Which finding is likely in a 5-year-old child diagnosed with Legg-Calvé-Perthes disease?

In the context of Legg-Calvé-Perthes disease, decreased internal rotation of the affected hip is a classic finding. This condition involves avascular necrosis of the femoral head, which leads to inflammation and eventual deformation of the hip joint. As the disease progresses, children typically exhibit a limited range of motion due to pain and mechanical changes in the joint. One of the hallmark presentations is a reduced ability to internally rotate the hip, as the child may naturally avoid movements that cause discomfort.

In contrast, the other options relate to different clinical presentations that are not typically associated with Legg-Calvé-Perthes disease. While leg length discrepancy might occur over a longer period as the disease leads to deformation, it is not one of the immediate findings. Pseudoparalysis would represent a much more advanced state or a different pathology. Similarly, inability to bend forward at the waist is not specifically related to the hip joint dysfunction seen in Legg-Calvé-Perthes, which primarily impacts hip motion. Thus, the identification of decreased internal rotation as a finding in this pediatric condition is consistent with the pathophysiological changes occurring in the affected hip joint.