74 children with ruptures of lateral ligaments of the ankle were treated surgically between 1979 to 1986. In ten cases we found chronical ligament changes. In these cases periostal flap modified after Kuner was performed. The follow up of our patients showed good results in all, thus we could show that the periostal flap was effective. As the functional conservative ligament rupture therapy increases the periostal flap plastic in the case of children with chronical ligament changes is indicated.