Our purpose was to determine whether glenoid retroversion associates with asymmetric rotator cuff muscle atrophy in eccentric glenohumeral osteoarthritis (GHOA) and if this asymmetry is worsening of GHOA-related atrophy.
Two groups of shoulder magnetic resonance images were studied: patients older than 50 years without a rotator cuff tear or GHOA (control group) and patients preoperative to anatomic total shoulder arthroplasty (GHOA group). Retroversion and rotator cuff muscle cross-sectional areas were measured using reliable and accurate techniques. Proportional muscle areas were created by dividing by total cuff area to correct for differences in overall patient size. Walch grades were assigned via consensus.
The control group consisted of 102 patients and the GHOA cohort consisted of 141 patients. Within the eccentric GHOA group, retroversion associated with relative increasing supraspinatus (r = 0.268, P = 0.035), increasing infraspinatus (r = 0.273, P = 0.032), and decreasing subscapularis areas (r = −0.343, P = 0.006). However, the combined GHOA group had a significantly higher relative subscapularis area than the control group (P = 0.026).
In the eccentric GHOA, increasing retroversion is associated with increasing volume of the posterior cuff relative to the anterior cuff muscles, which is a reversal of the asymmetric increasing volume of the anterior cuff relative to the posterior cuff muscles seen with concentric GHOA.
Diagnostic, level III
From the Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT.
Correspondence to Dr. Chalmers: firstname.lastname@example.org
Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (R01 AR067196). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Dr. Chalmers or an immediate family member serves as a paid consultant to Mitek. Dr. Tashjian or an immediate family member has received intellectual property royalties from Wright Medical Technologies, Shoulder Innovations, and Zimmer; serves as a paid consultant to Cayenne and Mitek; and has stock or stock options held in Conextions, INTRAFUSE, and KATOR. None of the following authors or any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article: Ms. Beck, Mr. Miller, Ms. Stertz, and Dr. Henninger.
Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.
This study was performed under the University of Utah Institutional Review Board-approved protocol #71740.