation of chronic symptomatic osteoporotic thoracolumbar fracture in the elderly

Objective To investigate the risk factors associated with the occurrence of proximal junctional kyphosis(PJK)after posterior long-segment internal fixation for type IV chronic symptomatic osteoporotic thoracolumbar fracture(CSOTLF)in the elderly.Methods A case-control study was used to analyze the clinical data of 95 elderly patients with type IV CSOTLF treated in Honghui Hospital affiliated to Xi′an Jiaotong University from January 2013 to June 2018,including 32 males and 63 females,aged from 60 to 85 years(67.4±6.5)years].Injured segments were T11 in 17 patients,T12 in 37,L1 in 30 and L2 in 11.All patients were treated with posterior long-segment internal fixation and divided into PJK group(n=30)and non-PJK group(n=65)according to whether PJK occurred after surgery.Univariate analysis was performed for the correlation of the following indices with the incidence of postoperative PJK,including general information such as gender,age,body mass index(BMI),bone mineral density(BMD),history of smoking,cause of injury,comorbidities,injury segments,American Spinal Injury Association(ASIA)classification and time from injury to surgery,preoperative imaging data such as posterior junctional angle(PJA),sagittal vertical axis(SVA),pelvic incidence-lumbar lordosis difference(PI-LL),pelvic tilt(PT)and sacral slope(SS),basic surgical data such as posterior ligament complex(PLC)injury,location of upper instrumented vertebrae(UIV),location of lower instrumented vertebrae(LIV)and number of fixed segments.Multifactorial Logistic regression analysis was used to measure the independent risk factors associated with the occurrence of postoperative PJK.Results Univariate analysis showed that the incidence of postoperative PJK was correlated with age,BMI,BMD,preoperative PJA,preoperative SVA,preoperative PI-LL,PLC injury,location of UIV,location of LIV and number of fixed segments(all P<0.05),rather than gender,history of smoking,cause of injury,comorbidities,injury segments,ASIA classification,time from injury to surgery,preoperative PT and preoperative SS(all P>0.05).Multifactorial Logistic regression analysis showed that age≥70 years(OR=32.28,95%CI 3.83-272.29,P<0.01),BMI>28.0 kg/m2(OR=7.88,95%CI 1.63-37.99,P<0.01),BMD T value<-3.5 SD(OR=20.84,95%CI 2.36-183.93,P<0.01),preoperative PI-LL>20°(OR=13.30,95%CI 1.54-113.87,P<0.05)and PLC injury(OR=13.98,95%CI 1.37-142.34,P<0.05)were significantly associated with the occurrence of postoperative PJK.Conclusions Age≥70 years,BMI>28 kg/m2,BMD T value<-3.5 SD,preoperative PI-LL>20°and PLC injury are independent risk factors for the incidence of PJK after posterior long-segment internal fixation in elderly patients with type IV CSOTLF.Attention should be paid to soft tissue protection and sagittal balance restoration of the spine intraoperatively and weight control and anti-osteoporosis treatment postoperatively.