ROLE OF 3D CT SCAN IN QUANTIFYING GLENOID BONE LOSS IN RECURRENT UNILATERAL SHOULDER DISLOCATION

Abstract

Purpose: Patients with recurrent shoulder instability often present with osseous injury to the glenoid and humeral head. Glenoid bone loss can easily be quantied on a three-dimensional computed tomography scan by modeling the inferior portion of the glenoid contour as a true circle on an en face view. This study investigated the accuracy of CT in determining the presence and severity of glenoid bone loss in patients with unilateral recurrent shoulder dislocation. Methodology: This prospective cross-sectional study was done among patients with unilateral recurrent shoulder dislocation. Forty patients with anterior shoulder dislocation underwent shoulder CT examination before arthroscopy. Results: Glenoid bone loss was evident in 38 (95%) of the 40 patients at arthroscopy. Compared with arthroscopy, CT had sensitivity in detecting glenoid bone loss of 92.1%; specicity, 100%; positive predictive value, 100%; and negative predictive value, 40.0%. Three false-negative CT assessments had 5%, 5%, and 20% glenoid bone loss, respectively, at arthroscopy. There was a strong correlation between CT and arthroscopy with respect to the severity of glenoid bone loss (r = 0.73). Conclusion: CT has both a high sensitivity and a high specicity for detecting glenoid bone loss, and agreement with arthroscopy regarding the severity of glenoid bone loss is good. CT can be used to assess glenoid bone loss and the need for bone augmentation surgery.