1997 年 11 巻 1 号 p. 61-66
The growth of OPLL after the posterior decompression of the cervical spine was reported by some authors. In this study 66 patients with cervical OPLL were operated with the spinous processes reconstructive laminoplasty (Yamagata University method). Regarding to the classification of OPLL, 35, 24 and 7 patients were of segmental, mixed and continuous type respectively. The average age at surgery was 61.6 years. The mean follow-up period was 4 years and 10 months ranging from 3 years to 10 years. The twenty-four out of 66 patients (36.4%) revealed growth of OPLL. The growth of OPLL was observed in 9 out of 35 patients (25.7%) classified as segmental type, 9 out of 24 of mixed type and 6 out of 7 of continuous type. The growth of OPLL did never cause neurological deterioration. The average preoperative JOA score was 9.2, which increased to 13.4 point 2 years after surgery (Hirabayashi's recovery rate was 62%). Preoperative range of motion of the cervical spine was 25.6 degree which decreased to 12.5 degree (48.8%) 2 years after surgery. Though 4 patients (6.1%) developed temporary paralysis of C5 after surgery, any other patients did not show operative complications. In conclusion, spinous processes reconstructive laminoplasty is recommended as one of the methods of posterior decompression in the cervical OPLL.