Elsevier

Joint Bone Spine

Volume 73, Issue 5, October 2006, Pages 527-531
Joint Bone Spine

Original article
Extrasynovial ultrasound abnormalities in the psoriatic finger. Prospective comparative power-doppler study versus rheumatoid arthritis

https://doi.org/10.1016/j.jbspin.2006.01.019Get rights and content

Abstract

We prospectively compared power Doppler ultrasound findings in 25 fingers with rheumatoid arthritis (RA) and 25 fingers with psoriatic arthritis (PsA). Erosive synovitis and tenosynovitis were seen in both groups. Extrasynovial changes were found in 21/24 (84%) fingers with PsA versus none of the fingers with RA. Of the 21 PsA fingers exhibiting extrasynovial changes, 15 (15/25, 60%) also had synovial changes. The extrasynovial changes reflected enthesitis or soft tissue inflammation, with the main patterns being capsular enthesophyte, juxtaarticular periosteal reaction, enthesopathy at the site of deep flexor tendon insertion on the distal phalanx, and subcutaneous soft tissue thickening of the finger pad or entire finger. In four fingers, ultrasonograhy showed pseudotenosynovitis, an underrecognized abnormality characterized by diffuse inflammation of the digital soft tissues. Pseudotenosynovitis may play a pivotal role in dactylitis (sausage digit), which is defined as diffuse uniform swelling of the entire finger. Our findings suggest that inflammation of the fibrous skeleton of the finger may lead to the clinical and radiological features that distinguish PsA from RA of the finger.

Introduction

The fingers are common sites of involvement in both rheumatoid arthritis (RA) and psoriatic arthritis (PsA). The synovial membrane of the joints and tendon sheaths is affected in both conditions. Selective involvement of the distal fingers consistent with enthesitis, in contrast, occurs in PsA but not in RA [1], [2]. We used ultrasonography to look for evidence of finger enthesitis in PsA, comparatively with RA. Ultrasonography is a simple and noninvasive tool capable of imaging the bone contours, synovial membrane, tendons, and soft tissues.

Section snippets

Methods

We prospectively included 21 patients meeting American College of Rheumatology criteria for RA [3] and 20 patients meeting Fournié criteria for PsA [4]. In the RA group, there were 16 women and five men (ratio, 3.2) with a mean age of 52.9 years and mean disease duration of 10.5 years. The PsA group comprised nine women and 11 men (ratio, 0.8) with a mean age of 42.8 years and mean disease duration of 90.3 years. The inclusion criterion was presence of symptoms in one or more fingers, without

Results

We studied 25 fingers in the 21 patients with RA (one finger in 18 patients, two in two patients, and three in one patient) and 25 fingers in the 20 patients with PsA (one finger in 15 patients and two in five patients) (Table 1).

Synovial abnormalities were consistently seen in the fingers with RA (Fig. 1, Fig. 2). A close correlation was noted in the RA group between the clinical manifestations and the ultrasound findings. A positive Doppler signal from foci of synovitis was found in eight

Discussion

Ultrasound imaging detected extrasynovial abnormalities that may be specific of PsA of the fingers. In keeping with earlier publications [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], we found no extrasynovial abnormalities in the fingers with RA. In a study of ultrasound imaging of the distal phalanx in patients with various rheumatic diseases, Grassi et al. [16] noted abnormal signals at the site of flexor tendon attachment in patients with PsA. Jevtic et al. [17] used magnetic

Conclusion

The findings from this study support the concept that PsA of the finger results both in synovial membrane abnormalities that resemble those seen in RA (erosive synovitis and tenosynovitis) and in enthesopathy of the fibrous skeleton of the finger. The involvement of the fibrous skeleton distinguishes clearly PsA from RA of the finger.

References (24)

  • W. Grassi et al.

    Sonographic imaging of the distal phalanx

    Semin. Arthritis Rheum.

    (2000)
  • B. Fournié

    Pathology and clinico-pathologic correlations in spondyloarthropathies

    Joint Bone Spine

    (2004)
  • B. Fournié et al.

    L'onycho-pachydermo-périostite psoriasique du gros orteil (OP3GO). Etude anatomoclinique et approche physiopathogénique à propos de 4 observations

    Rev. Rhum.

    (1989)
  • B. Fournié et al.

    Fréquence des signes évocateurs d'un rhumatisme psoriasique dans l'atteinte radiologique des doigts et des orteils. A propos de 193 cas d’arthropathie psoriasique

    Rev. Rhum.

    (1992)
  • F.C. Arnet et al.

    The American Rheumatism Association 1987 revised criteria for the classification of rheumatoïd arthritis

    Arthritis Rheum.

    (1988)
  • B. Fournié et al.

    Proposition de critères de classification du rhumatisme psoriasique. Etude préliminaire de 260 patients

    Rev. Rhum. [Ed. Fr.]

    (1999)
  • T.M. Spiegel et al.

    Measuring disease activity: comparison of joint tenderness, swelling and ultrasonography in rheumatoid arthritis

    Arthritis Rheum.

    (1987)
  • L. De Flaviis et al.

    Ultrasonography of the hand in rheumatoid arthritis

    Acta Radiol.

    (1988)
  • B. Fornage

    Soft tissue changes in the hand in rheumatoid arthritis: evaluation with US

    Radiology

    (1989)
  • C. Cervini et al.

    Sonography of MCP joints in rheumatoid arthritis by 13 MHz

    Br. J. Rheumatol.

    (1992)
  • P.J. Lund et al.

    Ultrasonographic imaging of the hand and wrist in rheumatoid arthritis

    Skeletal Radiol

    (1995)
  • M. Stone et al.

    Power Doppler US assessment of rheumatoid hand synovitis

    J. Rheumatol.

    (2001)
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