Pain in knee arthrography: comparison of air vs. CO2 and reaspiration vs. no reaspiration

A prospective study of 255 patients undergoing double-contrast arthrography of the knee was performed to evaluate postexamination knee pain after two procedural modifications: (1) intraarticular carbon dioxide versus room air and (2) postprocedural joint reaspiration versus no reaspiration. A moderate or severe increase in pain during the 24 hr after the examination was experienced by 20% of patients. Carbon dioxide resulted in slightly greater patient pain immediately after the procedure than did room air. However, there was no difference in morbidity in these two groups at 24 hr. Aspiration of the knee joint had no immediate or delayed effect on patient pain. Older patients, women, and patients with abnormal arthrograms, reported more baseline discomfort but, allowing for this, they tolerated the procedure as well as younger patients, men, and patients with normal arthrograms. It is recommended that double contrast arthrography of the knee be performed using intraarticular air without reaspiration of the joint.