The use of cervical lateral mass plate and screw for the treatment of fracture and dislocation of the lower cervical spine

Objective The cervical lateral mass plate and screw were used for the treatment of fracture and dislocation of the lower cervical spine. Methods 22 cases of lower cervical spine injury were treated by this technique from December 1991 to March 1997. There were 3 unilateral and 10 bilateral facet fractures and dislocations, 1 bilateral and 4 unilateral facet dislocations. 3 bilateral facet dislocations were associated with vertebral body fracture. 3 cases were neurologically intact. 7 were complicated with single or multiple nerve root injuries. 6 had incomplete and 6 complete spinal cord injury. The screws and plates were placed on the lateral mass of cervical vertebrae by using Roy - Camille (16 cases), and Margel or AO tech niques (6 cases). Lamina or facet bone grafting was performed to achieve a long-term stability. Results The follow-up ranged from 10 months to 7 years and 2 months (mean 34 months). All the cases had solid fusion based on flexion and extension radiographs at an average of 3. 5 months. Patients were encouraged to sit up wearing soft collar 3. 3 days (1 - 7 days) after the surgery. 7 of 22 cases that sustained nerve root injury were out of bed on an average of 7 days and returned to their work 3. 5 months afterwards. Their nerve root functions fully recovered at the time of follow-up. Patients with incomplete spinal cord injury had significant improvement on nerve root functions and one Frankel level improvement. There were no neurovascular complications during the operation. One case was reduced incompletely due to lost of anatomical landmark after removal of fractured facet. Loosening was found in 2 patients (4 screws). Neither of these affected neurological recovery and fusion. Conclusion This technique has the advantages of short segment fixation, strong stability, light extemal post-operative support and allowing early mobilization.