Perthes disease in children above 8 years old, generally has a worst prognosis. On this age group it is common that hinge abduction appears in a descentered and uncontained hip, situation that has a difficult solution with the standard surgical procedures. On those cases arthrodiastasis as described, can be a valuable treatment option.

The rationale of arthrodiastasis on Perthes is that it permits to reduce the hip, protect it during the fragmentation stage, and creating a vacuum phenomenon inside the acetabulum it “insufflate” the collapsed plastic head, permitting the reconstruction of a spherical head.

Our actual protocol to treat Perthes disease in a more than 5 years old child, include a transphyseal tunneling made as soon as possible on the necrotic stage and protection of the hip in a abduction-flexion brace. If at any time a hinge hip develops then arthrodiastasis is applied.

The procedure is simple, fast and low traumatic, including the positioning in a traction table, application of a Ilizarov frame with hinges centered on the center of rotation of the head, with the limb in a position of abduction and slight flexion, which permits the reduction and containment of the hip, and then a progressive arthrodiastasis to 1 1.5 cm. The frame was used for 3–5 months and during this period one could assist to the progressive growth of the collapsed femoral head. After arthrodiastasis the hip is protected with an abductionflexion brace for a mean of 8 months.

The Authors present the 5 first cases where this methodology was applied, standing out the good results obtained, without complications, mentioning the faster evolution to reconstruction stage in the cases where transphyseal tunneling was done, permitting a shorter period of arthrodiastasis.