(i) Irritable hip and septic arthritis of the hip

Transient synovitis needs to be differentiated from septic arthritis of the hip when a child presents with features of an irritable hip. Although there is considerable overlap in the clinical presentation of the two conditions, the natural history, treatment strategy and potential range of outcomes are quite distinct. While transient synovitis is a self limiting condition, emergent surgical intervention in the form of arthrotomy and wash out of joint is the mainstay of treatment of septic arthritis. Clinical decision algorithms have been developed using a combination of clinical and laboratory parameters to help differentiate the two conditions.