Arthrography in the assessment of septic hip joints in children

ABSTRACT

Acute septic arthritis of the hip joint in the pediatric patient is an emergency in which a satisfactory outcome hinges on an early and accurate diagnosis. The diagnosis is made primarily on clinical grounds and confirmed by finding pus on aspiration of the hip joint. Failure to obtain fluid on aspiration does not rule out the presence of pus in the joint, as in a small child it is difficult to be certain that the needle is indeed within the joint. In recognition of this difficulty, arthrograms were utilized at the Aga Khan University Hospital to obtain confirmatory evidence of the intra-articular position of the aspiration needle. From February 1989 to October 1990, ten children age range from 2 weeks to 10 years, presented to the Aga Khan University Hospital with symptoms suggestive of a septic hip. Five of these had a positive tap and underwent arthrotomy and drainage. In the other five, following a negative tap, an arthrogram was performed with the aspirating needle in situ. In three of these patients the arthrogram confirmed correct position of the needle within the joint and the diagnosis of septic hip was ruled out in these patients. In the remaining two, dye injection revealed the needle tip to be outside the joint cavity. The needle was successfully repositioned in one, pus aspirated and an arthrotomy and drainage performed. In the last patient, the needle was not repositioned and the surgeon proceeded with the arthrotomy. No pus was found in the joint. If arthrography had been pursued according to the protocol this negative arthrotomy could have been avoided. Our experience indicates that arthrography is a simple technique which improves the accuracy of hip aspiration in the diagnosis of septic hip disease in the child