An Unusual Cause of Late Pain and Effusion After Total Knee Arthroplasty: Pulmonary Hypertrophic Osteoarthropathy

The common causes of pain and effusion after total knee arthroplasty are infection, instability, loosening, and patellofemoral problems. Fehring et al. reported that the primary cause of failure in a series of 440 revision knee arthroplasties was infection and 63% of the revisions failed within five years after the operation1. In a review of 212 revision total knee arthroplasties performed at one center, Sharkey et al. reported that the three most common reasons for failure were polyethylene wear, aseptic loosening, and instability2.