The incidence of Legg-Calvé-Perthes disease (LCPD) ranges from 0.4/100,000 to 29.0/100,000 children <15 years of age. There is significant variability in incidence within racial groups and is frequently higher in lower socioeconomic classes. The typical age at presentation ranges from 4 to 8 years (average 6.5 years).The optimal treatment goal in Legg-Calvé-Perthes disease (LCPD) is to obtain a spherical femoral head with good congruency to prevent or delay the onset of osteoarthritis after skeletal maturity. There is agreement that patients younger than 5years with a good remodeling capacity have a particularly excellent prognosis, irrespective of treatment.

Older children more than 8 years usually have a poor prognosis, especially without treatment. Apart from the age at diagnosis and surgery, the severity of femoral head flattening and the signs of "head at risk" are also associated with the final clinical outcome. The current surgical treatment options, including proximal femoral varus osteotomy, innominate osteotomy, lateral shelf acetabuloplasty,triple pelvic osteotomy, and Chiari pelvic osteotomy have proved to be effective in covering the femoral head within the acetabulum. To promote the coverage of the femoral head, shelf acetabuloplasty directly increases the size of the acetabulum by implanting graft bone to the lateral rim. When used as salvage surgery, it may provide relief from pain and benefit the involved hip via femoral head flattening, especially in older children. It also improves the spherical remodeling of the femoral head and acetabulum by stimulating lateral acetabular growth. Lateral shelf acetabuloplasty is able to increase the coverage of the femoral head, which is an important tissue for remodeling and preventing further femoral head deformation.

Inclusion Criteria:

• Age between 8 up to 14 years
• Patients with Perthes disease and hinged abduction .
• Written consent, free and informed

Exclusion Criteria:

• Age below 8 or above 14 years
• Patients without hinged abduction based on clinical exam and arthrogram under general anaesthesia
• Epiphyseal dysplasia
• Coagulopathy
• Unfit for surgery

All patients will be admitted at orthopedic department of assiut university hospital. Clinical examination of the hip will be applied. Preoperative hip x ray anteroposterior and lateral views, Radiological classification and grading and clinical evaluation by Harris hip score.

Hip arthrogram under general anasthesia . if hinged abduction shelf acetabuloplasty will be done. Follow up by x ray and harris hip score at regular visits ( 1.5, 6, 12,24 months)