Spondyloarthritis: Does no clinical enthesitis mean no enthesitis at all? The role of ultrasonography in everyday practice

Abstract

Objectives. The purpose of this paper is to assess the frequency of ultrasonography detected enthesitis in spondyloarthritis (SpA) patients as well as it’s correlation to reported pain and disease activity. Methods. 80 SpA patients were evaluated clinically (medical history, clinical examination, inflammatory markers, clinical and composite indices) and using musculoskeletal ultrasonography (MSUS). The conducted evaluation focused on 16 entheseal sites for each patient, reaching a total of 1280 entheses. The medical history form included questions regarding present or past spontaneous pain and the clinical examination, which evaluated entheseal pain upon pressure (digital pressure on the enthesis overlying skin). Two Esaote My Lab machines with 6-12/8-18 MHz linear probes were used. One clinician/ultrasonographer performed all evaluations, in order to avoid interobserver variability. Results. Using musculoskeletal ultrasonography, up to 54.68% of the asymptomatic entheses in patients with axial/peripheral SpA were found with either GS and/or PD abnormalities. The tendons with the highest rates of ultrasound detected entesitis were the Achilles, followed by the quadriceps, both in gray scale (GS) (76.25%, 56.25% respectively) and power Doppler (PD) (24.4%, 20% respectively), while the least affected were the proximal patellar (20.65% GS, 8.15% PD) and flexor tendons (19.4% GS, 9.4% PD). Conclusions. Although it has a leading role in the pathogenesis of SpA, enthesitis is partially overlooked in everyday practice. This paper highlights the high percentages of both GS and PD entheseal abnormalities, both in peripheral and axial SpA. The low correlation between reported peripheral pain, especially in axial SpA, and MSUS signs of enthesitis proves the need for an imagistic enthesitis score in the diagnostic process, in order to establish the full extent of the disease and to personalize the treatment, considering the high and rising range of therapies to choose from.

Keywords

• spondyloarthritits
• axial
• peripheral
• enthesitis
• musculoskeletal ultrasonography