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Anatomical total shoulder arthroplasty in its modern form where it reproduces the normal shoulder has been utilized clinically for more than half a century. As the technology and the designs have changed to recreate the humeral and glenoid sides of the joint, the sophistication of design has resulted in the growing number of cases annually worldwide. This increase is due in part to the increasing number of indications that the prosthesis can treat with successful results. On the humeral side, there have been design changes to better reflect the proximal humeral anatomy, and humeral stems are increasingly placed safely without cement. Platform systems which allow conversion of a failed arthroplasty to a reverse configuration without stem extraction is another design change. Similarly, there has been increasing utilization of short stem and stemless humeral components. Extensive experience with shorter stem and stemless devices, however, has yet to demonstrate the purported advantages of these devices, as recent studies have demonstrated equivalent blood loss, fracture rates, operative times, and outcome scores. Easier revision with these shorter stems remains to be definitively established, with only one study comparing the ease of revision between stem types. On the glenoid side, hybrid cementless glenoids, inlay glenoids, cementless all-polyethylene glenoids, and augmented glenoids have all been investigated; however, the indications for these devices remain unclear. Lastly, innovative surgical approaches to implanting shoulder arthroplasty and the use of patient specific guides and computerized planning, while interesting concepts, still await validation before they are utilized on a widespread basis. While reverse shoulder arthroplasty has been increasingly used to reconstruct the arthritic shoulder, anatomic glenohumeral replacement maintains a significant role in the armamentarium of the shoulder surgeon.

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Total shoulder arthroplasty (TSA) has been the gold standard of care for end-stage glenohumeral arthritis. Outcomes are varied and have been affected by both patient and implant characteristics. Patient factors, such as age, preoperative diagnosis, and preoperative glenoid morphology, can affect the outcomes after TSA. Similarly, the different glenoid and humeral component designs significantly affect the survivorship of TSA. Significant evolution has occurred in the design of the glenoid component with the aim of decreasing the glenoid-sided causes of failure in TSA. On the other hand, focus on the humeral component has been increasing as well, with a trend towards using shorter humeral stems. This article aims to look at the outcomes of TSA as affected by the various patient characteristics and design options for the glenoid and the humeral components. This review also aims to compare survivorship data from global literature and the Australian joint replacement registry and to provide insights into the implant combination that may provide the best patient outcome.

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Background: The purpose of this study is to compare the 90-day complications and readmission rates between patients undergoing total shoulder arthroplasty (TSA) in an ambulatory surgery center (ASC) with glenoid bone loss requiring an augmented glenoid component compared to patients without bone loss. Methods: This is a retrospective cohort study of patients undergoing outpatient TSA at an ASC (2018-2021). Readmission, direct transfer, and complications were recorded. Major and minor complications were compared. Secondary outcomes included operative time, estimated blood loss, range of motion, and patient-reported outcome measures. Results: There were 44 patients (45 shoulders) included in the study, 20 with augmented implants for glenoid bone loss and 25 nonaugmented with a concentric glenoid. There were no statistical differences in demographics. Two complications were seen in both the augmented and nonaugmented groups (10% vs. 8%). There were no readmissions or direct transfers. The augmented group had significantly increased preoperative glenoid retroversion (23° vs. 9°, P < .05), posterior humeral head subluxation (78% vs. 61%., P < .05), and longer operative time (124.4 min vs. 112.3 min., P < .05). Patient-specific instrumentation was used in 60% of augmented cases and 29% of nonaugmented cases. Conclusion: There was no significant difference in complications, direct transfers, or readmissions between patients with and without glenoid bone loss being treated in an outpatient ASC. The augmented group had significantly worse preoperative deformities, longer operative times, and increased utilization of patient-specific instrumentation. Outpatient TSA in the setting of glenoid bone loss requiring augmentation was found to be safe and effective at a stand-alone ASC.

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BACKGROUND: Posteriorly augmented glenoid components in anatomic total shoulder arthroplasty (TSA) address posterior glenoid bone loss with inconsistent results. The purpose of this study was to identify preoperative and postoperative factors that impact range of motion (ROM) and function after augmented TSA in patients with type B2 or B3 glenoid morphology. METHODS: This was a retrospective review of all patients who underwent TSA with a step-type augmentation performed by a single surgeon between 2009 and 2018. Patients with Walch type B2 or B3 glenoids were included. Outcomes included forward elevation (FE), external rotation (ER), internal rotation (IR), Single Assessment Numeric Evaluation (SANE) score, and visual analog scale pain score. Preoperative imaging was reviewed to assess glenoid retroversion and posterior humeral head subluxation relative to the scapular body and midglenoid face. Postoperative measurements included glenoid retroversion, subluxation relative to the scapular body, subluxation relative to the central glenoid peg, and center-peg osteolysis. Measurements were performed by investigators blinded to ROM and functional outcome scores. RESULTS: Fifty patients (mean age, 68.1 ± 8.0 years) with a mean follow-up period of 42.0 months (range, 24-106 months) were included. Glenoid morphology included type B2 glenoids in 41 patients and type B3 glenoids in 9. One patient had center-peg osteolysis, and 1 patient had glenoid component loosening. Average preoperative FE, ER, and IR were 110°, 21°, and S1, respectively. Average postoperative FE, ER, and IR were 155°, 42°, and L1, respectively. The mean postoperative visual analog scale score was 0.5 ± 0.8, and the mean SANE score was 94.5 ± 5.6. Type B3 glenoids were associated with better postoperative IR compared with type B2 glenoids (T10 vs. L1, P = .024), with no other differences in ROM between the glenoid types. Preoperative glenoid retroversion did not significantly impact postoperative ROM. Postoperative glenoid component retroversion and residual posterior subluxation relative to the scapular body or glenoid face did not correlate with ROM in any plane. However, posterior subluxation relative to the glenoid face was moderately associated with lower SANE scores (r = -0.448, P = .006). CONCLUSION: Patients achieved excellent functional outcomes and pain improvement after TSA with an augmented glenoid component. Postoperative ROM and function showed no clinically important associations with preoperative or postoperative glenoid retroversion or humeral head subluxation in our cohort of posteriorly augmented TSAs, except for worse functional scores with increased humeral head subluxation in relation to the glenoid surface.

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PURPOSE: The purpose of this study was to compare the outcomes of primary reverse total shoulder arthroplasty (rTSA) using glenoid bone grafting (BG rTSA) with primary rTSA using augmented glenoid baseplates (Aug rTSA) with a minimum 2-year follow-up. METHODS: A total of 520 primary rTSA patients treated with 8° posterior glenoid augments (n = 246), 10° superior glenoid augments (n = 97), or combined 10° superior/8° posterior glenoid augments (n = 177) were compared with 47 patients undergoing glenoid bone grafting for glenoid bone insufficiency. The mean follow-up was 37.0(±16) and 53.0(±27) months, respectively. Outcomes were analyzed preoperatively and at the latest follow-up using conventional statistics and stratification by minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds where applicable. Radiographs were analyzed for baseplate failure, and the incidences of postoperative complications and revisions were recorded. RESULTS: The glenoid Aug rTSA cohort had greater improvements in patient-reported outcome measures (PROMs) and range of motion when compared with the BG rTSA group at a minimum of 2-year follow-up, including Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles score, Shoulder Pain and Disability Index score, shoulder function, Shoulder Arthroplasty Smart score, abduction, and external rotation (P < .05). Patient satisfaction was higher in the Aug rTSA group compared with the BG rTSA group (P = .006). The utilization of an augmented glenoid component instead of glenoid bone grafting resulted in approximately 50% less total intraoperative time (P < .001), nearly 33% less intraoperative blood loss volume (P < .001), approximately 3-fold less scapular notching (P < .01), and approximately 8-fold less adverse events requiring revision (P < .01) when compared with the BG rTSA cohort. Aside from SCB for abduction, the Aug rTSA cohort achieved higher rates of exceeding MCID and SCB for every PROM compared with BG rTSA. More specifically, 77.6% and 70.2% of the Aug rTSA achieved SCB for American Shoulder and Elbow Surgeons and Shoulder Pain and Disability Index vs. 55% and 48.6% in the BG rTSA, respectively (P = .003 and P = .013). CONCLUSION: The present midterm clinical and radiographic study demonstrates that the utilization of an augmented baseplate for insufficient glenoid bone stock is superior as judged by multiple PROMs and range of motion metrics when compared with bone graft augmentation at minimum 2-year follow-up. In addition, when analyzed according to MCID and SCB thresholds, the use of augmented baseplates outperforms the use of glenoid bone grafting. Complication and revision rates also favor the use of augmented glenoid baseplates over glenoid bone grafting. Long-term clinical and radiographic follow-up is necessary to confirm that these promising midterm results are durable.

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Background: The objective was to evaluate the short-term clinical and radiological outcomes following augmented anatomic total shoulder arthroplasty in patients with posterior glenoid deficiency. Methods: An electronic search of EMBASE, MEDLINE, and PubMed identified studies reporting clinical and radiographic outcomes following augmented anatomic total shoulder arthroplasty among patients with posterior glenoid deficiency. Results: Nine studies including 312 shoulders underwent anatomic total shoulder arthroplasty using an augmented glenoid implant between 2015 and 2020. A statistically significant improvement in range of motion (ROM), visual analog scale (VAS), American Shoulder & Elbow Surgeons (ASES), Constant, University of California - Los Angeles and Simple Shoulder Test (SST) scores was demonstrated at mean follow-up of 37.1 months. Glenoid retroversion improved from 21.8° to 9.5°. At final follow-up, radiolucency was reported in 35.1% of shoulders. The 16° full-wedge augment led to higher and more severe radiographic lucency, while high peg perforation rates (44%) were observed among 5-mm augment stepped implants. The overall rate of complication was 2.6%. Rate of revision surgery was 1.9%. Conclusions: Overall, early- to mid-term outcomes following augmented anatomic total shoulder arthroplasty for posterior glenoid deficiency demonstrate good to excellent overall clinical results. More radiographic and clinical failures were reported in larger full wedge (16°) augments and stepped augments (5 mm). Prospective studies examining mid- and long-term outcomes will help further elucidate safety and efficacy of these relatively new implants.

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BACKGROUND: Glenoid bone loss in anatomic total shoulder arthroplasty (aTSA) remains a controversial and challenging clinical problem. Previous studies have shown high rates of glenoid loosening for aTSA in shoulders with retroversion, posterior bone loss, and posterior humeral head subluxation. This study is the first to present minimum 2-year follow-up data of an all-polyethylene, biconvex augmented anatomic glenoid component for correction of glenoid retroversion and posterior humeral head subluxation. METHODS: This study is a multicenter, retrospective review of prospectively collected data on consecutive patients from 7 global clinical sites. All patients underwent aTSA using the biconvex posterior augmented glenoid (PAG). Inclusion criteria were preoperative computed tomographic (CT) scan, minimum 2 years since surgery, preoperative and minimum 2-year postoperative range of motion examination, and patient-reported outcome measures (PROMs). Glenoid classification, glenoid retroversion, and posterior humeral head subluxation were measured from preoperative CT and radiography and postoperative radiography. Statistical comparisons between pre- and postoperative values were performed with a paired t test. RESULTS: Eighty-six of 110 consecutive patients during the study period (78% follow-up) met the inclusion criteria and were included in our analysis. Mean follow-up was 35 ± 10 months, with a mean age of 68 ± 8 years (range 48-85). Range of motion statistically improved in all planes from pre- to postoperation. Mean visual analog scale score improved from 5.2 preoperation to 0.7 postoperation, Single Assessment Numeric Evaluation score from 43.2 to 89.5, Constant score from 41.8 to 76.9, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score from 49.8 to 86.7 (all P < .0001). Mean glenoid retroversion improved from 19.3° to 7.4° (P < .0001). Posterior subluxation improved from 69.1% to 53.5% and posterior decentering improved from 5.8% to -3.0% (P < .0001). There was 1 patient with both a prosthetic joint infection and radiographic glenoid loosening that required revision. Seventy-nine of 86 patients had a Lazarus score of 0 (no radiolucency seen about peg or keel) at final follow-up. CONCLUSIONS: This study shows that at minimum 2-year follow-up, a posterior-augmented all-polyethylene glenoid can correct glenoid retroversion and posterior humeral head subluxation. Clinically, there was significant improvement in both range of motion and PROMs.

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Background: Walch B2 glenoid morphology with glenohumeral osteoarthritis is a difficult degenerative pattern to manage for shoulder surgeons. Anatomic total shoulder arthroplasty (TSA) in combination with eccentric reaming or bone grafting are the traditional methods of treatment. Newer approaches such as TSA with posteriorly augmented glenoid components and reverse shoulder arthroplasty (RSA) may offer better stability for the posteriorly subluxated biconcave B2 wear pattern. The aim of this systematic review is to compare mid-term surgical and functional outcomes of Walch B2 glenoids without significant rotator cuff pathology treated with TSA and RSA. Methods: The review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by searching the MEDLINE (PubMed) and Embase (Elsevier) databases. Inclusion criteria were clinical studies that evaluated the outcomes and complications of TSA or RSA in the setting of B2 glenoid morphology without significant rotator cuff pathology. Data relevant to TSA and RSA surgical outcomes were extracted and compiled, and outcomes were compared. A meta-analysis of proportions of complication and revision rates among TSA and RSA groups was performed. Results: Overall, 16 articles were included with 414 TSAs and 78 RSAs. The average follow-up duration was 54.1 ± 14.8 months for patients undergoing TSA and 44.8 ± 10.1 months for patients undergoing RSA. The TSA group was further subdivided based on the use of eccentric reaming (135 TSAs), an augmented glenoid component (84 TSAs), or bone grafting (11 TSAs) or was unspecified (184 TSAs). Overall, patients undergoing TSA and RSA demonstrated mean improvements of 50.1 ± 8.5° and 64.7 ± 5.2° in active flexion, 58.5 ± 10.3° and 68.9 ± not reported° in active abduction, and 31.3 ± 5.7° and 29.0 ± 10.2° in active external rotation, respectively. In regard to functional outcome scores, patients undergoing TSA and RSA showed mean Constant score improvements of 38.8 ± 5.3 and 46.6 ± 3.1 points and American Shoulder and Elbow Surgeons score improvements of 48.2 ± 1.0 and 49.2 ± 25.3 points, respectively. Results of the meta-analysis with mid-term follow-up data demonstrated pooled complication rates of 9% (95% confidence interval [CI], 1%-22%) for TSA and 6% (95% CI, 0%-28%) for RSA and pooled revision rates of 2% (95% CI, 0%-8%) for TSA and 1% (95% CI, 0%-15%) for RSA. Conclusion: In the setting of Walch B2 glenoid morphology, TSA with eccentric reaming or an augmented component yields comparable outcomes to RSA. Based on the patient's age, activity level, and expectations, both TSA and RSA can be considered a reasonable option to treat Walch B2 glenoid morphology.

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BACKGROUND: Preoperative 3D planning and intraoperative navigation for shoulder arthroplasty has recently gained interest because of the potential to enhance the surgeon's understanding of glenoid anatomy and improve the accuracy of glenoid component positioning. The purpose of our study was to assess the impact of preoperative 3D planning on the surgeon's selection of the glenoid component (standard vs. augmented) and compare duration of surgery with and without intraoperative navigation. METHODS: We retrospectively analyzed 200 consecutive patients who underwent shoulder arthroplasty. The first group of 100 patients underwent shoulder arthroplasty using standard 2D preoperative planning based on standard radiographs and computed tomographic scans. The second group of 100 patients underwent shoulder arthroplasty using 3D preoperative planning and intraoperative navigation. Type of glenoid component and operative time were recorded in each case. RESULTS: For the group of patients with standard preoperative planning, only 15 augmented glenoid components were used, whereas in the group of patients with 3D preoperative planning and navigation, 54 augments were used (P < .001). The operative time was 11 minutes longer for the procedures that used intraoperative navigation, compared with those that did not (P < .001). This difference diminished as the surgeon became more proficient with the navigation technique. CONCLUSION: Use of preoperative 3D planning changes the surgeon's understanding of the patient's glenoid anatomy. In our study, using 3D planning increased the likelihood that the surgeon selected an augmented glenoid component compared with 2D planning. Intraoperative navigation slightly lengthened the duration of surgery, but this became insignificant as part of a learning curve within 6 months.

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BACKGROUND: Preoperative planning software is gaining utility in reverse total shoulder arthroplasty (RTSA), particularly when addressing pathologic glenoid wear. The purpose of this study was to quantify inter- and intrasurgeon variability in preoperative planning a series of RTSA cases to identify differences in how surgeons consider optimal implant placement. This may help identify opportunities to establish consensus when correlating plan differences with clinical data. METHODS: A total of 49 computed tomography scans from actual RTSA cases were planned for RTSA by 9 fellowship-trained shoulder surgeons using the same platform (Exactech GPS, Exactech Inc., Gainesville, FL, USA). Each case was planned a second time 6-12 weeks later. Variability within and between surgeons was measured for implant selection, version correction, inclination correction, and implant face position. Interclass correlation coefficients, and Pearson and Light's kappa coefficient were used for statistical analysis. RESULTS: There was considerable variation in the frequency of augmented baseplate selection between surgeons and between rounds for the same surgeon. Thresholds for augment use also varied between surgeons. Interclass correlation coefficients for intersurgeon variability ranged from 0.43 for version, 0.42 for inclination, and 0.25 for baseplate type. Pearson coefficients for intrasurgeon variability were 0.34 for version and 0.30 for inclination. Light's kappa coefficient for baseplate type was 0.61. CONCLUSIONS: This study demonstrates substantial variability both between surgeons and between rounds for individual surgeons when planning RTSA. Although average differences between plans were relatively small, there were large differences in specific cases suggesting little consensus on optimal planning parameters and opportunities to establish guidelines based on glenoid pathoanatomy. The correlation of preoperative planning with clinical outcomes will help to establish such guidelines.

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BACKGROUND: Failure rates in anatomic total shoulder arthroplasty (aTSA) are higher in case of asymmetric glenoid bone loss secondary to posterior wear, and in persistent static posterior subluxation of the humeral head (PSH). HYPOTHESIS: This study aimed to test the hypothesis that the combined use of posterior augmented glenoid (PAG) implants with three-dimensional (3D) surgical planning and patient-specific instrumentation (PSI) guides helps reduce short-term PSH after aTSA in patients with type B2-B3 glenoids. PATIENTS AND METHODS: We included nine consecutive patients with primary glenohumeral osteoarthritis and type B2 or B3 glenoids, who underwent aTSA with cemented keeled PAG implants (posterior augments of 15, 25, or 35 degrees). All patients underwent preoperative shoulder computed tomography (CT) scans, with 3D surgical planning coupled to PSI at the time of surgery. Postoperative shoulder CT scans were performed at an average of 14 weeks (range, 10-21 weeks). Scapulohumeral subluxation and glenoid version and inclination were measured in 3D, on both pre- and post-operative CT scans, using the same reliable quantitative method. RESULTS: There was a significant decrease in scapulohumeral subluxation from 49±12% preoperatively to 22±17% postoperatively (p=0.0039), with a large effect size (Cohen's d=1.89). Preoperative glenoid version was corrected from -17.3±9.4 degrees to -5.2±7.5 degrees postoperatively. The absolute difference between the postoperative and surgically planned version and inclination was 5.4±3.6 degrees and 3.3±2.0 degrees, respectively. DISCUSSION: The combined use of PAG implants with 3D preoperative planning and PSI results in a significant decrease in short-term PSH and glenoid version in patients with asymmetric posterior glenoid wear. We suggest that such implants should not be limited to posterior augmentation, because glenoid deficiency can also be observed in other glenoid sectors. LEVEL OF EVIDENCE: IV, Basic science study.

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INTRODUCTION: Walch type B2 has biconcave glenoid with posterior erosion, bone loss and humeral head subluxation. This leads to decreased glenohumeral contact area and increased contact pressure. During total shoulder arthroplasty(TSA), uncorrected retroversion causes eccentric loading and failure of glenoid component. It also leads to humeral head decentring with posterior rim loading, early glenoid wear and component loosening. This study aims to review anatomical restoration of glenoid version and humeral head centring in TSA with B2 glenoid using CT scans. METHODS: This is a retrospective review of TSA for glenohumeral osteoarthritis with B2 Glenoid morphology. All polyethylene posterior wedge augmented glenoid component was used. All patients underwent pre and post surgery CT Scans. Glenoid version was calculated using neoglenoid line and medial scapular border as reference point. Post-operative humeral head centering was calculated using offset of centre of rotation of humeral head with plane of scapula on axial CT-Scan. RESULTS: Study had 10 patients with 11 TSA between June 2017 and July 2018. Mean age was 59(45-80)years. Mean preoperative retroversion was 16(13-23)degrees. This was corrected to a mean of 0° retroversion postoperatively. 63% had good radiological correction (0-5° retroversion). Humeral head was well centered post-operatively with mean humeral scapula alignment offset of 2.1(0.8-4.5) mm posteriorly. All cases had well-centered humeral head postoperatively with offset less than 5 mm. CONCLUSIONS: Total shoulder replacement in B2 glenoid is technically demanding. Our radiological results show favourable outcome in terms of correction of gelenoid retroversion and eliminating posterior instability using wedge glenoid component. LEVEL OF EVIDENCE: IV.

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BACKGROUND: Osteoarthritis of the glenohumeral joint is often associated with posterior glenoid wear. The purpose of this study was to determine the clinical and radiographic outcomes of a posteriorly augmented glenoid in patients who have a Walch B glenoid deformity when treated with anatomic total shoulder arthroplasty (aTSA). METHODS: At total of 68 primary aTSA patients with osteoarthritis and a Walch B glenoid deformity were treated with an 8° posteriorly augmented glenoid. All patients were evaluated and underwent scoring preoperatively and at latest follow-up with 5 clinical outcome scoring metrics; active range of motion (ROM) was also measured. The mean follow-up period was 50 months, with a 2-year minimum follow-up period. RESULTS: All patients experienced significant improvements in pain and function following aTSA with a posteriorly augmented glenoid, and 90% of patients exceeded the minimal clinically important difference threshold for the clinical outcome metric scores and ROM measures. Two-thirds of patients exceeded the substantial clinical benefit threshold for the clinical outcome metrics and ROM. Preoperatively, the humeral head was posteriorly subluxated an average of 73% for each Walch B glenoid type, and at latest follow-up, all humeral heads were re-centered on the posteriorly augmented glenoid. Two patients with augmented glenoids who had Walch B2 glenoids underwent revision for aseptic glenoid loosening. DISCUSSION: Anatomic total shoulder arthroplasty patients with Walch B glenoids receiving an 8° posteriorly augmented wedge glenoid experienced excellent clinical and radiographic outcomes with a patient satisfaction rate greater than 97% and a low complication rate at a mean follow-up of 50 months. Humeral head centering was maintained for each type of Walch B glenoid.

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BACKGROUND: Managing posterior glenoid wear and retroversion remains a challenge in shoulder arthroplasty. Correcting glenoid version through asymmetric reaming (AR) with placement of a standard glenoid component and the use of posteriorly augmented glenoid (PAG) components are two methods used to address this problem. Our objective is to report the radiographic outcomes of patients with posterior glenoid wear and/or retroversion treated with either approach. METHODS: Patients with posterior glenoid wear and a minimum of 15 degrees of retroversion, treated with AR and standard glenoid component or with a PAG component (3 mm, 5 mm, or 7 mm posterior augmentation), were consecutively identified through retrospective chart review. Pre-operative axillary views were evaluated for version, humeral head subluxation in relation to scapular axis and to mid-glenoid face. Post-operative axillary views were reviewed to measure corrected inversion and humeral head subluxation. RESULTS: There were 48 patients in the AR group and 49 patients in the PAG group. Version improved 6.8 degrees in the AR group. In the PAG group, version improved 8.8 degrees with 3 mm augment, 13.4 degrees with 5 mm augment, and 12.8 with 7 mm augments. There were significantly more central peg perforations in the 5 mm PAG group compared to other groups. The humeral head was re-centered within 6.1% of normal in all groups except 7 mm augments. CONCLUSION: This study demonstrates that AR and PAGs have the ability to re-center the humeral head when utilized in patients with retroversion and posterior wear. Use of a PAG component may allow for greater correction of glenoid retroversion, however, there is an increased risk for central peg perforation with the specific implant utilized in this study. Long-term follow-up is ongoing and needed to understand the clinical implications of these findings.

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The Walch B2 glenoid is characterized by a biconcave glenoid deformity, acquired glenoid retroversion, and posterior humeral head subluxation. Surgical reconstruction of the B2 glenoid remains a challenge. Surgical management options include arthroscopic debridement, hemiarthroplasty, anatomic total shoulder arthroplasty with eccentric reaming, bone grafting or augmented glenoid implants, and reverse total shoulder arthroplasty. Multiple factors dictate the optimal surgical management strategy.. This article describes each of these techniques and presents the current available literature in an effort to guide evidence-based decisions in the surgical management of the B2 glenoid deformity.

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BACKGROUND: Augmented glenoid components restore the native joint line and preserve bone in shoulders with posterior glenoid bone loss. The purpose of this study was to compare the clinical and radiographic outcomes of augmented total shoulder arthroplasties (TSAs) vs. case-matched shoulders with standard implants to assess the early performance of a full-wedge augmented glenoid component. METHODS: Between 2010 and 2015, all TSAs using a full-wedge posteriorly augmented glenoid component with a minimum 2-year follow-up from a single institution were retrospectively reviewed. A total of 37 augmented TSAs were matched with 37 control shoulders with unaugmented glenoid components. The primary outcomes were revision and radiographic glenoid lucencies. Secondary outcomes included range of motion (ROM) and patient-reported outcomes (PROs). RESULTS: Both augmented and standard TSAs produced similar improvements in all ROM and PRO measures. Patients with augmented glenoid components were more likely to have type B2 or B3 deformities (P = .004). At final follow-up, 54% of augmented glenoids showed implant lucencies compared with 46% of control shoulders (P = .5). The mean Lazarus score remained similar between groups (1.5 vs. 1.2, P = .8). When 8° and 16° augmentations were compared, the 16° augmentation demonstrated a significantly higher mean Lazarus score (4.2 vs. 1.1, P = .03). Reoperation rates were similar between groups (5% vs. 3%, P = .6). DISCUSSION: Patients with posteriorly augmented glenoid components demonstrate similar improvements in ROM and PROs to patients with standard anatomic glenoid components. Radiographic loosening and revision rates were similar. However, a higher failure rate was seen with the 16° full-wedge augmentation, which is no longer used in our practice.

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BACKGROUND: Augmented glenoid implants are available to help restore the biomechanics of the glenohumeral joint with excessive retroversion. It is imperative to understand their behavior to make a knowledgeable preoperative decision. Therefore, our goal was to identify an optimal augmented glenoid design based on finite element analysis (FEA) under maximum physiological loading. METHODS: FEA models of 2 augmented glenoid designs-wedge and step-were created per the manufacturers' specifications and virtually implanted in a scapula model to correct 20° of retroversion. Simulation of shoulder abduction was performed using the FEA shoulder model. The glenohumeral force ratio, relative micromotion, and stress levels on the cement mantle, glenoid vault, and backside of the implants were compared between the 2 designs. RESULTS: The force ratio was 0.56 for the wedge design and 0.87 for the step design. Micromotion (combination of distraction, translation, and compression) was greater for the step design than the wedge design. Distraction measured 0.05 mm for the wedge design and 0.14 mm for the step component. Both implants showed a similar pattern for translation; however, compression was almost 3 times greater for the step component. Both implants showed high stress levels on the cement mantle. At the glenoid vault and on the implants, the stress levels were 1.65 MPa and 6.62 MPa, respectively, for the wedge design and 3.78 MPa and 13.25 MPa, respectively, for the step design. CONCLUSION: Implant design slightly affects joint stability; however, it plays a major role regarding long-term survival. Overall, the augmented wedge design provides better implant fixation and stress profiles with less micromotion.

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BACKGROUND: Augmented glenoid implants to correct bone loss can possibly reconcile current prosthetic failures and improve long-term performance for total shoulder arthroplasty. Biomechanical implant studies have suggested benefits from augmented glenoid components, but limited evidence exists on optimal design. METHODS: An integrated kinematic finite element analysis (FEA) model was used to evaluate optimal augmented glenoid design based on biomechanical performance in translation in the anteroposterior plane similar to clinical loading and failure mechanisms with osteoarthritis. Computer-aided design software models of 2 different commercially available augmented glenoid designs-wedge (Equinox; Exactech, Inc., Gainesville, FL, USA) and step (STEPTECH; DePuy Synthes, Warsaw, IN, USA) were created according to precise manufacturer's dimensions of the implants. Using FEA, they were virtually implanted to correct 20° of retroversion. Two glenohumeral radial mismatches, 3.5/4 mm and 10 mm, were evaluated for joint stability and implant fixation simulating high-risk conditions for failure. RESULTS: The wedged and step designs showed similar glenohumeral joint stability under both radial mismatches. Surrogate for micromotion was a combination of distraction, translation, and compression. With similar behavior and measurements for distraction and translation, compression dictated micromotion (wedge: 3.5 mm = 0.18 mm and 10 mm = 0.10 mm; step: 3.5 mm = 0.19 mm and 10 mm = 0.25 mm). Stress levels on the backside of the implant and on the cement mantle were higher using a step design. DISCUSSION: Greater radial mismatch has the advantage of providing higher glenohumeral stability with tradeoffs, such as higher implant and cement mantle stress levels, and micromotion worse when using a step design.

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BACKGROUND: The treatment of glenoid bone deficiencies in primary or revision total shoulder arthroplasty is challenging. This retrospective study evaluated the short-term clinical and radiologic results of a new custom-made patient-specific glenoid implant. METHODS: We treated 10 patients with severe glenoid deficiencies with the Glenius Glenoid Reconstruction System (Materialise NV, Leuven, Belgium). Outcome data included a patient-derived Constant-Murley score, a visual analog score (VAS), a satisfaction score, the 11-item version of the Disabilities of the Arm, Shoulder and Hand score, and the Simple Shoulder Test. We compared the postoperative position of the implant with the preoperative planned position on computed tomography scans. RESULTS: At an average follow-up period of 30.5 months, the mean patient-derived Constant-Murley score was 41.3 ± 17.5 points (range, 18-76 points) with a visual analog scale of 3.3 ± 2.5 points (range, 0-7 points). The mean 11-item version of the Disabilities of the Arm, Shoulder and Hand score was 35.8 ± 18.4 (range, 2-71), and the mean Simple Shoulder Test was 47.5% ± 25.3% (range, 8%-92%). Eight patients reported the result as better (n = 3) or much better (n = 5). One patient had an elongation of the brachial plexus, and 1 patient had a period of instability. The average preoperative glenoid defect size was 9 ± 4 cm3 (range, 1-14 cm3). The mean deviation between the preoperative planned and the postoperative version and inclination was 6° ± 4° (range 1°-16°) and 4° ± 4° (range 0°-11°), respectively. CONCLUSION: Early results of the Glenius Glenoid Reconstruction System are encouraging. Adequate pain relief, a reasonable functionality, and good patient satisfaction can be obtained in these difficult cases. Further follow-up will determine the bony ingrowth and subsequent longevity of this patient-specific glenoid component.

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Glenoid bone loss and retroversion increase the complexity of primary shoulder arthroplasty and affect the outcome. Although eccentric reaming, augmented glenoid implants, bone grafting, and reverse arthroplasty have been used to manage bone loss and retroversion, there is no consensus on treatment. Posteriorly augmented glenoid components can correct retroversion and avoid joint line medialization, which occurs with corrective reaming techniques. Full-wedged, half-wedged, and stepped polyethylene posteriorly augmented designs are currently available for use in the United States. The results of biomechanical and computer model studies support the use of augmented implants for the management of glenoid retroversion of greater than 15°. Currently, most clinical studies are retrospective case series. The short-term results of posteriorly augmented glenoid components are successful, with no clear evidence of the superiority of one design over another and unknown long-term survival rates.

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