Cervical Spondylotic Myelopathy: Functional Outcome after Modified Hirabayashi Laminoplasty

Spondylotic myelopathy is an old age problem of cervical spine. Different modes of treatment are available. Surgical intervention is indicated when conservative trials failed. Traditional laminectomy may cause multiple complications especially kyphotic deformity and epidural scarring. To avoid these complications a variety of laminoplasties were evolved in Japan as an alternative to laminectomy. This series is of twenty five cases having cervical Spondylotic myelopathy. All were having long tract signs preoperatively. Modified Hirabayashi laminoplasty was done at our centre and were assessed clinically and radiologically postoperatively. Root decompression was done if indicated on preoperative assessment. All patients were followed up for the mean post operative period of 12.2 months. Functional outcome of modified Hirabayashi laminoplasty was assessed by using Japanese Orthopedic Association (JOA) scoring system. The mean preoperative score was 7.8 (6-11) that was improved to the mean of 12 (8-16). The percentage of functional outcome was 19% to 85.71% (mean 47.21%) till the last follow up. Three patients (12 %) developed transient C5 palsy postoperatively. But it was recovered fully within three months period. Modified Hirabayashi laminoplasty is a better alternative of laminectomy & even that of traditional Hirabayashi laminoplasty because none of our patient developed post operative kyphotic deformity, epidural scaring & even spring-back phenomenon which is a common complication of traditional Hirabayashi laminoplasty. We recommend it a safer procedure in spondylotic cervical myelopathy.