Effect of reverse total shoulder arthroplasty humeral inclination on glenohumeral range of motion,deltoid force,and glenoid strain: a biomechanical study |
| |
| Authors: | Sheeba M Joseph Felix GE Dyrna Vivek Chadayammuri Taylor Wiley Elifho Obopilwe Bastian Scheiderer Knut Beitzel Mark P Cote Anthony A Romeo Augustus D Mazzocca |
| |
| Affiliation: | 1. Department of Orthopaedic Surgery, Michigan State University, East Lansing, MI, USA;2. Department of Trauma, Hand and Reconstructive Surgery, University Hospital Münster, Münster, Germany;3. Department of Orthopaedic Surgery, UConn Health Center, Farmington, CT, USA;4. Department of Orthopaedic Sports Medicine, Technical University of Munich, Munich, Germany;5. ATOS Clinic, Cologne, Germany;6. DuPage Medical Group, Downers Grove, IL, USA |
| |
| Abstract: | BackgroundReverse total shoulder arthroplasty (RSA) primarily varies between 2 implant design options: a 135 humeral stem inclination that closely resembles anatomic orientation, versus the Grammont-style 155 humeral stem inclination that further medializes and distalizes the center of rotation (COR). The purpose of this study was to compare deltoid force, glenoid strain, and simulated glenohumeral range of motion (ROM) between RSA 135 and RSA 155 designs, with a series of standardized permutations of glenosphere offset and rotator cuff pathology.MethodsTwelve fresh-frozen cadaveric shoulder specimens were studied using a shoulder simulator. Native shoulder motion profiles for reproducible abduction range of motion were established using a customized testing device. Optical 3-dimensional tracking and pressure sensors were used to accurately record glenohumeral range of motion (ROM), deltoid force, and glenoid strain for RSA 135 and RSA 155 designs. For each cohort, all combinations of glenosphere offsets and rotator cuff tendon involvement were evaluated.ResultsThere was no significant difference in the overall abduction ROM between the 155 and the 135 humeral stem implants (P = .75). Resting abduction angle and maximum abduction angle were significantly greater with a 155 + STD (standard offset) construct than with a 135 + STD construct (P < .001 and P = .01, respectively). Both stem inclinations decreased combined deltoid force requirements as compared the native shoulder with a massive cuff tear. Effective glenoid strain did not vary significantly between 135 + STD and 155 + STD constructs (P = .66).ConclusionOverall, range of motion between the 135 and the 155 humeral stem inclinations was not significantly different. The cumulative deltoid force was lower in RSA shoulders when compared to native shoulders with massive rotator cuff tears, highlighting the utility of both implant designs. The Grammont-style 155 stem coupled with a 2.5 mm inferior offset glenosphere required less deltoid force to reach maximum abduction than did the more anatomic, lateralized 135 stem coupled with a 4 mm lateral offset glenosphere.Level of EvidenceBasic Science, Biomechanics Controlled Laboratory Study |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
