强直性脊柱炎胸腰椎后凸畸形矫形术后近端交界性后凸表现形式及相关因素分析

Manifestations and related factors of proximal junctional kyphosis after correction of thoracolumbar kyphosis deformity of ankylosing spondylitis

目的分析强直性脊柱炎(AS)胸腰椎后凸畸形矫形术后近端交界性后凸(PJK)表现形式及相关因素。方法采用回顾性研究,收集驻马店市第二人民医院2012年1月至2017年12月162例行矫形术的AS胸腰椎后凸畸形患者的临床资料,根据术后是否发生PJK,分为PJK组(15例)与无PJK组(147例),比较两组患者临床资料和影像学参数的差异。结果162例患者随访3~36(25.04±3.05)个月;随访期间,15例(9.26%)发生PJK。与无PJK组比较,PJK组年龄、Smith-Petersen截骨术比例明显升高(P<0.05);PJK组术前矢状面平衡明显下降(P<0.05),术前和术后近端交界角明显下降(P<0.05),末次随访近端交界角明显升高(P<0.05)。15例术后发生PJK的患者中,存在三种PJK的不同表现形式,包括胸椎后凸的自然进展7例,压缩性骨折5例,假关节3例。结论胸椎后凸的自然进展、压缩性骨折、假关节是PJK的三种不同表现形式,且年龄、手术方式、术前近端交界角和矢状面平衡均为AS胸腰椎后凸畸形矫形术后PJK发生的影响因素。

Objective To analyze the manifestations and related factors of proximal junctional kyphosis (PJK) after thoracolumbar kyphosis correction in ankylosing spondylitis (AS).Methods A retrospective study on the clinical data of 162 AS patients with thoracolumbar kyphosis who underwent orthopedic operation in the Second People’s Hospital of Zhumadian from January 2012 to December 2017 was conducted. According to the occurrence of PJK after operation, they were divided into PJK group (15 cases) and non-PJK group(147 cases). The differences of clinical data and imaging parameters between the two groups were compared.Results A total of 162 patients were followed up for 3 to 36 months, with an average of (25.04±3.05) months. During the follow-up period, 15 patients (9.26%) developed PJK. Compared with the non-PJK group, the age and the proportion of Smith-Petersen osteotomy in the PJK group increased significantly (P<0.05). Compared with the non-PJK group, the sagittal balance of PJK group decreased significantly (P<0.05), the proximal junction angle was smaller significantly (P<0.05) before and after operation, and the proximal junction angle was bigger significantly (P<0.05) at the last follow-up. Among the 15 patients who had PJK after operation, there were 3 different manifestations of PJK, including 7 cases of natural progression of thoracic kyphosis, 5 cases of compressive fracture and 3 cases of pseudoarthrosis.Conclusions The natural progression of thoracic kyphosis, compressive fracture and pseudoarthrosis are three different manifestations of PJK. Age, surgical method, preoperative proximal junction angle and sagittal balance are all the influencing factors for the occurrence of PJK after thoracolumbar kyphosis correction for AS.