Helen S Zitkovsky1, Michael P Carducci, Kuhan A Mahendraraj, Florian Grubhofer, Andrew Jawa. 1. From the Tufts University School of Medicine (Ms. Zitkovsky), New England Baptist Hospital (Mr. Carducci, Mr. Mahendraraj, and Dr. Jawa), Boston Sports and Shoulder Center (Mr. Carducci, Mr. Mahendraraj, and Dr. Jawa), Waltham, and Massachusetts General Hospital (Dr. Grubhofer); Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA.
Abstract
BACKGROUND: Lateralization of the glenosphere in reverse shoulder arthroplasty likely mitigates scapular notching; however, there is a paucity of data evaluating the effect of heterotopic ossification (HO) at the inferior aspect of the glenoid neck. METHODS: We retrospectively reviewed 107 consecutive reverse shoulder arthroplasty patients between April 2013 and April 2016. During the study period, the surgeon switched from a 2.5-mm lateral center of rotation and a 155° neck-shaft angle (NSA) to a 6- or 10-mm lateralized design with a 135° NSA. Preoperative and minimum 2-year postoperative patient-reported outcomes and range of motion were collected. Two-year postoperative radiographs were evaluated for scapular notching and HO. RESULTS: The lateralized center of rotation implant was 72% less likely to develop HO and 85% less likely to produce scapular notching than the medialized prosthesis. CONCLUSION: Implants with laterally offset glenospheres and 135° NSA may decrease postoperative HO and scapular notching. LEVEL OF EVIDENCE: Level III, retrospective cohort study.
BACKGROUND: Lateralization of the glenosphere in reverse shoulder arthroplasty likely mitigates scapular notching; however, there is a paucity of data evaluating the effect of heterotopic ossification (HO) at the inferior aspect of the glenoid neck. METHODS: We retrospectively reviewed 107 consecutive reverse shoulder arthroplasty patients between April 2013 and April 2016. During the study period, the surgeon switched from a 2.5-mm lateral center of rotation and a 155° neck-shaft angle (NSA) to a 6- or 10-mm lateralized design with a 135° NSA. Preoperative and minimum 2-year postoperative patient-reported outcomes and range of motion were collected. Two-year postoperative radiographs were evaluated for scapular notching and HO. RESULTS: The lateralized center of rotation implant was 72% less likely to develop HO and 85% less likely to produce scapular notching than the medialized prosthesis. CONCLUSION: Implants with laterally offset glenospheres and 135° NSA may decrease postoperative HO and scapular notching. LEVEL OF EVIDENCE: Level III, retrospective cohort study.