Aims
To investigate the prevalence and distribution
of bone erosions in an early psoriatic arthritis (PsA)
population using conventional radiography (CR) and to
explore the agreement between CR and ultrasound (US)
detected bone erosions.
Methods
Newly diagnosed, treatment naïve PsA patients
fulfilling the ClASsification for Psoriatic Arthritis (CASPAR)
classification criteria of ≤5 years symptom duration
were recruited as part of the Leeds Spondyloarthropathy
Register for Research and Observation and underwent CR
and US examination of hands and feet.
Results
Overall, 4655 hand and feet joints were assessed
in 122 patients. CR erosions were detected in 24.6%
(n=30) with lowest prevalence seen below 8 months of
symptoms (17.5% vs 24.3%>24 months). The number of
erosions was higher on CR (1.55% (63/4,655); US 1.04%
(34/3,270)), with 5th metatarsophalangeal (MTP) joint
being the most affected site in both CR (5.21% (11/211))
and US (7.14% (15/210)). Erosions in CR were more evenly
distributed compared with US where three-quarters of the
total number of bone erosions were detected in wrists,
second metacarpophalangeal (MCP) and fifth MTP joints.
Most joints had almost perfect prevalence-adjusted bias-adjusted kappa values ranging from 0.91 to 1.
Conclusions
Erosions were seen in a quarter of patients
with newly diagnosed, untreated PsA with a declining trend
around the 8-month symptom duration cut-off. High levels
of agreement between CR and US were seen with CR
detecting more erosions. A focused US assessment of the
wrist, second MCP and fifth MTP joints may be useful to
detect bone erosions in early PsA.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)