Effect of reverse shoulder design philosophy on muscle moment arms
Open Access
- 29 January 2015
- journal article
- research article
- Published by Wiley in Journal of Orthopaedic Research
- Vol. 33 (4), 605-613
- https://doi.org/10.1002/jor.22803
Abstract
This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:605–613, 2015.Keywords
Funding Information
- Exactech Inc.
This publication has 29 references indexed in Scilit:
- A History of Reverse Total Shoulder ArthroplastyClinical Orthopaedics and Related Research, 2011
- Reverse Prostheses in Arthropathies With Cuff Tear: Are Survivorship and Function Maintained Over Time?Clinical Orthopaedics & Related Research, 2011
- Kinematic and clinical evaluation of shoulder function after primary and revision reverse shoulder prosthesesJournal of Shoulder and Elbow Surgery, 2011
- Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: A systematic reviewJournal of Shoulder and Elbow Surgery, 2011
- Moment arms of the muscles crossing the anatomical shoulderJournal of Anatomy, 2008
- Shoulder function: The perfect compromise between mobility and stabilityJournal of Biomechanics, 2007
- Neer Award 2005: The Grammont reverse shoulder prosthesis: Results in cuff tear arthritis, fracture sequelae, and revision arthroplastyJournal of Shoulder and Elbow Surgery, 2006
- Grammont reverse prosthesis: Design, rationale, and biomechanicsJournal of Shoulder and Elbow Surgery, 2005
- Stability and instability of the glenohumeral joint: The role of shoulder musclesJournal of Shoulder and Elbow Surgery, 2005
- Shoulder prostheses treating cuff tear arthropathy: A comparative biomechanical studyJournal of Orthopaedic Research, 2004