Long-term follow-up results of anterior interbody fusion applied for cervical myelopathy due to ossification of the posterior longitudinal ligament

Study Design. A long-term follow-up study was carried out in 30 patients wh o underwent anterior interbody fusion for cervical myelopathy associated wi th ossification of the posterior longitudinal ligament (OPLL). Objective. To investigate whether anterior interbody fusion without decompr ession is an appropriate surgical method for long-term relief of cervical O PLL myelopathy. Summary of Background Data. Several studies of operative results after post erior decompression for cervical myelopathy due to ossification of the post erior longitudinal ligament have been reported. There has been no report ab out anterior interbody fusion without decompression. The postoperative resu lts of this treatment method applied in cervical OPLL myelopathy have been evaluated by the authors of the present study for more than 10 years. No re ports on such a long-term follow-up study have been published in the litera ture. Methods. Thirty patients who underwent anterior interbody fusion for cervic al OPLL myelopathy were evaluated clinically and radiographically. The mean follow-up period was 14.7 years (range, 10-23 years). Results. Clinical results were evaluated according to Okamoto's classificat ion. At the time of the final follow-up evaluation, 16 patients had improve d in functional score by two grades, and their surgical results were regard ed as excellent; eight patients improved by one grade, and their clinical o utcomes were regarded as good; five patients showed no change; and the cond ition of one patient deteriorated. As for radiographic analysis, the type o f ossification had changed in four cases. Ossification width and thickness increased in 26 patients. Postoperative alignment of the cervical spine sho wed kyphosis in three patients, straight spine in 11 patients, and lordosis in 16 patients. Conclusion. Anterior interbody fusion without decompression is an effective treatment for cervical OPLL myelopathy that resulted in stable long-lastin g conditions.