MR arthrography of the shoulder: fluoroscopically guided technique using a posterior approach.

safety of the fluoroscopically guided intraarticular injection of contrast material into the glenohumeral joint using a posterior approach, although one report describes using the posterior approach for a sonographically guided method of needle placement [7]. Materials and Methods Over a 3-year period, 140 MR arthrograms of the glenohumeral joint were obtained from 140 patients; 132 of these patients described anterior instability, and the contrast media was introduced using a posterior approach. The remaining eight patients described posterior instability, and an anterior approach was used. Verbal consent was obtained from each patient who was placed in the prone position on the fluoroscopy table with the arm under investigation held by the patient’s side midway between supination and pronation so that the shoulder was in a neutral position. A pad was placed under the patient’s torso to raise the side under investigation (Fig. 1). Fluoroscopy was used to ensure that the glenohumeral joint was seen tangentially. A radiopaque marker was used to locate a site over the inferomedial quadrant of the humeral head; the skin at this entry site was then marked. After skin preparation, the patient’s shoulder was draped, and the injection site and the soft tissues were infiltrated with a local anesthetic (lignocaine 1%; Braun, Melsungen, Germany).