The long term effect of an intra-articular injection of corticosteroids in the acromioclavicular joint.

BACKGROUND: A prospective study was established to assess the effect of an intra-articular injection of corticosteroid and local anaesthetic into the acromioclavicular (AC) joint.

METHODS: Fifty-eight patients with isolated AC joint symptoms were included. Clinical tests were repeated immediately following the injection, as well as at 1-month follow-up. If symptoms failed to improve at this time, arthroscopic surgery was offered. All other patients were dismissed from standard care and contacted for this study. Both American Shoulder and Elbow Surgeons (ASES) and University of California at Los Angeles (UCLA) scores were obtained at final follow-up.

RESULTS: Sixteen patients had improved sufficiently. Between the 1 month and average final follow-up of 42 months, 1 patient had arthroscopic resection of the distal clavicle. Four of the 15 patients reported occasional mild pain. Average visual analogue scale (VAS) score for pain was 0.5 (0-3). Average ASES score was 94.1 (70-100) and average UCLA score was 33.9 (28-35).

DISCUSSION: Pain relief achieved with an injection into the AC joint has both a diagnostic and therapeutic value. The decrease of pain with clinical testing affirms the correct position of the injection. Only a minority of patients has sufficient pain relief from the injection at 1 month follow-up; however, this is sustained at the longer-term follow-up in the patients that have a positive reaction.

CONCLUSION: The diagnostic value of the injection of a local anaesthetic in the AC joint is immediate. Only 28% have a clear positive result at 1 month; but, this result is sustained at long-term follow-up. There were no complications.