The Prevalence of Cervical Ossification of the Posterior Longitudinal Ligament (OPLL) in the Māori and Non-Māori Population in the Bay of Plenty, New Zealand.

AIM: The primary objective of this study was to determine the prevalence of cervical ossification of the posterior longitudinal ligament (OPLL) among Māori compared to non-Māori populations in the Bay of Plenty (BOP) region of New Zealand.

METHODS

Cervical spine and trauma CT scans performed between 2021 and 2025 were retrospectively reviewed for evidence of cervical OPLL. Patients aged ≥ 40 years with available ethnicity data and adequate imaging was included. Cases with a prior diagnosis of OPLL were excluded to reduce selection bias.

RESULTS

A total of 423 CT scans were from the BOP region, comprising 224 Māori and 199 non-Māori patients. Cervical OPLL was identified in 15 Māori patients, with one case excluded due to prior diagnosis. This yielded a statistically significant OPLL prevalence of 6.4% (14/223, p = 0.0133) among Māori in BOP. Māori in BOP were 6.6 times more likely to have cervical OPLL compared to non-Māori (OR: 6.60, 95% CI: 1.48-29.4). In the non-Māori BOP cohort, two cases of cervical OPLL were identified, resulting in a prevalence of 1.0% (2/199).

CONCLUSIONS

This study demonstrates a significantly higher prevalence of cervical OPLL in the Māori population of the Bay of Plenty compared to non-Māori.