[Early outcome of different operation methods in treatment of multi-segmental cervical spondylotic myelopathy]

To explore the early outcome of 3 different operation methods in the treatment of multi- segmental cervical spondylotic myelopathy (CSM).

A retrospective analysis was made on the clinical data of 74 patients with multi-segmental CSM treated between January 2011 and March 2013. The patients were divided into 3 groups according to operation methods: open-door expansive laminoplasty by plate was used in 21 patients (group A), open-door expansive laminoplasty by anchor fixation in 28 patients (group B), and conventional unilaterally open-door expansive laminoplasty in 25 patients (group C). There was no significant difference in gender, age, disease druation, affected segments, preoperative Japanese Orthopaedic Association (JOA) score, and cervical curvature of C2-7 among 3 groups (P > 0.05). The peration time, intraoperative blood loss, and JOA score, cervical curvature, incidence of axial symptoms were recorded.

There was no significant difference of operation time and intraoperative blood loss between group A and group B (P > 0.05). All incisions healed by first intention. Cerebrospinal leak occurred in 2 cases (1 case of group B and 1 case of group C) and C5 nerve root palsy in 4 cases (2 cases of group A, 1 case of group B, and 1 case of group C); all the symptoms disappeared after symptomatic treatment. The patients were followed up 12-39 months (mean, 18.3 months). The position of internal fixation was good without loosening and pulling out in groups A and B. Reclosed open-door was observed in 2 cases of group C, which disappeared after the second surgery. The JOA scores were significantly increased at 6 months after operation when compared with preoperative scores in groups A, B, and C (P < 0.05). The cervical curvature of C2-7 at postoperation was significantly improved when compared with preoperative one in groups B and C (P < 0.05) except group A (P > 0.05) . There weresignificant differences in JOA score and the cervical curvature among 3 groups at 6 months after operation (P < 0.05). The incidence of axial symptoms were 4.76% (1/21), 35.71% (10/28), and 72.00% (18/25) in groups A, B, and C respectively, showing significant differences (P < 0.017).

Open-door expansive laminoplasty by plate has better early outcome than open-door expansive laminoplasty by anchor fixation and conventional unilaterally open-door expansive laminoplasty in the treatment of multi-segmental CSM.