scholarly journals Influence of Glenosphere and baseplate parameters on Glenoid bone strains in reverse shoulder Arthroplasty

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Leo Pauzenberger ◽  
Cory Dwyer ◽  
Elifho Obopilwe ◽  
Michael D. Nowak ◽  
Mark Cote ◽  
...  

Abstract Background Little is known about the strains at the glenoid near the bone-implant interface in reverse shoulder arthroplasty. The purpose of the current study was to evaluate the strains on the glenoid bone under a compressive load after implantation of three different sizes of metal-backed baseplates in either inferior or superior position in combination with three different sizes of glenospheres and three different glenosphere designs. Methods Three sizes of baseplates (small, medium, large) were implanted in thirty-six paired human cadaveric scapulae either inferior, flush with the glenoid neck, or with a 5 mm superior offset. Glenospheres were available in three sizes (36 mm, 39 mm, 42 mm) and designs (standard, 4 mm lateralized, 2.5 mm inferiorized). Specimens were mounted in a servo-hydraulic testing apparatus at a 60° angle between the glenoid and actuator holding the humeral component. Four strain-gauge rosettes were placed around the glenoid rim to measure strains transferred to the scapular bone under a compressive load (750 N) relative to the various baseplate-glenosphere combinations. Following repeated compression, a load-to-failure test was performed. Results Mean overall registered strains were 161με (range: − 1165 to 2347) at the inferior sensor, −2με (range: − 213 to 90) at the superior sensor, −95με (range: − 381 to 254) at the anterior sensor, and 13με (range: − 298 to 128) at the posterior sensor. Measured bone strains did not show any significant differences across tested baseplate and glenosphere design, size, or positioning combinations (p > 0.05 for all sensors). Furthermore, linear regression analysis did not identify any of the evaluated parameters as an independent influential factor for strains (p > 0.05 for all sensors). Mean load-at-failure was significantly higher in the group of inferior (3347.0 N ± 704.4 N) compared to superior (2763.8 N ± 927.8 N) positioned baseplates (p = 0.046). Conclusion Different baseplate positions, baseplate sizes, glenosphere sizes, and glenosphere design or various combinations of these parameters did not significantly influence the measured bone strains at the glenoid near the bone-implant interface in a contemporary reverse shoulder arthroplasty system. Level of evidence Basic Science Study, Biomechanical Study.

2020 ◽  
pp. 175857322093623
Author(s):  
Georges Haidamous ◽  
Alexandre Lädermann ◽  
Robert U Hartzler ◽  
Bradford O Parsons ◽  
Evan S Lederman ◽  
...  

Background The purpose was to evaluate the relationship of component size and position to postoperative range of motion following reverse shoulder arthroplasty. The hypothesis was that increased lateralization, larger glenospheres, and a decreased acromiohumeral distance would be associated with excellent postoperative range of motion. Methods A retrospective multicenter study was performed at a minimum of one year postoperatively on 160 patients who underwent primary reverse shoulder arthroplasty with a 135° humeral component. Outcomes were stratified based on postoperative forward flexion and external rotation into excellent ( n = 42), defined as forward flexion >140° and external rotation > 30°, or poor ( n = 36), defined as forward flexion <100° and external rotation < 15°. Radiographic measurements and component features were compared between the two groups. Results A larger glenosphere size was associated with an excellent outcome ( p = 0.009). A 2-mm posterior offset humeral cup ( p = 0.012) and an increased inferior glenosphere overhang (3.1 mm vs 1.4 mm; p = 0.002) were also associated with excellent outcomes. Humeral lateralization and distalization were not associated with an excellent outcome. Conclusion: Larger glenosphere size and inferior positioning as well as posterior humeral offset are associated with improved postoperative range of motion following reverse shoulder arthroplasty. Level of Evidence Level 3, retrospective comparative study.


2020 ◽  
pp. 175857322091765
Author(s):  
Betty Zhang ◽  
Gavinn Niroopan ◽  
Chetan Gohal ◽  
Bashar Alolabi ◽  
Timothy Leroux ◽  
...  

Background Primary anatomic total shoulder arthroplasty can be challenging in patients with complex glenoid wear patterns and bone loss. Severe retroversion (>15°) or significant bone loss may require bone grafting. This review summarizes the rate of revision and long-term outcomes of anatomic total shoulder arthroplasty with bone graft. Methods A systematic search of MEDLINE, Embase, PubMed, and CENTRAL databases was conducted from the date of inception to 23 October 2018. Two reviewers independently screened articles for eligibility and extracted data for analysis. The primary outcome was rate of revision. The secondary outcomes were rate of component loosening, functional outcome, and range of motion. Results Of the 1056 articles identified in the search, 26 underwent full-text screening and 7 articles were included in the analysis. All procedures were one-stage anatomic total shoulder arthroplasties. The rate of revision was 5.4% with component loosening and infection listed as indications over a weighted mean follow-up period of 6.3 years. Complications occurred in 12.6% of patients. Conclusion Glenoid bone grafting in anatomic total shoulder arthroplasty results in comparable revision rates and improvement in pain compared to augmented glenoid components and reverse shoulder arthroplasty. Due to the low quality of evidence, further prospective studies should be conducted. Level of evidence IV


2020 ◽  
Vol 9 (10) ◽  
pp. 3362
Author(s):  
Anna-K. Tross ◽  
Alexandre Lädermann ◽  
Thomas Wittmann ◽  
Marc Schnetzke ◽  
Philip-C. Nolte ◽  
...  

Background: The radiological phenomenon of subsidence following the implantation of uncemented short-stem reverse prostheses (USSP) has not yet been described. The purpose of this study was to describe the rate and potential risk factors for subsidence. We hypothesized that subsidence may be a frequent finding and that a subsidence of >5 mm (mm) is associated with an inferior clinical outcome. Methods: A total of 139 patients with an average age of 73 ± 9 years were included. The clinical and radiological outcome was evaluated at a minimum follow-up (FU) of 12 months. Results: No humeral component loosening was present at a mean FU of 18 (range, 12–51) months. Mean Constant Score (CS) and Subjective Shoulder Value (SSV) improved significantly from 34.3 ± 18.0 points and 37.0 ± 19.5% preoperatively to 72.2 ± 13.4 points and 80.3 ± 16.5% at final FU (p < 0.001). The average subsidence of the USSP was 1.4 ± 3.7 mm. Subsidence of >5 mm was present in 15 patients (11%). No association between a subsidence >5 mm and CS or SSV was found (p = 0.456, p = 0.527). However, a subsidence of >5 mm resulted in lower strength at final FU (p = 0.022). Complications occurred in six cases (4.2%), and the revision rate was 3.5% (five cases). Conclusions: Although subsidence of USSP is a frequent radiographic finding it is not associated with loosening of the component or a decrease in the clinical outcome at short term FU. Level of evidence: Level 4, retrospective study.


2012 ◽  
Vol 21 (9) ◽  
pp. 1121-1127 ◽  
Author(s):  
Lawrence V. Gulotta ◽  
Dan Choi ◽  
Patrick Marinello ◽  
Zakary Knutson ◽  
Joseph Lipman ◽  
...  

2017 ◽  
Vol 10 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Irfan Abdulla ◽  
Daniel G Langohr ◽  
Joshua W. Giles ◽  
James A. Johnson ◽  
George S. Athwal

Background There is little information on the effects of altering reverse shoulder arthroplasty (RSA) polyethylene constraint on joint load, load angle and deltoid force. The present biomechanical study aimed to investigate the effects of changing RSA polyethylene constraint on joint load, load angle, deltoid force and range of motion. Methods A custom RSA implant capable of measuring forces across the joint with varying polyethylene constraint was tested in six cadaveric shoulders. Standard-, low- and high-constraint (retentive) polyethylene liners were tested, and joint kinematics, loads and muscle forces were recorded. Results When polyethylene constraint was altered, joint load and load angle during active abduction were not affected significantly ( p > 0.19). Additionally, the force required by the deltoid for active abduction was not affected significantly by cup constraint ( p = 0.144). Interestingly, active abduction range of motion was also not affected significantly by changes in cup constraint ( p > 0.45). Conclusions Altering polyethylene cup constraint in RSA to enhance stability does not significantly alter resultant joint loads and deltoid forces. Surprisingly, terminal abduction range of motion was also not significantly different with varying cup constraint, indicating that terminal impingement may be tuberosity related rather than polyethylene.


2020 ◽  
Vol 14 (1) ◽  
pp. 154-160
Author(s):  
Ryan Bicknell ◽  
Michael Furlan ◽  
Alexander Bertelsen ◽  
Frederick Matsen

Background: The overall objective of this study was to investigate whether a reverse shoulder arthroplasty could provide adequate stability to a shoulder even with extreme soft tissue loss. The specific objectives of this study were: to determine if just the deltoid, conjoined tendon, and triceps are sufficient soft tissues to allow a Reverse Shoulder Arthroplasty (RSA) to provide shoulder stability and to determine the influence of load direction, rotation, shoulder position, and polyethylene thickness on RSA stability in this soft-tissue deficient model. Methods: This study utilized six cadaveric shoulders that had all soft tissue removed, with the exception of the deltoid, conjoint tendon, and long head of triceps. A reverse shoulder arthroplasty was then performed (Delta III, DePuy Inc., Warsaw, IN) and an increasing dislocation force was applied perpendicular to the humeral socket centerline until dislocation occurred, or a maximum load of 100 N was reached. This was repeated to measure the effect of four factors: load direction, arm position, polyethylene thickness, and arm rotation on force to dislocation. Results: For load direction, there was an increase in force to dislocate an inferior load direction (p=0.01). There was a lower not dislocated percentage and lower survival for a posterior load direction (p=0.02). For arm position, there was a decrease in force for dislocation and lower survival for both abduction and extension arm positions. There was a higher not dislocated percentage for a flexion arm position (p=0.01). For arm rotation, there was a lower not dislocated percentage and lower survival for an external rotation arm position (p=0.03). There was no statistically significant influence of polyethylene thickness (p=0.26). Conclusion: The deltoid, conjoined tendon, and triceps are sufficient to stabilize an RSA. Load direction, arm position, and arm rotation were all shown to significantly affect stability. Finally, polyethylene thickness may not affect overall RSA stability in this soft-tissue deficient model. Level of Evidence: Basic science study, Biomechanical study.


2020 ◽  
Vol 15 (3) ◽  
pp. 207-212
Author(s):  
Patric Raiss ◽  
Rainer Neumann

Abstract Introduction Reverse shoulder arthroplasty (RSA) has become a well-established treatment option for multiple disorders of the shoulder joint. In recent years, implant designs and configurations have been modified in order to improve function and avoid complications. Lateralization on the glenoid and the humeral side has been described to improve function and decrease radiographic scapular notching. Data on the clinical and radiographic results of bipolar lateralization in RSA are lacking. Methods In 38 cases, RSA was performed using an uncemented humeral short-stem component with a 145° neck–shaft angle in combination with bone lateralization on the glenoid side (Bony Increased-Offset Reversed Shoulder Arthroplasty, BIO-RSA; Wright Medical Inc., Memphis, TN, USA). Mean follow-up was 19 months (range 12–34 months). Patients were followed clinically using the Constant score as well as range of motion for shoulder flexion and external rotation. Radiographs in two different plains were analyzed for implant seating and the occurrence of scapular notching. Results There was a significant increase in all measured clinical parameters. Forward flexion increased from a mean of 75° preoperatively to 151° postoperatively, and mean Constant score increased from 21 to 71 points postoperatively (p < 0.001). Glenoid notching of grade 1 according to Sirveuax was observed in 3 out of 35 cases (9%); no grade 2, 3, or 4 notching was present. Revision surgery was necessary in one case (3%). Conclusion RSA with bipolar lateralization leads to excellent clinical outcomes, low complication rates, and low rates of radiographic scapular notching. Longer follow-up and prospective randomized trials are needed. Level of evidence Level IV.


2020 ◽  
pp. 175857322091009
Author(s):  
Jason S Lockhart ◽  
Murray T Wong ◽  
G Daniel G Langohr ◽  
George S Athwal ◽  
James A Johnson

Background Acromial fractures are a substantial complication following reverse shoulder arthroplasty, reported to affect up to 7% of patients. Previous studies have shown that implant placement affects acromial stress during elevation of the arm in the scaption plane. The purpose of this study was to investigate the results of arm loading and variation in plane of elevation on acromial stresses. Methods Nine elevation angles (0°–120°), in three planes of elevation (abduction (0°), scaption (30°), and forward elevation (60°)), and three hand loads (0, 2.5, 5 kg) were investigated. Finite element models were generated using computed tomography data from 10 cadaveric shoulders (age 68 ± 19 yrs) to determine acromial stress distributions. Models were created for a lateralized glenosphere (0, 5, 10 mm), inferiorized glenosphere (0, 2.5, 5 mm), and humeral offset (−5, 0, 5 mm). Results For all planes of elevation (0°, 30°, 60°) and hand loads (0, 2.5, 5 kg) investigated, glenoid lateralization consistently increased acromial stress, glenoid inferiorization consistently decreased acromial stress, and humeral offset proved to be insignificant in altering acromial stress. Abduction resulted in significantly higher peak acromial stresses (p = 0.002) as compared to scaption and forward elevation. Conclusions In addition to implant position and design, patient activity, such as plane of elevation and hand loads, has substantial effects on acromial stresses. Level of evidence Basic science study


2021 ◽  
pp. 175857322110671
Author(s):  
Garrett R Jackson ◽  
Joshua Meade ◽  
Bradley L Young ◽  
David P Trofa ◽  
Shadley C Schiffern ◽  
...  

Background Advances have been made to the traditional inlay Grammont Reverse Shoulder Arthroplasty (RSA) design such as the onlay humeral component prosthesis. Currently, there is no agreement in the literature regarding the best option for the humeral component when comparing inlay and onlay designs. This review compares the outcomes and complications between onlay versus inlay humeral components for RSA. Methods A literature search was conducted using PubMed and Embase. Only studies reporting outcomes comparing onlay versus inlay RSA humeral components were included. Results Four studies with 298 patients (306 shoulders) were included. Onlay humeral components were associated with better external rotation (ER) ( p < 0.0001). No significant difference in forward flexion (FF) or abduction was found. Constant scores (CS) and VAS scores did not differ. Increased scapular notching was found in the inlay group (23.18%) versus the onlay group (7.74%) ( p = 0.02). Postoperative scapular fractures and acromial fractures did not differ. Conclusion Onlay and inlay RSA designs are associated with improved postoperative range of motion (ROM). Onlay humeral designs may be associated with greater ER and lower rate of scapular notching; however, no difference was found in Constant and VAS scores, so further studies are required to assess the clinical significance of these differences.


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