Lateral mass screw of atlas combined with vertebra dentata pedicle screw for the treatment of atlantoaxial instability
- VernacularTitle:后路寰椎侧块螺钉结合枢椎椎弓根螺钉固定治疗寰枢椎不稳
- Author:
Dingjun HAO
;
Baorong HE
;
Jinsong ZHOU
- Publication Type:Journal Article
- Keywords:
Atlanto-axial joint;
Joint instability;
Spinal fusion;
Bone screws
- From:
Chinese Journal of Orthopaedics
1996;0(09):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To summary the results of fixation and fusion with lateral mass screw of atlas and vertebra dentata pedicle screw for the treatment of atlantoaxial instability. Methods From February 2002 to March 2004, 15 cases suffered with atlantoaxial instability were included in this study. There were 9 males and 6 females, with a mean age of 39.5 years old(ranged 15 to 57 years old). There were 5 cases for old odontoid fracture, 4 cases for congenital loose odontoid process, 6 cases for fresh odontoid fracture(Aderson ⅡC). 7 cases were fixed with Vertex, 3 Axis and 5 Cervifix instruments. JOA scores in preoperation were from 5.1 to 10.9, with an average of 7.6. Skull traction was performed in each patient preoperatively. The screws were placed in lateral mass of atlas beside the posterior arch of atlas about 18-20 mm and the point of intersection above 2 mm inferior boarder of posterior arch. Vertical with coronal plane, the tip of the screw made 5? to side of head in sagittal plane. The site of the screws were placed in vertebra dentate was divide equally the inferior articular process of axis, made 15? with sagittal plane and 30? with cross section. The diameter of the screw was 3.5 mm, the length of in lateral mass of atlas was from 28 to 32 mm, and from 22 to 26 mm in vertebra dentate pedicle screw. Results There were no spinal cord and vertebral artery injury after surgery. Follow-up duration was from 10 to 25 months, with average 14 months. The postoperative JOA scores were from 13.2 to 16.8, with average 14.8. The improve rate was 87.5 percent. The plant bones all fused and there were no internal fixation rupture and mobiled. Conclusion Lateral mass screw of atlas and vertebra dentata pedicle screw with three-dimension fixed virtues could be used to treat atlantoaxial instability.
