A study of the feasibility of posterior thoracic transarticular pedicle screw fixation
10.3760/cma.j.issn.0253-2352.2011.08.012
- VernacularTitle:胸椎经关节突关节椎弓根螺钉固定的可行性研究
- Author:
Guanyi LIU
;
Rongming XU
;
Weihu MA
;
Hongyong ZHAO
;
Shoohua SUN
;
Huajie LIN
;
Nanjian XU
;
Yanzhao ZHU
- Publication Type:Journal Article
- Keywords:
Thoracic vertebrae;
Internal fixators;
Anatomy
- From:
Chinese Journal of Orthopaedics
2011;31(8):892-896
- CountryChina
- Language:Chinese
-
Abstract:
Objective To identify the feasibility and the anatomical parameters of posterior transarticular pedicle screw fixation in the thoracic spine, provide a reference for clinical applications. Methods Twenty human cadaveric thoracic spine segments were dissected posteriorly and anteriorly, with care taken to expose the laminas and pedicles. The entrance point of transarticular pedicle screws was located in the 7 mm away from the above at the inferior margin of the lamina and the inside at the exterior margin, respectively. Posterior transarticular pedicle screws implantation was performed under direct visualization into T1,2,T5,6 and T9,10 Under direct abservation, the feasibility of posterior transarticular pedicle screw fixation was assessed. Then a CT was done. On the morphologic CT scan, the angle and length of the transarticular pedicle crew trajectory were measured. Results The thoracic transarticular pedicle screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the axial plane with successful placement. Screws were placed across the facet joint, and from the inferior articular process of upper thoracic vertebra into the pedicle of lower thoracic vertebra. There was little difference between different number of thoracic vertebrae of the angle, but without significance. The average angles of the screws were 41.4°+3.2°caudal tilting in the sagittal plane and 2.1°±0.7° lateral tilting in the axial plane. The average trajectory lengths were (40.6±4.9)mm, and the lengths increased gradually from upper thoracic vertebra to middle and lower. There were significant differences statistically among T1,2, T5,6 and T9.10 (F=74.09, P＜0.01 ). Conclusion Posterior transarticular pedicle screw fixation is feasible, and there are some directions for implantating the screws. Transarticular pedicle fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.
