<prompt> Commonest age of Perthes disease is:5-10 years10-20 years20 - 25 years20 - 30 years  <response>: 5 - 10 years: Ref: 269-M, 422-APERTHES DISEASE: Coxa plana, Pseudocoxalgia A painful disorder of childhood characterized by avascular necrosis of the femoral head. The disease commonly in boys in age groups of 5 - 10 years Limping or stiffness Limitation of abduction and internal rotation and shortening Age is the most important prognostic factorGuidelines of Treatment1. Children under 6 years of age - Symptomatic treatment including a period of traction and there after reduced activity, is appropriate2. Children aged 6-8 years - In this the bone age is more important than the chronological ageI Bone age at or below 6 years - Symptomatic treatment abduction braceII Bone age over 6 years - Abduction brace or osteotomy3. Children 9 years and older - Operative containment is the treatment of choice 