Outcome measures
| Primary outcome measure | |
| Deformity index | Assessment of femoral head sphericity on pelvic radiograph |
| Secondary outcome measures | |
| Extrusion index | Assessment of femoral head subluxation/coverage on pelvic radiograph |
| Faces Pain Scale | Ordinate scale for pain level |
| Hip range of motion | Clinical examination |
| Modified Harris hip score | Questionnaires for hip pain, associated symptoms, daily living and sports activities |
| PODCI | Pain, physical function and impact on the child’s psyche |
| Hip MRI | Perfusion of the femoral epiphysis |
| Bone age | Assessment on hand radiograph |
PODCI, Global Paediatric Outcomes Data Collection Instrument questionnaires.