Background The identification of urate monosodium crystals in aspirated joint fluid or tophi is the “gold standard” for its diagnosis, however clinical features helps in the assessment of typical cases. Ultrasound detects crystal deposition in joints hence it helps in diagnosis and management. Although the role of musculoskeletal HRU has not been established by consensus yet, many rheumatologists consider it an essential tool for the evaluation of patients with Gout.
Objectives The aim of our study is to describe the presence of the most specific sonography features in “real world” patients with Gout and determine its diagnostic and management role in routine evaluation.
Methods The musculoskeletal HRU specific features like Tophus, Crystal deposits (double contour sign), and Erosions were obtained in 83 outpatients with Gout (ACR criteria 1977) attended between January 2009 and November 2012. Data were collected for our academic program developed since 2007 by Colombian rheumatology association and the School of Medicine la Sabana University with the advisory of the Spanish Society of Rheumatology (SER). The ultrasonographic examinations were performed in symptomatic joints by rheumatologists in training with advisory of a rheumatologist and radiologist with experience in musculoskeletal HRU. EULAR protocols were followed and a HRU system (GE Logiq P5 /8-13MHz linear probe) was used.
Results In a descriptive study of 83 males patients with Gout, (mean age 55.83 years ± 11.09, mean disease duration 13.64 years ± 8.94, mean serum urate 8.07 mgr/dl ± 1.54, mean episodes of acute arthritis in last year 2.87 ± 2.44) musculoskeletal ultrasound features were studied. Only nine patients had a proven gout diagnosis by synovial fluid analysis and 19 patients (22.89%) had received urate lowering therapy (ULT). A total of 161 joints were analyzed (1° MTP 91, Knee 27, Ankle 11, MCP 9, Wrist 4, Elbow 3 others 16). Ultrasound specific findings seen in these joints were the following: crystal deposits in 112/161 joints (69.56%), tophus in 95/161 joints (59.00%) and erosions in 53/161 joints (32.91%). We found tophus by HRU in 72 patients (86.74%), crystal deposits in 71 patients (85.54%) and erosions in 48 patients (57.83%). In 78 patients were started ULT. Eight patients received permanently ULT between seven and twenty two months, in whom a second HRU detects absence or reduce the size of tophus and/or crystal deposits (mean serum urate 8.18 mgr/dl ± 1.40 vs. 4.81 mgr/dl ± 0.58 p<0.001). We found palpable tophus in 40 patients (48.19%) and 37 patients (44.57%) without tophus in clinical examination, but detected by HRU.
Conclusions The HRU is more sensitive than clinical examination to detect tophus, allowing the reclassification of the disease and ULT initiation, also being a useful tool for monitoring treatment. Although the role of musculoskeletal HRU has not been established by consensus, we consider it an essential part of the evaluation of all patients with “early” and chronic Gout.
Chowalloor PV, Keen HI.A systematic review of ultrasonography in Gout. Online published on January 3,2013 as 10.1136/annrheumdis 2012-202301.
Acknowledgements Universidad de La Sabana;Colombian Rheumatology Association.
Disclosure of Interest None Declared