Prevalence of ossification of the posterior longitudinal ligament (OPLL) in the Pacific populations in Auckland, New Zealand: A retrospective multicentre study

Introduction Primary objective was to investigate the prevalence of ossification of the posterior longitudinal ligament (OPLL) in a mixed demographic region, especially in the Pacific Island population. Secondary objective was to investigate the prevalence of diabetes mellitus and cervical diffuse skeletal hyperostosis (DISH) in patients with and without OPLL. Methods Using the local picture archiving and communication system (PACS), cervical spine computed tomography (CT) examinations over a 2‐month period were retrospectively assessed for the presence of OPLL. Basic demographic data were recorded—gender, age, ethnicity, presence of cervical DISH and the presence or absence of diabetes mellitus. Results A total of 1692 CT examinations were included in the study. The distribution of the ethnic groups was 57.3% European, 12.09% Pacific peoples, 11.9% Māori, 11.53% Asian, 0.95% Middle Eastern/Latin American/African and 6.3% not specified. Overall, 47 cases of OPPL were identified (2.78%). The prevalence of OPPL in the Pacific ethnic groups was significantly higher than the European ethnic group 8.4% versus 0.6%, P