Unilateral C1 Lateral Mass and C2 Pedicle Screw Fixation for Atlantoaxial Instability in Rheumatoid Arthritis Patients: Comparison with the Bilateral Method.
10.3340/jkns.2015.57.6.460
- Author:
Seung Chull PAIK
1
;
Hyoung Joon CHUN
;
Koang Hum BAK
;
Jeil RYU
;
Kyu Sun CHOI
Author Information
1. Department of Neurosurgery, Hanyang University Medical Center, Seoul, Korea. tdy815@hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
Atlantoaxial;
Bilateral;
C1-2;
Harm's Technique;
Instability;
Unilateral
- MeSH:
Arthritis, Rheumatoid*;
Humans;
Magnetic Resonance Imaging;
Osteoarthritis;
Postoperative Period;
Preoperative Period;
Tomography, X-Ray Computed;
Vertebral Artery
- From:Journal of Korean Neurosurgical Society
2015;57(6):460-464
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: Bilateral C1 lateral mass and C2 pedicle screw fixation (C1LM-C2P) is an ideal technique for correcting atlantoaxial instability (AAI). However, the inevitable situation of vertebral artery injury or unfavorable bone structure may necessitate the use of unilateral C1LM-C2P. This study compares the fusion rates of the C1 lateral mass and C2 pedicle screw in the unilateral and bilateral methods. METHODS: Over five years, C1LM-C2P was performed in 25 patients with AAI in our institute. Preoperative studies including cervical X-ray, three-dimensional computed tomography (CT), CT angiogram, and magnetic resonance imaging were performed. To evaluate bony fusion, measurements of the atlanto-dental interval (ADI) and CT scans were performed in the preoperative period, immediate postoperative period, and postoperatively at 1, 3, 6, and 12 months. RESULTS: Unilateral C1LM-C2P was performed in 11 patients (44%). The need to perform unilateral C1LM-C2P was due to anomalous course of the vertebral artery in eight patients (73%) and severe degenerative arthritis in three patients (27%). The mean ADI in the bilateral group was 2.09 mm in the immediate postoperative period and 1.75 mm in 12-months postoperatively. The mean ADI in the unilateral group was 1.82 mm in the immediate postoperative period and 1.91 mm in 12-months postoperatively. Comparison of ADI measurements showed no significant differences in either group (p=0.893), and the fusion rate was 100% in both groups. CONCLUSION: Although bilateral C1LM-C2P is effective for AAI from a biomechanical perspective, unilateral screw fixation is a useful alternative in patients with anatomical variations.
