Coxa plana is flattening of the femoral head epiphysis and is associated with many skeletal disorders:
- Legg-Calvé-Perthes disease
- haemophilic haemarthrosis
- Gaucher disease
- hypothyroidism
- spondyloepiphyseal dysplasia
- multiple epiphyseal dysplasia
- haemoglobinopathies, e.g. sickle cell anaemia, thalassaemia