An aetiological classification for developmental synostoses at the elbow.

Synostoses at the elbow joint are rare. The literature divides them into three groups based on the nature of bony ankylosis; the commonest are humeroradial synostoses. Approximately 150 cases have been reported. There are 29 reported cases of humeroradioulnar synostosis and five of humeroulnar synostosis. An anatomical classification was previously described for humeroradial synostoses. Due to significant phenotypic variability we believe a classification based solely on anatomical characteristics will in some cases be misleading. No classification exists for humeroradioulnar and humeroulnar synostosis. By re-examining the literature we have produced a combined classification for all elbow synostoses which more accurately predicts causes. Congenital elbow synostoses often cause little functional disability. Treatment by soft tissue release and osteotomy has been attempted, but although range of movement is initially, improved re-ossification is the norm. Investigation is more complicated and may be helped by classification which identifies syndrome association, risk of organ anomaly, and inheritance pattern.