Is there sub-clinical enthesitis in early psoriatic arthritis? A clinical comparison with power Doppler ultrasound
Arthritis Care & Research , 05/24/2012
Freeston JE et al. – The prevalence of sub–clinical enthesitis in this early psoriatic arthritis (PsA) cohort was low. Clinical examination (CE) may over–estimate active enthesitis. The few sub–clinically inflamed entheses were in the lower limb, where mechanical stress is likely to be more significant.Methods
- 42 patients with new onset PsA and 10 control subjects underwent CE of entheses for tenderness and swelling and grey scale (GS) and power Doppler (PD) US of a standard set of entheses.
- Bilateral elbow lateral epicondyles, Achilles tendons and plantar fascia were assessed by both CE and US, the latter scored using a semi–quantitative (SQ) scale.
- Inferior patellar tendons were assessed by US alone.
- A GS SQ score of >1 and/or a PD score >0 was used to describe significant US–entheseal abnormality.
- 24/42 (57.1%) of the PsA group and 0/10 (0%) of the control group had clinical evidence of at least 1 tender enthesis.
- In the PsA group, for sites assessed by both CE and US, 4% (7/177) of non–tender entheses had a GS>1 and/or PD>0 score compared to 24% (9/37) of tender entheses. CE over–estimated activity in 28/214 (13%) of entheses.
- All the non–tender, US–abnormal entheses were in the lower limb.