Transient synovitis of hip usually affects children below the age of 5 years, caused by a fall, unnoticed trauma or unaccustomed physical exercise. The child limps, may have slight rise of temperature & get irritable. Affected children are not acutely ill and can move the hip, but with some degree of stiffness. 

An effusion may be seen in ultrasound images and the condition is usually self -limiting. They respond to non-steroidal anti-inflammatory drugs well.

These children should not be allowed to bear weight on the affected limb for 2-3 weeks as they run the risk of avascular necrosis (AVN) of femoral head later in life.