Background Conventionally, the assessment of affected joint count in patients with psoriatic arthritis (PsA) was relied for the detection of swelling and tenderness in the joints and enthesis by clinical physical assessment. To date, the modern imaging tool such as ultrasound (US) can detect inflammation in the joint and enthesis more sensitively than clinical assessment.
Objectives The aim of this study was to research the prevalence of US syovitis and enthesitis findings in patients with PsA and psoriasis (PsO) comparing with clinical assessment.
Methods Total 100 patients, 54 patients with PsA and 46 patients with PsO, were consecutively included. HI VISION Ascendus (HitachiAloka Medical, Tokyo, Japan) was used with a 18-MHz linear array transducer. US examination was performed in MCP, PIP, DIP and wrist joints in both hand. Grayscale (GS) and power Doppler (PD) US were scored on a 0–3 semiquantitative scale for each joint. Moreover, the US assessment of enthesis was performed. Lateral epicondyle, triceps enthesis, the proximal and distal patella tendon enthesis, Achilles tendon and fascia plantaris tendon enthesis was scanned in both GS and PD assessment. Abnormal findings of enthesis was defined structure thickness, bursitis erosion, calcification and power Doppler signal.
Results US synovitis was found in 81.5% (n=44) and 60.9% (n=28) by GS, 66.7% (n=36) and 45.7% (n=21) by PD assessment, respectively in patients with PsA and PsO. Active synovitis (GS grade ≧ 2 and/or PD grade ≧ 1) was found 68.5% (n=37) in PsA and 45.7% (n=21) in PsO. US synovitis was more frequently found than clinical assessment. The most common sites of inflammatory synovitis were the wrist. US enthesopathy was found in 87.0% (n=47) in patients with PsA 56.5% (n=26) in patients with PsO. US enthesitis was also more frequently found than clinical assessment. The most common sites of enthesopathy were the enthesis in lateral epicondyle, quadriceps and Achilles tendon.
Conclusions Our results showed that US was able to detect a high prevalence of inflammatory synovitis in peripheral joints and enthesis in patients with PsA. Moreover, subclinical inflammatory findings were also found in patients with PsO by US. US examination is useful to detect the inflammatory condition in patients with PsA and PsO than clinical examination.
Acknowledgements We wish to thank Setsuko Takeda, Ayumi Hashimoto and Emi Yamashita for their special efforts as a sonographer and collecting data.
Disclosure of Interest None declared