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The Bone & Joint Journal
Vol. 102-B, Issue 11 | Pages 1438 - 1445
1 Nov 2020
Jang YH Lee JH Kim SH

Aims. Scapular notching is thought to have an adverse effect on the outcome of reverse total shoulder arthroplasty (RTSA). However, the matter is still controversial. The aim of this study was to determine the clinical impact of scapular notching on outcomes after RTSA. Methods. Three electronic databases (PubMed, Cochrane Database, and EMBASE) were searched for studies which evaluated the influence of scapular notching on clinical outcome after RTSA. The quality of each study was assessed. Functional outcome scores (the Constant-Murley scores (CMS), and the American Shoulder and Elbow Surgeons (ASES) scores), and postoperative range of movement (forward flexion (FF), abduction, and external rotation (ER)) were extracted and subjected to meta-analysis. Effect sizes were expressed as weighted mean differences (WMD). Results. In all, 11 studies (two level III and nine level IV) were included in the meta-analysis. All analyzed variables indicated that scapular notching has a negative effect on the outcome of RTSA . Statistical significance was found for the CMS (WMD –3.11; 95% confidence interval (CI) –4.98 to –1.23), the ASES score (WMD –6.50; 95% CI –10.80 to –2.19), FF (WMD –6.3°; 95% CI –9.9° to –2.6°), and abduction (WMD –9.4°; 95% CI –17.8° to –1.0°), but not for ER (WMD –0.6°; 95% CI –3.7° to 2.5°). Conclusion. The current literature suggests that patients with scapular notching after RTSA have significantly worse results when evaluated by the CMS, ASES score, and range of movement in flexion and abduction. Cite this article: Bone Joint J 2020;102-B(11):1438–1445


The Bone & Joint Journal
Vol. 95-B, Issue 4 | Pages 530 - 535
1 Apr 2013
Roche CP Marczuk Y Wright TW Flurin P Grey S Jones R Routman HD Gilot G Zuckerman JD

This study provides recommendations on the position of the implant in reverse shoulder replacement in order to minimise scapular notching and osteophyte formation. Radiographs from 151 patients who underwent primary reverse shoulder replacement with a single prosthesis were analysed at a mean follow-up of 28.3 months (24 to 44) for notching, osteophytes, the position of the glenoid baseplate, the overhang of the glenosphere, and the prosthesis scapular neck angle (PSNA).

A total of 20 patients (13.2%) had a notch (16 Grade 1 and four Grade 2) and 47 (31.1%) had an osteophyte. In patients without either notching or an osteophyte the baseplate was found to be positioned lower on the glenoid, with greater overhang of the glenosphere and a lower PSNA than those with notching and an osteophyte. Female patients had a higher rate of notching than males (13.3% vs 13.0%) but a lower rate of osteophyte formation (22.9% vs 50.0%), even though the baseplate was positioned significantly lower on the glenoid in females (p = 0.009) and each had a similar mean overhang of the glenosphere.

Based on these findings we make recommendations on the placement of the implant in both male and female patients to avoid notching and osteophyte formation.

Cite this article: Bone Joint J 2013;95-B:530–5.


The Bone & Joint Journal
Vol. 105-B, Issue 11 | Pages 1189 - 1195
1 Nov 2023
Kim JS Kim SH Kim SC Park JH Kim HG Lee SM Yoo JC

Aims. The aim of this study was to compare the clinical and radiological outcomes of reverse shoulder arthroplasty (RSA) using small and standard baseplates in Asian patients, and to investigate the impact of a mismatch in the sizes of the glenoid and the baseplate on the outcomes. Methods. This was retrospective analysis of 50 and 33 RSAs using a standard (33.8 mm, ST group) and a small (29.5 mm, SM group) baseplate of the Equinoxe reverse shoulder system, which were undertaken between January 2017 and March 2021. Radiological evaluations included the size of the glenoid, the β-angle, the inclination of the glenoid component, inferior overhang, scapular notching, the location of the central cage in the baseplate within the vault and the mismatch in size between the glenoid and baseplate. Clinical evaluations included the range of motion (ROM) and functional scores. In subgroup analysis, comparisons were performed between those in whom the vault of the glenoid was perforated (VP group) and those in whom it was not perforated (VNP group). Results. Perforation of the vault of the glenoid (p = 0.018) and size mismatch in height (p < 0.001) and width (p = 0.013) were significantly more frequent in the ST group than in the SM group. There was no significant difference in the clinical scores and ROM in the two groups, two years postoperatively (all p > 0.05). In subgroup analysis, the VP group had significantly less inferior overhang (p = 0.009), more scapular notching (p = 0.018), and more size mismatch in height (p < 0.001) and width (p = 0.025) than the VNP group. Conclusion. In Asian patients with a small glenoid, using a 29.5 mm small baseplate at the time of RSA was more effective in reducing size mismatch between the glenoid and the baseplate, decreasing the incidence of perforation of the glenoid vault, and achieving optimal positioning of the baseplate compared with the use of a 33.8 mm standard baseplate. However, longer follow-up is required to assess the impact of these findings on the clinical outcomes. Cite this article: Bone Joint J 2023;105-B(11):1189–1195


The Bone & Joint Journal
Vol. 106-B, Issue 3 | Pages 268 - 276
1 Mar 2024
Park JH Lee JH Kim DY Kim HG Kim JS Lee SM Kim SC Yoo JC

Aims. This study aimed to assess the impact of using the metal-augmented glenoid baseplate (AGB) on improving clinical and radiological outcomes, as well as reducing complications, in patients with superior glenoid wear undergoing reverse shoulder arthroplasty (RSA). Methods. From January 2016 to June 2021, out of 235 patients who underwent primary RSA, 24 received a superior-AGB after off-axis reaming (Group A). Subsequently, we conducted propensity score matching in a 1:3 ratio, considering sex, age, follow-up duration, and glenoid wear (superior-inclination and retroversion), and selected 72 well-balanced matched patients who received a standard glenoid baseplate (STB) after eccentric reaming (Group B). Superior-inclination, retroversion, and lateral humeral offset (LHO) were measured to assess preoperative glenoid wear and postoperative correction, as well as to identify any complications. Clinical outcomes were measured at each outpatient visit before and after surgery. Results. There were no significant differences in demographic data and preoperative characteristics between the two groups. Both groups showed significant improvements in patient-reported outcome measures (visual analogue scale for pain, visual analogue scale for function, American Shoulder and Elbow Surgeons, Constant, and Simple Shoulder Test scores) from preoperative to final assessment (p < 0.001). However, AGB showed no additional benefit. Notably, within range of motion, Group B showed significant postoperative decrease in both external rotation and internal rotation, unlike Group A (p = 0.028 and 0.003, respectively). Both groups demonstrated a significant correction of superior-inclination after surgery, while patients in Group B exhibited a significant decrease in LHO postoperatively (p = 0.001). Regarding complications, Group A experienced more acromial stress fractures (3 cases; 12.5%), whereas Group B had a higher occurrence of scapular notching (24 cases; 33.3%) (p = 0.008). Conclusion. Both eccentric reaming with STB and off-axis reaming with AGB are effective methods for addressing superior glenoid wear in RSA, leading to improved clinical outcomes. However, it is important to be aware of the potential risks associated with eccentric reaming, which include excessive bone loss leading to reduced rotation and scapular notching. Cite this article: Bone Joint J 2024;106-B(3):268–276


The Bone & Joint Journal
Vol. 103-B, Issue 2 | Pages 360 - 365
1 Feb 2021
Mahendraraj KA Shields MV Grubhofer F Golenbock SW Jawa A

Aims. Existing literature indicates that inferiorly inclined glenoid baseplates following reverse total shoulder arthroplasty (RSA) produce better outcomes compared to superiorly inclined baseplates. We aim to compare clinical outcomes for RSAs with superiorly and neutrally/inferiorly inclined lateralized glenospheres. Methods. We retrospectively reviewed 154 consecutive patients undergoing RSA between July 2015 and July 2017 by one single-fellowship trained surgeon (AJ). Two raters (KAM and MVS) independently measured glenoid inclination in preoperative and minimum two year follow-up radiographs (anteroposterior/Grashey) using the RSA angle. Inclination was then compared to patient-reported outcomes, range of motion (ROM), and independently assessed degree of scapular notching and staging of heterotopic ossification at two year follow-up. Results. Median postoperative inclination for each group was found to be -3.6° (interquartile range (IQR) -2.1 to -6.9) and 6.0° (3.2° to 10.1°) for the neutrally/inferiorly and superiorly inclined cohorts, respectively. Preoperative inclination was highly associated with postoperative inclination (p = 0.004). When comparing superiorly and neutrally/inferiorly inclined glenospheres, there were no differences in heterotopic ossification (p = 0.606), scapular notching (p = 0.367), American Shoulder and Elbow Surgeons score (p = 0.419), Single Assessment Numeric Evaluation (p = 0.417), Visual Analogue Scale (VAS) pain score (p = 0.290), forward elevation (p = 0.161), external rotation (p = 0.537), or internal rotation (p = 0.656). Conclusion. Compared to neutral and inferior inclination, up to 6° ± 3° of superior glenoid baseplate inclination on a lateralized RSA design produces no differences in postoperative ROM or patient-reported outcomes, and produces similar levels of scapular notching and heterotopic ossification. Additionally, the degree of preoperative inclination represents an important factor in surgical decision-making as it is strongly associated with postoperative inclination. It is important to note that the findings of this study are only reflective of lateralized RSA prostheses. Cite this article: Bone Joint J 2021;103-B(2):360–365


The Bone & Joint Journal
Vol. 103-B, Issue 5 | Pages 813 - 821
1 May 2021
Burden EG Batten TJ Smith CD Evans JP

Aims. This systematic review asked which patterns of complications are associated with the three reverse total shoulder arthroplasty (RTSA) prosthetic designs, as classified by Routman et al, in patients undergoing RTSA for the management of cuff tear arthropathy, massive cuff tear, osteoarthritis, and rheumatoid arthritis. The three implant design philosophies investigated were medial glenoid/medial humerus (MGMH), medial glenoid/lateral humerus (MGLH), and lateral glenoid/medial humerus (LGMH). Methods. A systematic review of the literature was performed via a search of MEDLINE and Embase. Two reviewers extracted data on complication occurrence and patient-reported outcome measures (PROMs). Meta-analysis was conducted on the reported proportion of complications, weighted by sample size, and PROMs were pooled using the reported standardized mean difference (SMD). Quality of methodology was assessed using Wylde’s non-summative four-point system. The study was registered with PROSPERO (CRD42020193041). Results. A total of 42 studies met the inclusion and exclusion criteria. Rates of scapular notching were found to be significantly higher in MGMH implants (52% (95% confidence interval (CI) 40 to 63)) compared with MGLH ((18% (95% CI 6 to 34)) and LGMH (12% (95% CI 3 to 26)). Higher rates of glenoid loosening were seen in MGMH implants (6% (95% CI 3 to 10)) than in MGLH implants (0% (95% CI 0 to 2)). However, strength of evidence for this finding was low. No significant differences were identified in any other complication, and there were no significant differences observed in PROMs between implant philosophies. Conclusion. This systematic review has found significant improvement in PROMS and low complication rates across the implant philosophies studied. Scapular notching was the only complication found definitely to have significantly higher prevalence with the MGMH implant design. Cite this article: Bone Joint J 2021;103-B(5):813–821


The Bone & Joint Journal
Vol. 100-B, Issue 9 | Pages 1182 - 1186
1 Sep 2018
Werner BS Chaoui J Walch G

Aims. Scapular notching is a frequently observed radiographic phenomenon in reverse shoulder arthroplasty (RSA), signifying impingement of components. The purposes of this study were to evaluate the effect of glenoid component size and glenosphere type on impingement-free range of movement (ROM) for extension and internal and external rotation in a virtual RSA model, and to determine the optimal configuration to reduce the incidence of friction-type scapular notching. Materials and Methods. Preoperative CT scans obtained in 21 patients (three male, 18 female) with primary osteoarthritis were analyzed using modelling software. Two concurrent factors were tested for impingement-free ROM and translation of the centre of rotation: glenosphere diameter (36 mm vs 39 mm) and type (centred, 2 mm inferior eccentric offset, 10° inferior tilt). Results. Glenosphere size was most predictive of increased extension and external rotation, whereas lateralization of the centre of rotation was the most predictive factor for internal rotation. A larger diameter of glenosphere combined with a 10° tilted configuration demonstrated superior values for extension and external rotation, whereas the eccentric component improved internal rotation by a mean 8.9° (standard deviation 2.7°) compared with a standard concentric glenosphere. Conclusion. Glenosphere configuration can be modified to increase range of movement in RSA. Friction-type scapular notching was most effectively reduced by use of a large-diameter glenosphere with 10° inferior tilt. Cite this article: Bone Joint J 2018;100-B:1182–6


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 8 - 8
1 May 2016
Roche C Flurin P Crosby L Wright T Zuckerman J
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Introduction. The clinical impact of scapular notching is controversial. Some reports suggest it has no impact while others have demonstrated it does negatively impact clinical outcomes. The goal of this clinical study is to analyze the pre- and post-operative outcomes of 415 patients who received rTSA with one specific prosthesis (Equinoxe; Exactech, Inc). Methods. 415 patients (mean age: 72.2yrs) with 2 years minimum follow-up were treated with rTSA for CTA, RCT, and OA by 8 fellowship trained orthopaedic surgeons. 363 patients were deemed to not have a scapular notch by the implanting surgeon at latest follow-up (72.1 yrs; 221F/131M) whereas 52 patients were deemed to have a scapular notch at latest follow-up (73.3 yrs; 33F/19M). Outcomes were scored using SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, forward flexion, and internal/external rotation were also measured to quantify function. Average follow-up was 38.1 months (No Notch: 37.2; Notch: 44.4). A two-tailed, unpaired t-test identified differences (p<0.05) in pre-operative, post-operative, and pre-to-post improvements. Results. The overall scapular notching rate was 12.5%. The rTSA cohort with a scapular notch had an average notching grade of 1.3 (41 grade 1, 6 grade 2, 5 grade 3, and 0 grade 4 notches). rTSA patients with a scapular notch on average weighed significantly less (168.0 vs. 154.7 lbs; p = 0.016) and had a significantly lower BMI (27.3 vs. 26.0; p = 0.032). 8 patients without scapular notching had a radiolucent line around the humeral component (2.2%); whereas, 5 patients with scapular notching had a radiolucent line around the humeral component (10.0%). Table 1 demonstrates no difference between the cohorts in pre-operative outcomes. Table 2 demonstrates rTSA patients without scapular notching were associated with significantly larger clinical outcome scores in all 5 metrics and also had significantly improved function according to 3 of the 6 measurements as compared to rTSA patients with scapular notching. Table 3 demonstrates only one significant difference was observed in pre-to-post improvement of outcome scores between cohorts. Finally, 27 complications were reported (6.5%), 20 for patients without scapular notching (5.5%) and 7 complications for patients with scapular notching (13.5%). Discussion and Conclusions. This large-scale clinical outcome study demonstrated that patients with scapular notching are associated with significantly poorer outcomes and a greater complication rate than patients without scapular notching at a similar average post-operative follow-up. The finding that patients with lower BMI were associated with a higher notching rate is new but also intuitive as these patients can likely adduct their arm more; it may also be that the lower average BMI and weight suggests that patients with notching were also more active. One additional new finding in this analysis is that patients with scapular notching had a 4.5X greater rate of radiolucent lines around the humeral component suggesting that the UHWMPE wear debris are related to the formation of humeral radiolucent lines. Additional and longer-term follow-up is needed to confirm these conclusions


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 103 - 103
23 Feb 2023
Gupta V Van Niekerk M Hirner M
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Scapular notching is a common problem following reverse shoulder arthroplasty (RSA). This is due to impingement between the humeral polyethylene cup and scapular neck in adduction and external rotation. Various glenoid component strategies have been described to combat scapular notching and enhance impingement-free range of motion (ROM). There is limited data available detailing optimal glenosphere position in RSA with an onlay configuration. The purpose of this study was to determine which glenosphere configurations would maximise impingement free ROM using an onlay RSA prosthesis. A three-dimensional (3D) computed tomography (CT) scan of a shoulder with Walch A1, Favard E0 glenoid morphology was segmented using validated software. An onlay RSA prosthesis was implanted and a computer model simulated external rotation and adduction motion of the virtual RSA prosthesis. Four glenosphere parameters were tested; diameter (36mm, 41mm), lateralization (0mm, 3mm, 6mm), inferior tilt (neutral, 5 degrees, 10 degrees), and inferior eccentric positioning (0.5mm, 1.5mm. 2.5mm, 3.5mm, 4.5mm). Eighty-four combinations were simulated. For each simulation, the humeral neck-shaft angle was 147 degrees and retroversion was 30 degrees. The largest increase in impingement-free range of motion resulted from increasing inferior eccentric positioning, gaining 15.0 degrees for external rotation and 18.8 degrees for adduction. Glenosphere lateralization increased external rotation motion by 13. 6 degrees and adduction by 4.3 degrees. Implanting larger diameter glenospheres increased external rotation and adduction by 9.4 and 10.1 degrees respectively. Glenosphere tilt had a negligible effect on impingement-free ROM. Maximizing inferior glenosphere eccentricity, lateralizing the glenosphere, and implanting larger glenosphere diameters improves impingement-free range of motion, in particular external rotation, of an onlay RSA prosthesis. Surgeons’ awareness of these trends can help optimize glenoid component position to maximise impingement-free ROM for RSA. Further studies are required to validate these findings in the context of scapulothoracic motion and soft tissue constraints


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_14 | Pages 3 - 3
1 Jul 2016
Ramesh K Baumann A Makaram N Finnigan T Srinivasan M
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Despite the high success rates of Reverse Shoulder replacements, complications of instability & scapular notching are a concern. Factors reducing relative motion of implant to underlying bone which include lateral offset to centre of rotation, screw & central peg insertion angle and early osteo-integration are maximized in the Trabecular Metal Reverse total shoulder system. We present clinico-radiological outcomes over 72 months. Analysis of a single surgeon series of 140 Reverse total shoulder replacements in 135 patients was done. Mean age was 72(range 58– 87 yrs); 81 females: 54 males. Indications were Rotator cuff arthropathy {n= 88} (63%); Osteo-arthritis with dysfunctional cuff {n= 22}(15%); post-trauma{n=23} (15%); revision from hemiarthroplasty {n=3} (2.4%) and from surface replacement {n=4} (2.8%). All patients were assessed using pre-operative Constants and Oxford scores and clinical & radiographic reviews with standard X-Rays at 6 weeks, 3, 6,12 months and yearly thereafter. X rays included an AP view in 45 degrees of external rotation and modified axillary view. Inferior Scapular notching using the Nerot-Sirveaux grades and Peg Glenoid Rim Distance were looked into by a consultant musculoskeletal radiologist/ Orthopaedic surgeon/ Senior Fellow (post CCT) or a specialist Trainee (ST4 and above). Pain on the visual analogue scale decreased by 98% (9.1 to 0.8) (p<0.01). Constant score improved by 81.8% (12.4 to 68.1) (p<0.05), Oxford shoulder score by 76.7% (56 to 13) (p<0.05). 95.6% of Humeral stems had no radiolucent lines and 4.4% had < 2mm of lucency. Scapular notching was calculated using Sirveaux grades with Peg scapular base angle distance (PSBA) measurements on PACS with Siemens calibration (grade 1= 4 (2.8%); grade 2 =1; grade 3 =0; grade 4=0). 3.57% showed radiographic signs of scapular notching at 72 months. Range of Peg Glenoid Rim Distance was 1.66 to 2.31 cm. Power analysis showed 65 patients were needed to have an 80% power to detect relation of Peg Glenoid Rim Distance to Scapular notching. A likelihood ratio test from Logistic regression model to check correlation of Peg Glenoid Rim Distance to Scapular notching gave a p value of 0.0005. A likelihood ratio from Logistic regression gave a p value of 0.0004 for Infraglenoid Scapular spurs. Highest incidence of spurring was seen in Reverse Total Shoulder Replacements done for Trauma and lowest in patients who got the procedure for Osteoarthritis. Complications included two glenosphere revisions; two stitch abscesses and two Acromial fractures in patients who had a fall two years after the procedure. Improved surgical outcomes can be attributed to surgical technique and implant characteristics. Trabacular metal promotes early osteointegration which resists shearing action of Deltoid on Glenoid component. This allows early mobilisation. Deltoid split approach preserves integrity of Subscapularis and Acromial osteotomy and lateral clavicle excision improve exposure and prevent Acromion fracture. Positioning the Glenoid component inferiorly on the Glenoid decreases incidence of Scapular notching. Our mid-term validated outcomes are promising with only 3.57% Grade I/II radiographic signs of scapular notching. Long term studies (10 year follow ups) are necessary to confirm its efficacy


Introduction. Reverse shoulder replacement is a surgical option for cuff tear arthropathy. However scapular notching is a concern. Newer designs of glenospheres are available to reduce scapular notching. Eccentric glenosphere with a lowered centre of rotation have been shown to improve range of adduction in vitro. We hypothesize that the eccentric glenosphere improve clinical outcomes and reduce scapular notching. Method. This is an ongoing randomized controlled double blind prospective clinical trial. Patients 70 years or older at North Shore hospital who have a diagnosis of cuff tear arthropathy and require surgery were consented for this study. Patients were allocated a concentric or eccentric 36 mm glenosphere intraoperatively, using a computer generated randomization contained in a sealed envelope. The surgical technique and post operative rehabilitation were standardized. Patients were followed up by a research nurse and postoperative radiographs were also taken at regular intervals. Clinical assessment include a visual analogue pain score, subjective shoulder rating, American Shoulder and Elbow Society Score, and Oxford shoulder score. Complications were checked for and radiographs were assessed for scapular notching. Results. There were 23 patients in the concentric and 24 patients in the eccentric glenosphere group. Average age and duration of follow up were comparable. There was no statistical significant difference but there was a trend towards better functional outcome and better range of motion in the eccentric glenosphere group. There was no scapular notching in the eccentric and three cases of scapular notching in the concentric glenosphere group. Conclusions. Reverse shoulder replacement significantly improve pain, function and range of motion in patients with cuff tear arthropathy. Eccentric glenosphere prevents scapular notching in the SMR reverse prosthesis


The Bone & Joint Journal
Vol. 103-B, Issue 8 | Pages 1333 - 1338
2 Aug 2021
Kankanalu P Borton ZM Morgan ML Cresswell T Espag MP Tambe AA Clark DI

Aims. Reverse total shoulder arthroplasty (RTSA) using trabecular metal (TM)-backed glenoid implants has been introduced with the aim to increase implant survival. Only short-term reports on the outcomes of TM-RTSA have been published to date. We aim to present the seven-year survival of TM-backed glenoid implants along with minimum five-year clinical and radiological outcomes. Methods. All consecutive elective RTSAs performed at a single centre between November 2008 and October 2014 were reviewed. Patients who had primary TM-RTSA for rotator cuff arthropathy and osteoarthritis with deficient cuff were included. A total of 190 shoulders in 168 patients (41 male, 127 female) were identified for inclusion at a mean of 7.27 years (SD 1.4) from surgery. The primary outcome was survival of the implant with all-cause revision and aseptic glenoid loosening as endpoints. Secondary outcomes were clinical, radiological, and patient-related outcomes with a five-year minimum follow-up. Results. The implant was revised in ten shoulders (5.2%) with a median time to revision of 21.2 months (interquartile range (IQR) 9.9 to 41.8). The Kaplan-Meier survivorship estimate at seven years was 95.9% (95% confidence interval (CI) 91.7 to 98; 35 RTSAs at risk) for aseptic mechanical failure of the glenoid and 94.8% (95% CI 77.5 to 96.3; 35 RTSAs at risk) for all-cause revision. Minimum five-year clinical and radiological outcomes were available for 103 and 98 RTSAs respectively with a median follow-up time of six years (IQR 5.2 to 7.0). Median postoperative Oxford Shoulder Score was 38 (IQR 31 to 45); median Constant and Murley score was 60 (IQR 47.5 to 70); median forward flexion 115° (IQR 100° to 125°); median abduction 95° (IQR 80° to 120°); and external rotation 25° (IQR 15° to 40°) Scapular notching was seen in 62 RTSAs (63.2%). Conclusion. We present the largest and longest-term series of TM-backed glenoid implants demonstrating 94.8% all-cause survivorship at seven years. Specifically pertaining to glenoid loosening, survival of the implant increased to 95.9%. In addition, we report satisfactory minimum five-year clinical and radiological outcomes. Cite this article: Bone Joint J 2021;103-B(8):1333–1338


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 9 | Pages 1240 - 1246
1 Sep 2011
Melis B DeFranco M Lädermann A Molé D Favard L Nérot C Maynou C Walch G

Radiological changes and differences between cemented and uncemented components of Grammont reverse shoulder arthroplasties (DePuy) were analysed at a mean follow-up of 9.6 years (8 to 12). Of 122 reverse shoulder arthroplasties implanted in five shoulder centres between 1993 and 2000, a total of 68 (65 patients) were available for study. The indications for reversed shoulder arthroplasty were cuff tear arthropathy in 48 shoulders, revision of shoulder prostheses of various types in 11 and massive cuff tear in nine. The development of scapular notching, bony scapular spur formation, heterotopic ossification, glenoid and humeral radiolucencies, stem subsidence, radiological signs of stress shielding and resorption of the tuberosities were assessed on standardised true anteroposterior and axillary radiographs. A scapular notch was observed in 60 shoulders (88%) and was associated with the superolateral approach (p = 0.009). Glenoid radiolucency was present in 11 (16%), bony scapular spur and/or ossifications in 51 (75%), and subsidence of the stem and humeral radiolucency in more than three zones were present in three (8.8%) and in four (11.8%) of 34 cemented components, respectively, and in one (2.9%) and two (5.9%) of 34 uncemented components, respectively. Radiological signs of stress shielding were significantly more frequent with uncemented components (p < 0.001), as was resorption of the greater (p < 0.001) and lesser tuberosities (p = 0.009)


The Bone & Joint Journal
Vol. 96-B, Issue 7 | Pages 936 - 942
1 Jul 2014
Middleton C Uri O Phillips S Barmpagiannis K Higgs D Falworth M Bayley I Lambert S

Inherent disadvantages of reverse shoulder arthroplasty designs based on the Grammont concept have raised a renewed interest in less-medialised designs and techniques. The aim of this study was to evaluate the outcome of reverse shoulder arthroplasty (RSA) with the fully-constrained, less-medialised, Bayley–Walker prosthesis performed for the treatment of rotator-cuff-deficient shoulders with glenohumeral arthritis. A total of 97 arthroplasties in 92 patients (53 women and 44 men, mean age 67 years (standard deviation (. sd. ) 10, (49 to 85)) were retrospectively reviewed at a mean follow-up of 50 months ((. sd. 25) (24 to 96)). The mean Oxford shoulder score and subjective shoulder value improved from 47 (. sd. 9) and 24 points (. sd. 18) respectively before surgery to 28 (. sd. 11) and 61 (. sd. 24) points after surgery (p <  0.001). The mean pain at rest decreased from 5.3 (. sd. 2.8) to 1.5 (. sd. 2.3) (p < 0.001). The mean active forward elevation and external rotation increased from 42. °. (. sd. 30) and 9. °. (. sd. 15) respectively pre-operatively to 78. °. (. sd. 39) and 24. °. (. sd. 17) post-operatively (p < 0.001). A total of 20 patients required further surgery for complications; 13 required revision of components. No patient developed scapular notching. The Bayley–Walker prosthesis provides reliable pain relief and reasonable functional improvement for patients with symptomatic cuff-deficient shoulders. Compared with other designs of RSA, it offers a modest improvement in forward elevation, but restores external rotation to some extent and prevents scapular notching. A longer follow-up is required to assess the survival of the prosthesis and the clinical performance over time. Cite this article: Bone Joint J 2014;96-B:936–42


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_8 | Pages 17 - 17
1 May 2019
Jobin C
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Reverse shoulder arthroplasty is becoming a frequent treatment of choice for patients with shoulder disorders. Complication rates after reverse shoulder arthroplasty may be three-fold that of conventional total shoulder arthroplasty especially in high risk patient populations and diagnoses like revision arthroplasty, fracture sequelae, and severe glenoid bone loss. Complications include component malposition, stiffness, neurological injury, infection, dislocation or instability, acromial or scapular spine fractures, scapular notching, and loosening of implants. Recognition of preoperative risk factors and appropriate 3D planning are essential in optimizing patient outcome and intraoperative success. Failure of reverse shoulder arthroplasty is a significant challenge requiring appropriate diagnosis of the failure mode. The most common neurological injuries involve the brachial plexus and the axillary nerve due to traction, manipulation of the arm, aberrant retractor placement, or relative lengthening of the arm. Intraoperative fractures are relatively uncommon but include the greater tuberosity, acromion, and glenoid. Tuberosity fracture can be repaired intraoperatively with suture techniques, glenoid fractures may be insignificant rim fractures or jeopardise baseplate fixation and require abandoning RSA until glenoid fracture ORIF heals and then a second stage RSA. Periprosthetic infection after RSA ranges from 1 to 10% and may be higher in revision cases and frequently is Propionibacterium acnes and Staphylococcus epidermidis. Dislocation was one of the most common complications after RSA approximately 5% but with increased surgeon experience and prosthetic design, dislocation rates are approaching 1–2%. An anterosuperior deltoid splitting approach has been associated with increased stability as well as subscapularis repair after RSA. Scapular notching is the most common complication after RSA. Notching may be caused by direct mechanical impingement of the humerosocket polyethylene on the scapular neck and from osteolysis from polyethylene wear. Sirveaux classified scapular notching based on the defect size as it erodes behind the baseplate towards the central post. Acromial fractures are infrequent but more common is severely eroded acromions from CTA, with osteoporosis, with excessive lengthening, and with superior baseplate screws that penetrate the scapular spine and create a stress riser. Nonoperative care is the mainstay of acromial and scapular spine fractures. Recognizing preoperative risk factors and understanding component positioning and design is essential to maximizing successful outcomes


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 38 - 38
1 Jun 2012
Biase CFD Giorgio GD Postacchini R
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Background. One of the main concern about reverse shoulder arthoplasty for the treatment of rotator cuff deficiency is scapular notching that is still an unsolved issue for this particular prosthesis. The purpose of this multicentric retrospective study is to compare two different concept of reverse prosthesis, one with a concentric glenoshere and the other one with a new eccentric glenoshere design that aim to minimize scapular notching. Methods. From 2004 to 2009 67 patients were treated with a SMR reverse shoulder prosthesis (LIMA) with either concentric (figure 2) or eccentric glenosphere (figure 1). We selected for the study patients with criteria as much homogeneous as possible by the age and pathology. We then included for the study 25 patients (Group 1) with a concentric glenosphere and 21 (Group 2) with a eccentric glenosphere. All baseplates of concentric glenospheres were implanted with the most inferior aspect of baseplate that matched with the inferior glenoid ream, so that the glenosphere extended 4 mm beyond the glenoid inferiorly in order to minimize scapular notching. Every patient were followed clinically (Constant and Murley Score [C.S.] and Simple Shuolder test [S.S.T.]) and radiographically (notching, loosening and mechanical failure) with a minimum follow-up of 24 months. We also evaluated at the final follow-up psna (prosthesis-scapular neck angle), pgrd (peg glenoid rim distance) and DBSNG (distance between scapular neck and glenosfere). Results. At two years of follow up R.O.M. increased significantly in both groups especially in those with a eccentric glenosphere. Notably in patients with an eccentric glenosphere elevation improved from 66° to 148° and abduction from 60° to 115° while in those with a concentric glenosphere improved from 78° to 122° and 71° to 98° respectively for elevation and abduction. Outcomes for external-rotation and internal-rotation were very similar in both groups. 14 (56%) patients among those with a concentric glenosphere had scapular notching while we didn't have any notch in those with eccentric glenosphere even though we didn't find any significant different between the two groups in term of clinical outcomes and patient's satisfaction. The average C.S. increased from 38% to 69% in those with concentric SMR and from 30% to 74% in the other group. At the final follow-up PSNA, DBSNG and PGRD were respectively 88°, 3,2mm and 18,2 mm in group 1, while they were 92°, 4,3 mm and 21,2 mm in the group 2. Conclusions. Putting concentric glenosphere more inferiorly reduce the incidence of scapular notching but it doesn't solve the problem whereas, at medium follow-up, the new eccentric design seems to solved completely this issue. This study sustains PSNA, DBSNG, PGRD as reliable measures to predict scapular notching. Besides eccentric SMR glenosphere seems to increase R.O.M. mostly in flexion, abduction and adduction


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 158 - 158
1 Mar 2013
De Biase CF Delcogliano M Polo RM Borroni M Castagna A
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Purpose. Reverse shoulder prosthesis may lead to scapular notching, caused by attrition of the upper humeral component with scapular neck. We compared the clinical and radiographic results obtained with a SMR prosthesis, which allows a concentric or an eccentric glenosphere to be applied. Patients and methods. 67 patients, mean age 73 years, were treated with reverse prosthesis using concentric and eccentric glenosphere. In patients with concentric glenosphere, the glenosphere extended about 4 mm below the glenoid. The eccentric glenosphere protected the upper glenoid neck by its inferior prolongment. Patients were followed for a mean of 33 months. At final F-U the Constant Score (C.S.) and the score with the Simple Shoulder test (S.S.T.) were calculated. Radiographs were obtained to evaluate the presence of scapular notching, psna (prosthesis-scapular neck angle), pgrd (peg- glenoid rim distance) and DBSNG (distance between scapular neck and glenosfere). Included in this study were patients, as much homogeneous as possible by age and pathology, 25 with concentric (Group I) and 30 with eccentric (Group II) glenosphere, who had a minimum F-U of 24 months. Statistical analysis was performed with a paired test. Results. 25 patients of group I and 26 in group II were available for the study. In Group I mean elevation improved from 78° to 122° and mean abduction from 71° to 98°; in Group II from 66° to 148° and 60° to 115°. External and internal rotations were similar in both groups. 14 (56%) patients of Group I, and none of Group II had scapular notching (p<0.001). CS increased from 38 pt to 69 pt in Group I and from 30 pt to 74 pt in Group II. Conclusions. Low implantation of glenosphere did not eliminate scapular notching. Instead, no notching was detected with eccentric glenosphere, which also increased the ROM. The PSNA, DBSNG, PGRD are reliable measures to predict scapular notching


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 92 - 92
1 Apr 2019
Matsuki K Matsuki K Sugaya H Takahashi N Hoshika S Tokai M Ueda Y Hamada H Banks S
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Background. Scapular notching is a complication after reverse shoulder arthroplasty with a high incidence up to 100%. Its clinical relevance remains uncertain; however, some studies have reported that scapular notching is associated with an inferior clinical outcome. There have been no published articles that studied positional relationship between the scapular neck and polyethylene insert in vivo. The purpose of this study was to measure the distance between the scapular neck and polyethylene insert in shoulders with Grammont type reverse shoulder arthroplasty during active external rotation at the side. Methods. Eighteen shoulders with Grammont type prosthesis (Aequalis Reverse, Tornier) were enrolled in this study. There were 13 males and 5 female, and the mean age at surgery was 74 years (range, 63–91). All shoulders used a glenosphere with 36mm diameter, and retroversion of the humeral implant was 10°in 4 shoulders, 15°in 3 shoulders, and 20°in 11 shoulders. Fluoroscopic images were recorded during active external rotation at the side from maximum internal to external rotation at the mean of 14 months (range, 7–24) after surgery. The patients also underwent CT scans, and three-dimensional glenosphere models with screws and scapula neck models were created from CT images. CT-derived models of the glenosphere and computer-aided design humeral implant models were matched with the silhouette of the implants in the fluoroscopic images using model-image registration techniques (Figure 1). Based on the calculated kinematics of the implants, the closest distance between the scapular neck and polyethylene insert was computed using the scapular model and computer-aided design insert models (Figure 2). The distance was computed at each 5° increment of glenohumeral internal/external rotation, and the data from 20°internal rotation to 40°external rotation were used for analyses. One-way repeated-measures analysis of variance was used to examine the change of the distance during the activity, and the level of significance was set at P < 0.05. Results. The mean glenohumeral abduction during the activity was 17°-22°. The mean distance between the neck and insert was approximately 1mm throughout the activity (Figure 3). The distance tended to become smaller with the arm externally rotated, but the change was not significant. Discussion. The reported incidence of scapular notching after Grammont type reverse shoulder arthroplasty is generally higher than the newer design prosthesis with the lateralized center of rotation. This may be associated with the design of the prosthesis, and the results of this study that the distance between the neck and insert was approximately 1mm throughout active external rotation at the side will support the high incidence of notching. We may need to analyze the distance with the newer design reverse shoulder prosthesis to prove the architectural advantage of the newer systems. Conclusion. The distance between the scapular neck and polyethylene insert was approximately 1mm throughout active external rotation activity in shoulders with Grammont type prosthesis


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 516 - 516
1 Dec 2013
Sabesan V Callanan M Sharma V Ghareeb G Moravek J Wiater JM
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Background. There has been increased focus on understanding the risk factors associated with scapular notching in reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the effect of scapular morphology and surgical technique on the occurrence of scapular notching using the notching index as a comprehensive predictive tool. Methods. Ninety-one patients treated with a primary RSA were followed for a minimum of 24 months. Using a previously published notching index formula ((PSNA × 0.13) + (PGRD)), a notching index value for all patients was calculated. Radiographic assessment of patients were grouped by Nerot grade of scapular notching, group mean differences for prosthetic scapular neck angle (PSNA), peg glenoid rim distance (PGRD), preoperative scapular neck angle (SNA), notching index and clinical outcomes were compared. Results. Seventy-five (82%) of the ninety one shoulders in the study developed scapular notching. There was no significant difference in average notching index for group 1, 31.8 ± 4.4, and group 2, 33.1 ± 7.2. No significant difference was demonstrated between the groups for SNA (102.7° vs. 105.4°, p = 0.3), PSNA (125.8° vs. 124.5°, p = 0.82), PGRD (15.4 mm vs. 16.8 mm, p = 0.47) or in clinical outcomes between groups. Discussion. Our results demonstrated an overall low notch index that lacked specificity in predicting notching for this cohort. These results suggest that perhaps PSNA and prosthetic design are more significant contributors to notching with certain scapular morphology


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 39 - 39
1 Mar 2009
Zumstein M Simovitch R Lohri E Helmy N Gerber C
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INTRODUCTION: The reverse DELTA III shoulder prosthesis can successfully relieve pain and restore function in cuff tear arthropathy. The most frequently reported complication is inferior scapular notching. The purpose of this study was to evaluate the clinical relevance of notching and to determine the anatomic and radiographic parameters that predispose to its occurrence. STUDY PROTOCOL: Seventy-seven consecutive shoulders of 76 patients of an average age of 71 years with an irreparable rotator cuff deficiency were treated with a reverse DELTA III shoulder arthroplasty and followed clinically and radiographically under fluoroscopic control for a minimum of 24 months (mean: 44, range: 24 to 96). The effect of glenoid cranial caudal component positioning and of the prosthesis–scapular neck angle on the development of inferior scapular notching and clinical outcome was assessed. RESULTS: All shoulders which developed notching did so in the first fourteen months. Forty-four percent of the shoulders had inferior scapular notching, 30% had posterior notching and anterior notching (8%) was rare. Osteophytes along the inferior scapula occurred in 27% of the shoulders. The angle between the glénosphère and the scapular neck (r=+0.677)) as well as the craniocaudal position of the glénosphère (r=+0.654) were highly correlated with inferior notching (p< 0.001). A notching index (notching index = height of prosthesis + (prosthesis scapular neck angle x 0.13) was calculated using the height of implantation of the glénosphère and the postoperative prosthesis scapular neck angle: This allowed a prediction of the occurrence of notching with a sensitivity of 91% and specificity of 88%. The height of implantation of the glenosphere had a greater influence on inferior notching than the prosthesis scapular neck angle by a factor of approximately 1:8. Inferior scapular notching was associated with a significantly poorer clinical outcome than absence of inferior notching: At final follow-up, the respective average subjective shoulder values were 62% and 71% (p=0.032), relative Constant scores were 72% and 83% (p=0.028), abduction strength was 4.3 versus 8.7 kilograms (p< 0.001), active abduction was 102° versus 118° (p=0.033) and flexion averaged 110° versus 127° (p=0.004). DISCUSSION: Inferior scapular notching after reverse total shoulder arthroplasty adversely affects midterm clinical outcome. It can be prevented by optimal positioning of the glenoid component


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 9 - 9
1 May 2016
Roche C Flurin P Grey S Wright T Zuckerman J Jones R
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Introduction. Due to the predictability of outcomes achieved with reverse shoulder arthroplasty (rTSA), rTSA is increasingly being used in patients where glenoid fixation is compromised due to presence of glenoid wear. There are various methods to achieve glenoid fixation in patients with glenoid wear, including the use of bone grafting behind the glenoid baseplate or the use of augmented glenoid baseplates. This clinical study quantifies clinical outcomes achieved using both techniques in patients with severe glenoid wear at 2 years minimum follow-up. Methods. 80 patients (mean age: 71.6yrs) with 2 years minimum follow-up were treated by 7 fellowship trained orthopaedic surgeons using rTSA with bone graft behind the baseplate or rTSA with an augmented glenoid baseplate in patients with severe posterior glenoid wear. 39 rTSA patients (14 female, avg: 73.1 yrs; 25 male, avg: 71.5 yrs) received an augmented glenoid (cohort composed of 24 patients with an 8° posterior augment baseplate and 15 patients with a 10° superior augment baseplate) for treatment of CTA, RCT, and OA with a medially eroded scapula. 41 rTSA patients (27 female, avg: 73.0 yrs; 14 male, avg: 66.9 yrs) received glenoid bone graft (cohort composed of 5 patients with allograft and 36 patients with autograft) for treatment of CTA, RCT, and OA with a medially eroded scapula. Outcomes were scored using SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, forward flexion, and internal/external rotation were also measured to quantify function. Average follow-up was 31.2 months (augment 28.3; graft 34.1). A two-tailed, unpaired t-test identified differences (p<0.05) in pre-operative, post-operative, and pre-to-post improvements. Results. A comparison of pre-operative, post-operative, and pre-to-post improvement in outcomes are presented in Tables 1–3, respectively. No difference was noted in pre-operative, post-operative, and pre-to-post improvement in outcomes between cohorts. The augmented glenoid baseplate rTSA cohort had 0 complications for a complication rate of 0%; whereas, the rTSA glenoid bone graft cohort had 6 complications (including 2 glenoid loosenings/graft failures) for a complication rate of 14.6%. Additionally, radiographic follow-up information was available for 30 of 39 augmented baseplate patients (76.9%) and 27 of 41 bone graft patients (65.9%); where the augmented baseplate rTSA cohort had a scapular notching rate of 10.0% with an average scapular notching grade of 0.1; whereas, the rTSA glenoid bone graft cohort had a scapular notching rate of 18.5% with an average scapular notching grade of 0.19. Conclusions. These results demonstrate positive outcomes can be achieved at 2 years minimum follow-up in patients with severe glenoid wear using either augmented glenoid baseplates or bone graft behind the glenoid baseplate with rTSA. While no statistical difference was noted between pre-operative, post-operative, and pre-to-post improvement in outcomes between rTSA cohorts, a substantial difference in the complication rate was noted between cohorts which may factor into the surgeon's decision of the choice of treatment technique for these patients. Additional and longer-term follow-up is needed to confirm these outcomes and trends


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_1 | Pages 47 - 47
1 Jan 2016
De Biase C Delcogliano M Borroni M Marotta D Ziveri G Pittalis G Castagna A
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Introduction. Reverse shoulder prosthesis has been developed to treat the clinical and pathological condition noted as cuff tear arthropathy (CTA). The current models of reverse shoulder arthroplasty (RSA) expose the procedure to the risk of scapular notching, possibly leading to loosening of the glenoid. Aim. The purpose of this study was to report updated results at a minimum follow-up of four years of 25 patients underwent reverse shoulder arthroplasty between 2006 and 2010 with an eccentric 36-mm glenoid component (SMR Lima). Methods. Clinical and radiographic evaluation was performed preoperatively and at every year of follow-up. All patients were evaluated with MRI or CT scan preoperatively and with X-ray examinations postoperatively to evaluate the presence of inferior scapular notching. To value the clinical outcome the Constant score and VAS score have been evaluated preoperatively and every year of follow up. Results. Since the last report the mean Constant remain stable (63.11±8.92) and the mean VAS score decreased to 1.75±2.38 (p<0.005). Radiographs showed one case of grade 1 inferior scapular notching at 7-year follow-up. Notching didn't have any influence on clinical outcome. In two patients radiolucent lines were visible around the central peg or screws. No patient had glenoid baseplate loosening or baseplate failure. Conclusion. Satisfactory results have been achieved in the treatment of cuff-deficient shoulder conditions with reverse shoulder arthroplasty using an eccentric glenosphere at medium follow up. The patients have maintained their improved function with durable clinical and radiographic results at a minimum of four years


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 261 - 261
1 May 2009
Lavigne C Boileau P Favard L Mole D Sirveaux F Walch G
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Scapular notching is of concern in reverse shoulder arthroplasty and has been suggested as a cause of glenoid loosening. Our purpose was to analyze in a large series the characteristics and the consequences of the notch and then to enlighten the causes in order to seek some solutions to avoid it. 430 consecutive patients (457 shoulders) were treated by a reverse prosthesis for various etiologies between 1991 and 2003 and analyzed for this retrospective multicenter study. Adequate evaluation of the notch was available in 337 shoulders with a follow-up of 47 months (range, 24–120 months). The notch has been diagnosed in 62% cases at the last follow-up. Intermediate reviews show that the notch is already visible within the first postoperative year in 82% of these cases. Frequency and grade extension of the notch increase significantly with follow-up (p< 0.0001) but notch, when present, is not always evolutive. At this point of follow-up, scapular notch is not correlated with clinical outcome. There is a correlation with humeral radiolucent lines, particularly in metaphyseal zones (p=0.005) and with glenoid radiolucent lines around the fixation screws (p=0.006). Significant preoperative factors are: cuff tear arthropathy (p=0.0004), muscular fatty infiltration of infraspinatus (p=0.01), narrowing of acromio-humeral distance (p< 0.0001) and superior erosion of the glenoid (p=0.006). It was more frequent with superolateral approach than with deltopectoral approach (p< 0.0001) and with standard cup than with lateralized cup (p=0.02). We conclude that scapular notching is frequent, early and sometimes evolutive but not unavoidable. Preoperative superior glenoid erosion is significantly associated with a scapular notch, possibly due to the surgical tendency to position the baseplate with superior tilt and/or in high position which has been demonstrated to be an impingement factor. Preoperative radiographic planning and adapted glenoid preparation are of concern


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 203 - 203
1 May 2011
Kohut G Irlenbusch U Joudet T Kääb M Proust J Reuther F
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Introduction: In most of the reported series, scapular notching in inverse shoulder arthroplasty has been identified as a major problem. Therefore, a novel concept has been developed in order to minimize the incidence and the evolution (pathophysiology) of scapular notching. The current cohort study is now large enough to examine the results with special attention on notching. Methods: A dual peg design of the metaglene with CaP coating provides high primary and secondary stability. “Geometrical” notching is reduced by inferior (eccentric) fixation of the glenosphere on the metaglene, beveling of the medial part of the humeral inlay, and by the choice of three different sizes of the glenosphere (36, 39 and 42). “Biological” notching is addressed by inversion of the components: the epiphysis – as the mobile part – is metallic. Its contact to the scapula, should this occur, cannot lead to polyethylene wear. This study is a prospective multicentric study on Affinis Inverse and Affinis Fracture Inverse shoulder prosthesis (Mathys Ltd Bettlach, Switzerland), which is running in 7 European hospitals since December 2007. All cases but two (lost to follow-up) are included. Preoperative and all postoperative radiographs were reviewed. Notching has been graded 0 to 4, on a scale adapted after Sirveaux. Results: At submission deadline for the abstract, 163 cases were included. Grade 1 notching was detected in 8 cases (4.9%), and grade 2 notching in one. In those cases, notching developed early, but was not progressive over time. There were no cases of grade 3 or 4. In 17 cases, the X-rays were not assessable and therefore it was impossible to definitively rule out a possible grade 1 notching. None of the Affinis Fracture Inverse prostheses produced any notching. New bone apposition on the inferior aspect of the scapula was detected in 15 cases. We postulate this to be a metaplasia of the long head of the triceps due to local periosteal stimulation. Conclusions: The present design leads to a very low rate of scapular notching. Even in the 9 cases where notching was present, it appears that the epiphysis only created the space it needed, without any ongoing osteolytic process beyond this. Specific prosthetic design improves both quantity and quality of scapular notching


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 123 - 123
1 Feb 2017
Lewicki K Bell J Van Citters D
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Introduction. A common phenomenon occurring as a result of reverse total shoulder arthroplasties (RSA) is scapular notching. While bone loss of the scapula may be quantified using radiographic techniques,[1] the material loss on the humeral bearing has not been quantified. Depending on their functional biological activity, a high volume of polyethylene wear particles has been shown to be related to osteolysis, bone loss and ultimately, loosening of implants in other joints.[2] In order to understand the threshold for osteolysis in the shoulder, it is important to have a method that can accurately quantify the amount of material loss. The aim of this research was to (I) create and validate a method for quantifying material loss from a single humeral implant design which can then (II) be used to measure retrieved devices. Methods. Measurement of the surface topography of the implant was completed using coordinate measurement machine (CMM). The resulting point cloud was then imported into MATLAB and run through a custom algorithm to determine the volumetric wear of the humeral liner. Two never implanted humeral liners with an artificially damaged material loss were used for validation purposes. Each component was scanned three times, analyzed using the custom MATLAB program, and compared to gravimetric analysis (Figure 1). Following validation, an IRB-approved database was queried to identify 10 retrieved components of the same design which were then analyzed using the validated method. Results. All average measurements of the never implanted components were within +/- 5 mm. 3. of the gravimetrically determined values, providing a reasonable estimate of the volumetric wear (Figure 1). Ten retrieved components of a single design were analyzed using the same method and material loss ranged from immeasurable (within the accuracy limits) to approximately 90 mm. 3. (Figure 3). One short term duration implant (1.8 mos) exhibited approximately 78 mm. 3. of wear, resulting in a polyethylene dosage of more than 500 mm. 3. /yr. Discussion. The posterior-inferior wear pattern on the rim of these reverse shoulders appears consistent with repetitive scapular impingement. The significant wear of short duration implants indicates that wear associated with scapular notching may progress very quickly, resulting in large dose rates of debris in the joint space. However, the impingement may result in a more abrasive wear mechanism as opposed to an adhesive wear mechanism as seen in other joint wear environments. This may result in different size and shaped polyethylene particles with different biological activity. The algorithms presented in this work can be used to establish a dose-response relationship for scapular notching in RSA


Abstract. Reverse shoulder arthroplasty (RSA) is being increasingly used for complex, displaced fractures of the proximal humerus. The main goal of the current study was to evaluate the functional and radiographic results after primary RSA of three or four-part fractures of the proximal humerus in elderly patients. Between 2012 and 2020, 70 consecutive patients with a recent three- or four-part fracture of the proximal humerus were treated with an RSA. There were 41 women and 29 men, with a mean age of 76 years. The dominant arm was involved in 42 patients (60%). All surgeries were carried out within 21 days. Displaced three-part fracture sustained in 16 patients, 24 had fracture dislocation and 30 sustained a four-part fracture of the proximal humerus. Patients were followed up for a mean of 26 months. The mean postoperative OSS at the end of the follow-up period was 32.4. The mean DASH score was 44.3. Tuberosity non-union occurred in 18 patients (12.6%), malunion in 7 patients (4.9%), heterotopic ossification in 4 patients (2.8%) and scapular notching in one patient. Anatomical reconstruction was achieved in 25 patients (17.5%), the influence of greater tuberosity healing on shoulder function could not be demonstrated. Heterotopic ossification seems to affect OSS and QDASH, we found statistically significant relation between HO and clinical outcomes. Patients with heterotopic ossification had significantly lower postoperative scores on DASH and OSS (P = .0527). Despite expecting good functional outcome with low complication rate after RSA, the functional outcome was irrespective of healing of the tuberosities


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 76 - 76
1 Aug 2020
Habis A Bicknell R Mei X
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Reverse shoulder arthroplasty (RSA) has an increasing effective use in the treatment of patients with a variety of diagnoses, including rotator cuff deficiency, inflammatory arthritis, or failed shoulder prostheses. Glenoid bone loss is not uncommonly encountered in these cases due to the significant wear. Severe bone loss can compromise glenoid baseplate positioning and fixation, consequently increasing the risk for early component loosening, instability, and scapular notching. To manage severe glenoid bone deficiencies, bone grafts are commonly used. Although, many studies report outcome of bone grafting in revision RSA, the literature on humeral head autograft for glenoid bone loss in primary RSA is less robust. The purpose of this study is to evaluate the clinical and radiographic outcomes of primary RSA with humeral head autograft for glenoid bone loss at our institution. Institutional review board approval was obtained to retrospectively review the records of 22 consecutive primary RTSA surgeries in 21 patients with humeral head autograft for glenoid bone loss between January 2008 and December 2016. Five patients died during follow-up, three were unable to be contacted and one refused to participate, leaving a final study cohort of 12 patients with 13 shoulders that underwent RSA. All patients had a clinical evaluation including detailed ROM and clinical evaluation using the American Shoulder and Elbow Surgeons (ASES) Score, Constant Score, Western Ontario Osteoarthritis of the Shoulder Index (WOOS), and Short Form-12 (SF-12) questionnaires. Preoperative and postoperative plain radiographs and CT scans were assessed for component position, loosening, scapular notching, as well as graft incorporation, resorption, or collapse. There were 6 males and 6 females, with an average age of 74 ± 6.8 years. The average BMI was 31.7 ± 5.3, and the median ASA score was 3. Average follow-up was 3.4 ± 1.1 years. The average postoperative range of motion measurements for the operative arm are: flexion = 120 ± 37, abduction = 106 ± 23, external rotation = 14 ± 12, internal rotation at 90 degrees of abduction = 49 ± 7, external rotation at 90 degrees of abduction = 50 ± 28. Average functional scores are: ASES: 76.9 ± 19.2, WOOS: 456 ± 347, SF12 physical: 34.2 ± 8.2, SF12 mental: 54.1 ± 10.2, Constant Score: 64.6 ± 14. No evidence of hardware loosening or evidence of bone graft resorption were encountered. On CT, the average of pre operative B-angle was 79.3 ± 9.3 while the pre operative reverse shoulder angle was 101.4 ± 28. Glenoid retroversion average on CT was 13.3 ± 16.6. Post operative baseplate inclination average was 82 ± 7.4 while the baseplate version 7.8 ±10. The operative technique was able to achieve up to 30 degrees of inclination correction and up to 50 degrees of version correction. In conclusion, primary reverse shoulder arthroplasty with humeral head autograft for glenoid bone loss provides excellent ROM and functional outcomes at mid-term follow-up. This technique has a high rate of bone incorporation and small risk of bone resorption at mid term follow up


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 40 - 40
23 Feb 2023
Critchley O Guest C Warby S Hoy G Page R
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Glenoid bone grafting in reverse total shoulder arthroplasty (RTSA) has emerged as an effective method of restoring bone stock in the presence of complex glenoid bone loss, yet there is limited published evidence on efficacy. The aim of this study was to conduct an analysis of clinical and radiographic outcomes associated with glenoid bone grafting in primary RTSA. Patients who underwent a primary RTSA with glenoid bone grafting were retrospectively identified from the databases of two senior shoulder surgeons. Inclusion criteria included minimum of 12 months clinical and/or radiographical follow up. Patients underwent preoperative clinical and radiographic assessment. Graft characteristics (source, type, preparation), range of movement (ROM), patient-reported outcome measures (Oxford Shoulder Scores [OSS]), and complications were recorded. Radiographic imaging was used to analyse implant stability, graft incorporation, and notching by two independent reviewers. Between 2013 and 2021, a total of 53 primary RTSA procedures (48 patients) with glenoid bone grafting were identified. Humeral head autograft was used in 51 (96%) of cases. Femoral head allograft was utilised in two cases. Depending on the morphology of glenoid bone loss, a combination of structural (corticocancellous) and non-structural (cancellous) grafts were used to restore glenoid bone stock and the joint line. All grafts were incorporated at review. The mean post-operative OSS was significantly higher than the pre-operative OSS (40 vs. 22, p < 0.001). ROM was significantly improved post-operatively. One patient is being investigated for residual activity-related shoulder pain. This patient also experienced scapular notching resulting in the fracturing of the inferior screw. One patient experienced recurrent dislocations but was not revised. Overall, at short term follow up, glenoid bone grafting was effective in addressing glenoid bone loss with excellent functional and clinical outcomes when used for complex bone loss in primary RTSA. The graft incorporation rate was high, with an associated low complication rate


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 82 - 82
23 Feb 2023
Rossignol SL Boekel P Rikard-Bell M Grant A Brandon B Doma K O'Callaghan W Wilkinson M Morse L
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Glenoid baseplate positioning for reverse total shoulder replacements (rTSR) is key for stability and longevity. 3D planning and image-derived instrumentation (IDI) are techniques for improving implant placement accuracy. This is a single-blinded randomised controlled trial comparing 3D planning with IDI jigs versus 3D planning with conventional instrumentation. Eligible patients were enrolled and had 3D pre-operative planning. They were randomised to either IDI or conventional instrumentation; then underwent their rTSR. 6 weeks post operatively, a CT scan was performed and blinded assessors measured the accuracy of glenoid baseplate position relative to the pre-operative plan. 47 patients were included: 24 with IDI and 23 with conventional instrumentation. The IDI group were more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane when compared to the conventional group (p=0.01). The IDI group had a smaller degree of error when the native glenoid retroversion was >10° (p=0.047) when compared to the conventional group. All other parameters (inclination, anterior/posterior plane, glenoids with retroversion <10°) showed no significant difference between the two groups. Both IDI and conventional methods for rTSA placement are very accurate. However, IDI is more accurate for complex glenoid morphology and placement in the superior-inferior plane. Clinically, these two parameters are important and may prevent long term complications of scapular notching or glenoid baseplate loosening. Image-derived instrumentation (IDI) is significantly more accurate in glenoid component placement in the superior/inferior plane compared to conventional instrumentation when using 3D pre-operative planning. Additionally, in complex glenoid morphologies where the native retroversion is >10°, IDI has improved accuracy in glenoid placement compared to conventional instrumentation. IDI is an accurate method for glenoid guidewire and component placement in rTSA


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 225 - 225
1 Dec 2013
Alta T Morin-Salvo N Bessiere C Moineau G Boileau P
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Introduction:. Lateralization of reversed shoulder arthroplasty provides improvement in range of motion and decreases inferior scapular notching. The purpose of this study was to verify if the autologous cancelous bone graft harvested from the humeral head does heal constantly in a large cohort of patients followed for a long time. Methods:. Cohort of 92 consecutive patients operated between 2006 and 2010 with a BIORSA for definitive shoulder pseudoparalysis, secondary to cuff tear arthropathy (CTA) or massive, irreparable cuff tear (MCT). The autogenous cancelous graft was harvested from humeral head in all cases. Eight patients were lost for follow up, and four died before 2 years. The remaining 80 patients underwent clinical, radiographic and CT assessment at a minimum FU of 24 months. Mean age was 73 years. Three independent observers evaluated notching, partial or total glenoid or humeral loosening and viability of the graft. Constant-Murley score, range of motion and subjective shoulder value (SSV) were recorded. The mean follow up was 39 months (range 24–74 months). Results:. The bone graft did healed completely in 96% of the cases (77/80); the thickness of the graft remained stable through the years. There were two cases of glenoid loosening: one nonunion of the graft at the scapular side was due to an important superior tilt of the glenosphere; one failure of fixation at the baseplate side was related to a low-grade infection. Another patient had a partial radiolucent line between graft and native glenoid located only above the central peg. No other radiolucent line around peg, screws or baseplate was found. Inferior scapula notching was observed in 19% of the cases (mainly grade 1 and 2). Each parameters of Constant score improved, and the mean SSV increased from 27% to 78%. Conclusion:. This study shows that: (1) autologous cancellous bone graft, harvested from the humeral head, does heal to the native glenoid despite the advanced age of the patients; and (2) BIO-RSA allows improvement of shoulder function (mobility, pain, strength, subjective value) with a low rate of scapular notching


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 383 - 383
1 Dec 2013
Kurdziel M Peers S Moravek J Budge M Newton M Baker K Wiater JM
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Purpose:. Although short term outcomes of reverse total shoulder arthroplasty (rTSA) have been promising, long-term success may be limited due to complications, including scapular notching. Scapular notching has been explained primarily as a mechanical erosion, however, generation of wear debris may lead to further biologic changes contributing to the severity of scapular notching. Highly cross-linked ultra-high molecular weight polyethylene (UHMWPE) has been used routinely in constrained joint applications such as total hip arthroplasty for reduction of wear debris particles. Although rTSA shares similarity in design conformity, conventional UHMWPE remains the gold standard. Methods:. A commercially available hip simulator was converted to a 12-station rTSA wear simulator. Conventional and highly cross-linked UHMWPE humeral liners were subjected to 5,000,000 cycles of alternating abduction-adduction and flexion-extension loading profiles. Every 250,000 cycles, liners were evaluated with gravimetric wear measurements and test serum was collected for morphological characterization of wear particles. Results:. Highly cross-linked UHMWPE liners (36.5 ± 10.0 mm. 3. /million cycle) exhibited significantly lower volumetric wear rates compared to conventional UHMWPE liners (83.6 ± 20.6 mm3/million cycle) (p < 0.001) (Figure 1). The flexion-extension loading profile exhibited significantly higher wear rates for both conventional (p < 0.001) and highly cross-linked UHMWPE (p < 0.001) compared to the abduction-adduction loading profile. Highly cross-linked wear particles had an equivalent circle diameter significantly smaller than wear particles from conventional UHMWPE (p < 0.001) (Figure 2). Highly cross-linked wear particles were also significantly less fibrillar than conventional UHMWPE particles with respect to particle aspect ratio (p < 0.001) and particle roundness (p < 0.001). Conclusion:. This is the first study to examine the effect of cross-linked PE in a rTSA wear simulation. Highly cross-linked UHMWPE liners significantly reduced UHWMPE wear and subsequent particle generation. More favorable wear properties with the use of highly cross-linked UHMWPE may lead to increased rTSA device longevity and fewer complications but must be weighed against the impact of reduced mechanical properties


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 38 - 38
1 Dec 2022
Kim J Alraiyes T Sheth U Nam D
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Thoracic hyperkyphosis (TH – Cobb angle >40°) is correlated with rotator cuff arthropathy and associated with anterior tilting and protraction of scapula, impacting the glenoid orientation and the surrounding musculature. Reverse total shoulder arthroplasty (RTSA) is a reliable surgical treatment for patients with rotator cuff arthropathy and recent literature suggests that patients with TH may have comparable range of motion after RTSA. However, there exists no study reporting the possible link between patient-reported outcomes, humeral retroversion and TH after RTSA. While the risk of post-operative complications such as instability, hardware loosening, scapular notching, and prosthetic infection are low, we hypothesize that it is critical to optimize the biomechanical parameters through proper implant positioning and understanding patient-specific scapular and thoracic anatomy to improve surgical outcomes in this subset of patients with TH. Patients treated with primary RTSA at an academic hospital in 2018 were reviewed for a two-year follow-up. Exclusion criteria were as follows: no pre-existing chest radiographs for Cobb angle measurement, change in post-operative functional status as a result of trauma or medical comorbidities, and missing component placement and parameter information in the operative note. As most patients did not have a pre-operative chest radiograph, only seven patients with a Cobb angle equal to or greater than 40° were eligible. Chart reviews were completed to determine indications for RTSA, hardware positioning parameters such as inferior tilting, humeral stem retroversion, glenosphere size/location, and baseplate size. Clinical data following surgery included review of radiographs and complications. Follow-up in all patients were to a period of two years. The American Shoulder and Elbow Surgeons (ASES) Shoulder Score was used for patient-reported functional and pain outcomes. The average age of the patients at the time of RTSA was 71 years old, with six female patients and one male patient. The indication for RTSA was primarily rotator cuff arthropathy. Possible correlation between Cobb angle and humeral retroversion was noted, whereby, Cobb angle greater than 40° matched with humeral retroversion greater than 30°, and resulted in significantly higher ASES scores. Two patients with mean Cobb angle of 50° and mean humeral retroversion 37.5° had mean ASES scores of 92.5. Five patients who received mean humeral retroversion of 30° had mean lower ASES scores of 63.7 (p < 0 .05). There was no significant correlation with glenosphere size or position, baseplate size, degree of inferior tilting or lateralization. Patient-reported outcomes have not been reported in RTSA patients with TH. In this case series, we observed that humeral stem retroversion greater than 30° may be correlated with less post-operative pain and greater patient satisfaction in patients with TH. Further clinical studies are needed to understanding the biomechanical relationship between RTSA, humeral retroversion and TH to optimize patient outcomes


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 224 - 224
1 Dec 2013
Alta T Morin-Salvo N Bessiere C Boileau P
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BACKGROUND:. Bony increased-offset reverse shoulder arthroplasty (BIO-RSA) creates a long-necked scapula, providing the benefits of lateralization. Experience with allogenic bone grafting of the glenoid in shoulder arthroplasty is mainly based on its use with total shoulder arthroplasty (TSA). Therefore, our study objectives were: 1) verify if the use of BIO-RSA together with glenoid surface grafting with allogenic bone would provide similar benefits (clinical and functional) as found with autologous bone, 2) determine if allograft could be a good alternative in the absence of (good quality) autograft bone, and 3) to see if the allograft would incorporate with the native glenoid bone. METHODS:. We included 25 patients (19 female, 6 male) in this prospective study. Indications for BIO-RSA were: fracture sequalle (n = 9), revisions (n = 11), 4-part humerus fracture (n = 1), rheumatoid arthritis (n = 1) and cuff tear arthropathy (CTA) with poor humeral head bone quality/osteonecrosis (n = 3). Mean (± SD) age 70 ± 11 years (range, 44–86). Clinical evaluation consisted of ROM, Constant scores, patient satisfaction (Subjective Shoulder Value (SSV)) and noted complications. Radiographic and CT scan evaluation consisted of bone graft healing, bone graft resorption/lysis, glenoid component loosening, inferior scapular notching, spur formation and anterior/posterior scapular notching. Mean follow-up was 34 ± 10 months (24–62). RESULTS:. Mean active mobility improved from 50 ± 39° to 123 ± 33° (50–170°) for anterior elevation, from 2.4 ± 17° to 12.1 ± 16° (−20–40°) for external rotation, and from 1.8 ± 2 to 4.7 ± 3 points (0–8) for internal rotation. Mean Constant scores improved from 19 ± 12 to 55 ± 16 points (30–83) and from 26 ± 16% to 77 ± 24% (40–111%). Mean SSV from 21 ± 16% to 65 ± 18% (30–100%). One patient sustained an acromial fracture (treated conservatively) and one patient had breakage of screws and complete glenoid component loosening (revised to a hemi arthroplasty). In 92% of cases (23 of 25) the allograft incorporated completely, partial lysis of the bone graft (n = 5), inferior scapular notching (n = 5), spur formation (n = 7), posterior notching (n = 5). CONCLUSIONS:. BIO-RSA with allograft bone grafting does not provide the same clinical and functional results as with autologous bone grafting. However, it does provide a good alternative in cases where humeral bone stock is not preserved and the allograft bone does incorporate with the native glenoid bone


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 37 - 37
1 Dec 2022
Fleet C de Casson FB Urvoy M Chaoui J Johnson JA Athwal G
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Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_15 | Pages 6 - 6
1 Aug 2017
Sperling J
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Lateralization of the reverse arthroplasty may be desirable to more effectively tension the remaining rotator cuff, decrease scapular notching, improve the cosmetic appearance of the shoulder, and improve stability as well as the arc of motion prior to impingement. There are two primary options to lateralise a reverse shoulder arthroplasty: bone graft with a long post (BIO-RSA) vs. using metal. The two metal options generally include a thicker glenosphere or a thicker glenoid baseplate. Potential benefits of a BIO-RSA include lateralization of the glenoid center of rotation but without placing the center of rotation lateral to the prosthetic-bone interface. By maintaining the position of the center of rotation, the shear forces at the prosthesis-bone interface are lessened and are converted to compressive forces which will minimise glenoid failure. Edwards et al. performed a prospective study on a bony increased offset reverse arthroplasty. Among the 18 shoulders in the BIO-RSA group, the incidence of notching was 78% compared to controls 70%. The graft completely incorporated in 12 (67%), partially incorporated in 4 (22%), and failed to incorporate in 2 (11%). Frankle et al. reported on the minimum 5-year follow-up of reverse arthroplasty with a central compression screw and a lateralised glenoid component. The survivorship was 94% at 5 years. There were seven (9%) cases of scapular notching and no patient had glenoid baseplate loosening or baseplate failure. The authors noted that the patients maintained their improved function and radiographic results at a minimum of five years. In summary, lateralisation of the glenosphere is an attractive option to improve the outcome of reverse arthroplasty. Benefits of lateralisation with metal rather than bone graft include elimination of concern over bone graft healing or resorption. In addition, the procedure has the potential to be more precise with the exact offset amount known pre-operatively as well as improved efficiency of the procedure. Preparing the graft takes additional OR time and there is variable quality of the bone graft


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 72 - 72
1 Dec 2021
Komperla S Giles W Flatt E Gandhi MJ Eyre-Brook AE Jones V Papanna M Eves T Thyagarajan D
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Abstract. Shoulder replacements have evolved and current 4th generation implants allow intraoperative flexibility to perform anatomic, reverse, trauma, and revision shoulder arthroplasty. Despite high success rates with shoulder arthroplasty, complication rates high as 10–15% have been reported and progressive glenoid loosening remains a concern. Objectives. To report medium term outcomes following 4th generation VAIOS® shoulder replacement. Methods. We retrospectively analysed prospectively collected data following VAIOS® shoulder arthroplasty performed by the senior author between 2014–2020. This included anatomical (TSR), reverse(rTSR), revision and trauma shoulder replacements. The primary outcome was implant survival (Kaplan-Meier analysis). Secondary outcomes were Oxford Shoulder Scores (OSS), radiological outcomes and complications. Results. 172 patients met our inclusion criteria with 114 rTSR, 38 anatomical TSR, and 20 hemiarthroplasty. Reverse TSR- 55 primary, 31 revision, 28 for trauma. Primary rTSR- 0 revisions, average 3.35-year follow-up. Revision rTSR-1 revision (4.17%), average 3.52-year follow-up. Trauma rTSR- 1 revision (3.57%), average 4.56-year follow-up OSS: Average OSS improved from 15.39 to 33.8 (Primary rTSR) and from 15.11 to 29.1 (Revision rTSR). Trauma rTSR-Average post-operative OSS was 31.4 Anatomical TSR38 patients underwent primary anatomical TSR, 8 were revisions following hemiarthroplasty. In 16/38 patients, glenoid bone loss was addressed by bone grafting before implantation of the metal back glenoid component. Mean age at time of surgery was 68.3 years (53 – 81 years). Mean follow-up was 34 months (12 – 62 months). The average Oxford shoulder score improved from 14 (7–30) to 30 (9–48). There were 3 revisions (7.8%); two following subscapularis failure requiring revision conversion to reverse shoulder replacement and one for glenoid graft failure. Conclusions. The medium-term results of the VAIOS® system suggest much lower revision rates across multiple configurations of the system than previously reported, as well as a low incidence of scapular notching. This system allows conversion to rTSR during primary and revision surgery


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 71 - 71
1 Dec 2021
Giles W Komperla S Flatt E Gandhi M Eyre-Brook A Jones V Papanna M Eves T Thyagarajan D
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Abstract. Background/Objectives. The incidence of reverse total shoulder replacement (rTSR) implantation is increasing globally, but apprehension exists regarding complications and associated challenges. We retrospectively analysed the senior author's series of rTSR from a tertiary centre using the VAIOS shoulder system, a modular 4th generation implant. We hypothesised that the revision rTSR cohort would have less favourable outcomes and more complications. Methods. 114 patients underwent rTSR with the VAIOS system, over 7 years. The primary outcome was implant survival. Secondary outcomes were Oxford shoulder scores (OSS), radiographic analysis (scapular notching, tuberosity osteolysis, and periprosthetic radiolucent lines) and complications. Results. There were 55 Primary rTSR, 31 Revision rTSR and 28 Trauma rTSR. Implant survival: Primary rTSR- 0 revisions, average 3.35-year follow-up. Revision rTSR-1 revision (4.17%), average 3.52-year follow-up. Trauma rTSR- 1 revision (3.57%), average 4.56-year follow-up OSS: Average OSS improved from 15.39 to 33.8 (Primary rTSR) and from 15.11 to 29.1 (Revision rTSR). Average post-operative OSS for the Trauma rTSR was 31.4 Radiological analysis and complications: Low incidence of scapular notching One hairline fracture below the tip of stem, noted incidentally, which required no treatment. One periprosthetic fracture after alcohol related fall. Treated non-surgically One joint infection requiring two-stage revision to rTSR. One dislocation noted at 2 year follow up. This patient had undergone nerve grafting within 6 months of rTSR for axillary nerve injury sustained during the original fracture dislocation. One acromial fracture with tibial and distal humeral fracture after a fall. Conclusions. The 4th generation modular VAIOS implant is a reliable option for various indications. The revision rTSR cohort had favourable outcomes with low complication rates. In this series, early-to-medium term results suggest lower revision rates and good functional outcomes when compared to published reports. We plan to monitor long-term implant survivorship and patient reported outcomes. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 4 | Pages 535 - 539
1 Apr 2010
Cazeneuve JF Cristofari D

We have previously described the short-term outcome of the use of reverse shoulder arthroplasty in the treatment of acute complex proximal humeral fractures in the elderly. We now report the clinical and radiological outcome of 36 fractures at a mean of 6.6 years (1 to 16). Previously, at a mean follow-up of 6 years (1 to 12) the mean Constant score was 58.5; this was reduced to 53 points with the further follow-up. A total of 23 patients (63%) had radiological evidence of loosening of the glenoid component. Nevertheless, only one patient had aseptic loosening of the baseplate at 12 years’ follow-up. The reduction in the mean Constant score with longer follow-up and the further development of scapular notching is worrying. New developments in design, bearing surfaces and surgical technique, and further follow-up, will determine whether reverse shoulder arthroplasty has a place in the management of complex proximal humeral fractures in the elderly


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 92 - 92
1 Feb 2017
Day J MacDonald D Kraay M Rimnac C Williams G Abboud J Kurtz S
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Utilization of reverse total shoulder arthroplasty (RTSA) has steadily increased since its 2003 introduction in the American market. Although RTSA was originally indicated for elderly, low demand patients, it is now being increasingly used to treat rotator cuff arthropathy, humeral fractures, neoplasms and failed total and hemi shoulder arthroplasty. There is, therefore, a growing interest in bearing surface wear of RTSA polyethylene humeral liners. In the current study, we examined humeral liners retrieved as part of an IRB approved study to determine the amount of bearing surface wear. We hypothesized that wear of the bearing surface by intentional contact with the glenosphere (mode I) would be minor compared to that produced by scapular notching and impingement of the humeral liner (mode II). Twenty-three retrieved humeral liners were retrieved at revision surgery after an average of 1.5 years implantation time. The average age at implantation was 68 years (range 50–85). Shoulders were revised for loosening (7), instability (6), infection (6), pain (2), and other/unknown reasons (2). The liners were scanned using microCT at a resolution of 50 µm and then registered against unworn surfaces to estimate the bearing surface wear depth. The depth of surface penetration due to impingement of the liner with surrounding structures was measured and the location of the deepest penetration was noted. Mode I wear of the bearing surface was detectable for five of the retrieved liners. The penetration depth was 100 µm or less for four of the liners and approximately 250 microns for the fifth liner. It was noted that the liners with discernable mode I wear were those with longer implantation times (average 2.4 years). Material loss and abrasion of the rim due to mode II wear was noted with measurable penetration in 18 of the liners. Mode II wear penetrated to the bearing surface in 11 liners. It was generally noted that volumetric material loss was dominated by mode II wear (Figure 1). In this study of short to medium term retrieved RTSA humeral liners, mode I wear of the bearing surface was a minor source of material loss. Mode II wear due to scapular notching or impingement of the rim was the dominant source of volumetric wear. This is in agreement with a previous study that we have performed on a smaller cohort of seven liners. It is noteworthy that we were able to detect measurable mode I wear for liners with moderate implantation times. The quantity of bearing surface wear that will be seen in long term retrievals remains unknown at this time


The Bone & Joint Journal
Vol. 97-B, Issue 12 | Pages 1662 - 1667
1 Dec 2015
Weber-Spickschen TS Alfke D Agneskirchner JD

If a modular convertible total shoulder system is used as a primary implant for an anatomical total shoulder arthroplasty, failure of the prosthesis or the rotator cuff can be addressed by converting it to a reverse shoulder arthroplasty (RSA), with retention of the humeral stem and glenoid baseplate. This has the potential to reduce morbidity and improve the results. . In a retrospective study of 14 patients (15 shoulders) with a mean age of 70 years (47 to 83) we reviewed the clinical and radiological outcome of converting an anatomical shoulder arthroplasty (ASA) to a RSA using a convertible prosthetic system (SMR system, Lima, San Daniele, Italy). . The mean operating time was 64 minutes (45 to 75). All humeral stems and glenoid baseplates were found to be well-fixed and could be retained. There were no intra-operative or early post-operative complications and no post-operative infection. The mean follow-up was 43 months (21 to 83), by which time the mean visual analogue scale for pain had decreased from 8 pre-operatively to 1, the mean American Shoulder and Elbow Surgeons Score from 12 to 76, the mean Oxford shoulder score from 3 to 39, the mean Western Ontario Osteoarthritis of the Shoulder Score from 1618 to 418 and the mean Subjective shoulder value from 15 to 61. On radiological review, one patient had a lucency around the humeral stem, two had stress shielding. There were no fatigue fractures of the acromion but four cases of grade 1 scapular notching. . The use of a convertible prosthetic system to revise a failed ASA reduces morbidity and minimises the rate of complications. The mid-term clinical and radiological results of this technique are promising. Cite this article: Bone Joint J 2015;97-B:1662–7


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 319 - 319
1 Dec 2013
Galasso O Gasparini G Castricini R Mastroianni V
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BACKGROUND:. Few studies have evaluated at a medium-term follow-up the use of semiconstrained reverse shoulder arthroplasty (RSA) for primary glenohumeral osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy excluding any other shoulder disease. Moreover, data on patients' quality of life after this surgery are lacking. METHODS:. In this prospective cohort study, 80 patients were evaluated after an RSA for either primary osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy with the Constant-Murley score (CMS), ROM, and Short Form Health Survey (SF-36). A radiologic assessment was performed pre- and postoperatively. RESULTS:. At a mean 5-year follow-up, the cumulative survival rate was 97.3% and significant improvements in the CMS and ROM were observed when compared with the baseline values. The CMS was 93.2% of the sex- and age-matched normal values. The postoperative SF-36 scores showed no significant differences compared with normative data. Younger patients and subjects with worse preoperative conditions achieved the greatest benefit after RSA. A 70% scapular notching rate was noted and the length of follow-up was found to be associated with the severity of scapular notching. CONCLUSIONS:. This study introduces new predictors for surgical outcomes, and it shows that patients who had undergone RSA a mean of 5 years earlier exhibit similar functionality and health-related quality of life with respect to healthy controls


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 460 - 460
1 Nov 2011
de Biase C Vitullo A Di Giorgio G d’Imperio F Carfagni A
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Purpose: The purpose of this retrospective studies is to evaluate the real effectiveness, with clinical and radiologic evalutation, of the eccentric glenosphere and also how a correct position can prevent the scapular notching. Material and Methods: We inplanted in 18 patients, with eccentric arthopaty, a 36 mm eccentric glenoshere.24 months’ clinical and radiographic follow up. All patient were assessed preoperatively and postoperatively with the Constant Score. In the post-operative radiographic control we have taken in consideration: the presence of notching, psna (prosthesis-scapular neck angle), pgrd (peg glenoid distance), glenoid inclination, craniocaudal position of the glenosphere in relation to the glenoid. Results: The ROM increased in all level. All of the 18 shoulder had no notching. The craniocaudal position of the glenosphere in relation to the glenoid is 4,3 mm. The PSNA was 92° and the PGRD was 21.2. Conclusion: The inferior scapular notching is the most important complicance of reverse prosthesis. The results of our study indicate that : the correct positioning of the metal back, at the center of the glenoid (better biomechanics stability), without overhang and with eccentric glenosphere, permits to lower the center of rotation of 4 mm avoiding the notch and so increasing the adduction and abduction range of motion


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 134 - 134
1 May 2016
Plachel F Heuberer P Schanda J Pauzenberger L Anderl W
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Background. The use of reverse total shoulder arthroplasty considerably increased since first introduced by Paul Grammont in the late 1980s. Over the past few years, results from several mid- and long-term clinical studies have demonstrated good functional outcomes and pain relief. However, several complications, especially inferior glenoid notching, and high revision rates were reported in the literature. Improvements in prosthesis design should contribute to a lower complication rate and lesser amount of glenoid erosion. Few studies have reported the clinical outcome andcomplications of Anatomical Shoulder Inverse/ Reverse Prosthesis. This study documents 2- and 6-year clinical and radiological results following reversed shoulder arthroplasty using this novel prosthesis. Methods. We report the results for sixty-eight consecutive patients (seventy shoulders) with cuff tear arthropathy (CTA) treated with Anatomical Shoulder Inverse/Reverse Prosthesis between 2006 and 2008. Two groups were defined: (A) primary treatment and (B) revision. Clinical evaluation tools comprised Constant-Murley score (CS), range of motion, and a visual analog scale to assess pain. Radiographs (anteroposterior view in neutral position) were evaluated for notching and radiolucent lines. Any complications were recorded. Results. In total, 66 shoulders (94%) with a mean follow-up of 30.0 months were initially analysed. CS increased from preoperatively 20.2 to postoperatively 53.6 points. Inferior scapular notching was identified in 58% of patients, primarily grade 1 and 2 (low-graded). 16% of patients experienced a complication, including instability, infection or periprosthetic fracture. 58 patients (83%) were re-evaluated 69.0 months after implantation. CS decreased to 50.2 points (n.s.). 16 patients (23%) had postoperative complication at final follow-up. We observed progressive radiographic changes in 75% and an increased frequency of large notches (grade 3 and 4). No significant difference regarding clinical outcome was detected between group A and B after both 2 and 6 years. Conclusion. Total shoulder arthroplasty with the Anatomical Shoulder Inverse/Reverse Prosthesis is a reliable treatment option in patients with cuff tear arthropathy. Primary and revision arthropathies result in similar improvements in range of motion and pain. Constant-Murley score and radiographic changes deteriorated with time. Inferior scapular notching appeared rapidly after implantation. A change of prosthesis design and prosthetic overhang intraoperatively seems to be the most effective way to prevent scapular conflict. The complication rate in our series is equally to previously reported rates


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 157 - 157
1 Mar 2013
De Biase CF Delcogliano M Polo RM Borroni M Castagna A
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INTRODUCTION. The aim of this retrospective study is to evaluate clinically and radiographically the effectiveness of implanting an eccentric glenosphere and if a correct glenosphere positioning would avoid the occurrence of notching. METHODS. since 2006 40 patients with shoulder eccentric osteoarthritis were treated with reverse shoulder arthroplasty with a 36 mm eccentric glenosphere. We have selected 25 patients, with a minimum follow up of 24 months. The patients were clinically evaluated with the Constant score and SST and with X-ray, MRI and/or CT before and after surgery. At the follow up we evaluated the presence or absence of notch, and we measured the PSNA (prosthesis-scapular neck angle), the DBSNG (distance between the scapular neck angle and glenosphere), the PGRD distance (peg glenoid distance). Stastistical analysis was performed with a paired t test. RESULTS. In every patient the range of motion was improved. The AP X-ray did not show inferior scapular notching. The mean DBSNG, was found to be 4.3 mm. The mean PSNA was 92 ° and the mean PGRD was 21.2. The Constant score improved from 30 to 74 points and the SST from 1.7 to 8.4 points. DISCUSSION and CONCLUSION. The scapular notching is shown as the most frequent complication in reverse shoulder replacement. In our study the results indicate that proper positioning of the glenosphere with the inferior part of the metal back that overlaps the lower glenoid rim without overhang and the implantation of an eccentric glenosfere, lowers the center of rotation of 4 mm and avoid contact between the humeral component and the scapular neck during the adduction. Thus, all the patients increased the total joint range of motion


The Bone & Joint Journal
Vol. 98-B, Issue 2 | Pages 218 - 223
1 Feb 2016
Scalise J Jaczynski A Jacofsky M

Aims. The eccentric glenosphere was principally introduced into reverse shoulder arthroplasty to reduce the incidence of scapular notching. There is only limited information about the influence of its design on deltoid power and joint reaction forces. The aim of our study was to investigate how the diameter and eccentricity of the glenosphere affect the biomechanics of the deltoid and the resultant joint reaction forces. . Methods. Different sizes of glenosphere and eccentricity were serially tested in ten cadaveric shoulders using a custom shoulder movement simulator. Results. Increasing the diameter of the glenosphere alone did not alter the deltoid moment arm. However, using an eccentric glenosphere increased the moment arm of the deltoid, lowered the joint reaction force and required less deltoid force to generate movement. Conclusion. Eccentricity is an independent variable which increases deltoid efficiency and lowers joint reaction forces in a reverse shoulder arthroplasty. Cite this article: Bone Joint J 2016;98-B:218–23


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 340 - 340
1 May 2009
Chou J Anderson I Astley T Poon P
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Reverse total shoulder replacement is a viable surgical option for Cuff Tear Arthropathy. Short term results have been promising. Longer term follow-up has demonstrated a high rate of scapular notching. This is attributed to mechanical impingement between the humeral cup and scapular neck when the arm is fully adducted. The long term sequelae of scapular notching are unclear but there is concern that it may compromise fixation of the glenoid component and affect functional outcomes. Design modifications to address this problem include the newly available eccentric glenospheres and larger diameter glenospheres. These glenospheres are designed to offer greater ranges of motion and theoretically may reduce the risk of impingement and notching. The purpose of this biomechanical study is to demonstrate the difference in range of motions with each design of glenosphere. To our knowledge there is no published literature evaluating this design differences. The SMR (Lima Orthotec) reverse total shoulder prothesis was implanted into a synthetic bone model (Sawbones, Pacific Laboratories, Vashon, Washington). Four different types of glenospheres (Standard 36 mm, Eccentric 36 mm, Standard 44 mm, Eccentric 44 mm) were then implanted into the same model which was fixed on a measurement table. The precision coordinate measurement device (FARO-Arm, SO6/Rev22, FARO Technologies Inc., Lake Mary, Florida) was used to establish the centres of rotation and ranges of motion. To date, the collection of data has just been completed, but the data are yet to be analysed. In conclusion, this is a biomechanical study evaluating the ranges of motion and risk of notching, comparing different designs of glenospheres in Reverse Total Shoulder Joint Replacement


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 1 | Pages 57 - 61
1 Jan 2011
Naveed MA Kitson J Bunker TD

The combination of an irreparable tear of the rotator cuff and destructive arthritis of the shoulder joint may cause severe pain, disability and loss of independence in the aged. Standard anatomical shoulder replacements depend on a functioning rotator cuff, and hence may fail in the presence of tears in the cuff. Many designs of non-anatomical constrained or semi-constrained prostheses have been developed for cuff tear arthropathy, but have proved unsatisfactory and were abandoned. The DePuy Delta III reverse prosthesis, designed by Grammont, medialises and stabilises the centre of rotation of the shoulder joint and has shown early promise. This study evaluated the mid-term clinical and radiological results of this arthroplasty in a consecutive series of 50 shoulders in 43 patients with a painful pseudoparalysis due to an irreparable cuff tear and destructive arthritis, performed over a period of seven years by a single surgeon. A follow-up of 98% was achieved, with a mean duration of 39 months (8 to 81). The mean age of the patients at the time of surgery was 81 years (59 to 95). The female to male ratio was 5:1. During the seven years, six patients died of natural causes. The clinical outcome was assessed using the American Shoulder and Elbow score, the Oxford Shoulder Score and the Short-form 36 score. A radiological review was performed using the Sirveaux score for scapular notching. The mean American Shoulder and Elbow score was 19 (95% confidence interval (CI) 14 to 23) pre-operatively, and 65 (95% CI 48 to 82) (paired t-test, p < 0.001) at final follow-up. The mean Oxford score was 44 (95% CI 40 to 51) pre-operatively and 23 (95% CI 18 to 28) (paired t-test, p < 0.001) at final follow-up. The mean maximum elevation improved from 55° pre-operatively to 105° at final follow-up. There were seven complications during the whole series, although only four patients required further surgery


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 259 - 259
1 Jul 2011
Bicknell R Boileau P Roussanne Y Brassart N Chuinard C
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Purpose: We hypothesized that lateralization of the RSA, with a glenoid bone graft taken from the osteotomised humeral head, would prevent those problems without increasing torque on the glenoid component by keeping the center of rotation within the glenoid. The objectives of this study were to describe the results of the first 12 patients that underwent a bony increased-offset RSA (BIO RSA). Method: Thirty-six shoulders in 34 consecutive patients with cuff tear arthritis (mean age 72 years, range 52–86 years) received a BIO RSA, consisted of a RSA incorporating an autogenous humeral head bone graft placed beneath the glenoid baseplate. A baseplate with a lengthened central peg (+25 mm) was inserted in the glenoid vault, securing the bone graft beneath the baseplate and screws. All patients underwent clinical and radiographic (computed tomography) review at a minimum 1-year follow-up. Results: All patients were satisfied or very satisfied and all had no or slight pain. Mean active elevation increased from 72° to 142° (p< 0.05), external rotation from 10° to 18° (p< 0.05) and internal rotation from L4 to L3 (p> 0.05). Constant Score improved from 27 to 63 points (p< 0.05). The Subjective Shoulder Value (SSV) increased from 27% to 73% (p< 0.05). Radiographically, the graft healed to the native glenoid in all cases and no graft resorption under the baseplate was observed. Complications included one patient with scapular notching (stage 1) and one patient with previous radiotherapy had a deep infection. No postoperative instability, and no glenoid loosening were observed. Conclusion: The use of an autologous bone graft harvested from the humeral head can lateralize the center of rotation of a RSA while keeping the center of rotation at the glenoid bone-prosthesis interface. The clinical advantages of a BIO RSA are a decrease in scapular notching, enhanced stability and mobility, and improved shoulder contour while keeping the center of rotation at the glenoid bone-prosthesis interface. This bony lateralization allows maintenance of the principles of Grammont and seems to be more appropriate than prosthetic lateralization. These promising early results of this novel procedure warrant further investigation


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 4 | Pages 516 - 520
1 Apr 2007
Bufquin T Hersan A Hubert L Massin P

We used an inverted shoulder arthroplasty in 43 consecutive patients with a mean age of 78 years (65 to 97) who had sustained a three- or four-part fracture of the upper humerus. All except two were reviewed with a mean follow-up of 22 months (6 to 58). The clinical outcome was satisfactory with a mean active anterior elevation of 97° (35° to 160°) and a mean active external rotation in abduction of 30° (0° to 80°). The mean Constant and the mean modified Constant scores were respectively 44 (16 to 69) and 66% (25% to 97%). Complications included three patients with reflex sympathetic dystrophy, five with neurological complications, most of which resolved, and one with an anterior dislocation. Radiography showed peri-prosthetic calcification in 36 patients (90%), displacement of the tuberosities in 19 (53%) and a scapular notch in ten (25%). Compared with conventional hemiarthroplasty, satisfactory mobility was obtained despite frequent migration of the tuberosities. However, long-term results are required before reverse shoulder arthroplasty can be recommended as a routine procedure in complex fractures of the upper humerus in the elderly


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 121 - 122
1 Mar 2010
Flores-Hernandez C Hoenecke H D’Lima D
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Reverse total shoulder arthroplasty (R-TSA) converts the glenohumeral joint into a ball-and-socket articulation by implanting a metal glenosphere on the glenoid and a concave polyethylene articulation in the humerus. This design increases the stability of the shoulder and is indicated for the treatment of end-stage shoulder arthropathy with significant rotator cuff deficiency. To minimise the risk of loosening, the glenosphere is often medialised (to keep the center of rotation within glenoid bone). Since bone grafting under the glenosphere is recommended as an alternate method to medialisation, we studied the effect of glenosphere placement on the biomechanical efficiency of the deltoid. A musculoskeletal model of the shoulder was constructed using BodySIM (LifeModeler, Inc, San Clemente, CA). The model simulated active dynamic glenohumeral and scapulothoracic abduction in a shoulder implanted with an R-TSA. Muscle forces and gleno-humeral contact forces were computed during shoulder abduction. The following conditions were simulated:. R-TSA with the center of rotation unchanged;. medialisation of center of rotation by 16 mm;. medialisation reduced to 10 mm with a 6-mm bone graft; and. inferior placement of R-TSA by 4 mm to preserve soft-tissue tension and prevent scapular notching. We validated our model by comparing peak glenohumeral contact forces (85% body weight) with previously reported in vivo measurements (Bergmann, J Biomech 2007). Inferior placement of the glenosphere component increased the mechanical advantage of deltoid muscle at 90° abduction by 25%. Medialisation of the glenosphere had little effect on deltoid forces. Reducing the medialisation (to 10 mm, by simulating the effect of a bone graft under the glenosphere) also did not change the mechanical advantage relative to full medialisation (16 mm). One disadvantage of R-TSA is that a center of shoulder rotation outside (lateral) to the glenoid increases the tendency for glenosphere loosening. Unfortunately, medialisation of the glenosphere reduces the tension on the deltoid, increases the incidence of prosthetic impingement resulting in scapular notching, and produces a shoulder contour that is cosmetically undesirable. To counter these disadvantages, reduced medialisation is proposed by bone grafting under the glenosphere and placing the glenosphere inferiorly. Our model indicates that the major mechanical advantage of the R-TSA is provided by the inferior placement of the glenosphere, which increases the moment arm of the deltoid muscle. On the other hand, the extent of glenosphere medialisation had an insignificant effect. These results support the use of reduced medialisation and bone grafting in the presence of other advantages, such as reduced notching and maintenance of infraspinatus tension and improved shoulder contour