Five-year Follow-up Evaluation of Surgical Treatment for Cervical Myelopathy Caused by Ossification of the Posterior Longitudinal Ligament A Prospective Comparative Study of Anterior Decompression and Fusion With Floating Method Versus Laminoplasty

Study Design. Prospective, comparative clinical study. Objective. To compare the clinical outcome of anterior decompression and fusion with floating method and laminoplasty in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). Summary of Background Data. There have been no reports that have accurately and prospectively compared surgical outcomes after anterior decompression and posterior decompression. Methods. For cervical myelopathy caused by OPLL, we performed anterior decompression and fusion with floating method (ADF) in 1997, 1999, 2001, 2003, and 2004 and French-door laminoplasty (LAMP) in 1996, 1998, 2000, and 2002 at one institution. Twenty patients in the ADF group and 22 patients in the LAMP group were evaluated for 5 years' follow-up. The following criteria were evaluated: operation time, blood loss, complications, and Japanese Orthopedic Association score. For radiographic evaluation, canal narrowing ratio of OPLL, lordotic angle at C2-C7, and postoperative progression of the ossified lesion were measured. Results. The operation time in the ADF group was longer than that in the LAMP group. The average blood loss showed no statistical difference between the 2 groups. Complications occurred in 5 cases in the ADF group, but none occurred in the LAMP group. The mean Japanese Orthopedic Association score system for cervical myelopathy and the recovery rate in the ADF group were superior to those in the LAMP group, especially for cases with greater than 50% of the spinal canal compromised by OPLL or kyphotic alignment of the cervical spine, preoperatively. Postoperative progression of OPLL was observed in 5% of the ADF group and 50% of the LAMP group. Conclusion. ADF is considered especially suitable for cases with massive OPLL and preoperative kyphotic alignment of the cervical spine, although it leads to a higher incidence of surgery-related complications compared with LAMP.