What is Jaccoud’s arthropathy and what are the disease associations?

From a recent review:

Jaccoud's arthropathy (JA) is a condition characterised clinically by 'reversible' joint deformities such as swan neck, thumb subluxation, ulnar deviation, 'boutonniere' and hallux valgus, along with an absence of articular erosions on a plain radiograph. JA was initially described in patients with rheumatic fever (RF), but as this disorder has become rare the main clinical entity associated to JA at present is systemic lupus erythematosus (SLE). JA has also been described in other connective tissue diseases, infections and neoplasia. In general, its prevalence in either SLE or RF is around 5%. The etiopathogenic mechanisms of JA are not known, but some authors have suggested an association with hypermobility syndrome. Several studies have attempted to identify an association of different antibodies with JA in SLE patients, but their findings do not allow for the drawing of any definite conclusions. Newer imaging techniques such as magnetic resonance and high-performance ultrasonography have revealed the presence of small erosions in joints of a few patients with JA. Presently, the therapy for JA is conservative and based on the use of non-hormonal anti-inflammatory drugs, low doses of corticosteroids, methotrexate and antimalarials. The role of surgery through either the realignment of soft tissue around the joint--or more aggressive procedures such as arthrodesis, silastic implant and arthroplasty--needs to be proven.