Objective: To determine the diagnostic value of ultrasonography (US) in detection of calcaneal enthesopathies and compare US findings with clinical examination and laboratory data in patients with seronegative spondyloarthropathy (SpA). Methods: We studied fifty six patients with SpA (ankylosing spondylitis 51; psoriatic arthritis 2; reactive arthritis 3). Gray scale US and power Doppler sonography (PDS) was performed in Achilles tendons and plantar fascia using a 40 mm, 12 MHz linear probe to detect tendon thickness, loss of normal fibrillar echogenecity, blurred tendon margin, calcification, fluid collection around tendon, bony erosion, enthesopathic spur, retrocalcaneal bursitis and increased vascularity. Clinical examination including Mander enthesis index (MEI) score, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were examined at the same time. Results: In 112 Achilles tendons, 72.3% showed abnormal US findings, as followings, increased tendon thickness 50.9%; loss of normal fibrillar echogenecity 32.1%; blurred tendon margin 24.1%; calcification 5.4%; fluid collection around tendon 17.7%; bony erosion 16%; enthesopathic spur 8.9%; retrocalcaneal bursitis 13.4%; and increased vascularity in power Doppler sonography (PDS) 14.2%. In 112 plantar aponeurosis, 59.8% showed abnormal US enthesopathic spur 8.9%; retrocalcaneal bursitis 13.4%; and increased vascularity in power Doppler sonography (PDS) 14.2%. In 112 plantar aponeurosis, 59.8% showed abnormal US findings, as followings, increased tendon thickness 12.5%; loss of normal fibrillar echogenecity 50%; blurred tendon margin 30.3%; bony spur 2.7%; and increased vascularity in PDS 4.5%. PDS findings well correlated with findings of gray scale US. While 46% of symptomatic patients and 41.2% of patients with tenderness have abnormal X-ray findings, 69.4% of symptomatic patients and 73.8% of patients with tenderness have abnormal US findings. Patients with clinical symptoms, elevated CRP level and ＞1 MEI score showed increased vascularity in PDS. Conclusion: US is a simple and useful method in the detection of enthesopathies of SpA, even in patients without clinical symptom nor abnormal radiographic finding, and PDS combined with gray scale US is more sensitive tool which reflects the clinical examination.

Keywords: Enthesopathy, Achilles tendinitis, Seronegative spondyloarthropathy, Ultrasonography