[Long-term results of surgery for cervical spondylotic myelopathy using open-door laminoplasty]

PURPOSE OF THE STUDY Cervical spondylotic myelopathy (CSM) is a serious disease which, in its advanced form, can markedly disable the patient. The aim of the present work was a prospective evaluation of a group of CSM patients treated by open-door laminoplasty. MATERIAL AND METHODS We evaluated 89 patients (59 men and 30 women; average age, 62 years; range, 39 to 81 years) who underwent surgery in the years 2001 to 2011. The average follow-up was 76 months. The patients were examined neurologically, radiologically, by magnetic resonance imaging (MRI) or CT. All of them had quadruparetic disability and showed signs of myelopathy on MRI examination. We used a modified Hirabayashi technique of open-door laminoplasty. We evaluated the surgery time, intra-operative blood loss, neurological deficit on the modified Japanese Orthopaedic Society (mJOA) scale, intra- and postoperative complications, neck pain (NP) and extremity pain (EP) on the visual analogue scale (VAS) and a radiographic sagittal profile change after laminoplasty. RESULTS The average operative time was 117 minutes and the average intra-operative blood loss was 330 ml. The average mJOA score of 12.7 before surgery improved to 14.4. Two patients (2.25 %) showed persisting deterioration of neurological symptoms, conditions of six patients (6.75 %) were assessed as stable and the remaining 81 patients (91 %) showed varying degrees of both subjective and objective amelioration/improvement. Infection was recorded as the most frequent complication (7.8 %). C5 paresis reported in the literature did not occur in our group. One patient (1.1 %) had a moderate epidural haemorrhage. The pre-operative VAS NP score of 5.4 improved to 3.2 and the VAS EP score of 7.7 improved to 4.4. The average value for the radiographic sagittal profile changed from -18.2 pre-operatively to -16.5 post-operatively. CONCLUSIONS Laminoplasty remains the basic surgical option for CSM treatment, particularly in progressive cases of the disease, in multi-segmental disease, and in need to preserve or restore cervical spine alignment Key words: cervical spondylotic myelopathy, laminoplasty, Hirabayashi open-door technique, mJOA score, complications, VAS.