Internet-Based case‐crossover study results issued in 'Arthritis Care & Research' explained that the hip injury and episodes of the hip "giving way" were significantly concerned with pain exacerbation in people with symptomatic hip OA.

Kai Fu et al. examined the association between hip injury/"giving way" and hip pain exacerbations in people with symptomatic hip OA. The eligible participants with symptomatic hip OA were followed up for 90 days. They were asked to complete online questionnaires at baseline and 10‐day intervals, i.e. control periods. They logged on to the study website to complete questionnaires for the occurrence of hip pain exacerbation (case periods) known as an increase of two points in pain intensity compared with baseline using a numeric rating scale (NRS: 0‐10). Conditional logistic regression assessed the connection between the hip injury and "giving way" to the risk of pain exacerbation.Out of 252 patients included in the study, the investigators collected data from both case and control periods 133 (53%) subjects. The hip injury during the last seven days enhanced the risk of hip pain exacerbation. Hip "giving way" during the last two days was concerned with an increased risk of hip pain exacerbation. It also revealed a significant relationship between the number of hips "giving way" events and the risk associated with hip pain exacerbations (p<0.001).

The investigators noted that "The results provide some insight into the possible mechanisms of pain exacerbation. Methods to prevent exposure to injury may aid to decrease the burden of pain in people with hip OA."