Air in painful total hip arthroplasty: diagnosis and treatment.

A 78-year-old woman presented with a painful total hip arthroplasty five years postoperation. Plain radiographs revealed air in the hip joint. Aspiration of the hip indicated hip sepsis, and arthrogram showed communication of the hip joint with the sigmoid colon. Cultures grew Bacteroides fragilis. Abdominal exploration showed a ruptured diverticulum that decompressed through the sciatic notch into the total hip arthroplasty. A colostomy was performed, and the hip joint was drained and debrided laterally at the same operation. The prosthesis was later removed with all cement, and the hip was converted to a Girdlestone resection. The authors conclude that air or gas shadows in a painful total hip arthroplasty are an ominous finding and mean either joint sepsis with a gas-forming bacteria or communication of the joint with a hollow viscus and sepsis.