Anterior floating method for cervical myelopathy caused by ossification ofthe posterior longitudinal ligament

Ossification of the posterior longitudinal ligament lessens the sagittal di ameter of the cervical canal and compresses the spinal cord anteriorly, and may produce severe disabling myelopathy. The anterior floating method is o ne of the anterior decompression and reconstructions used in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament. This procedure consists of subtotal resection of vertebral bodie s and discs, with slight thinning and release of the ossified ligament usin g air instrumentation. This is followed by reconstruction of the cervical s pine using autogenous strut bone graft accompanied by postoperative applica tion of a halo vest. This method is indicated for patients who present with moderate or severe myelopathies, and especially in those where the canal n arrowing ratio exceeds 60%. This radical procedure causes decompression of the spinal cord and restores its function by enlarging the neural canal wit h anterior migration of the ossified ligament. The procedure minimizes the extent of surgical invasions and avoids damage to the neural tissue, becaus e it does not require the removal of the ossification of the posterior long itudinal ligament. It also stops postoperative regrowth of the ossification . The operative results with long term followup indicate a 71% average reco very rate based on the criteria established by the Japan Orthopedic Associa tion.