Subtalar Extra-articular Screw Arthroereisis

Inclusion Criteria: Study Group: * Patients aged 14 years old and above that will remove the calcaneo stop screw, in place for at least 3 years after the implant, will be recruited * Patients willing and able to give informed consent for the participation in the study. For underage patients, a parent/legal representative will give consent for the participation in the study. * Male and female patients in fertile age can be recruited. Control Group: * Syndromic patients * Previous foot malformation (synostosis, congenital clubfoot) * Female participant who is pregnant, lactating or planning pregnancy during the course of the study. Exclusion Criteria: Control Group: * Syndromic patients * Previous foot malformation (synostosis, congenital clubfoot) * Female participant who is pregnant, lactating or planning pregnancy during the course of the study. Study Group: * Patients suffering from post-operative complications * Syndromic patients * Previous foot malformation (synostosis, congenital clubfoot) * Female participant who is pregnant, lactating or planning pregnancy during the course of the study.