Acute idiopathic chondrolysis and primary acetabular protrusio may be the same disease.

The case histories and investigations for five adolescent girls with a presumed diagnosis of either primary acetabular protrusio or acute idiopathic chondrolysis are presented. The follow-up ranged from three to nine years. All were treated by extensive soft-tissue release but in no case did this improve movement of the affected hip and permanent stiffness was the inevitable result. The literature is reviewed and methods of treatment are discussed in the light of the CT findings.