Long-term results of the anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament

Study Design, Results of the anterior floating method used to decompress os sification of the posterior longitudinal ligament were studied for an avera ge postoperative interval of 13 years. Objective. To investigate the long-term results of the anterior floating me thod used to manage ossification of the posterior longitudinal ligament. Summary of Background Data. The anterior floating method is a technique tha t differs from the extirpation method used to manage ossification of the po sterior longitudinal ligament. Reports of the long-term results from anteri or decompression used to manage cervical ossification of the posterior long itudinal ligament are rare. Methods. The anterior floating method was used to decompress cervical ossif ication of the posterior longitudinal ligament in 63 patients. These patien ts were followed for more than 10 years with neurologic evaluations using a scoring system proposed by the Japanese orthopedic Association (JOA score) . Results. The recovery rate was 66.5% at 10 years and 59.3% at 13 years, the time of the final survey. Operative outcomes most closely reflected the pr eoperative duration and severity of myelopathy (JOA score) and the preopera tive cross-sectional area of the spinal cord. There was no correlation with the canal narrowing ratio or the thickness of ossification of the posterio r longitudinal ligament. Delayed deterioration was attributed to an origina l inadequate decompression and progression of ossification of the posterior longitudinal ligament outside the original operative field. There was no e vidence of significant recurrent ossification of the posterior longitudinal ligament within the margins of prior decompression. Conclusions. The anterior floating method appears to yield adequate long-te rm outcomes when used to manage ossification of the posterior longitudinal ligament.