成人脊柱畸形矫形内固定术后发生断棒的危险因素及治疗策略

Risk factors for rod fracture after correction and internal fixation for adult spinal deformity and treatment strategy

中文关键词:  成人脊柱畸形  矫形手术  内固定  断棒  假关节

英文关键词:Adult spinal deformity  Corrective surgery  Internal fixation  Pseudoarthrosis

中文摘要:

  【摘要】 目的：探讨成人脊柱畸形矫形内固定术后断棒的发生率、相关危险因素及治疗策略。方法：回顾性分析2015年1月～2019年12月于陆军军医大学第二附属医院骨科就诊并接受后路矫形内固定手术治疗的成人脊柱畸形患者的临床资料，共纳入79例患者，年龄45~75岁（62.1±7.7岁），随访时间24~59个月（30.6±9.2个月）。按照随访期间是否发生断棒分为断棒组和无断棒组。记录两组患者的性别、年龄、身体质量指数（body mass index，BMI）、骨密度（bone mineral density，BMD）T值、合并症以及随访时间。测量两组患者手术前后的矢状面垂直轴（sagittal vertical axis，SVA）、骨盆入射角（pelvic incidence，PI）、骨盆倾斜角（pelvic tilt，PT）、骶骨倾斜角（sacral slope，SS）、胸椎后凸角（thoracic kyphosis，TK）、腰椎前凸角（lumbar lordosis，LL）、LL-TK值、PI-LL值以及冠状面Cobb角。收集两组患者的手术相关信息，包括手术时间、术中失血量、固定融合节段数、是否三柱截骨、下端固定椎是否累及骶骨或骨盆以及是否有椎间融合。记录断棒组患者的断棒部位、断棒时间以及是否行翻修手术。采用Spearman检验对两组患者的数据对比分析，将筛选出的阳性指标行多因素Logistic回归分析，计算比值比（OR）及95%置信区间（95%CI）。结果：79例患者中14例患者（17.7%）发生断棒，11例双侧断棒，3例单侧断棒。断棒发生时间为术后6~31个月（平均16个月），其中10例患者（71.4%）发生在术后24个月内，4例患者（28.6%）发生在术后24个月以后。11例患者断棒发生在截骨部位，3例位于T10～T12平面。Spearman检验结果显示较小的年龄（P=0.038）、较多的融合节段数（P＜0.001）、三柱截骨（P＜0.001）以及较大的术前SVA（P＜0.001）与断棒的发生相关。多因素Logistic回归分析结果显示融合节段数较多（P=0.037, OR=2.043，95%CI=1.046～3.992）、三柱截骨（P=0.044，OR=0.113，95%CI=0.014～0.941）以及术前SVA值大（P=0.006，OR=1.119，95%CI=1.032～1.212）是成人脊柱畸形术后断棒发生的高危因素。11例断棒患者（78.6%）因顽固性腰背痛症状或脊柱畸形进展而行翻修手术，均采用后路原切口入路更换断棒，并附加卫星棒技术，其中5例同时一期经腹膜后入路行前路取髂骨植骨融合术，随访效果满意。结论：成人脊柱畸形矫形内固定术后断棒发生率较高。断棒发生的危险因素主要有长节段融合、三柱截骨以及患者术前SVA较大。“多棒技术”以及前路植骨融合技术可用于断棒的翻修手术。

英文摘要:

  【Abstract】 Objectives: To investigate the incidence, relative risk factors and treatment strategies of rod breakage after correction and internal fixation of adult spinal deformity(ASD). Methods: The clinical data of ASD patients treated with posterior corrective operation and internal fixation in the Department of Orthopedics of Xinqiao Hospital between January 2015 and December 2019 were analyzed retrospectively. A total of 79 patients aged 45-75 years(62.1±7.7 years) were included. The follow-up period was 24-59 months(30.6±9.2 months). According to whether the rod was broken during the follow-up period, the patients were divided into rod fracture group(RF group) and rod non-fracture group(NRF group). The sex, age, body mass index(BMI), bone mineral density(BMD) T value, complications and follow-up time of the two groups were recorded. The sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), sacral slope(SS), thoracic kyphosis(TK), lumbar lordosis(LL), LL-TK value, PI-LL value, and coronal Cobb angle were measured before and after operation. The operation-related information of the two groups was collected, including operative time, intraoperative blood loss, the number of fixed fusion segments, whether three-column osteotomy, whether the lower fixed vertebrae involved the sacrum or pelvis, and whether there was interbody fusion. The position, time and revision operation of the broken rod in the RF group were recorded. The data of the two groups were compared and analyzed by Spearman test, and the positive parameters were further analyzed by multivariate logistic regression to find potential risk factors for rod fractures. Odds ratio(OR) and 95% confidence interval(CI) were calculated. Results: Among the 79 patients, rod fracture occurred in 14 patients(17.7%), with bilateral fracture in 11 cases and unilateral fractures in 3 cases. The time of rod fracture occurred at 6-31 months after operation(averaged 16 months), which occurred at the early stage after operation(within 24 months) in 10 patients(71.4%) and at 24 months after operation in 4 patients(28.6%). The rod fracture occurred at the osteotomy site in 11 cases and at T10-12 level in 3 cases. Spearman test showed that younger age(P=0.038), more levels of fusion(P<0.001), 3-column osteotomy(P<0.001) and bigger preoperative SVA(P＜0.001) were correlated with rod breakage. Multivariate logistic regression analysis showed that more levels of fusion (P=0.037, OR=2.043, 95%CI=1.046-3.992), 3-column osteotomy(P=0.044, OR=0.113, 95%CI=0.014-0.941), and bigger preoperative SVA(P=0.006, OR=1.119, 95%CI=1.032-1.212) were the risk factors of rod breakage after corrective surgery for ASD patients. 11 patients(78.6%) underwent revision surgery because of intractable low back pain or progression of spinal deformities, and were replaced the broken rods through posterior primary incision approach, combined with satellite rod technique; And meanwhile, out of which, 5 patients underwent one-stage retroperitoneal approach for anterior iliac bone graft fusion and received satisfactory results during follow-up. Conclusions: The incidence of rod breakage after correction and internal fixation in ASD patients is high. More levels of fusion, 3-column osteotomy, and greater preoperative SVA were significantly associated with rod fracture. The "Multi-rod technique" and anterior bone graft fusion technique can be used in the revision operation of rod fracture.