抄録
Background: In our hospital, the air-contrast computed tomography arthrography (CTA) is one of the preoperative examinations for patients with recurrent dislocation of the shoulder. Although the potency of CTA has improved by multidetector CT, there is some difficulty in detecting the antero-inferior glenoid labral lesions clearly. In this study, we examined features of the patients with antero-inferior glenoid labral lesions which were difficult to detect by the air-contrast CTA.
Methods: We performed air-contrast CTA in 29 patients who had no osseous fragment of glenoid and underwent arthroscopic Bankart repair between 2007.1 and 2012.5. The frequency of dislocation/subluxation, duration from the primary dislocation to arthrography, the bone-deficit size of the glenoid and the rotational position of the humeral head in CT image were evaluated in these patients.
Results: Antero-inferior glenoid labral lesions were undetectable in three patients by the air-contrast CTA and two of three were Perthes lesions. In these patients, the mean frequency of dislocation was lower than that of all other patients, and the mean duration from primary dislocation was 12.7 years. Mean bone-deficit size of glenoid was 2.9% that is smaller than that of all other patients (9.5%). The rotation of humeral head tended to be more external compared with the overall mean and we speculated that the subscapularis muscle holds the articular capsule down by external rotation.
Conclusion: Features of the patients with undetectable antero-inferior glenoid labral lesions by the air-contrast CTA were a lower frequency of dislocation, smaller bone-deficit of glenoid and more external rotation of the humeral head.
