Differentiating Transient Synovitis of the Hip from More Urgent Conditions.

A variety of traumatic and infectious processes can cause acute onset of hip pain and difficulty walking. Without a history of trauma, a common cause is transient (or "toxic") synovitis, but serious infectious causes, such as septic arthritis of the hip or osteomyelitis, must be ruled out. Differentiating between septic arthritis of the hip (a true emergency) and transient synovitis of the hip (a much more benign inflammatory process) can be difficult. The Kocher criteria have proven to be helpful in making the distinction between these two conditions, and they are reviewed in this article. In addition, imaging studies, especially hip ultrasound, are extremely helpful in the evaluation of the painful hip. [Pediatr Ann. 2016;45(6):e209-e213.].