The hip in arthrogryposis multiplex congenita.

The hip is involved in up to 80% of individuals with a diagnosis of arthrogryposis multiplex congenita. The hip deformity consists of contracture with or without dislocation. Isolated contracture can usually be treated conservatively by manipulation and splinting, only occasionally requiring operative intervention. Dislocation is as frequently bilateral as unilateral. Bilateral hip dislocations are best left unreduced; only accompanying contractures should be treated. The unilateral dislocation should be treated aggressively, because persistent dislocation will give rise to pelvic obliquity and scoliosis. Open reduction is always necessary.