RT Journal Article
SR Electronic
T1 Characteristics of Screw Perforation and Screw Loosening in Atlantoaxial Transarticular Fixation Using a Preoperative Computed Tomography-Based Navigation System
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 8604
DO 10.14444/8604
A1 Uehara, Masashi
A1 Ikegami, Shota
A1 Oba, Hiroki
A1 Miyaoka, Yoshinari
A1 Kamanaka, Takayuki
A1 Hatakenaka, Terue
A1 Fukuzawa, Takuma
A1 Hayashi, Koji
A1 Takahashi, Jun
YR 2024
UL https://www.ijssurgery.com/content/early/2024/05/13/8604.abstract
AB Background Atlantoaxial transarticular fixation, also called the Magerl technique, is said to be the most robust biomechanical method of fixation of the atlantoaxial vertebrae. However, the procedure carries a risk of spinal cord and vertebral artery injury during the insertion process, especially in patients with a high-riding vertebral artery. In this study, a computed tomography (CT)-based navigation system was used for preoperative planning and insertion. This investigation sought to determine the rate and direction of screw perforation as well as the incidence of screw loosening in computer-assisted atlantoaxial transarticular fixation.Methods Sixty patients (31 men and 29 women; mean ± SD age: 65.3 ± 19.6 years) who received atlantoaxial transarticular screw insertion with preoperative CT navigation were analyzed. We investigated screw position and loosening by CT at the final follow-up.Results Of the 108 screws inserted, the rate of Grade 2 or higher perforation was 4.6% (5/108). Nine of 81 (11.1%) screws inserted into the 44 patients who were followed for at least 6 months showed loosening. Logistic regression analysis revealed that unilateral insertion (odds ratio: 8.50, 95% confidence interval: 1.53–47.2, P = 0.014) was significantly associated with the incidence of screw loosening.Conclusions The screw perforation rate of Grade 2 or higher in computer-assisted atlantoaxial transarticular screw fixation was 4.6%, with comparable frequencies of perforation direction. Unilateral insertion was a significant independent factor associated with screw loosening, which occurred in 11.1% of insertions.Clinical Relevance Spine surgeons should follow up with patients with caution because screws with unilateral insertion are prone to loosening.Level of Evidence 4.