Selective posterior enlarged decompression and lateral mass screw fixation for multisegmental cervical spondylotic myelopathy with kyphosis

Abstract

Objective To investigate the effect and prevention of complications of selective posterior enlarged decompression and lateral mass screw fixation for multisegmental cervical spondylotic myelopathy with kyphosis.Methods From January 2008 to January 2011,43 patients with multisegmental cervical spondylotic myelopathy combined with kyphosis,aged from 42 to 74 years (average,59.6 years),underwent selective posterior enlarged decompression and lateral mass screw fixation.The JOA (Japanese Orthopaedic Association) scoring system and Neck Disability Index (NDI) were applied to evaluate the neurological function and axial neck/shoulder pain before and after surgery,respectively.The Ishihara method was employed to measure the cervical curvature index (CI).The expanding and shifting of the spinal cord was calculated in MRI.Results The decompression range was 3 to 5 segments (average,3.91±0.86 segments).All patients were followed up for 20 to 60 months (average,38 months).There were significant differences between preand post-operative JOA score (8.16±1.11 vs.14.31±1.33),CI (7.36％±9.69％ vs.15.30％±3.18％),anteroposterior diameter of the dural sac at the level of maximum stenosis in MRI [(2.92±1.49) mm vs.(6.10±0.89)mm],and NDI score (19.36±8.61 vs.4.90±2.46).The mean spinal cord posterior shift was (4.59±1.20) mm (range,2.97 to 6.68 mm).The complete bone graft fusion was achieved in all patients 3 to 6 months after surgery.No C5 nerve root palsy or instrument failure occurred.Conclusion The selective posterior enlarged decompression and lateral mass screw fixation is effective in treating multisegmental cervical spondylotic myelopathy with kyphosis,which can improve neurological function,recover and maintain the normal cervical curvature,and decrease the incidences of axial symptoms and C5 nerve root palsy Key words: Cervical vertebrae; Spinal cord compression; kyphosis