Smith Brandon W, Joseph Jacob R, Kirsch Michael, Strasser Mary Oakley, Smith Jacob, Park Paul
Department of Neurosurgery, Michigan Medicine, Ann Arbor, Michigan.
Neurosurg Focus. 2017 Aug;43(2):E9. doi: 10.3171/2017.5.FOCUS17200.
OBJECTIVE Percutaneous pedicle screw insertion (PPSI) is a mainstay of minimally invasive spinal surgery. Traditionally, PPSI is a fluoroscopy-guided, multistep process involving traversing the pedicle with a Jamshidi needle, placement of a Kirschner wire (K-wire), placement of a soft-tissue dilator, pedicle tract tapping, and screw insertion over the K-wire. This study evaluates the accuracy and safety of PPSI with a simplified 2-step process using a navigated awl-tap followed by navigated screw insertion without use of a K-wire or fluoroscopy. METHODS Patients undergoing PPSI utilizing the K-wire-less technique were identified. Data were extracted from the electronic medical record. Complications associated with screw placement were recorded. Postoperative radiographs as well as CT were evaluated for accuracy of pedicle screw placement. RESULTS Thirty-six patients (18 male and 18 female) were included. The patients' mean age was 60.4 years (range 23.8-78.4 years), and their mean body mass index was 28.5 kg/m (range 20.8-40.1 kg/m). A total of 238 pedicle screws were placed. A mean of 6.6 pedicle screws (range 4-14) were placed over a mean of 2.61 levels (range 1-7). No pedicle breaches were identified on review of postoperative radiographs. In a subgroup analysis of the 25 cases (69%) in which CT scans were performed, 173 screws were assessed; 170 (98.3%) were found to be completely within the pedicle, and 3 (1.7%) demonstrated medial breaches of less than 2 mm (Grade B). There were no complications related to PPSI in this cohort. CONCLUSIONS This streamlined 2-step K-wire-less, navigated PPSI appears safe and accurate and avoids the need for radiation exposure to surgeon and staff.
目的 经皮椎弓根螺钉置入术（PPSI）是微创脊柱手术的主要手段。传统上，PPSI是一个在荧光透视引导下的多步骤过程，包括用Jamshidi针穿过椎弓根、置入克氏针（K针）、置入软组织扩张器、椎弓根通道攻丝以及沿K针置入螺钉。本研究评估了一种简化的两步法PPSI的准确性和安全性，该方法使用导航锥钻攻丝，随后在不使用K针或荧光透视的情况下进行导航螺钉置入。方法 确定采用无K针法进行PPSI的患者。从电子病历中提取数据。记录与螺钉置入相关的并发症。评估术后X线片以及CT以确定椎弓根螺钉置入的准确性。结果 纳入36例患者（18例男性和18例女性）。患者的平均年龄为60.4岁（范围23.8 - 78.4岁），平均体重指数为28.5 kg/m²（范围20.8 - 40.1 kg/m²）。共置入238枚椎弓根螺钉。平均置入6.6枚椎弓根螺钉（范围4 - 14枚），平均涉及2.61个节段（范围1 - 7个节段）。术后X线片复查未发现椎弓根破裂。在进行CT扫描的25例（69%）亚组分析中，评估了173枚螺钉；170枚（98.3%）完全位于椎弓根内，3枚（1.7%）显示内侧破裂小于２mm（B级）。该队列中无与PPSI相关的并发症。结论 这种简化的两步无K针导航PPSI似乎安全且准确，避免了术者和工作人员受到辐射暴露。
