This is a case series of 11 children and adolescents who underwent femoral lengthening and percutaneous hip arthrodesis using a method of extra-articular joint compression in combination with callotasis. Clinical review indicated a significant improvement in physical function and psychological well-being. The average lengthening was 5.3 cm or 16% of the initial length. Complications were more frequent in patients older than 14 years (P = 0.034) as was a higher maturation index (P = 0.021). No additional operations were required to achieve the surgical objective.