A comparative study of the bony fusion in different degrees of vertebral plate hinge fracture after single open-door cervical expansive laminoplasty with centerpiece mini-plate fixation / 中国医师进修杂志

ABSTRACT

Objective To compare the bony fusion in different degrees of vertebral plate hinge fracture after single open-door cervical expansive laminoplasty with centerpiece mini-plate fixation.Methods The clinical data of 79 patients received the unilateral simple open-door cervical expansive laminoplasty with centerpiece mini-plate fixation from January 2010 to December 2012 were retrospectively analyzed.The vertebral plate hinge fracture was divided into incomplete fracture and complete fracture according to thepostoperative CT scan.The complete fracture was divided into four typestype Ⅰ in which there was no displacement;type Ⅱ in which there was mild to moderate displacement;type Ⅲ in which there was complete displacement or separated; type Ⅳ in which there was hinge' s collapse into cervical canal.The hinge fracture healing was observed and the difference of different types of fracture healing rate was compared.Results Follow-up of 12-45 (21.2 ± 5.6) months.CT scan found 395 segments 1 week after the operation,vertebral plate hinge complete fracture accounted for 58.2％ (230/395).And type Ⅰ accounted for 66.1％ (152/230),type Ⅱ accounted for 25.7％(59/230),type Ⅲ accounted for 6.5％(15/230) and type Ⅳ accounted for 1.7％ (4/230).The fusion rate of incomplete fracture at 6 months after the operation was higher than that complete fracture [97.6％(161/165) vs.80.9％(186/230)],there was significant difference (P＜ 0.05).The fracture rate in different types of complete fracture at 3,6 months after the operation had significant difference (P ＜ 0.05).Type Ⅲ fracture had the lowest healing rate.Conclusion Type Ⅰ fracture is the major type for vertebral plate hinge complete fracture,complete fracture get a relatively bad bony fusion and type Ⅲ fracture has the lowest healing rate.