Surgical Treatment for Ossification of the Posterior Longitudinal Ligament of the Cervical Spine

ABSTRACT

Ossification of the posterior longitudinal ligament(OPLL) is a degenerative disease of the spine, usually found in the cervical vertebrae. The etiology and pathogenesis have not been clarified, and its natural course is still unknown. The choice of operative approach, anterior vs. posterior, is still controversial. During the past 13 years, we have operated on 116 patients with myelopathy associated with cevical OPLL; 34 cases(29.3%) were of the continuous type, 30(25.9%) were segemental, 37(31.9%) were mixed, and 15(12.9%) were other type respectively. Forty-six patients underwent anterior cervical decompression by corpectomy, disectomy, and removal of the OPLL, and in these patients, segmental and other types of OPLL were more common and were found in 73% of these cases. On the other hand, 70 patients underwent posterior cervical decompression by cervical laminectomy or expansive laminoplasty; among them, the continuous and mixed type were more common and accounted for 84% of these cases. Surgical outcome was better in patients in whom the duration of pre-operative symptoms was shorter(p<0 .05). Age at surgery, trauma history and surgical approach did not, however, significantly affect the outcome. In conclusion, anterior cervical decompression was seen to give the best results, but was limited to patients with segmental or other types of OPLL, single or two levels of OPLL, and OPLL with herniated cervical disc. The posterior approach, on the other hand, was palliative, and gave better results in patients with continuous or mixed type of OPLL, OPLL of more than level three, and generally compromised patients.