Weiyu Jiang

Posterior short-segment fixation and fusion in unstable Hangman's fractures.

Study Design. A retrospective study. Objective. To introduce the method of C2–C3 posterior short-segment fixation and fusion in unstable Hangmans fracture and to evaluate the clinical effects. Summary of Background Data. Hangmans fracture can be managed by closed reduction and immobilization. However, surgery is usually preferable in highly unstable cases and in rigid arthrodesis failure. The outcome of surgical treatment for unstable Hangmans fracture has not been thoroughly investigated. Methods. Thirty-five patients with unstable Hangmans fracture were treated using C2–C3 posterior short-segment fixation and fusion. Twenty-six cases used C2–C3 short-segment pedicle screw fixation. Nine cases used both C2 pedicle screw and C3 lateral mass screw short-segment fixation and fusion. C-arm fluoroscopy was used for the whole procedure. Results. All patients were observed for an average of 44 months, ranging from 12 to 78 months. There was no screw loosening or breakage, nor was there any spinal cord or vertebral artery injury intraoperatively. A total of 140 screws were placed, with 70 screws inserted into the C2 pedicle, 52 into the C3 pedicle, and 18 into the C3 lateral mass. Computed tomography scans indicated 9 screws were placed too close to the vertebral artery canal in C2, and 12 screws were too close to the canal in the C3 pedicle, all without clinical consequences. C3 lateral mass screws were placed successfully. Neurologic status improved from C and D to E in all 8 cases. Static and dynamic films demonstrated that fusion was achieved in all cases 6 months after surgery. No graft or plate-related complications were observed in any patients during the entire follow-up period. Conclusion. C2–C3 posterior short-segment fixation and fusion is an effective method for the management of unstable Hangmans fracture, proving its value as a tech-nique for achieving solid bony fusion combined with a low rate of complications.

Comparison of two techniques for transarticular screw implantation in the subaxial cervical spine.

Study Design Cross-sectional study. Objective To compare 2 techniques of transarticular screw placement in the subaxial cervical spine. Summary of Background Data Transarticular screws have been used as an alternative method to achieve posterior cervical spine stability. According to current studies there are several techniques for the placement of transarticular screws in the subaxial cervical spine; however, there is no study that has compared these techniques. Methods The techniques of transarticular screw placement by Takayasu (group A) and Dalcanto (group B) were used in 8 cervical specimens. The position, number of facet fractures, involvement of the vertebral artery, encroachment of the anterior branches of cervical nerve roots, and instances that failed to go through the facets were observed and analyzed. Results Sixty-four screws were implanted, 32 for group A and the same for group B. Although no facet fractures were seen in group A, there were 10 in group B (&khgr;2=9.6, P<0.01). Eight screws involved the vertebral artery in group A and 0 in group B (&khgr;2=22.3, P<0.001). Eleven anterior branches of lower cervical nerve roots were encroached in group A and 2 in group B (&khgr;2=22.0, P<0.001). No screws failed to go through the facets in group B whereas 2 screws failed in group A, resulting in no significant difference (&khgr;2=0.52, P>0.05). Conclusions There was a high risk of injury to the vertebral artery and anterior branches of the cervical nerve roots if the screws were too long and Takayasu technique was used. However, more facets were fractured if Dalcanto technique was applied.

A new technique for anterior cervical pedicle screw implantation

Objective:  To introduce and evaluate a new technique, anterior pedicle screw implantation, for anterior cervical reconstruction.

The study on comparison of 3 techniques for transarticular screw placement in the lower cervical spine.

Study Design. Prospective comparative study. Objective. To compare 3 techniques for transarticular screw placement in the lower cervical spine. Summary of Background Data. The transarticular screw is found to have satisfactory biomechanical stability. According to current studies, there are several techniques for the placement of transarticular screws in the lower cervical spine. Although several techniques are available for transarticular screw implantation in the lower cervical spine, only a few studies in the literature have been carried out to compare these techniques. Methods. The techniques of transarticular screw placement used by Takayasu (group A), Dalcanto (group B), and Klekamp (group C) were applied in 24 cervical specimens. The facet fractures, the encroachment of the cervical anterior branches of nerve roots and vertebral arteries and the failure of the screws to go through the facets were observed and analyzed. Results. One hundred ninety-two transarticular screws were implanted on both sides in 24 cervical cadavers, 64 for each group. There were 25 splits of inferior facets in group B, 2 splits in group C, and none in group A. Thirty-six screws encroached the vertebral arteries in group A, none in groups B and C. Forty anterior branches of lower cervical nerve roots were involved in group A, 5 in group B, and 3 in group C. Although all screws went through facets in the study except for 5 in group A, there were no significant differences between each group (&khgr;AB2 = 3.33, P > 0.05; &khgr;AC2 = 3.33, P > 0.05). Conclusion. There is a high risk of injury to the anterior branch of the cervical nerve roots and vertebral artery if the screws were too long, and the Takayasu technique was used. However, the rate of facet splitting is high if the Dalcanto technique was applied. Klekamps technique is recommended.

Anterior Transpedicular Screw Technique for Failed Anterior Cervical Internal Fixation in Revision Surgery: a Case Report

Introduction Anterior cervical corpectomy and fusion (ACDF) is a widely used surgical approach for cervical diseases such as cervical trauma, spondylosis, tumor, deformity and degenerative spondylolisthesis. Although successful in achieving good outcomes, drawbacks to the anterior approach include screw and plate loosening, development of pseudarthrosis and lack of bioabsorbability. Zdeblick et al. reported excellent results can be achieved with repeat anterior decompression and autogenous bone-grafting. Wang et al. perform laminoplasty for failed anterior cervical spine surgery. To our knowledge, a cervical anterior transpedicular screw (ATPS) technique has not been used for revision surgery for failed anterior cervical internal fixation.

Evaluation of the value of pedicle screws for cervicothoracic fracture‐dislocation

Objective:  To explore the value of pedicle screw implantation for fracture‐dislocation injuries of the cervicothoracic junction (C6–T2).