Age / Sex : 37 / M

Chief complaint :

Rt. wrist pain, swelling since motorcycle accident (2 weeks ago)

acupuncture treatment history(+)

CRP: 5.49 mg/dl

What is your impression?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : Kim Na Ra, Konkuk University Medical Center

Discussion

Answer:  

Acute gouty arthritis of the wrist joint

Findings:

Fig 1. On an anteroposterior radiograph of both wrists, there is no predominant periarticular osteopenia. The joint spaces are preserved, and small bone erosion at dorsal aspect of the scapholunate joint is noted on a lateral radiograph.

Fig 2. Coronal fat suppressed proton density weighted MR image shows intermediate high signal synovial thickening without bone marrow edema, and diffuse tenosynovitis of the flexor tendons. Axial fat suppressed proton density weighted image reveals diffuse heterogeneous intermediate high signal synovial hypertrophy of the wrist joint. Axial T2 weighted image demonstrates focal bone erosion with overhanging edge at the scapholunate joint.

Fig 3. Long-axis ultrasound image of the wrist joint shows heterogeneous hypoechoic synovial hypertrophy with hyperechoic dot like foci on the synovium (arrows), and irregular hyperechoic line along the chondral surface of the scaphoid (arrowheads). The thickened synovium reveals hypervascularity on color Doppler ultrasound.

Differential Diagnosis:

Inflammatory arthritis including rheumatoid arthritis, calcium pyrophosphate dihydrate deposition disease, infectious arthritis with a low virulence organism

Discussion:

The typical presentation of gout is episodic acute monoarthritis of the first MTP joint with overlying erythema. As the disease progresses, the clinical presentation may become atypical; for instance, polyarticular attacks involving the hand joints and prolonged duration of arthritis. Ultrasonography provides assistance for diagnosing gout, as it could detect early deposition of MSU crystals in some joint structures, such as the surface of hyaline cartilage and the synovium.

The double contour sign describes the deposition of MSU crystals on cartilaginous surfaces that form an irregular hyperechoic band paralleling the bone contour. Typically, the hyperechoic band is as bright as the bony contour. The deposition of MSU crystals in the synovium generates two image signs: bright stippled foci (punctiform urate deposits) and hyperechoic areas (tophi). The arthroscopic image of the wrist joint in the present case revealed the irregular tophi depositions on the cartilage, and correlated with the ultrasound images.

References:

Thiele RG, Schlesinger N. Diagnosis of gout by ultrasound. Rheumatology 2007;46:1116-1121.

Lai KL, Chiu YM. Role of ultrasonography in diagnosing gouty arthritis. J Med Ultrasound 2011;19:7-13.

Burt HM, Dutt YC. Growth of monosodium urate monohydrate crystals: effect of cartilage and synovial fluid components on in vitro growth rates. Ann Rheum Dis 1986;45:858-864.

Han TS, Kwack KS, Park S, Min BH, Yoon SH, Lee HY, et el. A superficial hyperechoic band in human articular cartilage on ultrasonography with histological correlation: preliminary observations. Utrasonography 2015;34:115-124.