成人退变性脊柱侧凸后路长节段融合内固定术后相关并发症的危险因素

Risk factors of implant-related complications in adult degenerative scoliosis with posterior long segment internal fixation

目的分析后路长节段融合内固定术治疗成人退行性脊柱侧凸(adult degenerative scoliosis,ADS)内固定相关并发症的危险因素。方法回顾性分析2013年6月至2016年1月接受后路矫形长节段融合内固定术治疗ADS患者99例的病历资料。通过分析手术前后及随访期间的相关影像学资料,评估内固定及相关并发症的发生情况,观察时间点为术前、出院前、术后6个月、术后出现并发症症状时及末次随访时。内固定相关并发症包括近端交界性后凸畸形、近端交界性失败、远端交界性后凸畸形或失败、断棒、螺钉松动、断裂或拔出,以及随访期间X线片显示椎体间植入物、椎板钩或固定螺钉移位。统计术后内固定相关并发症的发生率。将所有纳入病例分为并发症组和无并发症组,对两组患者的基本情况及影像学指标进行统计学分析,采用单因素分析确定潜在危险因素,多元Logistics回归分析内固定相关并发症的独立危险因素。临床疗效评价采用Oswestry功能障碍指数、日本骨科协会评分、疼痛视觉模拟评分及腰椎僵硬性残疾指数等。再将患者按照骨盆入射角与腰椎前凸角差值(pelvic incidence minus lumbar lordosis mismatch,PI-LL)<10°、10°~20°和>20°进行分组,对组间手术前后影像学测量参数、临床评价参数进行统计分析,通过分析长节段融合矫形术治疗ADS的疗效验证国人最佳的PI-LL匹配值。结果共99例患者纳入研究,内固定相关并发症发生率为30.3%。单因素分析结果显示内固定相关并发症的慢性病危险因子包括糖尿病(OR= 3.52,P=0.001)和输血(OR=2.61,P=0.030),手术及术前影像学危险因子包括截骨(OR=4.33,P=0.000)和术前矢状面平衡(sagittal vertical axis,SVA,OR=1.03,P=0.000);内固定相关并发症风险增高的趋势因素包括贫血(OR=1.17,P=0.810)、心脏合并症(OR=1.80,P=0.290)和住院时间(OR=1.11,P=0.110)。多因素Logistic回归模型结果显示独立危险因子为截骨(OR=3.05,P=0.032)和术前SVA(OR=1.03,P=0.007)。PI-LL 10°~20°组的影像学参数和临床疗效参数均优于或部分优于其他两组。PI-LL 10°~20°组术后SVA明显小于PI-LL<10°组(t=2.399,P=0.020)和PI-LL>20°组(t=-3.074,P=0.005)。PI-LL 10°~20°组内固定相关并发症发生率明显低于PI-LL<10°组(t=1.584,P=0.003)。生存分析结果显示PI-LL 10°~20°组明显优于PI-LL<10°组(χ^2=7.782,P=0.005),且优于PI-LL>20°组但差异无统计学意义(χ^2=2.542,P=0.111)。结论成人退变性脊柱侧凸患者长节段融合内固定术后内固定相关并发症的危险因素包括截骨和术前SVA。PI-LL在10°~20°的患者术后有较好的影像学表现和临床疗效。

Objective To analyze the risk factors of implant-related complications in adult patients with adult degenerative scoliosis (ADS) who underwent long-level internal fixation. Methods This was a retrospective study that analyzed 99 cases of adult degeneration scoliosis patients who underwent long level posterior pedicle screw fixation in our hospital between June 2013 and January 2016. The internal fixation and related complications were evaluated by measuring and analyzing the radiographic data of the postoperative X-ray films. The timepoints of measurement were pre-operation, before discharge, half a year, 1 year, when complications occur and the final follow-up after operation. Implant-related complications included proximal junctional kyphosis (PJK), proximal junctional failure (PJF), distal junctional kyphosis/failure (DJK/DJF), rod breakage in addition to other radiographic implant-related complications (that were not related to PJF) such as screw loosening, breakage or pullout, or interbody graft and hook or set screw dislodgements seen on follow-up radiographs. The incidence of postoperative implant-related complications was counted. All the cases included in the study were divided into the complication group and the non-complication group. Statistical difference between groups at different follow-up time point was analyzed. Potential risk factors were identified using univariate testing. Multivariate Logistics regression was used to analyze the independent risk factors for implant-related complications. The postoperative functional scores were assessed using the Oswestry Disability Index (ODI), Japanese Orthopaedic Association Scores (JOA), Visual Analogue Scale (VAS), and Lumbar Stiffness Disability Index (LSDI). Functional scores were tested using group t tests. Patients were divided into groups according to PI-LL <10 °, 10°-20 ° and > 20 °. The preoperative and postoperative radiographical parameters and clinical function score among each groupwere compared.The best PI-LL matching value was verified by analyzing the effect of long-segment fusion orthopedics on ADS. Results Ninety-nine ADS patients who underwent long level posterior fixation were included. The incidence of patients with mechanical complications was 30.3%. Univariate analysis showed that chronic risk factors of postoperative implant-related complications after surgery of ASD included diabetes (OR=3.52, P=0.001) and blood transfusion (OR=2.61, P=0.030);surgical risk factor isosteotomy (OR=4.33, P=0.000);preoperative imaging risk factor was preoperative SVA (OR=1.03, P=0.000);the risk factors for increased risk of the implant-related complications included anemia (OR=1.17, P=0.810), cardiac complications (OR=1.80, P=0.290) and hospital stay (OR=1.11, P=0.110). Independent predictors identified on multivariate Logistics regression modeling included osteotomy (OR=3.05, P=0.032), and preoperative SVA (OR=1.03, P=0.007). The radiographical parameters and clinical function scores of the PI-LL 10°-20° group were better than or partially superior to those of the PI-LL<10° group and the PI-LL>20° group. The postoperative SVA of the PI-LL 10°-20° group was significantly lower than that of the PI-LL<10° group (t=2.399, P=0.020) and the PI-LL>20° group (t=-3.074, P=0.005). The incidence of implant-related complications in the PI-LL 10°-20° group was significantly lower than that in the PI-LL<10° group (t=1.584, P=0.003). Survival analysis showed that the PI-LL 10°-20° group was significantly better than the PI-LL<10° group (χ2=7.782, P=0.005), while the PI-LL 10°-20° group had better survival than PI-LL>20° group, althoughthatwas not statistically significant (χ2=2.542, P=0.111). Conclusion Risk factors of postoperative implant-related complications after surgery of ASD included osteotomy and preoperative SVA. Patients with one or more of these risk factors should be informed of the risk increase with informed consent. Patients with PI-LL between 10 ° and 20 ° had better postoperative radiographical parameters and clinical functional scores. They should be optimized preoperatively and followed up closely during the postoperative period.