TY - JOUR T1 - Intermetatarsal bursitis is frequent in patients with established rheumatoid arthritis and is associated with anti-cyclic citrullinated peptide and rheumatoid factor JF - RMD Open JO - RMD Open DO - 10.1136/rmdopen-2019-001076 VL - 5 IS - 2 SP - e001076 AU - Hilde Berner Hammer AU - Tore K Kvien AU - L Terslev Y1 - 2019/10/01 UR - http://rmdopen.bmj.com/content/5/2/e001076.abstract N2 - Key messagesWhat is already known about this subject?Intermetatarsal bursitis (IMB) is frequent in patients with rheumatoid arthritis (RA), but there are large discrepancies in the described prevalence and the most frequent localisations.What does this study add?We found that one in five patients with established RA had IMB, and that most of the bursitis were located in the spaces between metatarsophalangeal (MTP) joint 2 and 3 as well as between MTP 3 and 4. The presence of IMB was not associated with the total ultrasound scores of a high number of joints/tendons, but with the ultrasound scores of inflammation in the MTP joints. In addition, presence of IMB was associated with presence of anti-cyclic citrullinated peptide and rheumatoid factor antibodies.How might this impact on clinical practice?Clinicians should explore for IMB as a cause of forefoot pain especially in patients with seropositive rheumatoid arthritis.Ultrasound is sensitive for detection of inflammatory changes in patients with rheumatoid arthritis (RA).1 Intermetatarsal bursitis (IMB) is located on the dorsal side of the deep intermetatarsal ligament and may easily be detected by use of longitudinal and transverse dorsal scans between the metatarsophalangeal (MTP) joints.2 In a longitudinal scan, they are relatively large and have usually a round shape, caused by hypoechoic synovitis and they may contain fluid. They are often power Doppler (PD) positive. In the transverse plane, an IMB is detected as a hypoechoic structure between the metatarsal heads where the upper border is rounded. There are few studies on IMB,3–6 and the objective of this study was to explore the prevalence of IMB and its associations with subjective, clinical and laboratory assessments in established RA patients.This post hoc analysis of 209 patients with RA (mean (SD) age 53 (13) years, disease duration 10 (9) years, 81% women, 79% anti-cyclic citrullinted peptide (anti-CCP) positive, 69% rheumatoid factor (RF) positive) initiating biological disease-modifying antirheumatic drugs (bDMARDs)7 … ER -