Association between pain in the hip region and radiographic changes of osteoarthritis: results from a population-based study

Objectives. The relationship between hip pain and radiographic change in the population is unclear due to lack of agreed definition for hip pain and difficulties in obtaining radiographs from asymptomatic random samples. Our objective was to assess the relationship between hip pain and radiographic change in osteoarthritis (OA) in a population sample aged over 45. Methods. One thousand and seventy-one responders to a postal questionnaire using a recently validated approach to defining hip pain were stratified into hip pain-positive and -negative groups and samples of each were X-rayed and scored for OA using both minimum joint space and the Croft score. The association between pain and X-ray score was estimated, weighting back to the age and gender distribution of the original population. Results. Hip pain prevalence was 7% in males and 10% in females. Severe OA was present in 16% of those with and 3% of those without pain. Adjusting for age and gender, there was a very strong association of pain with severe OA [odds ratio (OR) 17.4, 95% confidence interval (CI) 3.0-102], but no association with mild/moderate OA (OR 1.4, 95% CI 0.4-4.7). By contrast, only 22% of men aged 45-54 with severe OA had current pain, though in older age groups the proportions with pain were higher (54-70%). Conclusions. Hip pain is relatively infrequent in the general population compared with the published reports of other regional pain syndromes. Mild/moderate radiographic change is very frequent and not related to pain, whereas severe change is rare but strongly related. In younger males, severe radiographic change is much less likely to be associated with pain.