Distribution of Urate Crystal Deposition in the Hands and Wrists of Patients with Chronic Gout

We sought to examine the frequency and patterns of monosodium urate (MSU) crystal deposition in the hand/wrist in non-acute gout patients using dual-energy computed tomography (DECT). Methods: All hand/wrist DECT imaging data of patients with chronic tophaceous gout undergoing their first examination before dissolution therapy from March 2015 to March 2019 were identified. Cases without positive MSU crystal deposition were excluded. The reports and images of the positive cases were retrospectively analysed, and the anatomical locations of all urate crystal depositions were recorded. Results: A total of 48 cases were identified with positive findings. Thirty of the cases had undergone DECT of both hands, and 18 had undergone DECT of a single hand. In total, 60 hands/wrists had flexor tendon involvement. The carpal joints were the most commonly involved site (78.2%). The carpal tunnel was the most commonly involved soft tissue site in the hand and wrist (71.8%), followed by the fourth (55.1%) and fifth (53.8%) extensor compartments. The second digit extensor digitorum (47.4%) was the most commonly involved soft tissue site in the hand while the fourth digit flexor digitorum was the most commonly (46.2%) involved flexor tendon in the hand. In the hand and wrist soft tissue sites, extensor pollicis brevis (11.5%), flexor carpi ulnaris (11.5%) and extensor compartment I (11.5%) were involved least commonly. We found Zones II (75%) and IV (78.3%) to be the most commonly involved flexor tendon zones in the hand.