Treatment of cervical OPLL by cervical anterior fusion using autologous vertebral bone grafts.

Abstract

In anterior fusion, we use autologous bone grafts from cervical vertebral bodies and bioabsorptive screws to prevent graft extrusion (Williams-Isu method). We report the application of and indication for the Williams-Isu method for OPLL and present our clinical and radiological results. Using the Williams-Isu method, we treated 17 patients with cervical OPLL; 15 had segmental- and 2 had continuous-type OPLL. The median follow-up term was 24 months. The patients underwent anterior decompression and fusion at a single level (n = 8) or at two levels (n = 9). As a control, 17 patients with cervical spondylosis underwent anterior single-level decompression and fusion using the Williams-Isu method. Pre- and postoperative radiographs of the cervical spine were obtained in all patients, and the alignment of the whole cervical and fused segment and the height of the fused segment were compared. All but one patient experienced alleviation of clinical symptoms without deterioration during the follow-up period. The recovery rate on the JOA score was 71.7%. The patient with continuous-type OPLL suffered postoperative neurological deterioration because of a remnant of the upper-level OPLL. Radiological studies confirmed the absence of bone graft dislocation and fracture, and of satisfactory bone fusion in all patients. There was no significant difference between the two patient groups with respect to whole spine alignment and the alignment and height of the fused segment. The Williams-Isu method is useful for treating not only cervical spondylosis but also cervical segmental OPLL at one or two levels.