Reflex sympathetic dystrophy.

This paper describes a patient with typical post-traumatic Sudeck's atrophy of the right foot, who subsequently developed an atraumatic, painful osteoporosis of the left foot and right knee. It is suggested that cases of 'migrating osteolysis' and 'transient osteoporosis' of the lower limbs be grouped with classical Sudeck's atrophy as a reflex sympathetic dystrophy; Theories of pathogenesis have been reviewed and a possible theory of causation in atraumatic cases is presented.