Likelihood of hip infection with image-guided hip aspiration dry tap: a 10-year retrospective study.

Majority of patients suspected of hip joint infection with dry-tap were non-infected. Synovial PMN% following lavage maintains high sensitivity for detection of PJI. In patients with THA, PD and subsequent extraarticular collection can be associated with dry-tap therefore, pre-aspiration MRI can help determine their presence and plan the aspiration.