Placement of intra-articular injections verified by mini air-arthrography

Objective-To develop and assess a simple, inexpensive method for ascertaini ng the placement of intra-articular injections for knee osteoarthritis Methods-During a one year period patients with "dry" osteoarthritis of the knee who received intra-articular therapy were tested by air-arthrography. Along with triamcinolone and Lignocaine (lidocaine), 5 mi of air was inject ed into the joint. On subsequent lateral and anterior-posterior radiographs a correct placement was verified by a sharply defined shadow of air in the suprapatellar pouch, while extraarticular air was diffusely spread in the surrounding tissue. Results-In 51 of 56 cases the injection was correctly placed. In the remain ing five cases the injection was immediately repeated and positioned within the joint. No adverse events were seen that could be ascribed to the use o f air during the study, although bleeding in the quadriceps was seen one we ek after an extra-articular injection. Conclusion-With mini-air arthrography, it is possible to test the placement of intra-articular injections in knee joints. The method is proposed as a learning tool as well as providing a means of quality assurance in studies involving intraarticular injections.