The study was stopped due to health-related issues in the research group, that hindered inrolement of patients.

The aim of the study is to investigate the incidence and clinical implications of intermetatarsal bursitis (IMB) in patients with rheumatoid arthritis (RA).

The hypothesis is that IMB is a cause of pain in patients with RA.

Within the recent years more research have focused on IMB in patients with rheumatologic disorders. There is emerging evidence that IMB is an inflammatory alteration in line with synovitis in patients with RA, and presence of IMB have been linked to the early stages of RA, especially due to the focus of the published literature.

The clinical implications of the presence of IMB for the patients are yet to be understood. Limited studies have linked the occurrence of IMB to foot impairment, but no studies have been conducted investigating the direct association between forefoot pain and the presence/absence of IMB.

Inclusion Criteria:

• Age > 18 years
• Forefoot pain and diagnosed with RA (patient group)
• Diagnosed with an axial arthritis (control group)

Exclusion Criteria:

• Age <18 years
• Open wounds or ongoing infection in the forefoot at the time of examination
• Persons with a history of significant trauma in the forefoot, e.g. any fracture or previous surgeries in the forefoot
• Persons who have previously received intermetatarsal treatment (Morton's neuroma or IMB) in the same foot, e.g. injection within 6 months or operation at any time
• Exclusion from MRI scan only:
• Persons with contraindications to participate in MRI scan
• Persons with severely impaired renal function (GFR <30 ml/min)

Outcome assessor is blinded to type of patient they are examining.