Special Focus: Resident Research AwardFirst Place Award: A quantitative analysis of the effect of glenoid bone volume on baseplate failure in reverse total shoulder arthroplasty in patients with inflammatory arthritis: a retrospective case control studyDelBello, Steven MDa; Dopico, Pablo PhDb; Mihalko, William MD, PhDa; Brolin, Tyler MDa; Azar, Frederick MDa; Throckmorton, Thomas W. MDaAuthor Information aDepartment of Orthopaedic Surgery & Biomedical Engineering, University of Tennessee-Campbell Clinic, Memphis, TN bDepartment of Orthopaedic Surgery & Biomedical Engineering, University of Tennessee, Memphis, TN Information from this study was presented in poster #62 at the Mid-America Orthopaedic Association April, 2017, meeting in Amelia Island, Florida, and the corresponding abstracts for that meeting. Financial Disclosure: Dr. Azar receives consulting fees from Iovera, 98.6, Myoscience, and Zimmer Biomet; Dr. Brolin receives consulting fees from DePuy and DJ Orthopaedics; Dr. Throckmorton receives IP royalties from Exactech and Zimmer Biomet; Dr. Mihalko receives research support from Aesculap/B.Braun, Department of Defense, National Institutes of Health, Myoscience, and Stryker, consulting fees from Aesculap/B.Braun, Smith-Nephew, and Zimmer Biomet, and IP royalties and speaker fees from Aesculap/B.Braun. Drs. DelBello and Dopico did not receive any financial payments or other benefits from any commercial entity related to the subject of this article. The authors report no conflicts of interest. Correspondence to Thomas W. Throckmorton, MD, 1211 Union Avenue, Suite 510, Memphis TN 38104 Tel: +901-759-3270; fax: +901-759-3278; e-mail: firstname.lastname@example.org. Current Orthopaedic Practice: July/August 2020 - Volume 31 - Issue 4 - p 327-329 doi: 10.1097/BCO.0000000000000875 Buy Metrics Abstract Background: The purpose of this study was to determine and compare the glenoid vault bone volumes in patients undergoing reverse total shoulder arthroplasty (RTSA) for inflammatory arthritis to determine if a threshold exists where baseplate fixation is at risk for failure. Methods: Fourteen patients who had primary RTSA for inflammatory arthritis were included in this study; 10 had humeral head autografting to augment glenoid deficiency. Four patients experienced baseplate failure with component pull-out from the glenoid. Preoperative glenoid vault volume was measured on CT images. Results: The average glenoid vault bone volumes were significantly different between failures and nonfailures for both men and women. The average volume in women with baseplate failure was 3.5 cm3, while the average nonfailure volume in women was 8.6 cm3 (P=0.03). The average glenoid volume in men with baseplate failure was 11.8 cm3, while the average volume in men without failure was 18.3 cm3 (P=0.02). There were no baseplate failures in men with glenoid vault volumes greater than 14 cm3 or in women with volumes greater than 5 cm3. Conclusions: Patients with baseplate failure after RTSA for inflammatory arthritis had significantly lower average glenoid vault volumes than their gender-specific counterparts without failure. These findings suggest a level of glenoid volume below which baseplate fixation is potentially compromised: 14 cm3 in men and 5 cm3 in women. Level of Evidence: Level III. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.