Noriega David C, Hernández-Ramajo Rubén, Rodríguez-Monsalve Milano Fiona, Sanchez-Lite Israel, Toribio Borja, Ardura Francisco, Torres Ricardo, Corredera Raul, Kruger Antonio
Unidad de Columna, Servicio Cirugía Ortopédica, Hospital Clínico Universitario de Valladolid, Calle Ramón y Cajal, 47008 Valladolid, Spain.
Unidad de Columna, Servicio Cirugía Ortopédica, Hospital Clínico Universitario de Valladolid, Calle Ramón y Cajal, 47008 Valladolid, Spain.
Spine J. 2017 Jan;17(1):70-75. doi: 10.1016/j.spinee.2016.08.004. Epub 2016 Aug 5.
Pedicle screws in spinal surgery have allowed greater biomechanical stability and higher fusion rates. However, malposition is very common and may cause neurologic, vascular, and visceral injuries and compromise mechanical stability.
The purpose of this study was to compare the malposition rate between intraoperative computed tomography (CT) scan assisted-navigation and free-hand fluoroscopy-guided techniques for placement of pedicle screw instrumentation.
STUDY DESIGN/SETTING: This is a prospective, randomized, observational study.
A total of 114 patients were included: 58 in the assisted surgery group and 56 in the free-hand fluoroscopy-guided surgery group.
Analysis of screw position was assessed using the Heary classification. Breach severity was defined according to the Gertzbein classification. Radiation doses were evaluated using thermoluminescent dosimeters, and estimates of effective and organ doses were made based on scan technical parameters.
Consecutive patients with degenerative disease, who underwent surgical procedures using the free-hand, or intraoperative navigation technique for placement of transpedicular instrumentation, were included in the study.
Forty-four out of 625 implanted screws were malpositioned: 11 (3.6%) in the navigated surgery group and 33 (10.3%) in the free-hand group (p<.001). Screw position according to the Heary scale was Grade II (4 navigated surgery, 6 fluoroscopy guided), Grade III (3 navigated surgery, 11 fluoroscopy guided), Grade IV (4 navigated surgery, 16 fluoroscopy guided), and Grade V (1 fluoroscopy guided). There was only one symptomatic case in the conventional surgery group. Breach severity was seven Grade A and four Grade B in the navigated surgery group, and eight Grade A, 24 Grade B, and one Grade C in free-hand fluoroscopy-guided surgery group. Radiation received per patient was 5.8 mSv (4.8-7.3). The median dose received in the free-hand fluoroscopy group was 1 mGy (0.8-1.1). There was no detectable radiation level in the navigation-assisted surgery group, whereas the effective dose was 10 µGy in the free-hand fluoroscopy-guided surgery group.
Malposition rate, both symptomatic and asymptomatic, in spinal surgery is reduced when using CT-guided placement of transpedicular instrumentation compared with placement under fluoroscopic guidance, with radiation values within the safety limits for health. Larger studies are needed to determine risk-benefit in these patients.
脊柱手术中的椎弓根螺钉可提供更高的生物力学稳定性和融合率。然而，位置不当非常常见，可能导致神经、血管和内脏损伤，并影响机械稳定性。
本研究旨在比较术中计算机断层扫描（CT）扫描辅助导航和徒手透视引导技术在椎弓根螺钉内固定置入时的位置不当率。
研究设计/地点：这是一项前瞻性、随机、观察性研究。
共纳入114例患者：辅助手术组58例，徒手透视引导手术组56例。
采用Heary分类法评估螺钉位置。根据Gertzbein分类法定义突破严重程度。使用热释光剂量计评估辐射剂量，并根据扫描技术参数估算有效剂量和器官剂量。
纳入连续接受徒手或术中导航技术进行经椎弓根内固定置入手术的退行性疾病患者。
625枚植入螺钉中有44枚位置不当：导航手术组11枚（3.6%），徒手组33枚（10.3%）（p<0.001）。根据Heary分级，螺钉位置为II级（导航手术4枚，透视引导6枚）、III级（导航手术3枚，透视引导11枚）、IV级（导航手术4枚，透视引导16枚）和V级（透视引导1枚）。传统手术组仅有1例有症状病例。导航手术组突破严重程度为7例A级和4例B级，徒手透视引导手术组为8例A级、24例B级和1例C级。每位患者接受的辐射剂量为5.8 mSv（4.8-7.3）。徒手透视组接受的中位剂量为1 mGy（0.8-1.1）。导航辅助手术组未检测到辐射水平，而徒手透视引导手术组的有效剂量为10 µGy。
与透视引导下置入相比，CT引导下经椎弓根内固定置入可降低脊柱手术中有症状和无症状的位置不当率，辐射值在健康安全范围内。需要更大规模的研究来确定这些患者的风险效益。
