To observe by magnetic resonance imaging (MRI) the pathologic changes in the posterior tibial tendon (PTT), subtalar joint complex (STJC), and sinus tarsi in patients with rheumatoid arthritis (RA), and if possible to determine their involvement in the course of the disease.
Sixty-seven rheumatoid feet with mid and hindfoot pain underwent MRI with gadolinium injection. Localized enhancement and anatomic lesions were assessed in the 3 sites.
On MRI, PTT involvement was seen to be more frequent than STJC or sinus tarsi. When there was gadolinium enhancement of the PTT there was no sinus tarsi enhancement (p = 0.014). Interosseous talocalcaneal ligament rupture was correlated with disability (p = 0.031).
In RA patients with hindfoot pain, PTT synovitis is observed when there is no sinus tarsi synovitis.