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

Introduction: 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.

Methods: 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.

Results: 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.

Conclusions: 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.