Prosthetic design of reverse shoulder arthroplasty contributes to scapular notching and instability

作     者：Gazi Huri Filippo Familiari Nima Salari Steve A Petersen Mahmut Nedim Doral Edward G Mc Farland 

作者机构：Department of Orthopaedic and Traumatology SurgeryHacettepe University Medical School Division of Shoulder SurgeryDepartment of Orthopaedic Surgerythe Johns Hopkins University 

出 版 物：《World Journal of Orthopedics》 (世界骨科杂志（英文版）)

年 卷 期：2016年第7卷第11期

页      面：738-745页

学科分类：0403[教育学-体育学] 1002[医学-临床医学] 10[医学] 

主　　题：Arthroplasty Reverse Instability Scapular notching Shoulder 

摘      要：AIM To evaluate whether implant design, glenoid positioning, and other factors influenced instability and scapular notching in reverse total shoulder arthroplasty.METHODS We retrospectively reviewed records of patients who had undergone reverse total shoulder arthroplasty by the senior author from July 2004 through October 2011 and who had at least 24 mo of follow-up. The 58 patients who met the criteria had 65 arthroplasties: 18 with a Grammont-type prosthesis(Grammont group) and 47 with a lateral-based prosthesis(lateral-design group). We compared the groups by rates of scapular notching and instability and by radiographic markers of glenoid position and tilt. We also compared glenoid sphere sizes and the number of subscapularis tendon repairs between the groups. Rates were compared using the Fisher exact test. Notching severity distribution was compared using the χ2 test of association. Significance was set at P 0.05.RESULTS The Grammont group had a higher incidence of scapular notching(13 of 18; 72%) than the lateral-design group(11 of 47; 23%)(P 0.001) and a higher incidence of instability(3 of 18; 17%) than the lateral-design group(0 of 47; 0%)(P = 0.019). Glenoid position, glenoid sphere size, and subscapularis tendon repair were not predictive of scapular notching or instability, independent of implantdesign. With the lateral-based prosthesis, each degree of inferior tilt of the baseplate was associated with a 7.3% reduction in the odds of developing notching(odds ratio 0.937, 95%CI: 0.894-0.983). CONCLUSION The lateral-based prosthesis was associated with less instability and notching compared with the Grammonttype prosthesis. Prosthesis design appears to be more important than glenoid positioning.