Differences in glenohumeral joint morphology between patients with anterior shoulder instability and healthy, uninjured volunteers

• Published in: Journal of shoulder and elbow surgery Vol. 24; no. 7; pp. 1014 - 1020
• Main Authors: Peltz, Cathryn D., Zauel, Roger, Ramo, Nicole, Mehran, Nima, Moutzouros, Vasilios, Bey, Michael J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2015
• Subjects: anterior instability; bony morphology; Case-Control Studies; Female; Glenohumeral instability; glenoid morphology; Healthy Volunteers; Humans; humeral head morphology; Imaging, Three-Dimensional; Joint Instability - diagnostic imaging; Joint Instability - physiopathology; Male; Orthopedics; radius of curvature; Retrospective Studies; Shoulder Dislocation - diagnostic imaging; Shoulder Dislocation - physiopathology; Shoulder Joint - diagnostic imaging; Shoulder Joint - injuries; Shoulder Joint - physiology; Tomography, X-Ray Computed; traumatic instability; Young Adult; traumatic instability; Retrospective Design; humeral head morphology; Level II; radius of curvature; anterior instability; glenoid morphology; Glenohumeral instability; Prognosis Study; bony morphology
• ISSN: 1058-2746; 1532-6500; 1532-6500
• DOI: 10.1016/j.jse.2015.03.024

Traumatic glenohumeral joint (GHJ) dislocations are common, resulting in significant shoulder disability and pain. Previous research indicates that bony morphology is associated with an increased risk of injury in other joints (eg, the knee), but the extent to which bony morphology is associated with traumatic GHJ dislocation is unknown. This study assessed GHJ morphology in patients with anterior GHJ instability and in a control population of healthy volunteers. Bilateral computed tomography scans were used to measure GHJ morphology in both shoulders of 11 patients with instability and 11 control subjects. Specific outcome measures included the glenoid radius of curvature (ROC) in the anterior/posterior (A/P) and superior/inferior (S/I) directions, humeral head ROC, A/P and S/I conformity index, and A/P and S/I stability angle. Compared with the control subjects, the glenoid of the instability the injured shoulder in patients with instability was flatter (ie, higher ROC) in the A/P (P = .001) and S/I (P = .01) directions and this finding was also true for uninjured, contralateral shoulder (A/P: P = .01, S/I: P = .03). No differences in GHJ morphology were detected between the instability patients' injured and contralateral shoulders (P > .07). Similarly, no differences in GHJ morphology were detected between the control subjects' dominant and nondominant shoulders (P > .51). There are significant differences in GHJ morphology between healthy control subjects and both shoulders (injured and uninjured, contralateral) of patients diagnosed with anterior instability after GHJ dislocation. These findings are important clinically because they suggest that glenoid morphology may influence the risk of GHJ dislocation.