McCarty Mary E, Mehlman Charles T, Tamai Junichi, Do Twee T, Crawford Alvin H, Klein Guy
Division of Pediatric Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA.
J Pediatr Orthop. 2009 Oct-Nov;29(7):755-9. doi: 10.1097/BPO.0b013e3181b76a2c.
Spondylolisthesis is often diagnosed and treated on the basis of measurements obtained from radiographs. Many physicians will perform surgery regardless of the patient's symptoms above a specific slip percentage. However, current methods used to assess slip percentage are vague and lack appropriate standardization, leaving physicians to devise personal evaluation techniques. This study presents a defined method to calculate slip percentage that takes advantage of modern technology, is fast and simple to perform, and shows excellent intraobserver/interobserver reliability.
Four pediatric orthopaedic attendings each reviewed 30 radiographic cases of spondylolisthesis (grades 1 to 4) at the L5 to S1 level. The radiographs were measured twice through computer using PACS information management software with an interval of 2 days to 2 weeks between sessions. Using the PACS line tool, observers superimposed 6 lines onto each radiograph from which measurements were derived. The numerator in slip percentage (anterior displacement) was determined by 2 methods: the distance between a line outlining the posterior border of the sacrum and A: a line outlining the posterior border of L5 or B: a line parallel starting at the inferior, posterior corner of L5. The denominator in slip percent was determined by 2 methods. C: length of the inferior border L5 or D: length of the superior border of L5. This resulted in 4 different equations of slip percentage: A/C, A/D, B/C, and B/D. Analysis was performed using intraclass correlation coefficient.
Slip percentage=A/D resulted in the highest intraclass correlation coefficient for both intraobserver and interobserver reliability (0.87 and 0.85, respectively). Slip percentage=B/C showed the poorest intraobserver reliability (0.69). Slip percentage=B/C and B/D had equally poor interobserver reliability (0.59).
Defining the numerator in slip percentage as the distance between a line outlining the posterior border of the sacrum and a line outlining the posterior border of L5 (A) results in the highest intraobserver/interobserver reliability. Defining the denominator in slip percentage as the length of the superior border of L5 (D) results in the highest intra/inter observer reliability.
Diagnostic level III.
腰椎滑脱症通常根据X线片测量结果进行诊断和治疗。许多医生在患者滑脱百分比高于特定数值时，无论其症状如何都会进行手术。然而，目前用于评估滑脱百分比的方法不明确且缺乏适当的标准化，导致医生只能自行设计个人评估技术。本研究提出了一种利用现代技术计算滑脱百分比的明确方法，该方法快速简便，并且在观察者内/观察者间具有出色的可靠性。
四位儿科骨科主治医师每人回顾了30例L5至S1水平的腰椎滑脱症（1至4级）的X线片病例。使用PACS信息管理软件通过计算机对X线片进行两次测量，两次测量之间间隔2天至2周。观察者使用PACS线工具在每张X线片上叠加6条线，并从中得出测量值。滑脱百分比（前移位）的分子通过两种方法确定：A：一条勾勒骶骨后缘的线与一条勾勒L5后缘的线之间的距离，或B：一条从L5下后角开始的平行线。滑脱百分比的分母通过两种方法确定。C：L5下缘的长度，或D：L5上缘的长度。这产生了4种不同的滑脱百分比计算公式：A/C、A/D、B/C和B/D。使用组内相关系数进行分析。
对于观察者内和观察者间的可靠性，滑脱百分比 = A/D的组内相关系数最高（分别为0.87和0.85）。滑脱百分比 = B/C的观察者内可靠性最差（0.69）。滑脱百分比 = B/C和B/D的观察者间可靠性同样较差（0.59）。
将滑脱百分比的分子定义为勾勒骶骨后缘的线与勾勒L5后缘的线之间的距离（A），可使观察者内/观察者间的可靠性最高。将滑脱百分比的分母定义为L5上缘的长度（D），可使观察者内/观察者间的可靠性最高。
诊断性III级。
