Fig. 2.

a Five-year-old girl with a Herring group C Perthes disease 6 months following a Salter osteotomy performed at another institution. There is persistent flattening and subluxation of the femoral epiphysis; the spherical acetabulum was unable to fully rotate over the flattened femoral head despite a good lateral displacement. b 1.5 year following surgery, there is worsening of the femoral head deformity and subluxation with an obvious adduction contracture of the hip joint. c 3.5 years following adductor tenotomy and Staheli’s shelf acetabuloplasty (SA). There is a good and lasting coverage with a satisfactory remodeling of the femoral head