Department of Orthopaedics, University of Minnesota, Minneapolis, USA.
Spine (Phila Pa 1976). 2011 Jul 1;36(15):E1027-32. doi: 10.1097/BRS.0b013e3181ff5b73.
Human Cadaveric Experimental Study.
To determine the validity of surgeon perception of pedicle screw position inserted using intraoperative three-dimensional (O-arm) image-guided screw insertion.
A surgeon's ability to detect pedicle wall violations intraoperatively is crucial for optimal pedicle screw placement. Accuracy of use of a probe or sound to assess pedicle breach is not optimal and may require experience. Intraoperative navigation has been shown to improve screw placement accuracy. It has not been shown, however, whether navigation in combination with screw tract palpation can further increase the surgeon's ability to detect a pedicle breach in pedicle screw placement in the cervical, thoracic, and lumbosacral spine.
Four hundred eighteen screws were inserted using three-dimensional image guidance transpedicularly from C2 to S1 in 10 fresh frozen cadavers. Screw tracts were created using navigation and then probed. After probing, the surgeon stated whether he perceived that the screw would be in, out laterally, or out medially. After screw insertion for all the levels, open dissection was then performed to determine the actual pedicle screw position. The surgeon's perception of screw position was compared to the dissection results.
The overall specificity, sensitivity, positive predictive value, and negative predictive value of the surgeon perception of pedicle screw position were 87%, 80%, 78% and 88%, respectively. Accuracy of surgeon perception of pedicle screw position was significantly less than in the cervical spine when compared with thoracic and lumbosacral spine.
Surgeon perception of a navigated pedicle screw position is accurate in the thoracic and lumbar spine. Detection of pedicle screw violations by surgeon perception in the cervical spine is less accurate and does not reliably lead to accurate screw placement.
人体尸体实验研究。
确定术中三维（O 臂）图像引导下椎弓根螺钉置入时外科医生对椎弓根螺钉位置的感知的有效性。
外科医生在术中检测椎弓根壁侵犯的能力对于最佳椎弓根螺钉放置至关重要。使用探针或声音评估椎弓根破裂的准确性并不理想，并且可能需要经验。术中导航已被证明可以提高螺钉放置的准确性。然而，尚未表明导航与螺钉轨迹触诊相结合是否可以进一步提高外科医生在颈椎、胸椎和腰骶椎椎弓根螺钉放置中检测椎弓根破裂的能力。
在 10 个新鲜冷冻尸体中，从 C2 到 S1 经皮使用三维图像引导插入了 418 个螺钉。使用导航创建螺钉轨迹，然后进行探查。探查后，外科医生表示他是否认为螺钉会在内侧、外侧或内侧。在所有水平插入螺钉后，然后进行开放性解剖以确定实际的椎弓根螺钉位置。将外科医生对螺钉位置的感知与解剖结果进行比较。
外科医生对椎弓根螺钉位置的感知的总体特异性、敏感性、阳性预测值和阴性预测值分别为 87%、80%、78%和 88%。与颈椎相比，外科医生对胸椎和腰椎椎弓根螺钉位置的感知准确性明显更高。
外科医生对导航椎弓根螺钉位置的感知在胸椎和腰椎中是准确的。在颈椎中，外科医生对椎弓根螺钉侵犯的检测准确性较低，并且不能可靠地导致准确的螺钉放置。
