Latent period best predicts acetabular cup failure after total hip arthroplasties in radiated hips

We retrospectively analyzed the prognostic factors related to the failure of acetabular components after total hip arthroplasties in radiated hips. Eighteen hips from 12 patients who had primary arthroplasties were followed up for a mean of 58 months (range, 20-139 months). The patients' age, total radiation dose, latent period, presence of infection, and the type of the acetabular component were examined as possible predictors of failure using the Cox proportional hazard regression. Multivariate analyses showed that a longer latent period was the most important risk factor for failure, increasing 1.72 times when the latent period was greater than 1 year, after adjusting for other predictors. The latent period might be helpful for clinicians in choosing a treatment method for patients.