Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion

Lateralized glenosphere reverse shoulder arthroplasty: inlay and onlay designs have similar clinical outcomes in patients with glenohumeral osteoarthritis

BACKGROUND

Whether or how the position of the humeral tray (inlay or onlay) in reverse shoulder arthroplasty (RSA) affects outcomes is unclear. Our goal was to compare the clinical and radiographic results of RSA systems with inlay vs. onlay designs but with similar neck shaft angles (NSAs) and lateralized glenospheres.

METHODS

We screened the institutional database at our tertiary academic center for patients who underwent primary RSA (with a lateralized glenosphere and a 135° NSA) from 2009 through 2017. The indication for surgery was glenohumeral osteoarthritis with glenoid bone loss (Walch classification A2, B2, B3, or C) and an intact rotator cuff. All patients were followed for a minimum of 2 years (mean, 47 months; range, 24-123 months). The humeral tray design was inlay for 79 patients and onlay for 71. All patients underwent preoperative and postoperative evaluations, including physical examination, radiography, and patient-reported outcome measures (visual analog scale for pain, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and Western Ontario Osteoarthritis of the Shoulder index).

RESULTS

Compared with preoperative values, both groups achieved minimal clinically important differences in range of motion and patient-reported outcomes at the final follow-up. We found no significant differences between groups in any of these measures at the final follow-up. Rates of revision (inlay, 3.8% vs. onlay, 1.4%), scapular notching (inlay, 5.1% vs. onlay, 7.0%), acromial stress fracture (inlay, 0% vs. onlay, 2.8%), and tuberosity resorption (inlay, 25% vs. onlay, 27%) were not significantly different between groups (all, P > .05).

CONCLUSION

For patients with glenohumeral osteoarthritis with glenoid bone loss and an intact rotator cuff who underwent RSA using a lateralized glenosphere prosthesis with a 135° NSA, there were no significant differences between the inlay and onlay groups for range of motion, patient-reported outcomes, or complication rates. These findings are limited to this off-label indication for RSA.

Bony increased-offset reverse shoulder arthroplasty vs. metal augments in reverse shoulder arthroplasty: a prospective, randomized clinical trial with 2-year follow-up

BACKGROUND

Reverse shoulder arthroplasty (RSA) is rapidly being adopted as the standard procedure for a growing number of shoulder pathologies. Lateralization of the glenoid component is known to reduce the incidence of scapular notching and possibly improve postoperative range of motion. A number of methods are used for glenoid component lateralization, including bony increased-offset reverse shoulder arthroplasty (BIO-RSA) and porous metal-augmented baseplates. Presently, there exists little comparative literature on bone vs. metal lateralization. Therefore, the purpose of this study was to compare BIO-RSA to metal-augmented glenoid baseplates by assessing clinical outcomes and baseplate migration using model-based radiostereometric analysis.

METHODS

A power analysis indicated 40 patients would be required for this radiostereometric study. Therefore, 41 shoulders were prospectively randomized to receive either glenoid bone grafting (BIO-RSA) or a porous metal-augmented wedge-shaped titanium baseplate for primary reverse shoulder arthroplasty. At the time of primary surgery, all patients also underwent implantation of 8 tantalum marker beads in the glenoid and coracoid. Following surgery, participants were imaged using a calibrated, stereo radiographic technique. Radiographs were acquired at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years postoperatively. Migration of the prosthesis was compared between bone and metal lateralization groups at each time point using a mixed effects model with Bonferroni test for multiple comparisons. Outcome measures were acquired preoperatively and 2 years postoperatively.

RESULTS

No significant differences were observed along any translation or rotation axis at any time point for either glenoid fixation group (P ≥ .175). Mean total glenoid component translation (± standard deviation) 2 years postoperatively was 0.4 ± 0.2 mm and 0.5 ± 0.3 mm for BIO-RSA and metal-augmented baseplates, respectively (P = .784). No significant differences were observed between groups in active range of motion; pain; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score; Simple Shoulder Test score; Disabilities of the Arm, Shoulder, and Hand score; Constant Shoulder score; or Subjective Shoulder Value (P ≥ .117), with the exception of increased active external rotation in the BIO-RSA cohort (P = .036).

CONCLUSION

This randomized clinical trial assessed reverse shoulder arthroplasty glenoid component migration using model-based radiostereometric analysis. At 2-year follow-up, our results indicate both BIO-RSA and porous metal wedge augmented baseplates provide stable initial fixation, which is maintained at 2 years' follow-up, with no substantial differences in clinical outcomes.

Shoulder arthroplasty after prior anterior shoulder instability surgery: a matched cohort analysis

PURPOSE

To evaluate the effect of prior anterior shoulder instability surgery (SIS) on the outcomes and complications of primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA).

METHODS

Between 2007 and 2018, 38 primary total shoulder arthroplasties (TSA) (22 aTSA and 16 rTSA) with a prior SIS and a minimum of 2 years of follow-up were identified. This cohort was matched 1:3 based on age, sex, body mass index, year of surgery, and dominant shoulder. aTSA and rTSA were matched to patients with primary osteoarthritis (OA) and rotator cuff tear arthropathy (CTA), respectively.

RESULTS

TSA produced similar postoperative pain, ROM, patient-reported outcome measures, complications, and revisions in those with prior SIS vs. controls. aTSA with prior SIS demonstrated worse final postoperative abduction (116° vs. 133°; P = 0.046) and abduction improvement (24° vs. 47°; P = 0.034) compared to OA controls. Both aTSA and rTSA with prior SIS demonstrated significant improvements from baseline across all metrics, with no significant differences between the groups. aTSA and rTSA with prior SIS demonstrated no differences to controls in complications (4.6% vs. 6.1%; P = .786 and 0% vs. 6.3%. P = .183) or revisions (4.6% vs. 4.6%; P = .999 and 0% vs. 4.2%; P = .279).

CONCLUSIONS

TSA after prior SIS surgery can improve both pain and function without adversely increasing the rates of complications or revision surgery. When compared to patients without prior SIS, aTSA demonstrated worse abduction; however, all other functional differences remained statistically similar.

LEVEL OF EVIDENCE

III; Retrospective Cohort Comparison; Treatment Study.

The base of coracoid process as a reference for glenoid reconstruction in primary or revision reverse shoulder arthroplasty: CT-based anatomical study

INTRODUCTION

Joint replacement surgery as a treatment for glenohumeral arthritis with glenoid bone loss is challenging. The aim of this study is to offer an anatomical orientation for glenoid reconstruction.

METHODS

In this study, we measured size, inclination and version of the glenoid surface, as well as the distance between the articular line of the glenoid, base of the coracoid process, and acromion using computer tomographic (CT) imaging of 131 study participants aged 19-88 years in the period of 2010-2013.

RESULTS

We measured a mean distance of 6.5 ± 0.2 mm from the glenoid articular line to the base of the coracoid process in the transverse CT plane. Body height has shown no significant impact on the glenoid morphology. We observed significant differences between males and females: The glenoid appeared to be located 5.2 ± 0.9 mm higher and the humeral head was 4.5 ± 0.7 mm larger in male subjects compared with females (r = .699; p < .01).

CONCLUSION

In our study, the base of the coracoid offers an anatomical reference during reconstruction of the glenoid in primary and revision shoulder arthroplasty. As only 2D-CT imaging allows for accurate assessment of glenoid bone defects, we consider conventional X-ray imaging insufficient for proper preoperative planning before shoulder arthroplasty.

LEVEL OF EVIDENCE

III.

Glenohumeral osteoarthritis with intact rotator cuff treated with reverse shoulder arthroplasty: a systematic review

BACKGROUND

Although reverse shoulder arthroplasty (RSA) has shown satisfactory outcomes in rotator cuff-deficient shoulders, its performance in shoulders with an intact rotator cuff has not been fully elucidated. Shoulder osteoarthritis can present with alterations in glenoid morphology, which have contributed to inconsistent outcomes in anatomic shoulder replacement. The glenoid component is responsible for a predominance of these arthroplasty complications. Given these glenoid-related difficulties, RSA may provide a more favorable option. We aimed to summarize the current literature on rotator cuff intact osteoarthritis treated with primary RSA and to determine whether morphologic changes in the glenoid led to inferior outcomes.

METHODS

A literature search was performed using an inclusion criterion of primary RSA for osteoarthritis with an intact rotator cuff. The Modified Coleman Methodology Score was calculated to analyze reporting quality. Following appropriate exclusions, of the 1002 studies identified by the databases, 13 were selected.

RESULTS

Postoperative improvement in weighted means for Constant scores reached statistical significance (P = .02). The mean rate of major complications was 3.8%. A subset of 8 studies was created that detailed the following descriptions of altered glenoid morphology: "static posterior instability," "severe posterior subluxation," "posterior glenoid wear >20°," "significant posterior glenoid bone loss," "biconcave glenoid," "B2 glenoid," and "B/C glenoid." Within this subset, the mean complication rate was 4.7%, with 4 of the 7 studies having a rate ≤ 3%, and improvements in the Constant score (P = .002) and external rotation (P = .02) reached statistical significance.

DISCUSSION

RSA as treatment for osteoarthritis with an intact rotator cuff provides optimal outcomes with low complication rates across a short term of follow up. Preoperative considerations for using reverse arthroplasty in the treatment of osteoarthritis with an intact rotator cuff include glenoid retroversion, posterior humeral subluxation, and glenoid bone loss. The attributes of reverse arthroplasty that contribute to favorable outcomes in arthritic shoulders include its semiconstrained design and robust glenoid fixation. Soft-tissue imbalances as a consequence of pathologic glenoid morphology and chronic humeral subluxation can be mitigated with the RSA semiconstrained design. Glenoid bone loss can be effectively managed with RSA's robust glenoid fixation, with and without the use of bone graft. The capability to lateralize the joint center of rotation may be valuable when faced with a medialized glenoid wear pattern. The current findings suggest that reverse arthroplasty can achieve highly favorable outcomes for glenohumeral osteoarthritis with an intact rotator cuff.

Lateralization in Reverse Shoulder Arthroplasty

Indications for Reverse Shoulder Arthroplasty (RSA) have been extended over the last 25 years, and RSA has become the most frequently implanted shoulder arthroplasty worldwide. The initial Grammont design with medialization of the joint center of rotation (JCOR), placement of the JCOR at the bone–implant interface, distalization and semi-constrained configuration has been associated with drawbacks such as reduced rotation and range of motion (ROM), notching, instability and loss of shoulder contour. This review summarizes new strategies to overcome these drawbacks and analyzes the use of glenoid-sided, humeral-sided or global bipolar lateralization, which are applied differently by surgeons and current implant manufacturers. Advantages and drawbacks are discussed. There is evidence that lateralization addresses the initial drawbacks of the Grammont design, improving stability, rates of notching, ROM and shoulder contour, but the ideal extent of lateralization of the glenoid and humerus remains unclear, as well as the maximal acceptable joint reaction force after reduction. Overstuffing and spine of scapula fractures are potential risks. CT-based 3D planning as well as artificial intelligence will help surgeons with planning and execution of appropriate lateralization in RSA. Long-term follow-up of lateralization with new implant designs and implantation strategies is needed.

Biconcave glenoids show 3 differently oriented posterior erosion patterns

BACKGROUND

Posterior glenoid wear remains a challenge in anatomic and reverse total shoulder arthroplasty (rTSA) because of an asymmetric erosion with altered retroversion. The purpose of this study was to assess glenoid morphology and evaluate the influence of acromial orientation in posterior glenoid erosion patterns by using 3-dimensional (3D) models.

MATERIAL AND METHODS

Computed tomographic (CT) shoulder scans from 3 study centers of patients awaiting rTSA between 2017 and 2018 were converted into 3D models and analyzed by 2 observers. Morphology, orientation and greatest depth of erosion, inclination, current retroversion and premorbid retroversion, surface areas of the glenoid, and external acromial orientation and posterior acromial slope were assessed. Measurements were compared between wear patterns, glenoid erosion entities, and genders.

RESULTS

In the complete cohort of 68 patients (63.8 ± 10.0 years; 19 female, 49 male), a mean of 85.9° (±22.2°) was observed for the glenoid erosion orientation. Additionally, a further distinct classification of the glenoid erosion as posterior-central (PC, n = 39), posterior-inferior (PI, n = 12), and posterior-superior (PS, n = 17) wear patterns was possible. These wear patterns significantly (P < .001) distinguished by erosion orientation (PC = 86.9° ± 12.0°, PI = 116.3° ± 10.3°, PS = 62.3° ± 18.9°). The greatest depth of erosion found was 7.3 ± 2.7 mm in PC wear patterns (PC vs. PI: P = .03; PC vs. PS: n.s.; PI vs. PS: n.s.). Overall, the observed erosion divided the glenoid surface into a paleoglenoid proportion of 48% (±11%) and a neoglenoid proportion of 52% (±12%). For the complete cohort, glenoid inclination was 85.4° (±6.6°), premorbid glenoid retroversion was 80.7° (±8.1°), and current glenoid retroversion was 73.4° (±7.4°), with an estimated increase of 6.9° (±6.0°). The mean external acromial orientation was 118.2° (±8.9°), and the mean posterior acromial slope was 107.2° (±9.6°). There were no further significant differences if parameters were compared by wear patterns, entities, and gender.

CONCLUSION

Three significantly differently oriented wear patterns (posterior-superior, posterior-central, and posterior-inferior) were distinguished in shoulders demonstrating posterior wear on axillary imaging. No significant differences between the observed erosion patterns or any relevant correlations were found regarding the orientation of the acromion.

Reverse shoulder arthroplasty used for revision of reverse shoulder arthroplasty: a systematic review

Background

As reverse shoulder arthroplasty (RSA) cases increase, so too will the need to revise subsequent failures. Many of the complications associated with revising anatomic total shoulder and hemiarthroplasty have been adequately addressed by RSA including glenoid bone deficiency, instability, and functional outcomes. However, the risk for complication when revising a failed reverse prosthesis may be more pronounced with increased bone and soft tissue deficiency. The ability for the reversed prosthesis to accommodate these insufficiencies following a prior reversed prosthesis is unclear.

Methods

PubMed, Embase, and Google Scholar were queried for articles which fit the inclusion criteria of a reversed prosthesis used to revise a failed primary reverse prosthesis with a minimum follow-up of 12 months and clinical outcome reporting.

Results

After exclusions, 9 studies reporting on 242 reverse shoulders with a mean follow-up of 40.29 months were analyzed. The differences between preoperative and postoperative weighted means were not significant for Constant (P = .26), American Shoulder and Elbow Surgeons Shoulder score (P = .61), SSV (P = .57), and visual analog scale for pain (P = .48). Functional improvements in elevation (74°-102°) and external rotation (18°-21°) were consistent with those reported for primary reverse procedures, although differences in preoperative and postoperative measures were not statistically significant. Patient satisfaction was 89% with a major complication rate of 25%.

Discussion

The reverse shoulder prosthesis has proven satisfactory in revising hemiarthroplasty and anatomic total shoulder arthroplasty. The current results indicate RSA is also a satisfactory treatment option when revising a prior reverse prosthesis. Inherent to revision shoulder surgery is the obstacle of humeral and glenoid bone loss, an attenuated soft-tissue envelope, and instability. The reverse prosthesis may adequately address these commonly confronted difficulties with its inherent design characteristics. RSA provides a secure glenoid fixation for bone grafting, the ability to increase construct stability with component sizing, and a reliance on the deltoid for function. As our learning about revision of RSA improves, so will our ability to preemptively address potential issues which may lead to decreased complications in these cases. Despite the 25% rate of major complication, patients reported satisfaction of 89% which demonstrates the improvements in function and pain relief that are provided by the reverse prosthesis.

A Sequential Approach to the Management of Posterior Glenoid Defects in RSA: Angulated BIO Versus Multiple Bioresorbable Pinning-Assisted Structural Bone-Grafting

Large posterior glenoid defects pose problems in reverse shoulder arthroplasty (RSA). We have adopted a sequential approach to the management of posterior glenoid defects using asymmetrical reaming, the placement of a ring graft around the central peg (bony-increased offset, or BIO), or structural bone-grafting, depending on the amount of glenoid retroversion. Furthermore, we have devised multiple bioresorbable pinning (MBP)-assisted bone-grafting, in which as many bioresorbable pins as required are inserted, from whichever aspects of the graft necessary, to achieve initial stability.

Preoperative three-dimensional computer planning for reverse total shoulder arthroplasty and bone grafting for severe glenoid deformity

BACKGROUND

Computer assisted planning without patient specific instrumentation may be utilized to guide reverse total shoulder arthroplasty baseplate placement. The purpose of this study was to determine the difference between planned and achieved inclination and retroversion correction with three-dimensional preoperative computer assisted planning in reverse total shoulder arthroplasty without patient specific instrumentation with bone grafting for severe glenoid erosion.

METHODS

Preoperative three-dimensional computer assisted planning without patient specific instrumentation was performed on 15 patients undergoing primary reverse total shoulder arthroplasty with glenoid bone grafting for severe glenoid erosion. On preoperative and immediate postoperative computed tomography slices, two-dimensional retroversion and inclination were measured. Preoperative three-dimensional baseline retroversion and inclination and planned postoperative three-dimensional retroversion and inclination were measured. Planned and achieved version and inclination changes were compared.

RESULTS

The planned and achieved retroversion corrections were 18° and 12°, respectively (p < 0.001). The planned and achieved inclination corrections were 11° and 11°, respectively (p = 0.803).

CONCLUSIONS

Three-dimensional computer assisted planning without patient specific instrumentation in the setting of reverse total shoulder arthroplasty with severe glenoid erosion requiring bone grafting can accurately guide baseplate placement. All cases in which failure to correct retroversion or inclination within 10° of planning occurred in patients with severe erosion (B3 or E3 glenoids), therefore patient specific guides may be warranted in these cases to improve accuracy of implantation.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Tomographic Analysis of Positioning of Reverse Baseplates Positioning

Objective

To verify whether reverse baseplate positioning without the support of intraoperative three-dimensional technology is within the acceptable parameters in the literature and whether glenoid bone deformity (GBD) compromises this positioning.

Methods

Sixty-nine reverse shoulder arthroplasties were evaluated with volumetric computed tomography (CT). Two radiologists performed blinded CT scan analysis and evaluated baseplate position within 2mm of the inferior glenoid; the inclination and version of the baseplate in relation to the Friedman line; and upper and lower screw and baseplate metallic peg end point positionings. The patients were divided according to the presence of GBD for statistical analyses.

Results

The two radiologists concurred reasonably in their interpretations of the following analyzed parameters: baseplate position within 2mm of the inferior glenoid rim (97.1% and 95.7%), baseplate inclination (82.6% and 81.2%), baseplate version (69.6% and 56.5%), the upper screw reaching the base of the coracoid process (71% and 79.7%), the inferior screw remaining inside the scapula (88.4% and 84.1%), and the metallic peg of the baseplate considered intraosseous (88.4% and 72.5%).

Conclusion

Reverse baseplate positioning without intraoperative three-dimensional technology is within the acceptable parameters of the literature, except for baseplate version and upper screw position. GBD did not interfere with baseplate positioning in reverse shoulder arthroplasty.

Mid-term outcomes of bony increased offset-reverse total shoulder arthroplasty in the Asian population

Background

To evaluate clinical and radiological outcomes of bony increased offset-reverse total shoulder arthroplasty (BIO-RSA) in the Asian population at mid-term follow-up.

Methods

From June 2012 to August 2017 at a single center, 43 patients underwent BIO-RSA, and 38 patients with minimum 2 years follow-up were enrolled. We evaluated the clinical and radiological outcomes, and complications at the last follow-up. In addition, we divided these patients into notching and no-notching groups and compared the demographics, preoperative, and postoperative characteristics of patients.

Results

Visual analogue scale, American Shoulder and Elbow Surgeons, University of California-Los Angeles Shoulder Scale, and Simple Shoulder Test scores improved significantly from preoperative (5.00, 3.93, 1.72, 3.94) to postoperative (1.72, 78.91, 28.34, 7.66) (p<0.05) outcomes. All range of motion except internal rotation improved significantly at the final follow-up (p<0.05), and the bone graft was well-incorporated with the native glenoid in all patients (100%). However, scapular notching was observed in 20 of 38 patients (53%). In the comparison between notching and no-notching groups (18 vs. 20 patients), there were no significant differences in demographics, radiological parameters, and clinical outcomes except acromion-greater tuberosity (AT) distance (p=0.003). Intraoperative complications included three metaphyseal fractures and one inferior screw malposition. Postoperative complications included ectopic ossification, scapular neck stress fracture, humeral stem relaxation, and late infection in one case each.

Conclusions

BIO-RSA showed improved clinical outcomes at mid-term follow-up in Asian population. However, we observed higher scapular notching compared to the previous studies. In addition, adequate glenoid lateralization with appropriate humeral lengthening (AT distance) might reduce scapular notching.

Analysis of the coaptation role of the deltoid in reverse shoulder arthroplasty. A preliminary biomechanical study

Background

Lateralization of the glenoid implant improves functional outcomes in Reverse Shoulder Arthroplasty. Lateralization does not appear to impact the Deltoid’s Moment Arm. Therefore, the stabilizing effect described in the literature would not be the result of an increase this moment arm. A static biomechanical model, derived from Magnetic Resonance Imaging, can be used to assess the coaptation effect of the Middle Deltoid. The objective of this study was to analyze the impact of increasing amounts of glenoid lateralization on the moment arm but also on its coaptation effect.

Methods

Eight patients (72.6 ± 6.5 years) operated for Reverse Shoulder Arthroplasty were included in the study. Three-dimensional models of each shoulder were created based on imaging taken at 6 months postoperative. A least square sphere representing the prosthetic implant was added to each 3D models. A static biomechanical model was then applied to different planar portions of the Middle Deltoid (from 3D models), first without lateralization and then with simulated lateralization of 6, 9 and 12mm. This static model enables to compute a Coaptation/Elevation Ratio and to measure the Deltoid’s Moment Arm. The inter- and intra-rater agreement of the 3D models was evaluated.

Results

One patient was excluded due to motion during imaging. The inter- and intra-rater agreement was over 0.99. The ratio increased starting at 6 mm of lateralization (p<0.05), compared to the initial position. The moment arm was not affected by lateralization (p<0.05), except in two slices starting at 9 mm (S1 p<0.05 and S2 p<0.05).

Conclusion

Our hypothesis that the Middle Deltoid’s coaptation role would be greater with glenosphere lateralization was confirmed. This trend was not found in the moment arm, which showed little sensitivity to lateralization. The stabilizing effect therefore appears to stem from the coaptation role of the Middle Deltoid.

Problems, complications, and reinterventions in 4893 onlay humeral lateralized reverse shoulder arthroplasties: a systematic review (part I-complications)

Background

Several modifications to the original Grammont reverse shoulder arthroplasty (RSA) design have been proposed to prevent distinctive issues, such as both glenoid and humeral lateralization. The aim of this systematic review was to determine rates of problems, complications, reoperations, and revisions after onlay lateralized humeral stem RSA, hypothesizing that these are design related.

Methods

This systematic review was performed in accordance with the PRISMA statement guidelines. A literature search was conducted (01.01.2000–14.04.2020) using PubMed, Cochrane Reviews, Scopus, and Google Scholar employing several combinations of keywords: “reverse shoulder arthroplasty,” “reverse shoulder prosthesis,” “inverse shoulder arthroplasty,” “inverse shoulder prosthesis,” “problems,” “complications,” “results,” “outcomes,” “reoperation,” “revision.”

Results

Thirty-one studies with 4893 RSA met inclusion criteria. The 892 postoperative problems and 296 postoperative complications represented overall problem and complication rates of 22.7% and 7.5%, respectively. Forty-one reoperations and 63 revisions resulted, with an overall reoperation rate of 1.7% and overall revision rate of 2.6%.

Conclusions

Problem, complication, and reintervention rates proved acceptable when implanting a high humeral lateralization stem in RSA. The most frequent problem was scapular notching (12.6%), and the most common postoperative complication was scapular stress fracture (1.8%). An overall humeral complication rate of 1.9% was identified, whereas short stems reported no humeral fractures or stem loosening. Infections (1.3%) proved to be the most common reason for component revision, and instability had a complication rate of 0.8%.

Level of evidence

Systematic review IV

Lateralized versus nonlateralized glenospheres in reverse shoulder arthroplasty: a systematic review with meta-analysis

HYPOTHESIS/BACKGROUND

Lateralization in reverse shoulder arthroplasty (L-RSA) was proposed to overcome some limitations of the original Grammont-style design (S-RSA). This systematic review aims to compare the clinical and functional outcomes and complications of S-RSA with L-RSA, and to assess the individual results of metallic and bony lateralization implants.

METHODS

A systematic search from January 1980 to December 2019 was performed. Studies were selected in 2 phases by 2 independent reviewers; disagreements were solved by discussion. Inclusion criteria were: (1) original studies; (2) written in English or French; (3) adult individuals submitted to RSA surgery; and (4) RSA with a lateralization device in at least one of the groups. Exclusion criteria were: (1) nonoriginal studies or case reports; (2) absence of clinical or radiographic outcomes; and (3) no comparison group using S-RSA. Data were extracted for outcomes of functional status (American Shoulder and Elbow Surgeons, Constant, visual analog scale, Simple Shoulder Test, Subjective Shoulder Value, Activities of Daily Life that require External Rotation, and Disabilities of the Arm, Shoulder, and Hand), range of motion (ROM), complications, revisions, and notching. Meta-analyses were performed when possible. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed.

RESULTS

Fifteen articles/16 studies were included (865 participants: 440 L-RSA and 425 S-RSA). Most studies found no differences between the L-RSA and S-RSA groups in qualitative and meta-analysis for American Shoulder and Elbow Surgeons, Constant, Simple Shoulder Test, Activities of Daily Life that require External Rotation, and Disabilities of the Arm, Shoulder, and Hand scores. Meta-analysis demonstrated significantly lower visual analog scale (1 point) and higher Subjective Shoulder Value (6 points) in L-RSA than in S-RSA. No significant differences were found in the qualitative analyses of most studies regarding ROM in forward elevation, abduction, and internal/external rotation, but meta-analysis reported a significantly higher external rotation in L-RSA groups and specifically in osseous lateralization. Complication rate was significantly lower in L-RSA (odds ratio = 0.38), but no significant differences were found for revision rates. Notching rate was significantly lower in the L-RSA group (odds ratio = 0.14), both for osseous and metallic lateralization.

DISCUSSION/CONCLUSION

This systematic review focused on studies comparing L-RSA and S-RSA and found significantly lower notching and complication rates in L-RSA groups. This review highlighted similar outcomes in clinical scores and a slight advantage for L-RSA in ROM, especially in external rotation. L-RSA was not associated with increased revision rates, while presenting lower complication and notching rates. Inclusion of studies with metallic and osseous lateralization has helped to provide further evidence on this subject, but heterogeneity and low evidence levels of the included studies may limit our conclusions.

Early clinical and radiographic outcomes of an augmented baseplate in reverse shoulder arthroplasty for glenohumeral arthritis with glenoid deformity

BACKGROUND

Glenoid deformity is commonly encountered in patients undergoing reverse shoulder arthroplasty (RSA). Augmented baseplates can correct glenoid deformity while potentially avoiding certain complications encountered with structural bone graft. Limited evidence exists to support the use of metallic augmented baseplates in RSA.

METHODS

We performed a retrospective review to identify all patients treated with an augmented baseplate during primary RSA with a minimum of 1 year of clinical and radiographic follow-up. Preoperative radiographs and advanced imaging were used to determine glenoid morphology and deformity. Postoperative radiographs were used to evaluate for deformity correction, radiographic complications, and early baseplate loosening or failure. Prospectively collected clinical data and patient-reported outcome scores were determined.

RESULTS

Primary RSA was performed with an augmented baseplate in 44 patients (mean age, 72 ± 6 years; 15 half-wedge and 29 full-wedge augmentations). Glenoid retroversion was significantly improved for the entire cohort (P = .001). Among the 22 patients with either Walch type B2, B3, or C glenoid morphology, glenoid version improved from 28° ± 8° to 16° ± 8° (P = .001). Glenoid inclination, as determined by the β angle, was significantly improved for the entire cohort (P < .001). Among the 18 patients with Favard type E2 or E3 glenoid morphology, glenoid inclination improved from 67° ± 7° to 81° ± 8° (P < .001). Postoperative range of motion and functional outcome scores including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale score for pain significantly improved within the entire cohort (P < .05). No patients had evidence of baseplate loosening or failure of the glenoid component. Acromial stress fractures developed in 5 patients (11.4%), and 2 patients (4.5%) underwent a reoperation unrelated to the glenoid component.

DISCUSSION AND CONCLUSION

Primary RSA with an augmented baseplate results in excellent short-term clinical outcomes and significant deformity correction in patients with advanced glenoid deformity. There were no complications related to the augmented baseplate or glenoid component. The rate of acromial stress fractures appears higher than typically reported and warrants further investigation.

Three-dimensional kinematics of reverse shoulder arthroplasty: a comparison between shoulders with good or poor elevation

Background

Various factors may be related to outcomes of reverse shoulder arthroplasty (RSA) including patient and surgical factors. Differences in shoulder kinematics might be associated with poor function after RSA; however, kinematic differences between shoulders with good or poor elevation have not been elucidated. The purpose of this study was to compare RSA kinematics between shoulders with good or poor elevation.

Methods

The study included 28 shoulders with a minimum 6-month follow-up after RSA using Grammont-type prostheses. Subjects comprised 17 men and 11 women with the mean age of 75 years (range, 63-91). Subjects underwent fluoroscopy during active scapular plane abduction. Computed tomography of their shoulders was performed to create 3-dimensional scapular implant models. Using model-image registration techniques, poses of 3-dimensional implant models were iteratively adjusted to match their silhouettes with the silhouettes in the fluoroscopic images, and 3-dimensional kinematics of implants were computed. Kinematics and glenosphere orientation were compared between shoulders with good (>90 degree) or poor (<90 degree) scapular plane abduction.

Results

Nineteen and 9 shoulders were assigned to the good- and poor-elevation groups, respectively. There were no significant differences between the groups in age, sex, height, weight, preoperative range of motion, or Constant score, but body mass index in the poor elevation shoulders was significantly larger than that in the good elevation shoulders. There were no significant differences in glenosphere (upward/downward rotation, anterior/posterior tilt, internal/external rotation) or glenohumeral (internal/external rotation, abduction/adduction) kinematics between the good and poor elevation shoulders. Scapulohumeral rhythm was significantly higher in the good elevation shoulders than the poor elevation shoulders (P = .04). Glenosphere superior tilt was 2.3° ± 4.2° in the good-elevation group and 8.1° ± 8.9° in the poor-elevation group, and the difference was statistically significant (P = .03).

Discussion

Shoulders with good elevation after RSA demonstrated better scapulohumeral rhythm than those with poor elevation, though there were no significant differences in glenosphere and glenohumeral kinematics. It may be important for better elevation to achieve good glenohumeral motion in shoulders with RSA. Glenosphere orientations may affect postoperative shoulder function.

Glenoid baseplate screw fixation in reverse shoulder arthroplasty: does locking screw position and orientation matter?

BACKGROUND

The longevity of a reverse total shoulder arthroplasty prosthesis can be compromised by glenoid baseplate loosening. Circular baseplate designs can be secured with superoinferior (SI) locking screws and anteroposterior (AP) compression screws or vice versa (AP-locking and SI-compression screws). This biomechanical cadaveric study investigated screw position (locking screws SI vs. AP and compression screws AP and SI) and screw orientation (parallel vs. divergent) to determine quantitative differences in baseplate micromotion.

METHODS

Ten paired fresh-frozen cadaveric scapulae (n = 20) were implanted with a standard circular baseplate (∅ = 29 mm). The specimens were randomized into SI-locking or AP-locking screw configurations with the screw orientation directed either parallel or angled divergently at 15°. This yielded a total of 4 groups for statistical comparison: SI-locking_parallel, SI-locking_divergent, AP-locking_parallel, and AP-locking_divergent, which were subjected to axial eccentric loading on the implanted baseplates, similar to the American Standard of Testing of Materials standard for shoulder joint arthroplasty.

RESULTS

In both static and cyclic testing, there were no statistically significant differences (P = .6) in micromotion between SI-locking (2.9 ± 0.8 μm) and AP-locking (3.5 ± 1.5 μm) configurations. In addition, there were no statistically significant differences (P = .2) in the divergent screw orientation group (2.0 ± 0.7 μm) vs. the parallel group (4.0 ± 1.5 μm).

CONCLUSION

All configurations of screw position and screw orientation tested in a circular reverse baseplate have similar time-zero fixation in an intact glenoid bone model. In addition, the resultant micromotions for all configurations tested fell far below the 150 μm threshold for bone ongrowth.

A novel method for localization of the maximum glenoid bone defect during reverse shoulder arthroplasty

Background

Management of glenoid bone defects during reverse shoulder arthroplasty remains a challenge. The aim of our study was to preoperatively localize the maximal depth of glenoid bone defects in relation to glenoid reaming.

Methods

Thirty preoperative shoulder computed tomography scans were collected. Three assessors created standardized surgical plans, using 3-dimensional (3D) computed tomography–based Blueprint planning software in which the reaming axis was held constant at zero degrees of version and inclination. Each plan resulted in a 2-dimensional (2D) image of the reamer’s contact on the glenoid and a corresponding 3D representation of the glenoid bone defect. The position of the maximum glenoid defect was localized on both the 2D and 3D images. Descriptive statistics were calculated. The correlation between angles from 2D and 3D images was assessed, and intraclass correlation was used to assess inter-rater and intrarater reliability.

Results

Twenty-eight patients were included. The overall mean difference between 2D and 3D angles was 5.4° (standard deviation 5.2°). The correlation between 2D and 3D angles was almost perfect. Intraclass correlation results demonstrated near-perfect agreement. The maximal glenoid defect was within 5% of a circle (or +/- 9°) from perpendicular to the high-side ream line in 85.1% of comparisons and was within 10% of a circle in 97.6% of comparisons.

Conclusion

Using Blueprint planning software, we have demonstrated with almost perfect agreement among 3 assessors that when the reaming axis is held constant, the maximum glenoid bone defect is reliably located perpendicular to the glenoid ream line.

The effect of glenoid lateralization and glenosphere size in reverse shoulder arthroplasty on deltoid load: A biomechanical cadaveric study

Purpose

Use of a relatively larger glenosphere with some larger overhang helps to minimize posterior impingement and some degree of glenoid lateralization is also beneficial in reverse shoulder arthroplasty (RSA). The optimal amounts of inferior overhang and lateralization are not agreed upon. The purpose of this in-vitro biomechanical study is to analyze the effect of glenosphere size and glenoid lateralization on deltoid load, focusing on differences in its three distinct heads.

Methods

Reverse shoulder arthroplasty (DeltaXtend, Fa. Depuy/Synthes) was performed on six cadaveric specimens. The load on each head of the deltoid muscle (spinalis, acromialis, and clavicularis) was measured indirectly by transferring deformation (μm/m) via strain gauges (Fa. Vishay) with stepwise lateralization: +0 mm (subgroup I), +5 mm (subgroup II), +10 mm (subgroup III). Each scenario was done with a 38 mm (group A) and a 42 mm (group B) glenosphere.

Results

In group A as well in group B, the mean measured deformation in the respective titanium omega increased with lateralization in the clavicular (AI: 119.6 μm/m, AIII: 307.3 μm/m; BI: 173.3 μm/m, BIII: 358.5 μm/m), in the spinal (AI: 85.3 μm/m, AIII: 188.5 μm/m; BI: 138.8 μm/m, BIII 261.2 μm/m) and in the acromial head (AI: 340.5 μm/μ; AIII: 454.2 μm/m; BI: 388.5 μm/m, BIII: 538.8 μm/m). A significant difference between the subgroups in the spinal (p = .048) and clavicular heads (p = .028) was found. The use of a 42 mm glenosphere increased significantly the load in each segment.

Conclusion

Lateralization and glenosphere size increased significantly deltoid muscle loading, especially in the clavicular head. According to these in-vitro data, the high variability in the amount of lateralization influences the soft-tissue balance in reverse shoulder arthroplasty.

Level of evidence

Basic science study.

Survivorship of autologous structural bone graft at a minimum of 2 years when used to address significant glenoid bone loss in primary and revision shoulder arthroplasty: a computed tomographic and clinical review

BACKGROUND

Severe glenoid bone loss remains a challenge in patients requiring shoulder arthroplasty and often requires autogenous bone grafting. The purpose of this study was to assess the integrity of the bone graft at 2 years in a series of primary and revision shoulder replacements where glenoid bone loss was managed using a structural autograft (humeral head or iliac crest bone graft) in combination with a trabecular titanium (TT) implant.

METHODS

Ethical approval was sought, and the study has a portfolio study status by the NIHR (17/YH/0318). We contacted patients who had primary and revision shoulder arthroplasty with Lima Axioma TT metal-back glenoid with autologous bone graft and were more than 2 years since their operation. All eligible patients underwent computed tomographic evaluation, clinical review, and scoring. Early failures of composite fixation and patients who had revision procedures were excluded (2 patients).

RESULTS

Forty-one patients (43 shoulders) with a mean age of 65 years (range 33-85 years) were reviewed. There were 24 women and 17 men. The average follow-up period was 40 months (range 24-59 months). Primary arthroplasty was performed in 24 shoulders, whereas 19 shoulders had revision arthroplasty. Twenty-five shoulders had reverse shoulder replacement and 18 had anatomic shoulder replacement. Twenty-four shoulders had graft taken from the humeral head, and 19 had iliac crest bone graft, reflecting the number of revisions. We used Wrightington classification for porous metal implant and bone graft incorporation. Satisfactory bone graft incorporation (>50%) was seen in 40 shoulders, and only 3 patients had <50% graft incorporation. The scans at 2 years or later showed no significant deterioration in the bone graft from the early postoperative scans. Average forward elevation improved from 50° (preoperative) to 98° (range 35°-150°). The mean improvement in mean Oxford Shoulder Score was 16 (preoperative, 15; postoperative, 31) and the mean improvement in Constant score improvement was 36 (preoperative, 12; postoperative, 48). The mean postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score was 64 (range 30-85).

CONCLUSION

The use of TT in conjunction with autologous bone graft provides a reliable method of addressing glenoid bone defects in primary and revision shoulder arthroplasty. This graft-trabecular metal composite has been shown to integrate well and remain largely unchanged over a 2-year period. A stable baseplate is essential in difficult primary and revision arthroplasty situations. The stability of this construct in our series is reflected in the satisfactory outcomes.

Computed tomographic evaluation of glenoid joint line restoration with glenoid bone grafting and reverse shoulder arthroplasty in patients with significant glenoid bone loss

BACKGROUND

Restoration of native glenohumeral joint line is important for a successful outcome after reverse shoulder arthroplasty (RSA). The aims of this study were to quantify the restoration of glenoid joint line after structural bone grafting and RSA, and to evaluate graft incorporation, correction of glenoid version, and rate of notching.

METHODS

This is a retrospective review of 21 patients who underwent RSA (20 primary, 1 revision) with glenoid bone grafting (15 autografts, 6 allografts). Grammont design implants and baseplate with long peg were used in all patients. Preoperative and postoperative 3D models were created using MIMICS 21.0. Preoperative defects were classified, and postoperative joint line restoration was assessed based on the lateral aspect of the base of the coracoid. Postoperative computed tomographic (CT) scans were evaluated for graft incorporation, version correction, and presence of notching.

RESULTS

Preoperative glenoid defects were classified as massive (5%), large (29%), moderate (52%), and small (14%). The average preoperative version was 8° of retroversion. The average postoperative version was 5° of retroversion. The average preoperative medialization was noted to be 8.4 mm medial to native joint line or 0.6 mm (range -16.8 to 13.2) lateral to the coracoid base. The postoperative CT scans demonstrated a mean joint line at 12.1 mm (range 1.3-22.4) lateral to the coracoid base. At the 3-month follow-up, all patients demonstrated graft incorporation on CT scans. Graft osteolysis was observed on CT scan in 4.8% of patients at a mean follow-up of 19.5 months.

DISCUSSION

Structural bone grafting of glenoid defect effectively re-creates the glenoid anatomy, restores glenoid bone stock, re-creates the true glenohumeral joint line, and corrects glenoid deformity. The use of bone grafting also allows lateralization of the baseplate and glenosphere, reducing the risk of severe scapular notching.

CONCLUSION

Restoration of the glenoid joint line was achieved in all patients. Glenoid bone grafting is a viable option for restoring glenoid joint line in cases of significant glenoid defects encountered during RSA.

The effect of metaglene lateralization on joint mobility of reverse shoulder arthroplasty: A cadaveric biomechanical study

Introduction

Lateralization of the metaglene reduces scapular notching or impingement. However, the effect on joint mobility remains unclear. With increased attention to reverse shoulder arthroplasty over the past years, the aim of this biomechanical study is to analyze the effect of metaglene lateralization on range of motion in reverse shoulder arthroplasty.

Methods

Reverse shoulder arthroplasty (DeltaXtend; Fa. Depuy/Synthes) was performed in 7 cadaveric shoulders. Lateralization of the metaglene was performed in increments, using spacers of +0 mm (subgroup I), +5 mm (subgroup II), +10 mm (subgroup III). Deltoid muscle (pars clavicularis, acromialis and spinalis), teres minor (TMI), infraspinatus (IF) and subscapularis muslces (SSC) were loaded separately. Range of motion was measured by using a motion capture system (Optotrak Certus) in the sagittal plane (z-axis), coronar plane (x-axis) and transversal plane (y-axis). A custom-made biomechanical test set up was used to test the samples with a constant preload with additional testing load up to 4 kg on each muscle.

Results

Specimens showed a tendency towards increased range of motion in abduction (deltoid, pars acromialis), external rotation (IS/TMI) and internal rotation (SSC) in subgroup II, compared to subgroups I and III, without reaching the level of significance Abduction at maximum used load was 46° (subgroup I), 62° (subgroup II) and 22° (subgroup III). The mean external rotation (ISF) at maximum used load was 25° (I), 28° (II) and 24° (III). Mean internal rotation was 22° (subgroup I), 48° (subgroup II) and 26° (subgroup III).

Conclusion

Moderate lateralization of the glenosphere of +5 mm has improved the range of motion in our experimental cadaveric setup. Especially a higher internal and external rotation can be reached with less load.Level of evidence III.

In vivo reverse total shoulder arthroplasty contact mechanics

BACKGROUND

Several in vitro studies have investigated the biomechanics of reverse total shoulder arthroplasty (RTSA); however, few in vivo studies exist. The purpose of this study was to examine in vivo RTSA contact mechanics in clinically relevant arm positions. Our hypothesis was that contact would preferentially occur in the inferior region of the polyethylene liner.

METHODS

Forty patients receiving a primary RTSA were recruited for a prospective cohort study. All patients received the same implant design with a nonretentive liner. Stereo radiographs were taken at maximal active range of motion. Model-based radiostereometric analysis was used to identify implant position. Contact area between the polyethylene and glenosphere was measured as the geometric intersection of the 2 components and compared with respect to polyethylene liner size, arm position, and relative position within the liner.

RESULTS

There were no differences in the proportion of contact area in any arm position between polyethylene liner sizes, ranging from 30% ± 17% to 38% ± 23% for 36-mm liners and 32% ± 21% to 41% ± 25% for 42-mm liners. Contact was equally distributed between the superior and inferior halves of the liner at each arm position (P = .06-.79); however, greater contact area was observed in the outer radius of the liner when the arm was flexed (P = .002).

CONCLUSION

This study highlights that contact mechanics are similar between 36- and 42-mm liners. Contact area is generally equally distributed throughout the liner across the range of motion and not preferentially in the inferior region as hypothesized.

Neuroapraxia and early complications after reverse shoulder arthroplasty with glenoid bone grafting

BACKGROUND

Bone grafting during primary reverse shoulder arthroplasty (RSA) is a technique used to restore poor glenoid bone, increase lateralization, and restore abnormal inclination or version. The purpose of this article is to analyze early outcomes of bone grafting during RSA, assessing the influence of technical and patient considerations.

METHODS

In a 4.5-year time period, 137 RSAs with glenoid bone grafting were performed with a minimum 3 months' follow-up. The mean follow-up was 17 months (range, 3-38). The mean age was 71 years (range, 45-89), and body mass index was 28 (range, 19-44). The source of the autografts were humeral head (n = 113) and iliac crest autograft (ICBG; n = 24). The humeral components included 84 onlay and 53 inlay designs.

RESULTS

Overall, there were 16 complications (12%), of which 6 were major (5%) (3 graft nonunions and 3 infections) and 10 minor (8%) (1 carpal tunnel syndrome and 9 transient axillary neuropraxias). Of the 9 axillary neuropraxias, 8 resolved by the most recent follow-up, whereas 1 patient was lost to follow-up. There were 4 reoperations (3%): 2 for glenoid baseplate loosening, 1 for severe notching associated with severe glenoid bone loss, and 1 for deep periprosthetic infection. One additional patient had a baseplate failure and is undergoing further treatment. There was no difference in the occurrence of graft nonunions, revision surgery, or glenoid component loosening when comparing type of graft or humeral component used. There was an association of revision surgery (P = .02) with ICBG and older age at the time of surgery (P = .02) and an association of transient neuroapraxia with onlay humeral components (P = .01) and workers' compensation cases (P = .04).

CONCLUSIONS

There is a high union rate and low complication rate after bone grafting of the glenoid performed with RSA. Transient neuropraxias are the most frequent complication, but the majority resolve within the first postoperative year. These early findings can serve as the basis for future long-term, comprehensive analysis of complications and outcomes after bone grafting during RSA.

Bony increased-offset reverse shoulder arthroplasty: A meta-analysis of the available evidence

BACKGROUND

Reverse shoulder arthroplasty (RSA) has revolutionized the management of many shoulder pathologies. Lateralization has become favourable to combat complications (e.g. notching, compromised external rotation), using a metallic, or autogenous bone-graft baseplates - bony increased-offset reverse shoulder arthroplasty (BIO-RSA). We systematically reviewed the literature to determine: Does BIO-RSA improve range of motion and outcome scores?Are notching rates decreased?Does the graft heal?

METHODS

All available prospective studies, trials and case series reporting on BIO-RSA were included. Outcomes were grouped into outcome scores, range of motion and radiographic outcomes. Data were pooled and statistical analysis performed.

RESULTS

Eight studies reported on 385 RSA - 235 BIO-RSA and 150 standard-RSA (STD-RSA). Follow-up was 20-36 months; average age 74 years. Outcome scores: Constant-Murley and SSV scores showed statistically significant post-operative benefit of BIO-RSA (mean-difference 4.0 (95% confidence interval (CI): 0.79,7.1) and 6.8 (95% CI: 3.8, 9.9)). No Minimal Clinically Importance Difference was surpassed. Range of motion: No difference was found in any direction. Notching: Notching was less likely with BIO-RSA (odds ratio 0.19 (95% CI: 0.10, 0.38)). Healing and loosening: 92% grafts fully healed/incorporated. Loosening rate was 2.4%.

CONCLUSIONS

Literature on BIO-RSA is limited with only one randomised controlled trial (RCT). Weak evidence exists for improved outcome scores. Range of motion is equivocal. Notching rates are significantly lower in BIO-RSA. The graft usually heals.

The risk of postoperative scapular spine fracture following reverse shoulder arthroplasty is increased with an onlay humeral stem

BACKGROUND

The purpose of this study was to assess the effects of lateralization and distalization on scapular spine fracture (SSF) after reverse shoulder arthroplasty (RSA). The hypothesis was that postoperative distalization would increase the risk of SSF, whereas lateralization would not.

METHODS

A multicenter retrospective review was performed at a minimum of 1 year postoperatively on primary RSAs with 3 different implants, 2 with an inlay design (n = 342) and 1 with an onlay design (n = 84). Functional outcome, range of motion, stem design, and radiographic measurements, including acromiohumeral distance and lateralization, were compared between groups with and without fracture.

RESULTS

The incidence of SSF in the onlay group (11.9%) was significantly higher compared with the inlay group (4.7%; P = .043). Postoperative acromiohumeral distance was approximately 4 mm higher in the SSF group (37.5 mm) compared with the control group (33.7 mm; P = .042), whereas lateralization was similar between the 2 groups (52.8 mm vs. 53.9 mm; P = .362). Higher return to activity (92.1% vs. 71.4%; P < .001) as well as postoperative forward flexion was observed in the group without fracture (135° vs. 120°; P = .009).

CONCLUSION

Increased postoperative distalization is associated with an increased risk of SSF after RSA. An onlay stem resulted in a 10 mm increase in distalization compared with an inlay stem, and a 2.5 times increased risk of SSF. Lateralization, however, does not appear to increase the risk of SSF.

Effect of Reverse Shoulder Arthroplasty Lateralization Design on Scapular Notching: A Single-Surgeon Experience

Scapular notching remains a concern with both medialized and lateralized reverse shoulder arthroplasty (RSA) designs. Few studies have directly compared the rate of notching among various designs. The purpose of this study was to compare a single surgeon's rate of scapular notching in relation to RSA design. A total of 156 primary RSAs were performed for cuff tear arthropathy or osteo-arthritis with rotator cuff insufficiency by a single surgeon. Follow-up was controlled to between 3 and 5 years. Shoulders were grouped according to implant design: medialized center of rotation (CoR; n=17), lateralized CoR (n=14), and lateralized humerus (n=125). Objective clinical outcomes, patient-reported outcomes, and radiographic outcomes were compared. Scapular notching occurred more frequently with medialized CoR (82%) and lateralized CoR (57%) designs compared with a lateralized humerus design (22%; P<.001). Mean notching grade was also lower in the lateralized humerus design (0.2) compared with the medialized CoR (2.1; P<.001) and lateralized CoR (1.1; P=.01) designs. Postoperative pain, range of motion, and patient-reported outcomes were not significantly different among groups. A low rate of reoperation was seen in all groups. The lateralized humeral RSA design showed less frequent and less severe scapular notching compared with medialized CoR and lateralized CoR designs. There were no observed differences in range of motion or patient-reported outcomes between different implant designs. [Orthopedics. 2020;43(6):e585-e591.].

Baseplate Options for Reverse Total Shoulder Arthroplasty

PURPOSE OF REVIEW

Baseplate fixation has been known to be the weak link in reverse total shoulder arthroplasty (RTSA). A wide variety of different baseplates options are currently available. This review investigates the recent literature to present the reader with an overview of the currently available baseplate options and modes of fixation.

RECENT FINDINGS

The main elements that differentiate baseplates are the central fixation element, the size of the baseplate, the shape, the backside geometry, whether or not an offset central fixation exists, the number of peripheral screws, and the availability of peripheral augmentation. The wide array of baseplate options indicates that no particular design has proven superiority. As such, surgeons should be aware of their options and choose an implant that the surgeon is comfortable with and one that best suits the individual patient anatomy. With the growing number of RTSA procedures and registries with long-term follow-up, future investigations will hopefully delineate the ideal baseplate design to optimize survivorship.

Bony increased-offset-reverse shoulder arthroplasty: 5 to 10 years' follow-up

BACKGROUND

Glenoid lateralization has been shown to be the most imortant factor in maximizing passive range of motion and shoulder stability while preventing scapular impingement and notching. We aimed to evaluate mid- to long-term functional and radiologic outcomes after bony increased-offset-reverse shoulder arthroplasty (BIO-RSA) using a Grammont-style (medialized) humeral implant.

METHODS

The study included 143 consecutive shoulders (140 patients; mean age, 72 years) treated with a BIO-RSA for rotator cuff deficiency. A cylinder of autologous cancellous bone graft, harvested from the humeral head, was placed between the reamed glenoid surface and baseplate; fixation was achieved using a long central peg (25 mm) and 4 screws. A large baseplate (29 mm) with a small baseplate sphere (36 mm) was used in 77% of cases, and a Grammont-style (medialized) humeral implant with 155° of inclination was used in all cases. All patients underwent clinical and radiographic assessment at a minimum of 5 years after surgery; in addition, 86 cases (60%) underwent computed tomography scan assessment.

RESULTS

At a mean follow-up of 75 months (range, 60-126 months), the survivorship of the BIO-RSA using revision as an endpoint was 96%. No cases of dislocation or humeral loosening were observed. Overall, 118 patients (83%) were either very satisfied (61%) or satisfied (22%). The adjusted Constant score improved from 40% ± 18% to 93% ± 23%, and the Subjective Shoulder Value improved from 31% ± 15% to 77% ± 18% (P < .001). The humeral bone graft incorporated completely in 96% of cases (137 of 143). Severe inferior scapular notching (grade 3 or 4) occurred in 18% (24 of 136). The risk of postoperative notching correlated to a lower body mass index (P < .05), superior glenosphere inclination (P = .02), and high or flush glenosphere positioning (P = .035).

CONCLUSIONS

BIO-RSA is a safe and effective technique to lateralize the glenoid, providing consistent bone graft healing, excellent functional outcomes, a low revision rate, and a high rate of patient satisfaction. Thin patients (with a low body mass index) and glenosphere malposition (with persistent superior inclination and/or insufficient lowering of the baseplate and sphere) are associated with higher risk of scapular notching.Our data confirm the importance of implanting the baseplate with a neutral inclination (reverse shoulder arthroplasty angle < 5°) and with sufficient glenosphere inferior overhang (>5 mm) in preventing scapular notching. The use of a less medialized humeral implant (135° or 145° inclined) and smaller (25-mm) baseplate (when using a small, 36-mm sphere) should allow reduction in the incidence of scapular notching.

Pseudoaneurysm of the Posterior Humeral Circumflex Artery After Reverse Shoulder Arthroplasty: A Case Report

CASE

A 78-year-old woman with rheumatoid arthritis and a massive rotator cuff tear of the right shoulder was treated with reverse shoulder arthroplasty, but a pseudoaneurysm in the posterior humeral circumflex artery suddenly ruptured 7 months after surgery. Embolization of the pseudoaneurysm and skin treatment successfully relieved her symptoms without implant removal.

CONCLUSION

Although a rare occurrence, vascular complication can occur after shoulder arthroplasty. The cause of the pseudoaneurysm was hypothesized to be repetitive contact between the humeral component and the artery and/or chronic traction of the blood vessel because of its chronic onset.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this study was to provide a focused, updated systematic review for each of the most common complications of RSA by limiting each search to publications after 2010. In this part II, the following were examined: (1) instability, (2) humerus/glenoid fracture, (3) acromial/scapular spine fractures (AF/SSF), and (4) problems/miscellaneous.

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Overall, 137 studies for instability, 94 for humerus/glenoid fracture, 120 for AF/SSF, and 74 for problems/miscellaneous were included in each review, respectively. Univariate analysis was performed with chi-square and Fisher exact tests.

Results

The Grammont design had a higher instability rate vs. all other designs combined (4.0%, 1.3%; P < .001), and the onlay humerus design had a lower rate than the lateralized glenoid design (0.9%, 2.0%; P = .02). The rate for intraoperative humerus fracture was 1.8%; intraoperative glenoid fracture, 0.3%; postoperative humerus fracture, 1.2%; and postoperative glenoid fracture, 0.1%. The rate of AF/SSF was 2.6% (371/14235). The rate for complex regional pain syndrome was 0.4%; deltoid injury, 0.1%; hematoma, 0.3%; and heterotopic ossification, 0.8%.

Conclusions

Focused systematic reviews of recent literature with a large volume of shoulders demonstrate that using non-Grammont modern prosthesis designs, complications including instability, intraoperative humerus and glenoid fractures, and hematoma are significantly reduced compared with previous studies. As the indications continue to expand for RSA, it is imperative to accurately track the rate and types of complications in order to justify its cost and increased indications.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part I

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this 2-part study was to systematically review each of the most common complications of RSA, limiting each search to publications in 2010 or later. In this part (part I), we examined (1) scapular notching (SN), (2) periprosthetic infection (PJI), (3) mechanical failure (glenoid or humeral component), and (4) neurologic injury (NI).

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Overall, 113 studies on SN, 62 on PJI, 34 on mechanical failure, and 48 on NI were included in our reviews. Univariate analysis was performed with the χ² or Fisher exact test.

Results

The Grammont design had a higher SN rate vs. all other designs combined (42.5% vs. 12.3%, P < .001). The onlay humeral design had a lower rate than the lateralized glenoid design (10.5% vs. 14.8%, P < .001). The PJI rate was 2.4% for primary RSA and 2.6% for revision RSA. The incidence of glenoid and humeral component loosening was 2.3% and 1.4%, respectively. The Grammont design had an increased NI rate vs. all other designs combined (0.9% vs. 0.1%, P = .04).

Conclusions

Focused systematic reviews of the recent literature with a large volume of RSAs demonstrate that with the use of non-Grammont modern prosthesis designs, complications including SN, PJI, glenoid component loosening, and NI are significantly reduced compared with previous studies. As the indications for RSA continue to expand, it is imperative to accurately track the rates and types of complications to justify its cost and increased indications.

Clinical application of intraoperative O-arm navigation in reverse shoulder arthroplasty

BACKGROUND

Inaccurate fixation and positioning of the glenoid component using conventional techniques are problematic in reversed shoulder arthroplasty (RSA). Our objective was to investigate the accuracy of O-arm navigation of the glenoid component in RSA.

METHODS

This retrospective case-control study comprised 2 groups of 25 patients who underwent reversed shoulder arthroplasty with or without intraoperative O-arm navigation. The intraoperative goal was to place the component neutrally in the glenoid in the axial plane and 10° inferiorly tilted in the scapular plane. Glenoid version angle and inclination were measured by computed tomography obtained preoperatively and a year postoperatively. Operative time, intraoperative bleeding, and the presence of postoperative complications were recorded.

RESULTS

Compared with the ideal, the range of error for version was 7.3° (SD 3.6°) in the control group and 5.6° (SD 3.6°) in the navigated group (P = 0.278), and the range of error for inclination was 18.3° (SD 11.7°) in the control group and 4.9° (SD 3.8°) in the navigated group (P = 0.0004). The mean operative time was 164.6 (SD 21.2) min in the control group and 192.0 (SD 16.2) min in the navigated group (P = 0.001). The mean intraoperative bleeding was 201.0 (SD 37.0) mL in the control group and 185.3 (SD 35.6) mL in the navigated group (P = 0.300). There were no complications reported related to the intraoperative O-arm navigation.

CONCLUSION

O-arm navigation may be a useful tool for the placement with inferior tilt of the glenoid procedure in reversed shoulder arthroplasty.

Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: Early Outcomes, Pitfalls, and Challenges

Objective

To evaluate the early outcomes and risk factors of reverse shoulder arthroplasty (RSA) in patients with rheumatoid arthritis (RA).

Methods

A retrospective study was performed on RA patients who had undergone RSA between January 2016 and January 2018. Preoperative glenohumeral joint damage was evaluated according to two radiographic classification systems. The severity of joint damage was estimated using Larsen's method, while the Levigne‐Franceschi method was used to assess the type of destruction. Further, we recorded intra‐ and postoperative complications. Visual Analogue Scale (VAS) was used to assess the degree of shoulder pain while shoulder function was evaluated with the American Shoulder and Elbow Surgeons (ASES) Shoulder Score. In addition, patients' subjective outcome and range of shoulder motion were recorded. Radiographs were taken and examined during the follow‐up period. Paired t‐test was used to determine the difference in measurement data between preoperative and the last follow‐up. VAS was analyzed using the Wilcoxon matched‐pairs signed‐rank test.

Results

A total of 14 patients with 14 shoulders were included. All the patients were female with an average age of 60.29 years (range, 49–71 years) at the time of surgery and an average RA disease duration of 24.57 years (range, 5–40 years). Seven of the 14 patients had a history of joint surgery related to RA. Meanwhile, 11 of the 14 shoulders showed glenoid bone defect, and eccentric reaming was performed intraoperatively to avoid base plate malposition. The mean follow‐up period for the 14 patients was 2.76 years (range, 2–4 years). The mean VAS decreased from a value of 5.71 ± 1.10 preoperatively to 1.36 ± 0.61 postoperatively (P < 0.001). On the contrary, the ASES score showed an increase from 33.93 ± 6.89 to 76.67 ± 5.23 (P < 0.001). An increase in active forward elevation, abduction, and external rotation with the arm in 90° of abduction from 85.71° ± 17.61°, 77.14° ± 19.43°, and 17.14° ± 10.97° to 126.43° ± 5.23°, 106.42° ± 11.72°, and 38.57° ± 14.57°, respectively, was observed (P < 0.001). Subjective outcome assessment showed that 13 of the 14 patients were very satisfied or satisfied with the operation, while one patient was uncertain due to co‐existing ipsilateral elbow lesion. Notably, one patient acquired a humeral periprosthetic fracture during the operation. In this study, no major complications such as periprosthetic joint infection and dislocation or implant loosening were observed. Further, no patients underwent revision for any reason at the end of the follow‐up.

Conclusions

RSA could achieve good early outcomes without high complication rates in patients with RA. Glenoid bone defects and adjacent joints involvement were common in this patient group, which might increase the risk of surgery and affect postoperative satisfaction.

Clinical characteristics and patient-reported outcomes of total shoulder arthroplasty after anterior stabilization: a retrospective matched control study

BACKGROUND

Instability arthropathy is a known cause of glenohumeral osteoarthritis (OA) among patients with and without prior shoulder stabilization. This study aims to compare the clinical, radiographic, and patient-reported outcome measure (PROM) scores among total shoulder arthroplasty (TSA) patients with and without a history of shoulder stabilization.

METHODS

A case-control study was performed comparing 20 patients with a history of anterior shoulder stabilization (11 open, 9 arthroscopic) who underwent TSA to a matched cohort of 20 TSA patients without a history of shoulder surgery (mean follow-up = 2.8 years). Patients were matched by sex, age, and baseline American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score within 10 points (mean age 59.6 ± 9.6 years). Patient characteristics, operative findings, and preoperative and postoperative radiographic characteristics for both groups were reported. Comparisons were made regarding PROM scores (ASES, 12-Item Short Form Health Survey (SF-12), Shoulder Activity Scale [SAS], numeric rating scale for pain) at baseline, 2 years, and 5 years and patient satisfaction at 2 years.

RESULTS

Intraoperative findings of subscapularis scarring or attenuation was common among patients with prior anterior stabilization. The instability cohort did have a higher percentage of B2/B3 glenoid types than the OA cohort (45% vs. 15%), but this was not significantly different possibly because of the small sample size. At 2 years, both instability and OA groups reported significant improvement in pain, function, and activity level. There was no difference between groups on any PROMs or patient satisfaction level. At 5 years, instability patients had significantly lower scores on the ASES and the SF-12 PCS than the OA group.

CONCLUSION

There was notable alterations in both soft tissue and bony morphology among patients with prior anterior stabilization. After TSA, both instability and primary OA groups showed significant improvements at 2 years. However, PROMs for instability patients deteriorated at 5 years compared with the control group. Complex bony and soft tissue imbalances may contribute to more unpredictable long-term PROM scores. Thoughtful preoperative consideration of these factors should influence decision making regarding selection of TSA for management of OA in this complex patient cohort.

Early results of reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency

BACKGROUND

Reverse total shoulder arthroplasty (rTSA) in the presence of significant glenoid bone loss remains a challenge. This study presents preliminary clinical and radiographic outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed custom metal glenoid implant to address severe glenoid bone deficiency.

METHODS

Between September 2017 and November 2018, 19 patients with severe glenoid bone deficiency underwent primary (n = 9) or revision rTSA (n = 10) using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet, Warsaw, IN, USA) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand score, Constant score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale pain score and active range of motion were compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05.

RESULTS

Complications occurred in 4 patients (21%), including a nondisplaced greater tuberosity fracture treated conservatively in 1, intraoperative cortical perforation during humeral cement removal treated with an allograft strut in 1, and recurrent instability and hematoma formation treated with humeral component revision in 1. One patient with an early periprosthetic infection was treated with component removal and antibiotic spacer placement at an outside facility and was subsequently lost to follow-up. Eighteen patients with 1-year minimum clinical and radiographic follow-up were evaluated (mean, 18.2 months; range, 12-27 months). Significant improvements were noted in the mean Disabilities of the Arm, Shoulder and Hand score (57.4 ± 16.5 vs. 29.4 ± 19.5, P < .001), mean Constant score (24.6 ± 10.2 vs. 60.4 ± 14.5, P < .001), mean American Shoulder and Elbow Surgeons score (32 ± 18.2 vs. 79 ± 15.6, P < .001), mean Simple Shoulder Test score (4.5 ± 2.6 vs. 9.3 ± 1.8, P < .001), mean Single Assessment Numeric Evaluation score (25.4 ± 13.7 vs. 72.2 ± 17.8, P < .001), mean visual analog scale pain score (6.2 ± 2.9 vs. 0.7 ± 1.3, P < .001), mean active forward flexion (53° ± 27° vs. 124° ± 23°, P < .001), and mean active abduction (42° ± 17° to 77° ± 15°, P < .001). Mean external rotation changed from 17° ± 19° to 32° ± 24° (P = .06). No radiographic evidence of component loosening, scapular notching, or hardware failure was observed at last follow-up in any patient.

CONCLUSION

The preliminary results of rTSA using the VRS to manage severe glenoid bone deficiency are promising, but longer follow-up is necessary to determine the longevity of this implant.

Preoperative glenoid considerations for shoulder arthroplasty: a review

Preoperative assessment of the glenoid in the setting of shoulder arthroplasty is critical to account for variations in glenoid morphology, wear, version, inclination, and glenohumeral subluxation.

Three-dimensional computed tomography (3D CT) scan assessment of the morphology of glenoid erosion allows for a more accurate surgical decision-making process to correct deformity and restore the joint line.

Newer technology has brought forth computer-assisted software for glenoid planning in shoulder arthroplasty and patient-specific instrumentation.

There have been promising early findings, although further evaluation is needed to determine how this technology impacts implant survivorship, function, and patient-reported outcomes.

Cite this article: EFORT Open Rev 2020;5:126-137. DOI: 10.1302/2058-5241.5.190011

Do Preoperative and Postoperative Glenoid Retroversion Influence Outcomes After Reverse Total Shoulder Arthroplasty?

Background

There are limited data on the effect of glenoid retroversion in clinical outcomes following reverse total shoulder arthroplasty (RTSA). The purpose of this study was to evaluate if surgical correction of retroversion affects outcomes following RTSA.

Methods

An institutional database was utilized to identify 177 patients (mean age: 68.2 ± 10.1 years) with minimum 2-year follow-up after primary RTSA. Glenoid version was measured on preoperative and postoperative radiographs. American Shoulder and Elbow Surgeons (ASES) scores and range of motion were collected before and after RTSA. Change in retroversion was determined by comparing preoperative and postoperative glenoid retroversion on radiographs using paired Wilcoxon signed-rank test. Spearman’s rank correlation was used to investigate relationships between ASES scores and glenoid retroversion.

Results

The mean postoperative ASES composite score (75.5 ± 22.7) was significantly higher than preoperative (36.8 ± 19.2; P < .0001). The mean preoperative glenoid retroversion was 9.1 ± 6.7° compared to 6.5 ± 5.1° postoperatively (P < .0001). There was no correlation between postoperative ASES scores and preoperative retroversion (r = .014, P = .85) or postoperative retroversion (r = −.043, P = .57). There was no statistical relationship between postoperative retroversion and range of motion, though there is a risk of inadequate power given the sample size.

Conclusions

Patient-reported outcomes and range of motion measurements following RTSA at short-term follow-up appear to be independent of either preoperative or postoperative glenoid retroversion.

Pre-operative factors affecting the indications for anatomical and reverse total shoulder arthroplasty in primary osteoarthritis and outcome comparison in patients aged seventy years and older

BACKGROUND

We evaluated the pre-operative factors affecting anatomical and reverse total shoulder arthroplasty (TSA and RTSA) indications in primary osteoarthritis and compared outcomes in patients aged 70 years and older.

METHODS

Fifty-eight patients received a TSA with an all-polyethylene glenoid component (APGC) or an RTSA with/without glenoid lateralization and the same curved short-stem humeral component. Active anterior and lateral elevation (AAE, ALE), internal and external rotation (IR, ER), pain, and the Constant-Murley score (CS) were recorded pre and post-operatively. Pre-operative rotator cuff (RC) fatty infiltration (FI) and modified Walch glenoid morphology were assessed. Humeral and glenoid component radiological outcomes were recorded.

RESULTS

RTSA were older than TSA patients (p = 0.006), had lower pre-operative AAE (p < 0.001), ALE (p < 0.001), IR (p = 0.002), pain (p = 0.008) and CS (p < 0.001), and greater supraspinatus FI (p < 0.001). At a mean of 28.8 months, both implants yielded significantly different post-operative scores and similar complication rates. Both groups achieved similar post-operative AAE, ER, and IR; ALE was higher in TSA (p = 0.006); and AAE and ALE delta scores were higher in RTSA (p = 0.045 and p = 0.033, respectively). Radiolucent line rates were higher around the TSA APGC than the RTSA baseplate (p = 0.001). High-grade RC FI adversely affected mobility improvement. Humeral cortical thinning was significantly higher in TSA (p = 0.001).

CONCLUSION

RTSA patients were older, had poorer pre-operative active mobility, and had greater RC FI than TSA. Both devices provided good mid-term clinical and ROM improvement.

Early radiographic failure of reverse total shoulder arthroplasty with structural bone graft for glenoid bone loss

INTRODUCTION

Structural glenoid bone grafting in reverse total shoulder arthroplasty (RSA) has previously been reported to have good functional outcomes and low complication rates. We have observed different complication rates and hypothesized that baseplate fixation and severity of deformity may be predictors of early failure.

METHODS

We retrospectively identified 44 patients who underwent RSA with structural bone grafting for glenoid bone defects. All patients had preoperative and postoperative (Grashey and axillary) radiographs at a minimum of 1 year after surgery and within 3 months of surgery for evaluation of implant and graft positioning. Clinical data and outcome scores were collected at the same intervals.

RESULTS

There were 61% females and 39% males, with an average age of 74 ± 8 years at the time of surgery. The median final radiographic follow-up was 20 months, with 37 primary RSA and 7 revision RSA. Graft resorption was found in 11 of 44 patients (25%), and radiographic failure was found in 11 of 44 patients (25%) at a median of 8 months (range 3-51 months). Forward elevation, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) scores all significantly improved postoperatively (P < .0001). Radiographic baseplate failure was associated with graft resorption (P = .002), more retroversion correction (P = .02), and worse SANE scores at final follow-up (P = .01).

DISCUSSION/CONCLUSION

RSA with structural bone graft improved range of motion and function, but there was a larger than previously reported baseplate loosening rate. This early radiographic loosening appeared to be associated with graft resorption, retroversion correction, and worse outcome scores.

Structural glenoid allograft reconstruction during reverse total shoulder arthroplasty

BACKGROUND

Large glenoid defects present a challenge during primary and revision reverse total shoulder arthroplasty (RTSA) especially when humeral head autograft is not available as a bone graft source. The purpose of this study was to evaluate the clinical and radiographic outcomes of RTSA with concomitant structural allografting to reconstruct large glenoid defects.

METHODS

From May 2008 to July 2016, 22 patients underwent primary or revision RTSA with structural glenoid allografting. Of 22 patients, 19 (86%) were available for a minimum 2-year clinical follow-up (average, 2.8 ± 1.3 years), and 17 of 22 (77%) were available for a minimum 1-year radiographic follow-up. Functional outcomes, range of motion, radiographic deformity correction, allograft incorporation, and complication rates were determined.

RESULTS

From preoperatively to postoperatively, significant improvements in the average Simple Shoulder Test score (2 ± 2 preoperatively vs. 10 ± 8 postoperatively, P = .002), the average American Shoulder and Elbow Surgeons score (31 ± 19 preoperatively vs. 70 ± 25 postoperatively, P < .001), and average active forward elevation (71° ± 41° preoperatively vs. 128° ± 28° postoperatively, P < .001) were noted. Coronal-plane radiographic correction was 29° ± 12° as measured with the reverse shoulder arthroplasty angle (P < .001) and 14° ± 11° as measured with the β angle (P < .001). Postoperatively, of 17 patients with a minimum 1-year radiographic follow-up, 14 (82%) had complete radiographic incorporation of the graft. Acromial fracture nonunions developed in 2 patients and loosening and migration of the baseplate were found in 2 patients, although no patients elected to undergo further surgery.

CONCLUSIONS

RTSA with allograft reconstruction of severe glenoid defects allows restoration of glenoid anatomy and leads to high rates of bony incorporation with low rates of glenoid loosening or requirement for revision. Structural allograft is an excellent alternative to autograft in revision RTSA to avoid graft-site morbidity.

The influence of glenoid component position on scapular notching: a detailed radiographic analysis at midterm follow-up

Background

Glenoid baseplate and glenosphere positioning may affect scapular notching rates. The purpose of this study was to assess various radiographic parameters and correlate them with scapular notching after primary reverse total shoulder arthroplasty (RTSA) at a minimum follow-up time of 5 years.

Methods

The study sample included 147 primary RTSA with good-quality postoperative radiographs at least 5 years after implantation (mean follow-up 6.1 years, range 5-12 years). The center of rotation (COR) of the glenosphere in reference to the bone-baseplate interface was medialized in 71 and lateralized in 76 shoulders, with a varus polyethylene opening angle in 134 shoulders. Preoperative and immediate postoperative radiographs were measured to determine (1) glenoid baseplate inclination: α, β, and the reverse shoulder arthroplasty (RSA) angles; (2) glenoid component inferiorization—peg glenoid rim distance (PGRD); and (3) sphere bone overhang distance (SBOD). Scapular notching was graded according to the Sirveaux classification.

Results

Scapular notching was noted in 98 shoulders (67%) and classified as grade 1 in 46, grade 2 in 25, grade 3 in 20, and grade 4 in 7. There were statistically significant associations between notching and both medialized glenospheres (91% vs. 45%, P = .001) and varus polyethylene angle (P = .0001). The mean postoperative RSA angle, PGRD, and SBOD were 6.6 degrees, 23.8 mm, and +2.6 mm, respectively. Preoperative α and postoperative β, RSA, PGRD, and SBOD were all associated with notching (P < .05). The rate of reoperation was 2.7% at a minimum of 5 years, with reasons for reoperation related to component failure in only one shoulder.

Conclusion

Scapular notching correlates with glenoid and baseplate inclination, baseplate inferiorization, inferior glenosphere overhang, glenosphere COR, humeral polyethylene angle, and longer clinical follow-up. SBOD is a clinically useful measurement with decreased values associated with notching. It is the superior measurement in implants with eccentric glenospheres. Moderate or severe notching was seen in only approximately 15% of the shoulders. Revision surgery was extremely low in this cohort, and it was not related to notching or instability.

Clinical results of bony increased-offset reverse shoulder arthroplasty (BIO-RSA) associated with an onlay 145° curved stem in patients with cuff tear arthropathy: a comparative study

BACKGROUND

The main limits of the Grammont design reverse shoulder arthroplasty (RSA) are loss of external rotation and scapular notching. They can be addressed with glenoid or humeral lateralization. The aim of the study was to compare outcomes of lateralized bony increased-offset RSA (BIO-RSA) vs. standard RSA in patients with an onlay 145° curved stem.

METHODS

A comparative cohort study of 29 standard RSAs and 30 BIO-RSAs was performed. At 2 years postoperatively, Constant score, American Shoulder and Elbow Surgeons score, visual analog scale score, range of motion, and radiographs were evaluated. After comparison between the groups, patients were analyzed considering patients younger and older than 65 years.

RESULTS

All parameters significantly improved after surgery in both groups. Postoperatively, the 2 groups did not show any clinical and radiographic differences (P > .05). In patients <66 years, BIO-RSA showed a significantly higher value of external rotation (49° ± 12° vs. 30° ± 19° [P = .025], elbow at side; 81° ± 17° vs. 56° ± 22° [P = .016], elbow at 90° of abduction) and a positive trend for all other parameters (P > .05). In patients >65 years, standard technique showed a positive trend for all the parameters (P > .05). No other significant differences were found.

CONCLUSIONS

At 2 years of follow-up, the use of standard RSA or BIO-RSA in an implant with an onlay 145° curved stem provided similar outcomes. The humeral lateralization alone is sufficient to decrease notching and to improve external rotation. BIO-RSA increases external rotation in patients between 50 and 65 years old. Glenoid bone graft in RSA has a high incorporation rate (completed in 90%).

Reverse Shoulder Arthroplasty for B2 Glenoid Deformity

In shoulder osteoarthritis, the B2 glenoid presents challenges in treatment because of the excessive retroversion and posterior deficiency of the glenoid. Correction of retroversion and maintenance of a stable joint line with well-fixed implants are essential for the successful treatment of this deformity with arthroplasty. Reverse shoulder arthroplasty offers several key advantages in achieving this goal, including favorable biomechanics, a well-fixed baseplate, and proven success in other applications. Techniques such as eccentric reaming, bone grafting, and baseplate augmentation allow surgeons to tailor treatment to the patient’s altered anatomy. Eccentric reaming is favored for correction of small defects or mild version anomalies. Current trends favor bone grafting for larger corrections, though augmented components have shown early promise with the potential for expanded use. With overall promising results reported in the literature, reverse shoulder arthroplasty is a useful tool for treating older patients with B2 glenoid deformities.

Bone grafting in primary and revision reverse total shoulder arthroplasty for the management of glenoid bone loss: A systematic review

Purpose

We performed a systematic review of the studies including clinical/functional outcomes and complications of bone grafting for glenoid defects in reverse total shoulder arthroplasty (RTSA).

Methods

The PubMed and Cochrane databases were searched for relevant papers.

Results

Thirteen articles were included. The mean clinical/functional subjective scores significantly improved postoperatively. The implant revision rate for primary and revision RTSA was 3.1% and 21.1% respectively. The reoperation rate was 3.5% and 24.4% respectively.

Conclusions

There was moderate evidence that bone grafting is effective for glenoid defects in primary RTSA. Further high-quality research is required about revision RTSA for moderate-to-severe glenoid defects.