[Radiological studies of the cervical spine after laminoplasty by longitudinal splitting of the spinous process].

This study involved a clinical evaluation and radiological follow-up of patients who underwent laminoplasty by longitudinal splitting of the spinous process for compressive myelopathy. The subjects were 47 patients with myelopathy caused by cervical spondylosis or ossification of the posterior longitudinal ligament in the cervical spine. The average age at the time of surgery was 61, and the average follow-up period was 3 years. Overall results: the preoperative score, by the Japanese Orthopaedic Association scoring system, was 9.8, and the postoperative score was 13.9; the average recovery rate was 54.3%. Lateral roentgenograms showed a decreased lordosis in the cervical curvature in 50% of the patients after laminoplasty, especially in those patients where stripping of the attachments of the semispinalis cervices to the spinous process of C2 occurred. The recovery rate was good in patients with postoperative lordotic or straightened necks (61.1% and 55.0%, respectively), but it was poor in those with kyphotic or S-shaped necks (average: 36.1%). The postoperative range of motion of the cervical spine had decreased to 43% of the preoperative range.