what is the difference between Caffey Sign and Sectoral sign as in both of them hip goes into obligatory external rotation?
Caffey sign and sectoral sign are two different terms used in the context of pediatric radiology and pediatric orthopedics to describe specific findings related to the hip joint. Although they both involve the obligatory external rotation of the hip, they refer to different clinical scenarios and have distinct underlying causes. Let’s differentiate them:
- Caffey Sign:
- Caffey sign, also known as the “Caffey angle,” is a radiological finding seen in infants with infantile cortical hyperostosis, which is a rare condition characterized by increased bone formation in the cortex of the long bones, especially the mandible and the shafts of the long bones.
- When the Caffey angle is observed on X-rays, it refers to an angle formed by the diaphysis (shaft) and the metaphysis (flared end) of a long bone, such as the humerus or the femur. The angle is increased due to the cortical hyperostosis, resulting in bone expansion.
- The Caffey sign does not directly involve the hip joint or hip rotation, and it is typically seen in other long bones of the body.
- Sectoral Sign:
- The sectoral sign, also known as “sectoral coxa valga,” is a specific finding seen on X-rays of the hip joint in children with Perthes disease (also called Legg-Calvé-Perthes disease). Perthes disease is a childhood hip disorder characterized by a temporary loss of blood supply to the femoral head, leading to its subsequent deformity.
- In the sectoral sign, the femoral head takes on a wedge-shaped appearance on X-rays, and there is an increased neck-shaft angle (coxa valga) in a specific “sector” of the femoral head, while other parts of the femoral head remain relatively unaffected.
- As a result of this sectoral deformity, the hip goes into obligatory external rotation, which is one of the characteristic signs of Perthes disease.
In summary, the Caffey sign is related to cortical hyperostosis in long bones and does not involve the hip joint, while the sectoral sign is specific to Perthes disease and involves the hip joint with its characteristic obligatory external rotation due to the sectoral deformity of the femoral head.