What is the likely diagnosis for a 5-year-old with left hip pain, normal x-rays, and mild decreased range of motion?

The symptoms presented in this scenario suggest a likely diagnosis of transient synovitis. This condition is characterized by inflammation of the synovial membrane surrounding the hip joint, often occurring in children following a viral infection or after minor trauma.

In this case, the 5-year-old exhibits unilateral hip pain and has normal x-rays, which is consistent with transient synovitis, as radiographic findings typically appear normal or only show mild changes during the early stages of this condition. Additionally, decreased range of motion in a child with hip pain is common when transient synovitis is present, as inflammation can lead to discomfort during movement.

Transient synovitis typically resolves with conservative treatment, such as rest and nonsteroidal anti-inflammatory medications, and it’s important to monitor symptoms because while it is usually self-limiting, differentiating it from other conditions like septic arthritis is crucial, especially if fever or severe symptoms are present.

In contrast, conditions such as Legg-Calvé-Perthes disease may lead to more significant long-term changes reflected in imaging, and hip dislocation or septic arthritis would present with more acute, severe symptoms and often abnormal x-ray findings. By understanding the nuances of transient synovitis, including its common presentation