S. Gray McClatchy, MD1 Griffin M. Heise, BS2 William M. Mihalko, MD, PhD1 Frederick M. Azar, MD1 Richard A. Smith, PhD1 Dexter H. Witte, MD3 John G. Stanfill, MD3 Thomas W. Throckmorton, MD1 Tyler J. Brolin, MD1 1
University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering Memphis, Tennessee
2
University of Tennessee Health Science Center College of Medicine Memphis, Tennessee
3
Mid-South Imaging and Therapeutics Memphis, Tennessee
Effect of Deltoid Volume on Range of Motion and Patient-Reported Outcomes Following Reverse Total Shoulder Arthroplasty in Rotator Cuff-Intact and Rotator Cuff-Deficient Conditions Background Deltoid muscle function is paramount to the success of reverse total shoulder arthroplasty (RTSA). The purpose of this study was to investigate the role of deltoid volume on shoulder range of motion and patient-reported outcomes following RTSA in rotator cuff-intact and rotator cuff-deficient conditions.
Methods Retrospective review of records identified 107 patients who met inclusion criteria. The rotator cuff (RC) integrity was evaluated by two musculoskeletal-trained radiologists. Volumetric deltoid measurements were calculated from preoperative CT or MRI scans. Satisfactory outcomes were defined as forward elevation (FE) of at least 135 degrees, external rotation of at least 35 degrees, and scores of at least 70 on the American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numerical Evaluation (SANE) patient-reported outcomes.
Results Mean total deltoid muscle volume was significantly higher in patients with satisfactory FE (57.8 cm³ ± 18.1 cm³) versus unsatisfactory FE (48.6 cm³ ± 19.5 cm³) (p = 0.013). When separated by RC integrity, total deltoid volume was significantly higher (p = 0.030) in patients who achieved satisfactory FE in the RC-deficient group but not the RC-intact group (p = 0.533).
Discussion Preoperative deltoid volume directly correlated with achieving satisfactory FE after RTSA in RC-deficient conditions and may be one factor in determining the ability to achieve satisfactory outcomes in the RC-deficient patient. Corresponding Author Tyler J. Brolin, MD 1458 W. Poplar Avenue, Suite 100 Collierville, TN 38017 P: 901-759-5522 F: 901-435-5713 tbrolin@campbellclinic.com
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CAMPBELL ORTHOPAEDIC JOURNAL • VOLUME 7, 2021
