[目的]通过测量胸、腰椎爆裂性骨折在手术前、后骨折椎体内因骨质缺遗留的空隙大小在CT影像上的变化,探讨伤椎椎体高度丢失的程度与手术后椎体高度恢复的程度对骨折椎体内空隙大小的影响及其临床意义.[方法]回顾性分析总结40例胸、腰椎爆裂性骨折患者手术前、后的影像资料.40例患者均采用后路开放复位椎弓根螺钉内固定术.在术前和术后均行胸腰椎CT扫描,选取正中矢状位或旁正中矢状位CT片用来测量出手术前骨折椎体残留的最小高度与下位邻椎高度的百分比(Pre-VBH)、手术复位后骨折椎体恢复的最大高度与下位邻椎高度的百分比(Po-VBH)以及骨折复位后椎体内垂直方向上空隙的高度与下位邻椎高度的百分比(GH).分析GH与Pre-VBH、Po-VBH的关系.同时对15例椎体骨折不愈合而导致的内固定断裂病例进行回顾性分析以探讨因为复位后椎体内空隙过大导致骨折不愈合的椎体压缩百分比的临界值.[结果]手术前骨折椎体残留的最小高度(Pre VBH)为20.8％～60％,平均为48.2％;手术后骨折椎体恢复的最大高度(Po-VBH)为71.5％～127.3％,平均为93.3％;Po-VBH与Pre-VBH的差值为21.4％～79.1％,平均为45.7％;手术后骨折椎体内实测的空隙高度(GH)为19.3％～76.7％,平均为45.3％.经统计学分析Po-VBH与Pre-VBH的差值数值与GH数值无显著性差异.15例骨折不愈合导致内固定失败病例测算出的骨折椎体复位后椎体内GH为44.5％～67.5％.[结论]伴随压缩性骨折椎体高度的恢复、骨折椎体内在垂直方向会出现骨缺损空隙,空隙高度的实测数值近似于“术后骨折椎体恢复的最大高度减去术前骨折椎体残留的最小高度”,可以用以下公式计算:GH≌“Po VBH”-“Pre-VBH”.如果复位后椎体内空隙的百分比大于骨折椎体复位后高度的44.5％,很可能会导致胸腰椎爆裂性骨折手术后不愈合.“,”[Objective]To investigate the significance of the degree of vertebral height loss and the degree of recovery of vertebral body height after operation and the clinical significance by measuring the size of the gap left by the bone defect in the thoracolumbar spine burst fracture before and after operation in CT images.[Methods]A retrospective review was made based on imaging material of forty patients who accepted posterior restoration and instrumentation through pedicle-screw implant technique because of thoracic or lumbar spine burst fracture.The preoperative and postoperative computed tomography (CT) scans were performed for each case,mid-sagittal or para mid sagittal scans were selected to measure the preoperative minimal residual vertebral body height (Pre-VBH),postoperative maximal vertebral body height restoration (Po VBH) and the maximal vertical gap-height (GH) within the restored vertebral body;the relationship between GH and PreVBH,Po-VBH was analyzed.At the same time,15 cases of internal fixation fracture caused by nonunion of vertebral fracture were analyzed retrospectively in order to explore the critical value of the percentage of vertebral compression,because of the too large gap in the vertebral body resulting in fracture nonunion.[Results] Preoperative minimal residual vertebral body height (Pre-VBH) ranged from 20.8％ to 60％,averaged 48.2 ％;postoperative maximal vertebral body height restoration (Po VBH) was 71.5 ％ ～ 127.3 ％,averaged 93.3％;difference between Po-VBH and Pre-VBH was 21.4％～79.1％,averaged 45.7％;the maximal vertical gap-height (GH) within the restored vertebral body was 19.3 ％ ～76.7％,averaged 45.3 ％.Statistical analysis demonstrated there was no significant difference between the value of Po-VBH minus Pre-VBH and the value of GH.The value of gap height in restored vertebral body measured and calculated in 15 failed cases of bone nonunion ranged from 44.5 ％ to 67.5％.[Conclusion] Accompanying the restoration of compressed vertebral body height,there is always vertical gap left within the fractured vertebral body,the height of vertical gap is nearly equal to postoperative maximal vertebral body height restoration (Po-VBH) minus preoperative minimal residual vertebral body height (Pre-VBH),which can facilitate us to formulate a formula:postoperative gap height (GH)≌(Po-VBH)-(Pre-VBH).If the value of the gap-height within restored vertebral body is 44.5％ more than the height of vertebral body after fracture reduction,bone nonunion may be an inevitable result for thoracic or lumbar burst fracture.