Ossification of the Posterior Longitudinal Ligament in a Chilean Population: A CT-Based Prevalence Study in Patients Aged 60 Years and Older.

INTRODUCTION

The prevalence of ossification of the posterior longitudinal ligament (OPLL) has been primarily studied in East Asian countries; its prevalence in Western populations remains to be elucidated. We aimed to determine the prevalence of OPLL in a Chilean population aged 60 years and older using fluorine-18 fluorodeoxyglucose positron emission tomography and CT (PET-CT) as screening tool.

METHODS

We evaluated patients between 60 and 73 years consecutively studied with PET-CT in a University Hospital. We assessed whole-body CT scans in both sagittal and axial views to detect the presence of OPLL. We used the Mann-Whitney test to analyze continuous variables, the Fisher test for categorical variables, and a logistic regression analysis to determine the independent effect of age and sex on the presence of OPLL.

RESULTS

We studied 1,009 patients (median age = 66 years); 597 were males (59.17%). Nineteen patients had OPLL, with a prevalence of 1.88% (1.04 to 2.72). OPLL was more prevalent in men (2.68%) than in women (0.73%; P = 0.02). All cases presented cervical involvement; only one had cervical and thoracic OPLL. The median age of patients with OPLL (64 years) and without OPLL (66 years) was not statistically different (P = 0.09). Male sex independently influenced the presence of OPLL (odds ratio = 3.85 [1.11 to 13.33]), age did not (odds ratio = 0.89 [0.78 to 1.02]).

DISCUSSION: This is the first study evaluating the prevalence of OPLL in Latin America. It shows a prevalence alike that in non-Asian populations in the United States and lower than the prevalence described in Asian populations.