Comparative distribution of ultrasound-detectable forefoot bursae in patients with osteoarthritis and rheumatoid arthritis

• Main Authors: Hooper, Lindsey (Author), Bowen, Catherine J. (Author), Gates, Lucy (Author), Culliford, David (Author), Arden, Nigel K. (Author), Edwards, Christopher J. (Author)
• Format: Article
• Language: English
• Published: 2014-06.
• Subjects: Article
• Online Access: Get fulltext; Get fulltext

Objective: To investigate the prevalence and distribution of forefoot bursae (FFB) in individuals with osteoarthritis (OA), rheumatoid arthritis (RA) and healthy controls (HC). Additionally, we sought to identify mechanical or inflammatory factors predicting FFB count. Methods: A cross-sectional, observational study was completed in three cohorts; 1. OA (n=50), 2. RA (n=56), 3. HC (n=50). FFB were recorded as present if detectable in two ultrasound (US) scanning planes. The comparative probabilities of FFB presence between groups was expressed as odds ratios. Mechanical factors, including joint deformity, range of motion and foot posture, were determined for both patient groups. Inflammatory factors, including serology, DAS28 and US-detected metatarsophalangeal joint hypertrophy and metatarsal head erosion, were determined for RA patients. Multiple linear regression analyses were used to determine factors related to FFB count in patient groups. Results: FFB were highly prevalent in both OA and RA groups (OA: 94 per 100 patients; RA: 88 per 100 patients), compared to HC (56 per 100 participants). FFB distribution significantly differed between patient groups (RA-OA: X2=15.64, p?0.001). In OA patients FFB were commonly located in the medial/lateral forefoot region but across all regions for RA patients. In OA patients reduced ankle joint range of motion predicted FFB count (R2=0.030, p=0.037). In RA patients erosion presence was related to FFB count (R2=0.42, p?0.001). Conclusion: FFB are highly prevalent in patients with OA and RA. FFB distribution significantly differs between patient groups. FFB in patients with OA may be related to mechanical factors.