Lehman Ronald A, Potter Benjamin K, Kuklo Timothy R, Chang Audrey S, Polly David W, Shawen Scott B, Orchowski Joseph R
Orthopaedic Surgery Service, Walter Reed Army Medical Center, Washington, DC, USA.
J Spinal Disord Tech. 2004 Aug;17(4):277-83. doi: 10.1097/01.bsd.0000095399.27687.c5.
Preparation of the thoracic pedicle screw tract is a critical step prior to the placement of screws. The ability to detect pedicle wall violation(s) by probing prior to insertion of thoracic pedicles screws, however, has not been studied. The purpose of this study was to evaluate the inter- and intraobserver agreement and the accuracy in detecting thoracic pedicle screw tract violation(s) among surgeons at various levels of training.
With use of a straightforward trajectory, under direct visualization, 108 thoracic pedicle screw tracts (54 cadaveric thoracic vertebrae) were prepared in a standard fashion, followed by tapping with a 4.5-mm cannulated tap. A deliberate pedicle violation was randomly created by an independent investigator in either the anterior, the medial, or the lateral wall in 65 pedicles. Following this, four blinded, independent surgeons at various levels of training probed the specimens on three separate occasions to determine if a breach was present (1,296 discrete data points). Surgeon findings were then recorded as breach present or absent and, if present, breach location. The Cohen kappa correlation coefficient (kappa a) and 95% confidence interval were used to assess the accuracy of the observers and the inter- and intraobserver agreement.
The mean accuracy over three iterations, the validity in detecting the breach location, and the intraobserver agreement varied by level of training and experience, with the most experienced observer (observer 1) scoring the best and the least experienced observer (observer 4) scoring the worst. The three most senior surgeons had good intraobserver agreement. Interobserver agreement was low between the four observers.
An observer's ability to accurately detect the presence or absence of a pedicle tract violation and the breach location, if present, is dependent on the surgeon's level of training. Probing the pedicle tract prior to placement of pedicle screws in the thoracic spine is likely a learned skill that improves with repetition and experience.
胸椎椎弓根螺钉通道的制备是螺钉置入前的关键步骤。然而，在插入胸椎椎弓根螺钉之前通过探查检测椎弓根壁破损的能力尚未得到研究。本研究的目的是评估不同培训水平的外科医生在检测胸椎椎弓根螺钉通道破损方面的观察者间和观察者内一致性以及准确性。
采用直接可视化下的简单轨迹，以标准方式制备108个胸椎椎弓根螺钉通道（54个尸体胸椎），随后用4.5毫米空心丝锥攻丝。一名独立研究者在65个椎弓根的前壁、内侧壁或外侧壁随机制造故意的椎弓根破损。在此之后，四名不同培训水平的盲法独立外科医生在三个不同场合对标本进行探查，以确定是否存在破损（1296个离散数据点）。然后记录外科医生的发现为存在或不存在破损，若存在，则记录破损位置。采用Cohen κ相关系数（κa）和95%置信区间来评估观察者的准确性以及观察者间和观察者内的一致性。
在三次重复过程中的平均准确性、检测破损位置的有效性以及观察者内一致性因培训水平和经验而异，经验最丰富的观察者（观察者1）得分最高，经验最少的观察者（观察者4）得分最低。三名资历最深的外科医生具有良好的观察者内一致性。四名观察者之间的观察者间一致性较低。
观察者准确检测椎弓根通道是否存在破损以及若存在时破损位置的能力取决于外科医生的培训水平。在胸椎中放置椎弓根螺钉之前探查椎弓根通道可能是一项通过重复和经验得以提高的习得技能。
