Modified Double-Door Laminoplasty in Managing Multilevel Cervical Spondylotic Myelopathy Surgical Outcome in 520 Patients and Technique Description

Study Design: This is a prospective study on surgical outcomes of double-door laminoplasty in patients with cervical spondylotic myelopathy (CSM). Objective: The purpose of this study was to report the efficacy and safety of modified double-door laminoplasty in a large series of patients with CSM. Summary of Background Data: Laminoplasty is an established procedure for the decompression of multisegmental CSM. However, no report has described the clinical outcomes of laminoplasty for a large number of patients with CSM (> 500 patients). Methods: Between April 1995 and December 2006, 520 consecutive patients (331 male and 189 female) with CSM who underwent double-door laminoplasty and were followed-up for more than 1 year were enrolled in this study. The mean age was 62.2 years (23 to 93 y), and the mean duration of disease was 20.1 +/- 32.0 months. The severity of myelopathy before and after surgery was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for cervical myelopathy (JOA score). Functional improvement was expressed by the recovery rate (RR) of the JOA score. Results: The average surgery time for laminoplasty was 75.2 +/- 23.3 minutes, and the average blood loss was 72.6 +/- 84.6 mL. The average follow-up period was 33.3 +/- 15.7 months. The mean JOA score was 10.4 +/- 2.8 points preoperatively and 13.6 +/- 2.5 points at final follow-up. The mean RR was 51.2 +/- 29.0%. On the basis of RR, we found that the conditions of 493 patients (94.8%) improved (RR, > 1%), 20 patients (3.8%) showed no change (RR, 0%), and 7 patients (1.3%) in worse condition (RR, < 0%). The 7 patients deteriorated for reasons (lumbar spinal canal stenosis and cerebral infarction) that were unrelated to CSM. Conclusions: Modified double-door laminoplasty is a safe, reliable, and effective procedure for patients with CSM.