Discusión entre pares / 1.6 years old female child complaining of Rt.side limping for more than 3 months

1.6 years old female child complaining of Rt.side limping for more than 3 months, all investigations were normal , X-Ray : to me Rt.side femoral head mildly smaller than Lt . 
 whats your opinion regarding X-Ray & Dx ?