Objectives
To evaluate the ankle, hindfoot, and heel changes (determined by physical examination, ultrasound and baropodometry) in patients with rheumatoid arthritis, to compare the findings with healthy subjects, and to analyze if these findings are associated with ankle pain and could affect the quality of life.
Methods
We enrolled 35 rheumatoid arthritis patients and 35 healthy controls, and evaluated their ankles (tibiotalar joints, tendons), hindfeet (talonavicular, subtalar joints) and heels using clinical examination, DAS28-CRP, RAPID3 for the evaluation of functional status, quality of life in rheumatoid arthritis questionnaire, ultrasound, and baropodometry.
Results
The ultrasound inter-observer agreement was good for the subtalar joint, and very good for the other structures. Flat foot was identified in 50% of feet in rheumatoid arthritis patients, with 83.8% having concomitant hindfoot valgus and less subtalar joint synovitis visible from the lateral approach (32.4%
vs
55.6%,
p
= 0.041). The body mass index, RAPID3 and subtalar synovitis were independent predictors for the symptomatic ankle (all
p
<0.05). Midfoot and heel plantar pressures were higher in rheumatoid arthritis patients compared to healthy controls, but when subtalar synovitis was present, the pressures decreased (avoidance of heel support). Poor quality of life in rheumatoid arthritis patients was independently predicted by DAS28-CRP, RAPID3, disease stage, hindfoot valgus, tibiotalar and subtalar synovitis, tendon pathology, Achilles tendon enthesophytes, calcaneal erosions, plantar fasciitis, and perifasciitis (all
p
<0.05).
Conclusion
The quality of life of rheumatoid arthritis patients is significantly affected by ankle and hindfoot pathology (inflammatory modifications, but also degenerative findings and deformities). Ultrasound scanning is an important tool in the evaluation of inflammatory and degenerative lesions in these regions, and their early detection might contribute to a better therapeutic management in these patients.