Abstract:

Objective To observe the relationship between cervical curvature and spinal drift distance after laminectomy with lateral mass screw fixation, and its effect on clinical outcome.Methods From January, 2017 to October, 2018, a total of 117 patients with cervical spondylotic myelopathy (CSM) underwent laminectomy with lateral mass screw fixation, and 90 of them completed the follow-up. According to the patients' cervical curvature (CC), they were divided into three groups: those CC between 0° to 5° were in Group A (n = 28), 5° to 16.5° in Group B (n = 36) and CC > 16.5° in Group C ( n = 26). The spinal drift distance, nerve recovery, axial symptoms and C₅ palsy were recorded and analyzed.Results There were significant differences in CC and spinal drift distance (F > 152.119, P < 0.001), and no significant difference was found in laminectomy width and incidence of C ₅ palsy (P > 0.05) among three groups. The Japanese Orthopaedic Association (JOA) score significantly increased in all the groups post operation and at the last follow-up ( t > 8.869, P < 0.001), and no significant difference was found among there groups at the same time ( P > 0.05), as well as the incidence of C ₅ palsy (F = 0.472, P = 0.625). There was significant difference in the score of Visual Analogue Scale of axial symptoms among three groups (F > 34.800, P < 0.001), which was lower in groups B and C than in group A ( t > 5.845, P< 0.001), and no significant differene was found between group B and group C.Conclusion On the basis of the same laminectomy width, the greater the CC was, the more favorable the spinal drift went backwards. The loss of CC was related to the occurrence of axial symptoms, but was not correlated with the neurological recovery and C₅ palsy.

Key words: cervical spondylotic myelopathy, lateral mass screw fixation, cervical curvature, C₅ palsy, axial symptoms