Ankle sprains are mainly benign lesions, but if not well addressed can evolve into permanent disability. A non-treated lateral, syndesmotic or medial ankle instability can evolve into ankle osteoarthritis. For this reason, diagnosis and treatment of these entities is of extreme importance. In general, acute instabilities undergo conservative treatment, while chronic instabilities are better addressed with surgical treatment. It is important to identify which acute instabilities are better treated with early surgical treatment. Syndesmosis injuries are frequently overlooked and represent a cause for persistent pain in ankle sprains. Unstable syndesmotic lesions are always managed by surgery. Non-treated deltoid ligament ruptures can evolve into a progressive valgus deformity of the hindfoot, due to its links with the spring ligament complex. This concept would give new importance to the diagnosis and treatment of acute medial ligament lesions. Multi-ligament lesions are usually unstable and are better treated with early surgery. A high suspicion rate is required, especially for combined syndesmotic and medial lesions or lateral and medial lesions. Ankle arthroscopy is a powerful tool for both diagnostic and treatment purposes. It is becoming mandatory in the management of ankle instabilities and multiple arthroscopic lateral/syndesmotic/medial repair techniques are emerging. Cite this article: EFORT Open Rev 2021;6:420-431. DOI: 10.1302/2058-5241.6.210017

The well-recognised susceptibility alleles to rheumatoid arthritis, HLA-DRB1*04, were associated with rheumatoid arthritis in Portuguese patients. The relatively rare DRB1*10 was also associated with rheumatoid arthritis, as was described previously in other southern European countries. Both groups were associated with high anti-CCP titres, reinforcing its relevance to disease onset.

Case: A 65-year-old man presented with plantar foot pain associated with a mass in the first webspace. A Morton neuroma was considered the probable diagnosis. Despite nonoperative treatment the pain continued. Surgical excision was performed, and histology was interpreted as a schwannoma. Symptoms resolved after surgery. Conclusion: Schwannoma of the foot is a rare condition, and to the best of our knowledge, this is the first case reported in the first webspace. Definitive treatment and diagnosis is surgical excision. Surgeons should consider schwannomas in the differential diagnosis of plantar foot pain because this can be misdiagnosed as a Morton neuroma.

N. Medial malleolus malunion with secondary tibiotalar and syndesmotic incongruence -two case reports and «box resection» for its treatment.