Atlantoaxial Joint Interlocking Following Type II Odontoid Fracture Associated with Posterolateral Atlantoaxial Dislocation: a Case Report and Review of Published Reports.

A rare case of atlantoaxial lateral mass joint interlocking secondary to traumatic posterolateral C1,2 complete dislocation associated with type II odontoid fracture is herein reported and the impact of atlantoaxial joint interlocking on fracture reduction discussed. A 72-year-old man presented with traumatic atlantoaxial lateral mass joint interlocking without spinal cord signal change, the diagnosis being confirmed by radiography and 3-D reconstruction digital anatomy. Posterior internal fixation was performed after failure to achieve closed reduction by skull traction. After many surgical attempts at setting had failed because of interlocking of the lateral mass joints, reduction was achieved by compressing the posterior parts of the atlantal and axial screws. Odontoid bone union and C1,2 posterior bone graft fusion were eventually obtained by the 12-month follow-up. The patient had a complete neurological recovery with no residual neck pain or radiculopathy.

[Centerpiece plating in the cervical single open-door laminoplasty].

OBJECTIVE: To evaluate the value of the Centerpiece plate in the cervical single open-door laminoplasty and compared its advantages with conventional suture fixation methods. METHODS: From December 2009 to August 2011,32 patients with cervical spondylotic myelopathy were treated with operation. Of them, 15 cases underwent cervical single open-door laminoplasty and Centerpiece plate fixation (group A),there were 8 males and 7 females,aged from 51 to 65 years old with an average of 60.5 years and ranged in course of disease from 2 to 15 months; 17 cases underwent cervical single open-door laminoplasty and silk suture fixation (group B), there were 9 males and 8 females, aged from 49 to 66 years old with an average of 61.5 years and ranged in course of disease from 1 to 14 months. All the patients with unsteady gait symptom before operation and cervical MR imaging showed spinal cord compression and denaturation. According to standard of Japanese Orthopaedics Association (JOA) to evaluate the spinal nervers function before operation and at 6 months after operation;according to CT scan to determine the sagittal diameter (AP) of upper vertebral canal and cervical activity (ROM). RESULTS: All the patients were followed up from 8 to 20 months with an average of 13 months. All the incisions healed well and no complications such as internal fixation loosening and breakage,spinal cord injury, reclose-door were found. Postoperative symptoms relieved obviously and MRI and CT showed vertebral canal volume expanded significantly. Operative time and blood loss in group A were respectively (155.0+/-12.3) min, (407.0+/-11.8) ml and in group B were respectively (148.0+/-14.4) min, (398.0+/-15.4) ml. There was no significantly differenc, between two groups (P>0.05). JOA score in group A improved from preoperative 9.1+/-2.6 to postoperative 15.5+/-1.8 and in group B improved from preoperative 9.3 +/- 2.1 to postoperative 13.1 +/- 2.5 (P<0.05). CT sagittal diameter (AP) in group A increased from preoperative (10.7+/-2.4) mm to postoperative (17.6+/-3.2) mm and in group B increased from preoperative (11.6+/-1.7) mm to postoperative (15.9+/-2.0) mm (P<0.05). Cervical activity (ROM) in group A be- fore and after operation were respectively (51.0+/-2.6) degrees, (45.0+/-3.5) degrees and in group B were respectively (52.0+/-1.8) and (42.0+/-2.4). There was no significantly difference before operation between two groups (P>0.05) and there was significantly difference after operation between two groups (P<0.05). CONCLUSION: Treatment of cervical spondylotic myelopathy with posterior single open-door laminoplasty and Centerpiece plate fixation can enlarge spinal canal volume,keep original cervical activity, improve postoperative JOA score. The method has obviously advantages compared with traditional suture fixation methods.