Coracoacromial Ligament Integrity Influences Scapular Spine Strain After Reverse Shoulder Arthroplasty

Overview

Journal JSES Int

Date 2025 Feb 3

PMID 39898219

Authors

Cole T Fleet

Alicia Kerrigan

G Daniel G Langohr

James A Johnson

George S Athwal

Affiliations

Soon will be listed here.

Abstract

Background: The purpose of this biomechanical study was to examine the effect of coracoacromial (CA) ligament state (intact vs. released) and arm position on acromial and scapular spine strain following reverse total shoulder arthroplasty (rTSA).

Methods: Eight cadaveric shoulders were implanted with a custom rTSA system and tested using an in-vitro shoulder simulator. The specimens were cycled through static range of motion in both abduction and forward elevation; first with the CA ligament in the "intact" state followed by the "released" state. Scapular spine strain was quantified via 4 strain gauges placed along anatomic locations on the acromion and scapular spine.

Results: Increases in strain were observed across all 4 strain gauge locations upon release of the CA ligament in both 0° of abduction and forward elevation. Increases in the mean strain were observed to be as great as 14% in abduction and 31% in forward elevation. The increases in strain at 0° elevation approached but did not reach statistical significance ( ≥ .072). At 90° of abduction and forward elevation, no increases in the mean strain were observed. The greatest strain was consistently observed with the arm positioned in 0° of forward elevation ( < .001).

Discussion: CA ligament release in the setting of rTSA resulted in increased scapular spine and acromial strain with the arm adducted, although these increases in strain were not statistically significant. Caution should be taken intraoperatively as the release of the CA ligament may alter scapular spine and acromion stresses from deltoid loading, which may increase the risk for postoperative scapular spine fracture.

References

Su W, Budoff J, Luo Z . The effect of coracoacromial ligament excision and acromioplasty on superior and anterosuperior glenohumeral stability. Arthroscopy. 2008; 25(1):13-8. DOI: 10.1016/j.arthro.2008.10.004. View

Langohr G, Giles J, Athwal G, Johnson J . The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion. J Shoulder Elbow Surg. 2014; 24(6):972-9. DOI: 10.1016/j.jse.2014.10.018. View

Taylor S, Shah S, Chen X, Gentile J, Gulotta L, Dines J . Scapular Ring Preservation: Coracoacromial Ligament Transection Increases Scapular Spine Strains Following Reverse Total Shoulder Arthroplasty. J Bone Joint Surg Am. 2020; 102(15):1358-1364. DOI: 10.2106/JBJS.19.01118. View

Collin P, Herve A, Walch G, Boileau P, Muniandy M, Chelli M . Mid-term results of reverse shoulder arthroplasty for glenohumeral osteoarthritis with posterior glenoid deficiency and humeral subluxation. J Shoulder Elbow Surg. 2019; 28(10):2023-2030. DOI: 10.1016/j.jse.2019.03.002. View

Haidamous G, Ladermann A, Frankle M, Gorman 2nd R, Denard P . The risk of postoperative scapular spine fracture following reverse shoulder arthroplasty is increased with an onlay humeral stem. J Shoulder Elbow Surg. 2020; 29(12):2556-2563. DOI: 10.1016/j.jse.2020.03.036. View

Kerrigan A, Reeves J, Langohr G, Johnson J, Athwal G . The influence of reverse arthroplasty humeral component design features on scapular spine strain. J Shoulder Elbow Surg. 2020; 30(3):572-579. DOI: 10.1016/j.jse.2020.06.011. View

Cassidy J, Paszicsnyek A, Ernstbrunner L, Ek E . Acromial and Scapular Spine Fractures following Reverse Total Shoulder Arthroplasty-A Systematic Review of Fixation Constructs and Techniques. J Clin Med. 2022; 11(23). PMC: 9736861. DOI: 10.3390/jcm11237025. View

Shah S, Roche A, Sullivan S, Gaal B, Dalton S, Sharma A . The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II. JSES Int. 2021; 5(1):121-137. PMC: 7846704. DOI: 10.1016/j.jseint.2020.07.018. View

Giles J, Langohr G, Johnson J, Athwal G . Implant Design Variations in Reverse Total Shoulder Arthroplasty Influence the Required Deltoid Force and Resultant Joint Load. Clin Orthop Relat Res. 2015; 473(11):3615-26. PMC: 4586233. DOI: 10.1007/s11999-015-4526-0. View

10.

Grammont P, Baulot E . Delta shoulder prosthesis for rotator cuff rupture. Orthopedics. 1993; 16(1):65-8. DOI: 10.3928/0147-7447-19930101-11. View

11.

Wall B, Nove-Josserand L, OConnor D, Edwards T, Walch G . Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am. 2007; 89(7):1476-85. DOI: 10.2106/JBJS.F.00666. View

12.

Levy J, Anderson C, Samson A . Classification of postoperative acromial fractures following reverse shoulder arthroplasty. J Bone Joint Surg Am. 2013; 95(15):e104. DOI: 10.2106/JBJS.K.01516. View

13.

Scibek J, Carcia C . Assessment of scapulohumeral rhythm for scapular plane shoulder elevation using a modified digital inclinometer. World J Orthop. 2012; 3(6):87-94. PMC: 3377910. DOI: 10.5312/wjo.v3.i6.87. View

14.

Paszicsnyek A, Jo O, Rupasinghe H, Ackland D, Treseder T, Pullen C . Factors Influencing Acromial and Scapular Spine Strain after Reverse Total Shoulder Arthroplasty: A Systematic Review of Biomechanical Studies. J Clin Med. 2022; 11(2). PMC: 8778957. DOI: 10.3390/jcm11020361. View

15.

Giles J, Ferreira L, Athwal G, Johnson J . Development and performance evaluation of a multi-PID muscle loading driven in vitro active-motion shoulder simulator and application to assessing reverse total shoulder arthroplasty. J Biomech Eng. 2014; 136(12):121007. DOI: 10.1115/1.4028820. View

16.

Cuff D, Pupello D . Comparison of hemiarthroplasty and reverse shoulder arthroplasty for the treatment of proximal humeral fractures in elderly patients. J Bone Joint Surg Am. 2013; 95(22):2050-5. DOI: 10.2106/JBJS.L.01637. View

17.

INMAN V, Saunders J, Abbott L . Observations of the function of the shoulder joint. 1944. Clin Orthop Relat Res. 1996; (330):3-12. DOI: 10.1097/00003086-199609000-00002. View

18.

Routman H, Simovitch R, Wright T, Flurin P, Zuckerman J, Roche C . Acromial and Scapular Fractures After Reverse Total Shoulder Arthroplasty with a Medialized Glenoid and Lateralized Humeral Implant: An Analysis of Outcomes and Risk Factors. J Bone Joint Surg Am. 2020; 102(19):1724-1733. DOI: 10.2106/JBJS.19.00724. View

19.

Nabergoj M, Denard P, Collin P, Trebse R, Ladermann A . Mechanical complications and fractures after reverse shoulder arthroplasty related to different design types and their rates: part I. EFORT Open Rev. 2021; 6(11):1097-1108. PMC: 8631242. DOI: 10.1302/2058-5241.6.210039. View

20.

Hao K, Dean E, Hones K, King J, Schoch B, Dean N . Influence of humeral lengthening on clinical outcomes in reverse shoulder arthroplasty. Orthop Traumatol Surg Res. 2022; 109(4):103502. DOI: 10.1016/j.otsr.2022.103502. View