Posterior Cervical Screw Placement Without Image Guidance
Department of Orthopaedic and Trauma Surgery, Merlin Park Regional Hospital, Galway, Ireland. Journal of Spinal Disorders & Techniques
(Impact Factor: 2.2).
09/2006; 19(6):383-8. DOI: 10.1097/00024720-200608000-00001
The use of lateral mass screws for posterior cervical fixation has become widespread. It allows for stable fixation in the absence of the posterior elements and confers immediate stability. Lateral mass fixation has been shown to impart equal or greater biomechanical stability when compared to posterior interosseous wiring or anterior plating. The utilization of intraoperative fluoroscopy to guide screw placement has been recommended previously and is considered routine practice in many centers. This prospective study shows that lateral mass screws can be safely positioned without intraoperative fluoroscopy. The procedure is both safe and effective, provided that the operator has a thorough understanding of lateral mass anatomy coupled with careful adherence to the established guidelines for screw positioning. Exposure to radiation is reduced and time taken for operation can be shortened.
Available from: ncbi.nlm.nih.gov
- "However, exposure to radiation during surgery is associated with radiation-related complications13,17). Thus, other surgeons such as Roche et al.23) introduced the modified An's method for performing lateral mass screw fixation without the help of a fluoroscope. The entrance point was 1 mm medial to the center of the lateral mass, and the screw was fixed at 33° laterally and 17° cranially. "
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ABSTRACT: The purpose of this study was 1) to analyze clinically-executed cervical lateral mass screw fixation by the Kim's technique as suggested in the previous morphometric and cadaveric study and 2) to examine various complications and bicortical purchase that are important for b-one fusion.
A retrospective study was done on the charts, operative records, radiographs, and clinical follow up of thirty-nine patients. One hundred and seventy-eight lateral mass screws were analyzed. The spinal nerve injury, violation of the facet joint, vertebral artery injury, and the bicortical purchases were examined at each lateral mass.
All thirty-nine patients received instrumentations with poly axial screws and rod systems, in which one hundred and seventy-eight screws in total. No vertebral artery injury or nerve root injury were observed. Sixteen facet joint violations were observed (9.0%). Bicortical purchases were achieved on one hundred and fifty-six (87.6%). Bone fusion was achieved in all patients.
The advantages of the Kim's technique are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known techniques. The Kim's technique can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.
Available from: Keishi Maruo
- "There have been several articles claiming that lateral mass screwing is simple, safe, and effective compared to other fixation techniques. An additional advantage of lateral mass screwing is the elimination of the need for intraoperative fluoroscopic control [14, 15]. As a result, this fixation method is presently one of the most prevailing procedures in posterior cervical fixation throughout the world [14–22]. "
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ABSTRACT: To examine the outcome of cervical lateral mass screw fixation focusing on analysis of the risk factors for screw-related complications.
Ninety-four patients who underwent posterior cervical fixation with a total of 457 lateral mass screws were included in the study. The lateral mass screws were placed using a modified Magerl method. Computed tomographic (CT) images were taken in the early postoperative period in all patients, and the screw trajectory angle was measured on both axial and sagittal plane images.
In the postoperative CT analysis for the screw trajectory, 56.5 % of the screws were directed within the acceptable range (within 21-40° on both axial and sagittal planes). As intraoperative screw-associated complications, 9.6 % of the screws were found to contact with or breach the vertebral artery foramen. In this group, the screw trajectory angle on axial plane was significantly lower than in the group without contact. Facet violation was observed in 13 screws (2.8 %). This complication was associated with a significantly lower trajectory angles in the sagittal plane, predominantly at C6 level (69.2 %). In the patient chart review, no serious neurovascular injuries were documented.
In the analysis of potential risk factors for violation of the VA foramen as well as FV during screw insertion, the former incidence was significantly related to the screw trajectory angle (lack of lateral angulation) in the axial plane, while the latter incidence was related to a poor screw trajectory angle in the sagittal plane.
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