Posterior Tibial Tendon and Spring Ligament Lesions in Rheumatoid Arthritis

In rheumatoid arthritis, a significant number of patients have hindfoot pain while they are considered in low disease activity. Then the rheumatoid hindfoot may evolve in valgus flat foot with disability. The aim of our study was to observe the lesions of the main stabilizers of the hindfoot in rheumatoid arthritis to improve the followup and the treatment of the disease. Thirty-three feet (from 21 patients) with rheumatoid arthritis and pain of the hindfoot were consecutively observed. The patients have had no biologic treatment. Every foot had Magnetic Resonance Imaging (MRI) of the hindfoot with gadolinium injection. The tendon of the tibialis posterior muscle, the spring ligament and the inter-osseous talocalcaneal ligament were considered. All the feet presented tenosynovitis of the posterior tibial tendon. Structural lesions of the posterior tibial tendon (23/33 feet, 69.7%) were more frequent than lesions of the spring ligament (12/33 feet, 36.4%). There was no inferior spring ligament lesion without superior spring ligament lesion. No interosseous talocalcaneal ligament lesion was observed. In rheumatoid arthritis, the hindfoot, and particularly the posterior tibial tendon, should be evaluated during patient follow-up to detect a possible lesion. Posterior tibial tendon lesion arises at the same time as the spring ligament lesion, before interosseous talocalcaneal ligament lesion. Imaging, especially MRI, may complete clinical examination. If rheumatoid involvement of the posterior tibial tendon is observed, treatment intensification is required.