Up to 50% of individuals with trichorhinophalangeal syndrome may have Perthes-like hip changes. Thirteen hips in nine skeletally immature patients were studied. Follow-up averaged 4.7 years. The patients were categorized as juvenile (4-8 years) and adolescent (12-14 years) according to their age at presentation. The universal severity of involvement, often older age at presentation, and disproportionate number developing severe deformity with hinge abduction and pain in adolescence distinguished these patients from those with true Perthes' disease. Whether the process can be modified significantly to produce a better outcome is unclear, but management must be directed at avoiding the development of hinge abduction.