[Value of arthro-CT in decision for arthroscopic or open stabilization in ventral shoulder instability]

A prospective study was performed on 30 patients with anterior instability of the shoulder to assess the diagnostic value of preoperative arthro-CT. One special diagnostic problem was the definition of diagnostic criteria for arthroscopic or open surgery. Arthro-CT of the shoulder was performed with a double-contrast technique. Visualization of labral tears, bony lesions, glenohumeral ligaments and disruption of the rotator cuff was registered. Findings of arthro-CT were verified by diagnostic arthroscopy. Therapy consisted of either arthroscopic or open surgery depending on the lesion pattern found in diagnostic arthroscopy. The most common cause of anterior instability (90% of cases) was damage of the ventro-caudal labral complex, which was diagnosed by arthro-CT with a sensitivity of 93% and a positive predictive value of 93%. Specificity and negative predictive value were reduced to 33%; the overall accuracy was 87%. In all, 16 patients were successfully treated using arthroscopic stabilization because whereas 14 patients required open surgery because diagnostic arthroscopy contraindicated an arthroscopic approach. The preoperative arthro-CT failed to define all criteria mandatory for the decision for arthroscopic or open surgery because pathoanatomy of the joint was not sufficiently demonstrated with the current technique of arthro-CT.