Heterotopic ossification after total ankle replacement: The role of prosthesis alignment

Background: The aetiology of heterotopic ossifications (HO) after total ankle arthroplasty ( TAR) remains controversial. The aim of the study was to evaluate the prevalence and localisation of HO and the effect of alignment. Methods: 88 TARs with a series of radiological controls and follow-up of 36 months were evaluated. Frontal and sagittal alignment parameters (alfa and beta angle defined by Hintermann) and tibial coverage were evaluated. Results: The prevalence and grading of HO increased over time, mostly in the posterior gutter. Varus alignment correlated with HO increase in the ventral and lateral gutters the first year. A dorsally located rotational centre correlated with total HO growth and HO in the posterior gutter. These correlations were not detected after 3 years, as HO were seen in all prostheses, regardless of alignment. Conclusions: HO grow over time with a prevalence up to 100% after 3 years. TAR alignment correlates with gutter-specific HO formation within the first year. (C) 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.