顶椎远端截骨治疗强直性脊柱炎胸腰椎后凸畸形

Osteotomy distal to apex for thoracolumbar kyphosis secondary to ankylosing spondylitis

中文关键词:  强直性脊柱炎  胸腰椎后凸  经椎弓根椎体截骨  顶椎远端

英文关键词:Ankylosing spondylitis  Thoracolumbar kyphosis  Pedicle subtraction osteotomy  Distal to apex

中文摘要:

  【摘要】 目的：探讨顶椎远端经椎弓根椎体截骨（pedicle subtraction osteotomy，PSO）治疗强直性脊柱炎（ankylosing spondylitis，AS）胸腰椎后凸畸形的适应证和疗效。方法：2001年1月~2017年8月采用顶椎远端PSO手术治疗39例AS胸腰椎后凸畸形患者，男35例，女4例；年龄20~59岁（38.2±10.5岁）。顶椎分布于T9~L1之间。9例合并假关节，其中5例位于顶椎远端者伴神经功能损害，4例位于顶椎者不伴神经功能损害。2例术前已行双侧髋关节置换术；37例术前伴一侧或双侧髋关节功能障碍，巴氏AS放射指数（BASRI）左侧为2.56±0.77分，右侧为2.42±0.65分，其中24例患者单侧或双侧髋关节间隙明显狭窄（BASRI≥3分）。22例术前腰椎前凸不足，1例腰椎后凸。腰背痛VAS评分4.83±2.03。记录患者的截骨节段和手术并发症；术前、术后及末次随访时摄站立位全脊柱正、侧位X线片，测量胸腰椎最大后凸角（global kyphosis，GK）、矢状面躯干偏移（sagittal vertical axis，SVA）、腰椎前凸角（lumbar lordois，LL）、固定节段后凸角（angle of fused segments，AFS）和颌眉角（chin-brow vertical angle，CBVA）。结果：39例患者均完成矫形手术，截骨节段：T12 2例，L1 8例，L2 16例，L3 12例，L5 1例。1例术中截骨椎脱位；1例术中不良置钉；1例术中硬脊膜破裂，术后脑脊液漏；无术中大血管损伤、术后无感染等并发症。术后所有患者后凸畸形及平视功能得到改善，腰背痛症状缓解。随访14~144个月（40.26±28.52个月），2例内固定断裂，其中1例行翻修术，3个月随访内固定在位，融合良好；1例无症状，固定区域稳定，未处理。所有患者术后无假关节形成。术前GK、LL、SVA、CBVA分别为69.47°±14.37°、19.32°±19.19°、120.77±48.34mm、23.00°±17.08°，术后分别为28.76°±12.83°、51.62°±16.08°、26.56±41.12mm、4.19°±6.58°，末次随访时分别为30.53°±13.95°、49.32°±16.64°、32.56±35.14mm、4.78°±6.22°，术后与术前比较均有显著性差异（P<0.05），末次随访时与术后比较均无统计学差异（P>0.05）。术后AFS平均为22.77°±10.86°，末次随访时为24.29°±10.99°，无统计学差异（P>0.05）。末次随访时VAS评分为1.82±1.64，与术前比较有显著性差异（P<0.05）。结论：AS胸腰椎后凸畸形患者于顶椎远端行PSO手术可以明显改善矢状面平衡，对以矫正SVA为主要目的、术前顶椎区假关节不伴有神经损害、顶椎远端假关节伴有神经损害、术前髋关节功能受限、顶椎位置位于胸腰段以上、腰椎前凸不足或后凸且顶椎位置位于胸腰交界处的患者，于顶椎远端截骨可以取得满意手术疗效。

英文摘要:

  【Abstract】 Objectives: To investigate the indications and efficacy of performing pedicle subtraction osteotomy (PSO) distal to the apex for thoracolumbar kyphosis caused by ankylosing spondylitis(AS). Methods: Between January 2001 and August 2017, 39 AS patients(35 males and 4 females) treated with osteotomy distal to apical region were retrospectively reviewed. The mean age was 38.2±10.5 years(range, 20 to 59 years). The location of apex ranged from T9 to L1. Preoperative pseudarthrosis was found in 9 cases, involving 4 cases with pseudarthrosis located at apex but without neurologic deficit and 5 cases with the lesions located below apex with neurologic deficit. Bilateral total hip replacement(THR) was performed for 2 patients. Besides, 37 cases presented with unilateral or bilateral hip dysfunction before surgery. The mean BASRI-hip scores were 2.56±0.77 for the left side and 2.42±0.65 for the right side. Severe narrowing of unilateral or bilateral hip joint space(BASRI≥3) was found in 24 out of 39 cases. Hypolordotic lumbar spine was found in 22 cases while kyphotic lumbar spine was identified in 1 case. Preoperative CBVA and VAS were 23.00°±17.08° and 4.83±2.63, respectively. The osteotomy level, complications were assessed. Also, the radiographic parameters including global kyphosis(GK), sagittal vertical axis(SVA), lumbar lordosis(LL), angle of fused segments(AFS), and chin-brow vertical angle(CBVA) were evaluated. Results: All the 39 patients underwent correction surgery. The osteotomy level varied from T12 to L5(T12 2 cases, L1 8 cases, L2 16 cases, L3 12 cases and L5 1 case). Surgical complications included one case of intraoperative vertebral subluxation and one case of screw malposition. Intraoperative dural tears with cerebrospinal fluid leakage was observed in one case and was resolved at discharge. Also, no vascular complication, infection or postoperative nonunion was found. Kyphotic deformity, persistent back pain and impaired horizontal gaze were all resolved postoperatively. The average follow-up was 40.26±28.52 months, ranging from 14 to 144 months. One patient underwent revision surgery for rod breakage and achieved solid bone union at 3-month follow-up. On the contrary, conservative treatment was performed for another case with stable fused region. The preoperative GK, LL, SVA and CBVA were 69.47°±14.37°, 19.32°±19.19°, 120.77±48.34mm and 23.00°±17.08°, respectively. The above-mentioned parameters were changed to 28.76°±12.83°, 51.62°±16.08°, 26.56±41.12mm and 4.19°±6.58° after operation, respectively, and there was significant difference with that of preoperation(P<0.05). At the final follow-up, the above-mentioned parameters were 30.53°±13.95°, 49.32°±16.64°, 32.56±35.14mm, 4.78°±6.22°, and there was no significant difference with that of postoperation(P>0.05). AFS was 22.77°±10.86° of postoperation, and 24.29°±10.99° at the final follow-up(P>0.05). VAS was 1.82±1.64 at the final follow-up, and there was significantly difference with that of preperation(P<0.05). Conclusions: PSO distal to apex was a feasible and effective method to restore sagittal balance in AS-related kyphosis. Osteotomy distal to apex can be considered with the following criteria including primary surgical goal was to correct the SVA instead of GK, pseudarthrosis located at apex without neurologic deficit, pseudarthrosis located below apex with neurologic deficit, preoperative restricted hip function, apex located at middle thoracic spine, and flattening of the lumbar spine with apex at thoracolumbar junction.