Clinical Evaluation of Cervical Ossification of the Posterior Longitudinal Ligament

ABSTRACT

The authors treated 32 patients with Ossification of the Posterior Longitudinal Ligament(OPLL). Seventeen of these patient had surgery during the past 1 year between 1987 and 1988. In this study we present a radiological and clinical analysis of these cases with a literature review. We also discuss a clinical system of grading, different types of radiological patterns, the indication of surgical treatment and the choice of operative methods. 1) The incidence of the cervical OPLL was about 5.4% in our annual study, which was based on the cervical CT and CTM. 2) The highest incidence was in patients 50-60 years of age and male female ratio was about 31. 3) The highest incidence was in C5, C6 and C4 levels of cervical spine and two and three level involvement was prominent. 4) The pattern of OPLL was devided into a continuous type (21%), a multiple segmented type(48%), a mixed type(25%), a localized type(6%). 5) Absolute diameter did not always parallel the extent of spinal cord signs as did the percentage of spinal canal narrowing. 6) In cases of a clinical grading of more than III, surgery must be considered. In grade II, surgery is indicative if conservative management failed to improve the clinical symptoms. 7) For the evaluation of the cervical OPLL, the CT-Scan of CT metrizamide myelography was more useful method. 8) Cervical Corpectomy and fusion with or without bone cement were found to be advisable in Cases of cervical OPLL.