Turkish Neurosurgery
Comparison of the efficacy of a anchored cage with unidirectional and bidirectional screw fixation in single-level cervical discectomy and fusion surgery
Lee Jung Jae1, Park Jin Hoon 2, Park Byong Gon5, Shin Hong Kyung2, Lee Su Bum4
1Gangneung Asan Hospital, Neurological Surgery, Gangneung,
2Asan Medical Center, Neurological Surgery, Seoul,
3Gangneung Asan Hospital, Emergency Medicine, Gangneung,
4KOREA UNIVERSITY MEDICINE, Neurological Surgery, Seoul,
5Catholic Kwandong University, Physiology, Gangneung,
DOI: 10.5137/1019-5149.JTN.41249-22.2

Aim:This study aimed to compare and analyze the clinical and radiological signs between bidirectional and unidirectional screw fixation.Material and Methods:We retrospectively reviewed data collected from 90 patients and divided them into the upper or lower spine fixation group (unidirectional) and the normal upper and lower spine fixation group (bidirectional). The patients’ demographic data and preoperative and postoperative (24 months) clinical outcomes were collected. Pre- and postoperative (immediately and at 3, 6, 12, and 24 months) changes in the segmental angle in the operating field (SA), cervical lordosis, C2–7 sagittal vertical axis, and active disc height (aDH) were evaluated. We also compared the rate of fusion and muscle size change between the groups.Results:The operation time in the bidirectional screw fixation group was significantly longer than that in the unidirectional screw fixation group (>6 min; p = 0.03). There was no significant difference between the two groups in radiographic parameters before and immediately after surgery. From 3 months postoperatively, the unidirectional group had significantly higher SA and aDH than the bidirectional group (p = 0.03). The fusion rate was higher in the bidirectional screw fixation group than in the unidirectional group, but this was not statistically significant (97% vs. 88%, p = 0.07). Conclusion:The results of this study suggest that unidirectional screw fixation surgery can be useful as it has been associated with simple surgery, short surgery time, and maintenance of the lordotic curvature of SA and disc height.

Corresponding author : Park Jin Hoon