Radiographic factors associated with hip osteoarthritis: a systematic review

The purpose of this study was to outline factors that contribute to the appearance of hip osteoarthritis (OA). Secondarily, this study aims to describe radiographic factors that are associated with the progression of OA in the arthritic hip. Pubmed/MEDLINE and Embase were searched in November 2018 for radiographic risk factors for hip OA. All articles were eligible if they (i) were written in the English language and (ii) commented on OA as it relates to radiographic description, appearance or progression of OA. Demographic characteristics of the study cohort, definition of OA, baseline OA and factors for prediction or progression of OA were recorded. Nine articles were included in this review. A total of 3268 patients were analyzed across all studies. The mean age was 60.0 years (range 18-91.5). The most common descriptors for OA were dysplasia and cam impingement. Six of the nine articles found acetabular under-coverage to be associated with developing OA. Four articles found cam morphology to be an associated factor. Finally, four articles commented on the factors associated with the progression to more severe grades of OA, reporting exclusively on acetabular under-coverage, whereas only one reported on cam morphology to be associated. This systematic review found acetabular under-coverage followed by cam morphology to be strongly associated with both the development and progression of hip OA. These findings define patients at risk for developing hip OA and emphasize the importance of early awareness of future joint degeneration.