Monosodium Urate Crystal Deposits Are Common Ultrasound Findings at Hip Joint in Gout

Monosodium urate crystal deposits in the hip joint were a common ultrasound finding in patients with gout, according to study data published in Joint Bone Spine.

Investigators conducted bilateral ultrasound assessment of the hip joint in 40 consecutive patients with gout, diagnosed according to the latest American College of Rheumatology/European League Against Rheumatism classification criteria for gout. The hip joint was scanned with both longitudinal and transverse views and the presence of hip intra-articular aggregates or tophi and the double contour sign over the hyaline cartilage of the femoral head. The Outcome Measure in Rheumatology definitions for each of these abnormalities were used to determine the presence of lesions. An additional 25 healthy control participants were recruited and underwent ultrasound assessment of the hip joints.

Ultrasound examination indicated crystal deposits in at least 1 hip joint in 42.5% of patients with gout and 8.0% of control participants (P =.0029). Aggregates, tophi, and the double contour sign were found in at least 1  hip in 32.5%, 15.0%, and 15.0% of patients with gout, respectively.

Longer disease duration (P =.004), greater number of gout “attacks” in the prior year (P =.029), and presence of subcutaneous tophi (P =.037) were associated with the presence of crystal deposits. No other demographic or clinical factors were predictive of ultrasound findings.

These data suggest a relatively high prevalence of crystal deposits in the hip joint in patients with gout. Therefore, the investigators suggested that clinicians incorporate the hip into their disease management approach in patients with gout.

Reference

Di Matteo A, Filippucci E, Cipolletta E, et al. Ultrasound and clinical features of hip involvement in patients with gout [published online February 16, 2019]. Joint Bone Spine. doi:10.1016/j.jbspin.2019.01.027