Glenoid inclination: in vivo measures in rotator cuff tear patients and associations with superior glenohumeral joint translation.

Glenoid inclination has been associated with rotator cuff tears and superior humeral translation, but the relationship between glenoid inclination and superior humeral translation has not been assessed in vivo. This study compared glenoid inclination between repaired and contralateral shoulders in 21 unilateral rotator cuff repair patients. As a secondary analysis, we assessed the relationship between glenoid inclination and in vivo superior humeral translation. Glenoid inclination was measured from patient-specific, computed tomography-based bone models. Glenohumeral joint motion was measured from biplane radiographs collected during coronal-plane abductions. Glenoid inclination was significantly lower for the rotator cuff tear shoulders (90.7 degrees ) than the asymptomatic, contralateral shoulders (92.3 degrees , P = .04). No significant correlation existed between increased glenoid inclination and superior-inferior translation of the uninjured shoulder (P > .30). This study failed to support the theory that glenoid inclination is responsible for superior humeral translation and the development of subacromial impingement.