Air arthrography: a safe technique for intra-articular hip injections

Diagnosing the specific causes of young adult hip pain remains challenging due to non-specific symptoms. Fluoroscopy-guided injections are useful for confirming intra-articular hip pain and differentiating it from extra-articular pathology. When performing injections, accurate needle placement into the hip joint is critical. Traditionally, a contrast agent is used to confirm intra-articular positioning. Air arthrograms are an alternative technique that avoids adverse reactions to contrast, which may compromise interpretation of results, as well as being more cost-effective. This study presents the air arthrography technique for intra-articular hip injections, and assesses outcomes and complications in a consecutive patient cohort.

A retrospective review was performed on patients who underwent an air arthrography guided intra-articular hip injection at a single institution between April 2019 and September 2022. We identified 352 hips in 294 patients. Patient records were evaluated for complications from the injection or any subsequent hip surgery.

Mean age at time of injection was 38 years (±14.7 SD) for 216 females and 78 males. Mean follow-up time post injection was 138 days (IQR = 46-186). Results showed a 2.56% complication rate, primarily attributed to steroid flares, all of which resolved without further intervention. 102 patients proceeded to subsequent hip surgery; the mean time from injection to procedure was 341 days (IQR = 194-456) and the mean follow-up post subsequent procedure was 346 days (IQR = 87-531). There were no infective complications following the injections or any subsequent procedures.

This is the first study that evaluates longer-term patient outcomes following air arthrography guided injections with or without subsequent surgery. Our results demonstrate that the use of air arthrograms is a reliable, safe, and cost-effective method for intra-articular hip injections, without the additional risks posed by contrast media.