The treatment of rheumatoid flatfoot should take into account two distinct patterns of joint destruction associated with the disease, recommend investigators in the journal Clinical Rheumatology.
Around 90% of patients with rheumatoid arthritis (RA) have radiological changes in their feet. However, various studies investigating these changes have so far been unable to consistently characterize exactly how and where they happen.
Takako Hattori (Osaka University Medical School) and colleagues investigated further by examining radiographs of the feet of 216 individuals with RA.
By measuring the medial arch and talar angles of each foot, the researchers were able to separate patients into three distinct groups. In the first group, the joints were largely unaffected by RA, while in the second group, RA had led to abnormalities in the talonavicular but not the subtalar joints; and, in the third group, both the talonavicular and subtalar joints were affected.
The authors caution that they were unable to evaluate anteroposterior X-ray images of the calcaneus or horizontal displacement of the navicular to talar head. Despite this, the researchers highlight the fact that they were still clearly able to demonstrate distinct foot deformation patterns.
"The present results are therefore important for evaluating deformation and are useful for choosing treatment options," conclude Hattori and team.