The effects of prosthetic humeral head shape on glenohumeral joint kinematics during humeral axial rotation in total shoulder arthroplasty

Background Accurate restoration of anatomy is critical in reestablishing proper glenohumeral joint function in total shoulder arthroplasty (TSA). However, even experienced surgeons inconsistently achieve anatomic restoration. This study evaluates whether a new canal-sparing arthroplasty system, designed using the principles of calibrated bone resection and incorporating a nonspherical humeral head prosthesis, can assist in more accurate and reliable reproduction of proximal humeral anatomy compared to a stemmed arthroplasty system. Methods The difference between the anatomic center of rotation (COR) of the humeral head and the postoperative prosthetic COR (defined as ΔCOR) was measured in a consecutive case series of 110 shoulder arthroplasties performed by a single surgeon. The first 55 cases used a stemmed arthroplasty system and the subsequent 55 cases used a new canal-sparing implant system that uses a multiplanar osteotomy (MPO) during humeral head preparation. Cases with ΔCOR ≥3.0 mm were deemed clinically significant outliers. Results The average ΔCOR in the MPO group was 1.7 ± 1.2 mm versus 2.8 ± 1.5 mm in the stemmed group ( P = .00005). The incidence of outliers was lower (14.5% vs 40.0%, P = .005), and there were more cases with a ΔCOR ≤1.0 mm (32.7% vs 3.6%, P = .0001) in the MPO group compared to the stemmed group. Conclusion The MPO TSA system provided improved accuracy and precision in restoring proximal humeral anatomy compared to stemmed arthroplasty systems, even in its initial use. This alternative method of humeral replacement may increase consistency in restoring proper anatomy and kinematics in TSA.

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Humeral Head Shape in Native and Prosthetic Joint Replacement

Journal of Shoulder and Elbow Arthroplasty ◽

10.1177/2471549219848150 ◽

2019 ◽

Vol 3 ◽

pp. 247154921984815

Author(s):

Joseph P Iannotti ◽

Bong Jae Jun ◽

Jason Teplensky ◽

Eric Ricchetti

Keyword(s):

Joint Replacement ◽

Shoulder Arthroplasty ◽

Humeral Head ◽

Total Shoulder Arthroplasty ◽

Biomechanical Properties ◽

Head Shape ◽

Prosthetic Joint ◽

The Subject ◽

Kinematic Properties

Background Nonspherical prosthetic humeral head designs have become increasingly popular as they better approximate the native shoulder anatomy and biomechanical properties and is supported by the existing literature. It remains to be seen how this will impact postoperative outcomes for total shoulder arthroplasty providing a justification for this review. Methods A review and synthesis of the literature on the subject of joint replacement in the native and prosthetic humeral head was performed. Results Our review encompasses the anatomical, biomechanical, and finite element data present in the literature for native and prosthetic joint replacement. They describe the native humeral head as more elliptical (nonspherical) than circular (spherical) and that nonspherical prosthetics more closely approximate glenohumeral kinematic properties. Conclusion A nonspherical prosthetic may influence long-term clinical outcomes in hemiarthroplasty and anatomic total shoulder arthroplasty though further research in this area is necessary.

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Elliptical heads result in increased glenohumeral translation along with micro-motion of the glenoid component during axial rotation in total shoulder arthroplasty

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-04018-4 ◽

2021 ◽

Author(s):

Lukas N. Muench ◽

Cameron Kia ◽

Matthew Murphey ◽

Elifho Obopilwe ◽

Mark P. Cote ◽

...

Keyword(s):

Internal Rotation ◽

Shoulder Arthroplasty ◽

Humeral Head ◽

External Rotation ◽

Total Shoulder Arthroplasty ◽

Axial Rotation ◽

Glenoid Component ◽

Spherical Design ◽

Inferior Aspect ◽

Micro Motion

Abstract Introduction Elliptical-shaped humeral head prostheses have recently been proposed to reflect a more anatomic shoulder replacement. However, its subsequent effect on micro-motion of the glenoid component is still not understood. Materials and methods Six fresh-frozen, cadaveric shoulders (mean age: 62.7 ± 9.2 years) were used for the study. Each specimen underwent total shoulder arthroplasty using an anatomic stemless implant. At 15°, 30°, 45° and 60° of glenohumeral abduction, 50° of internal and external rotations in the axial plane were alternatingly applied to the humerus with both an elliptical and spherical humeral head design. Glenohumeral translation was assessed by means of a 3-dimensional digitizer. Micro-motion of the glenoid component was evaluated using four high-resolution differential variable reluctance transducer strain gauges, placed at the anterior, posterior, superior, and inferior aspect of the glenoid component. Results The elliptical head design showed significantly more micro-motion in total and at the superior aspect of glenoid component during external rotation at 15° (total: P = 0.004; superior: P = 0.004) and 30° (total: P = 0.045; superior: P = 0.033) of abduction when compared to the spherical design. However, during internal rotation, elliptical and spherical heads showed similar amounts of micro-motion at the glenoid component at all tested abduction angles. When looking at glenohumeral translation, elliptical and spherical heads showed similar anteroposterior and superoinferior translation as well as compound motion during external rotation at all tested abduction angles. During internal rotation, the elliptical design resulted in significantly more anteroposterior translation and compound motion at all abduction angles when compared to the spherical design (P < 0.05). Conclusion In the setting of total shoulder arthroplasty, the elliptical head design demonstrated greater glenohumeral translation and micro-motion at the glenoid component during axial rotation when compared to the spherical design, potentially increasing the risk for glenoid loosening in the long term. Level of evidence Controlled Laboratory Study

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Static posterior humeral head subluxation and total shoulder arthroplasty

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2009.03.003 ◽

2009 ◽

Vol 18 (4) ◽

pp. 505-510 ◽

Cited By ~ 106

Author(s):

Christian Gerber ◽

John G. Costouros ◽

Atul Sukthankar ◽

Sandro F. Fucentese

Keyword(s):

Shoulder Arthroplasty ◽

Humeral Head ◽

Total Shoulder Arthroplasty

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Prosthetic Humeral Head Center of Rotation Shift from Ideal is Associated with Inferior Clinical Outcomes after Anatomic Total Shoulder Arthroplasty

Seminars in Arthroplasty ◽

10.1053/j.sart.2021.04.004 ◽

2021 ◽

Author(s):

Brian C. Werner ◽

R. Alexander Creighton ◽

Patrick J. Denard ◽

Evan Lederman ◽

Anthony Romeo ◽

...

Keyword(s):

Clinical Outcomes ◽

Shoulder Arthroplasty ◽

Humeral Head ◽

Total Shoulder Arthroplasty ◽

Center Of Rotation

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The role of eccentric and offset humeral head variations in total shoulder arthroplasty

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2012.09.008 ◽

2013 ◽

Vol 22 (7) ◽

pp. 886-893 ◽

Cited By ~ 12

Author(s):

Adam Sassoon ◽

Bradley Schoch ◽

Peter Rhee ◽

Cathy D. Schleck ◽

William S. Harmsen ◽

...

Keyword(s):

Shoulder Arthroplasty ◽

Humeral Head ◽

Total Shoulder Arthroplasty

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Postarthroscopic Humeral Head Osteonecrosis Treated With Reverse Total Shoulder Arthroplasty

Orthopedics ◽

10.3928/01477447-20130222-30 ◽

2013 ◽

Vol 36 (3) ◽

pp. e377-e380 ◽

Cited By ~ 11

Author(s):

Matthew F. Dilisio ◽

Jeffrey S. Noble ◽

Robert H. Bell ◽

Curtis R. Noel

Keyword(s):

Shoulder Arthroplasty ◽

Humeral Head ◽

Total Shoulder Arthroplasty ◽

Reverse Total Shoulder Arthroplasty ◽

Reverse Total Shoulder

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Eccentric Reaming for B2 Glenoids: History, Preoperative Planning, Surgical Technique, and Outcome

Journal of Shoulder and Elbow Arthroplasty ◽

10.1177/2471549219870348 ◽

2019 ◽

Vol 3 ◽

pp. ???

Author(s):

Matthew J Smith ◽

Christopher M Loftis ◽

Nathan W Skelley

Keyword(s):

Surgical Technique ◽

Cortical Bone ◽

Shoulder Arthroplasty ◽

Humeral Head ◽

Preoperative Planning ◽

Total Shoulder Arthroplasty ◽

Joint Line ◽

Neutral Position ◽

Anterior Portion ◽

Surgical Options

Background The biconcave (B2) glenoid is characterized by preservation of the anterior portion of the native glenoid with asymmetric wear of the posterior glenoid. Surgical options for glenoid correction have evolved. The goal of shoulder arthroplasty is to place the implants in such a manner to return the humeral head to a centered position and restore the joint line to a neutral position. There is no current consensus on method of treatment and correction. Methods The current and historical literature on total shoulder arthroplasty was used to examine technique viability. Results Asymmetric remaining can be used to address up to 15° of version correction without compromise of cortical bone. It is important to have the proper presurgical planning, to understand the limitations of correction, and to have other options available to treat the biconcave glenoid.

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