Consistency of the Sonographic Image (Double Contour Sign) in Patients with Gout after Ambulation

The aim of this study was to know whether or not any crystal shedding occurs after ambulation in patients with gout and how it affects the consistency of the sonographic image of crystal deposition on hyaline cartilage. A total of 18 consecutive patients (29 knees), 11 with early gout (17 knees) and seven with chondrocalcinosis (12 knees), were prospectively scanned by ultrasound. Examination at rest and after ambulation was performed in each patient. Crystal aggregates were measured in a transverse view. Crystal shedding after ambulation was noted in two patients (two knees) with gout. However, crystal deposits on the surface of the articular cartilage in gout kept invariable size. In patients with chondrocalcinosis, crystal shedding by ambulation was absent. The conclusion of this study is that the size of crystal deposits on the hyaline cartilage in gout and chondrocalcinosis assessed by ultrasound is not modifiable by ambulation.