J Scalise 1 , A Jaczynski 2 , M Jacofsky 2 Show Affiliations »
Abstract
AIMS: The eccentric glenosphere was principally introduced into reverse shoulder arthroplasty to reduce the incidence of scapular notching. There is only limited information about the influence of its design on deltoid power and joint reaction forces. The aim of our study was to investigate how the diameter and eccentricity of the glenosphere affect the biomechanics of the deltoid and the resultant joint reaction forces. METHODS: Different sizes of glenosphere and eccentricity were serially tested in ten cadaveric shoulders using a custom shoulder movement simulator. RESULTS: Increasing the diameter of the glenosphere alone did not alter the deltoid moment arm. However, using an eccentric glenosphere increased the moment arm of the deltoid, lowered the joint reaction force and required less deltoid force to generate movement. CONCLUSION: Eccentricity is an independent variable which increases deltoid efficiency and lowers joint reaction forces in a reverse shoulder arthroplasty. Cite this article: Bone Joint J 2016;98-B:218-23. ©2016 The British Editorial Society of Bone & Joint Surgery.
AIMS: The eccentric glenosphere was principally introduced into reverse shoulder arthroplasty to reduce the incidence of scapular notching. There is only limited information about the influence of its design on deltoid power and joint reaction forces. The aim of our study was to investigate how the diameter and eccentricity of the glenosphere affect the biomechanics of the deltoid and the resultant joint reaction forces. METHODS: Different sizes of glenosphere and eccentricity were serially tested in ten cadaveric shoulders using a custom shoulder movement simulator. RESULTS: Increasing the diameter of the glenosphere alone did not alter the deltoid moment arm. However, using an eccentric glenosphere increased the moment arm of the deltoid, lowered the joint reaction force and required less deltoid force to generate movement. CONCLUSION: Eccentricity is an independent variable which increases deltoid efficiency and lowers joint reaction forces in a reverse shoulder arthroplasty. Cite this article: Bone Joint J 2016;98-B:218-23. ©2016 The British Editorial Society of Bone & Joint Surgery.
Entities: Disease
Keywords:
shoulder arthroplasty; reverse shoulder arthroplasty; biomechanics; deltoid
Mesh： See more »
Year: 2016
PMID： 26850427 DOI： 10.1302/0301-620X.98B2.35912
Source DB: PubMed Journal: Bone Joint J ISSN： 2049-4394 Impact factor: 5.082