Aseptic Glenoid Baseplate Loosening After Reverse Total Shoulder Arthroplasty

Primary and revision reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency

BACKGROUND

Severe glenoid bone loss in the setting of both primary and revision reverse total shoulder arthroplasty (rTSA) continues to remain a significant challenge. The purpose of this study was to report on radiographic and clinical outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed metal glenoid implant to address severe glenoid bone deficiency. This is a follow-up study to previously reported preliminary results.

METHODS

A retrospective review was performed on 62 patients with severe glenoid bone deficiency who underwent either primary or revision rTSA using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand (DASH), Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Simple Shoulder Test (SST), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain scores as well as active range of motion (ROM) were collected and compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05. The percentage of patients achieving minimal clinically important difference (MCID) and substantial clinical benefit (SCB) was also calculated.

RESULTS

Fifty-five of 62 shoulders (88.7%) were able to be contacted at a minimum of 2 years postoperatively, with 47 of 62 (75.8%) having complete clinical and radiographic follow-up with a mean age of 67.5 years (range, 48-85 years) and follow-up of 39.2 months (range, 25-56 months). There were 19 primary and 28 revision rTSAs. Significant improvements were seen in mean active forward flexion (63.1° ± 30.3° to 116.8° ± 35°), abduction (48.1° ± 16.1 to 76.2° ± 13.4°) (P < .001), external rotation (16° ± 23.7° to 32.1° ± 24.5°) (P < .005), DASH (59.9 ± 17.7 to 35.7 ± 24.3), Constant (23.4 ± 13.1 to 53.1 ± 17.4), ASES (27.8 ± 16.2 to 69.1 ± 25.2), SST (3.3 ± 2.5 to 7.6 ± 3.5), SANE (28.9 ± 18.3 to 66.7 ± 21.2), and VAS pain (7.1 ± 2.4 to 1.8 ± 2.6) scores (P < .001). MCID and SCB was achieved in a majority of patients postoperatively. The overall complication rate was 29.1%, with only 1 baseplate failure.

CONCLUSION

This study demonstrates promising evidence that the VRS implant can be used as a viable option to achieve clinically important improvement in a majority of patients treated for severe glenoid bone deficiency with rTSA in both the primary and revision setting.

Revision reverse shoulder arthroplasty for the management of baseplate failure: an analysis of 676 revision reverse shoulder arthroplasty procedures

BACKGROUND

Baseplate failure in reverse shoulder arthroplasty (RSA) is a rare but potentially catastrophic complication owing to poor patient outcomes and significant glenoid bone loss. The purpose of this study was to report on the prevalence, causes, and outcomes of revision RSA (rRSA) for baseplate failure or loosening.

METHODS

A retrospective review of our institutional database was performed to identify all patients treated for a failed RSA from 2006 to 2021 who required revision to another RSA (rRSA) performed by a single surgeon. A total of 676 failed RSA procedures were identified, and further analysis identified 46 patients (6.8%) who underwent rRSA for baseplate failure with a confirmed loose baseplate at the time of rRSA. The primary outcome was repeated failure of the reimplanted baseplate following rRSA. The mode of failure associated with baseplate failure was stratified into 1 of 3 groups: aseptic, septic, or traumatic. Twenty-four patients underwent primary revision, and 22 had undergone >1 previous arthroplasty prior to undergoing re-revision. Five patients underwent previous rRSA for baseplate failure performed by an outside surgeon. The criteria for secondary outcome analysis of final American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and range of motion were met by 32 patients and 23 patients at 1- and 2-year follow-up, respectively.

RESULTS

Three patients (6.5%) had repeated baseplate failure requiring re-revision; 2 had baseplate failure at <1 year with associated periprosthetic infections and underwent conversion to hemiarthroplasty. The third patient experienced traumatic failure at 10 years and underwent successful rRSA. The mean American Shoulder and Elbow Surgeons scores at 1 and 2 years were 62.3 and 61.7, respectively. There was no significant difference in outcomes based on mode of baseplate failure (P = .232) or total arthroplasty burden (P = .305) at 1 year. There were 13 total complications in 11 patients, 5 of which required reoperation for reasons other than baseplate failure.

CONCLUSION

In this study, rRSA for baseplate failure constituted 6.8% of all revisions performed over a period of 15 years. Re-revision for recurrent baseplate failure was required in 3 of 46 patients (6.5%). Complications and reoperation rates were higher than those for primary RSA but outcomes were comparable for revision of failed anatomic shoulder arthroplasty.

Ten technical aspects of baseplate fixation in reverse total shoulder arthroplasty for patients without glenoid bone loss: a systematic review

The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation.

How to avoid baseplate failure: the effect of compression and reverse shoulder arthroplasty baseplate design on implant stability

BACKGROUND

Failure to achieve fixation of the glenoid baseplate will lead to clinical failure. The fixation of the baseplate to the scapula must be able to withstand sufficient shear forces to allow bony ingrowth. The importance of compression to neutralize the forces at the baseplate-bone interface has been assumed to be critical in limiting excessive micromotion. The purpose of this study is to determine the effect of compression on implant stability with different baseplate designs.

METHODS

Various baseplate designs (1-piece monolithic central screw [1P], 2-piece locking central screw [2PL], and 2-piece nonlocking center screw [2PNL]) were investigated at 3 different compressive forces (high [810 N], medium [640 N], and low [530 N]). Synthetic bone cylinders were instrumented, and peripheral screws were used in all models. The combination of 1 locking and 3 nonlocking peripheral screw fixation was selected as worst-case scenario. Dynamic testing protocol followed the ASTM F2028-17 standard. The baseplate micromotion at high compression was compared to low compression. Additionally, the baseplate micromotion for each design was compared at baseline (first 50 cycles) and at 10,000 cycles for the 3 different compressive forces where motion above 150 μm was defined as failure.

RESULTS

Baseplate micromotion was found to negatively correlate with compression (rpb = -0.83, P < .0001). At baseline, all baseplate designs were considered stable, regardless of compression. With high compression, average micromotion at the glenoid baseplate-bone interface remained below the 150-μm threshold for all baseplate designs at 10,000 cycles (1P: 50 ± 10 μm; 2PL: 78 ± 32 μm; 2PNL: 79 ± 8 μm; P = .060). With medium compression, average micromotion at 10,000 cycles for all 3 designs remained below the 150-μm threshold (1P: 88 ± 22 μm; 2PL: 132 ± 26 μm; 2PNL: 107 ± 39 μm). The 2PL design had the highest amount of micromotion (P = .013). With low compression, both 2-piece designs had an average micromotion above the 150-μm threshold whereas the 1-piece design did not (1P: 133 ± 35 μm; 2PL: 183 ± 21 μm; 2PNL: 166 ± 39 μm). The 2PL design had significantly higher micromotion when compared to 1P design (P = .041).

DISCUSSION

The stability of a central screw baseplate correlates with the amount of compression obtained and is affected by implant design. For the same amount of compression, more micromotion is observed in a 2-piece design than a 1-piece design.

Clinical outcomes of anatomical versus reverse total shoulder arthroplasty in patients with primary osteoarthritis, an intact rotator cuff, and limited forward elevation

Aims

Both anatomical and reverse total shoulder arthroplasty (aTSA and rTSA) provide functional improvements. A reported benefit of aTSA is better range of motion (ROM). However, it is not clear which procedure provides better outcomes in patients with limited foward elevation (FE). The aim of this study was to compare the outcome of aTSA and rTSA in patients with glenohumeral osteoarthritis (OA), an intact rotator cuff, and limited FE.

Methods

This was a retrospective review of a single institution's prospectively collected shoulder arthroplasty database for TSAs undertaken between 2007 and 2020. A total of 344 aTSAs and 163 rTSAs, which were performed in patients with OA and an intact rotator cuff with a minimum follow-up of two years, were included. Using the definition of preoperative stiffness as passive FE ≤ 105°, three cohorts were matched 1:1 by age, sex, and follow-up: stiff aTSAs (85) to non-stiff aTSAs (85); stiff rTSAs (74) to non-stiff rTSAs (74); and stiff rTSAs (64) to stiff aTSAs (64). We the compared ROMs, outcome scores, and complication and revision rates.

Results

Compared with non-stiff aTSAs, stiff aTSAs had poorer passive FE and active external rotation (ER), whereas there were no significant postoperative differences between stiff rTSAs and non-stiff rTSAs. There were no significant differences in preoperative function when comparing stiff aTSAs with stiff rTSAs. However, stiff rTSAs had significantly greater postoperative active and passive FE (p = 0.001 and 0.004, respectively), and active abduction (p = 0.001) compared with stiff aTSAs. The outcome scores were significantly more favourable in stiff rTSAs for the Shoulder Pain and Disability Index, Simple Shoulder Test, American Shoulder and Elbow Surgeons score, University of California, Los Angeles score, and the Constant score, compared with stiff aTSAs. When comparing the proportion of stiff aTSAs versus stiff rTSAs that exceeded the minimal clinically important difference and substantial clinical benefit, stiff rTSAs achieved both at greater rates for all measurements except active ER. The complication rate did not significantly differ between stiff aTSAs and stiff rTSAs, but there was a significantly higher rate of revision surgery in stiff aTSAs (p = 0.007).

Conclusion

Postoperative overhead ROM, outcome scores, and rates of revision surgery favour the use of a rTSA rather than aTSA in patients with glenohumeral OA, an intact rotator cuff and limited FE, with similar rotational ROM in these two groups.

Anterosuperior versus deltopectoral approach for primary reverse total shoulder arthroplasty

Aims

The current evidence comparing the two most common approaches for reverse total shoulder arthroplasty (rTSA), the deltopectoral and anterosuperior approach, is limited. This study aims to compare the rate of loosening, instability, and implant survival between the two approaches for rTSA using data from the Dutch National Arthroplasty Registry with a minimum follow-up of five years.

Methods

All patients in the registry who underwent a primary rTSA between January 2014 and December 2016 using an anterosuperior or deltopectoral approach were included, with a minimum follow-up of five years. Cox and logistic regression models were used to assess the association between the approach and the implant survival, instability, and glenoid loosening, independent of confounders.

Results

In total, 3,902 rTSAs were included. A deltopectoral approach was used in 54% (2,099/3,902) and an anterosuperior approach in 46% (1,803/3,902). Overall, the mean age in the cohort was 75 years (50 to 96) and the most common indication for rTSA was cuff tear arthropathy (35%; n = 1,375), followed by osteoarthritis (29%; n = 1,126), acute fracture (13%; n = 517), post-traumatic sequelae (10%; n = 398), and an irreparable cuff rupture (5%; n = 199). The two high-volume centres performed the anterosuperior approach more often compared to the medium- and low-volume centres (p < 0.001). Of the 3,902 rTSAs, 187 were revised (5%), resulting in a five-year survival of 95.4% (95% confidence interval 94.7 to 96.0; 3,137 at risk). The most common reason for revision was a periprosthetic joint infection (35%; n = 65), followed by instability (25%; n = 46) and loosening (25%; n = 46). After correcting for relevant confounders, the revision rate for glenoid loosening, instability, and the overall implant survival did not differ significantly between the two approaches (p = 0.494, p = 0.826, and p = 0.101, respectively).

Conclusion

The surgical approach used for rTSA did not influence the overall implant survival or the revision rate for instability or glenoid loosening.

The Value of Computer-Assisted Navigation for Glenoid Baseplate Implantation in Reverse Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time.

METHODS

We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method.

RESULTS

Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was -0.44 (95% confidence interval [CI], -3.26; p = 0.76; I2 = 36%) for version and -8.75 (95% CI, -16.83 to -0.68; p = 0.02; I2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I2 = 71%).

CONCLUSIONS

Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Mid-term comparative study between the glenoid and humerus lateralization designs for reverse total shoulder arthroplasty: which lateralization design is better?

INTRODUCTION

The complications of the conventional medialized design for reverse total shoulder arthroplasty (RSA) are increased scapular notching, and decreased external rotation and deltoid wrapping. Currently, lateralization design RSA, which avoid scapular notching and improve impingement-free range of motion, is commonly used. Especially, humeral lateralization design was most commonly used and glenoid lateralization design was preferred for glenoid abnormities. We compared mid-term clinical and radiologic outcomes of glenoid and humeral lateralization RSA in an Asian population in this study.

MATERIALS AND METHODS

We enrolled 124 shoulders of 122 consecutive patients (mean age 73.8 ± 6.8 years) who received glenoid or humeral lateralization RSA from May, 2012 to March, 2019. We divided these patients into two groups according to RSA using either glenoid or humeral lateralization design. These different designs were introduced consecutively in Korea. The clinical and radiological results of 60 glenoid lateralization RSA (Group I, 60 patients) and 64 humeral lateralization RSA (Group II, 62 patients) were retrospectively evaluated and also were compared between the two groups. All patients were followed for mean 3 years.

RESULTS

The clinical and radiologic outcomes of the two groups did not differ significantly, including scapular notching (p = 0.134). However, humeral lateralization RSA showed a larger glenoid-tuberosity (GT) distance (p = 0.000) and less distalization shoulder angle (DSA) (p = 0.035). The complication rate did not differ significantly either. But, revision surgery was performed for 2 humeral loosening in the Group II.

CONCLUSION

The clinical and radiologic outcomes of the two groups did not differ significantly, including scapular notching at mid-term follow-up. However, humeral lateralization design showed larger GT distance and less DSA. Humeral lateralization design RSA could preserve the normal shoulder contour due to a larger GT distance (more lateralization) and provide less deltoid tension due to less DSA (less distalization of COR).

Surgeon-designed patient-specific instrumentation improves glenoid component screw placement for reverse total shoulder arthroplasty in a population with small glenoid dimensions

PURPOSE

Glenoid component loosening is a potential complication of reverse total shoulder arthroplasty (rTSA), occurring in part due to lack of adequate screw purchase in quality scapular bone stock. This study was to determine the efficacy of a surgeon-designed, 3D-printed patient-specific instrumentation (PSI) compared to conventional instrumentation (CI) in achieving longer superior and inferior screw lengths for glenoid component fixation.

METHODS

A multi-centre retrospective analysis of patients who underwent rTSA between 2015 and 2020. Lengths of the superior and inferior locking screws inserted for fixation of the glenoid baseplate component were recorded and compared according to whether patients received PSI or CI. Secondary outcomes included operative duration and incidence of complications requiring revision surgery.

RESULTS

Seventy-three patients (31 PSI vs. 42 CI) were analysed. Average glenoid diameter was 24.5 mm (SD: 3.1) and 81% of patients had smaller glenoid dimensions compared to the baseplate itself. PSI produced significantly longer superior (44.7 vs. 30.7 mm; P < 0.001) and inferior (43.0 vs. 31 mm; P < 0.001) mean screw lengths, as compared to CI. A greater proportion of maximal screw lengths for the given rTSA construct (48 mm) were observed in the PSI group (71.9% vs. 11.9% superior, 59.4% vs. 11.9% inferior). Operative duration was not statistically significantly different between the PSI and CI groups (150 min vs. 169 min, respectively; P = 0.229). No patients had radiographic loosening of the glenoid component with an average of 2-year follow-up.

CONCLUSION

PSI facilitates longer superior and inferior screw placement in the fixation of the glenoid component for rTSA. With sufficient training, PSI can be designed and implemented by surgeons themselves.

Early clinical outcomes following navigation-assisted baseplate fixation in reverse total shoulder arthroplasty: a matched cohort study

BACKGROUND

Accurate placement of the glenoid baseplate is an important technical goal of reverse total shoulder arthroplasty (RSA). The use of computer navigated instrumentation has been shown to improve the accuracy and precision of intraoperative execution of preoperative planning. The purpose of this study was to compare early clinical outcomes of patients undergoing navigated RSA vs. a non-navigated matched cohort.

METHODS

A retrospective review of a prospectively collected shoulder arthroplasty database was used to identify 113 patients from a single institution who underwent navigated primary RSA with a minimum 2-year follow-up. A matched cohort of 113 non-navigated RSAs was created based on sex, age, follow-up, and preoperative diagnosis. Preoperative and postoperative range of motion, functional outcome scores, and complications were reported.

RESULTS

A total of 226 shoulders with a mean age of 71 years were evaluated after navigated (113) or non-navigated (113) RSAs. The mean follow-up was 32.8 months (range: 21-54 months). At the final postoperative follow-up, the navigated group had better active forward elevation (135° vs. 129°, P = .023), active external rotation (39° vs. 32°, P = .003), and Constant scores (71.1 vs. 65.5, P = .003). However, when comparing improvements from the preoperative state, there was no statistically significant difference in range of motion or functional outcome scores between the groups. Complications occurred in 1.8% (2) of patients undergoing navigated RSA compared with 5.3% (6) in the non-navigated group (P = .28). Scapular notching (3.1% vs. 8.0%, P = .21) and revision surgery (0.9% vs. 3.5%, P = .37) were more common in non-navigated shoulders.

CONCLUSION

At early follow-up, navigated and non-navigated RSAs yielded similar rates of improvement in range of motion and functional outcome scores. Notching and reoperation was more common in non-navigated shoulders, but did not reach statistical significance. Longer follow-up and larger cohort size are needed to determine if intraoperative navigation lengthens the durability of RSA results and reduces the incidence of postoperative complications.

Arthroscopic Removal of the Polyethylene Glenoid Component After Total Shoulder Arthroplasty: A Systematic Review

Purpose

To identify prior studies of arthroscopic glenoid component removal after total shoulder arthroplasty (TSA) and understand indications, techniques and patient outcomes.

Methods

A search of the English language literature on arthroscopic removal of the glenoid component (ARGC) after TSA published between 2005 and 2021 was performed from MEDLINE and EMBASE databases. Articles with ARGC after TSA were identified and we recorded article characteristics as well as patient demographics and outcomes contained within the studies.

Results

A total of six publications (two case reports and four retrospective case series) detailing the outcome of ARGC performed on twenty-five shoulders were identified. The average time from index procedure to glenoid removal was 117 months and mean age at time of ARGC was 75 years. Although patient reported outcomes measures (PROMs) varied in type and reporting style, all articles reported improvements in PROMs. Twenty patients in this systematic review were evaluated for post-operative complications and the complication rate was found to be 15% (n = 3). There were 2 cases (18%) of superior migration of the humeral head relative to the glenoid and no reported cases of anterior or posterior humeral head subluxation. Two of 25 patients (8%) underwent subsequent open revision procedures.

Conclusions

The limited number of publications in this systematic review demonstrates that ARGC after TSA can result in improvements in both pain and PROMs. This less-invasive arthroscopic technique may be an alternative to open revision for lower demand patients; however, future prospective, comparative studies are necessary to better define indications.

The Causal Relationship Between Rheumatoid Arthritis and Mechanical Complications of Prosthesis After Arthroplasty: A Two-Sample Mendelian Randomization Study

The causal effects of rheumatoid arthritis (RA) on complications of arthroplasty are yet to be established. This study was the first to explore the causal effect of RA on mechanical complications of prosthesis through two-sample Mendelian randomization (MR). In the MR analysis, RA was selected as the exposure in this study while single-nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS) were selected as the instrumental variables (IVs). Summary statistics data on mechanical complications of prosthesis was extracted from publicly available GWAS data, including 463,010 European descent individuals. MR analysis was performed using the standard inverse variance weighted method (IVW). Furthermore, other methods (MR Egger, weighted median, simple mode, and weighted mode) were also done to verify the results. Finally, the sensitivity analysis was executed. Results of the standard IVW showed that RA possibly increases the risk of mechanical complications of prosthesis [OR = 1.000255; 95% CI = (1.0001035, 1.000406); p = 9.69 × 10 ^-4 ]. This outcome was also verified by other methods including weighted median [OR = 1.000285; 95% CI = (1.0001032, 1.000466); p = 1.41 × 10^-3], simple mode [OR = 1.000446; 95% CI = (1.0001116, 1.000781); p = 1.04 × 10^-2], and weighted mode [OR = 1.000285; 95% CI = (1.0001032, 1.000466); p = 2.29 × 10^-3]. No heterogeneity and directional pleiotropy was observed upon sensitivity analysis, indicating the stability and reliability of the result. In summary, the present study showed that RA potentially increases the risks of complications of prosthesis, which might provide guidance in arthroplasty on RA patients.

Does Lateralizing the Glenosphere Center of Rotation by 4 mm Decrease Scapular Notching in Reverse Shoulder Arthroplasty with a 135° Humeral Component?

Background

Scapular notching continues to be associated with reverse shoulder arthroplasty (RSA) and is thought to lead to fewer outcomes. Decreasing the humeral neck-shaft angle (NSA) has been associated with decreased incidence of scapular notching. Lateralizing the glenosphere center of rotation (COR) has also been proposed to decrease notching; however, its effect in lower NSA RSA is less understood. The purpose of this study was to compare the impact of the medial (0 mm) and lateral (4 mm) COR on the incidence of scapular notching and clinical outcomes after RSA with a 135° NSA humeral component.

Methods

We performed a multicenter retrospective comparative cohort of 82 patients with cuff tear arthropathy (41 in each cohort) who underwent RSA with a 135° NSA humeral component and a glenosphere COR of either 0 mm (medialized COR [MCOR]) or 4 mm (lateralized COR [LCOR]) of lateralization. RSA was performed using the same 135° humeral system and baseplate design. All patients had 2-year radiographic and clinical follow-up. Postoperative radiographs were evaluated for scapular notching. Clinical outcomes included American Shoulder and Elbow Surgeons scores, visual analog pain scale, Simple Assessment Numeric Evaluation, and active range of motion.

Results

The overall incidence of scapular notching was 22.0%. There was no significant difference in scapular notching between cohorts: 24.4% in the MCOR and 19.5% in the LCOR (P = .625). Both cohorts had significant improvements in American Shoulder and Elbow Surgeons scores, visual analog pain scale, Simple Assessment Numeric Evaluation, and active range of motion postoperatively (P < .005). Improvements did not significantly differ between cohorts. The presence of scapular notching did not have a significant negative effect on any clinical outcome measure. Complications occurred in 5 patients (2 MCORs and 3 LCORs), none of which occurred in patients with scapular notching.

Discussion and conclusion

Lateralizing the glenosphere COR by 4 mm does not significantly affect the incidence of scapular notching in RSA when using a 135° NSA humeral component at short-term follow-up. Furthermore, such offset does not significantly improve functional outcome scoring systems or range of motion when compared with the MCOR (0 mm). Scapular notching did not have a negative impact on any clinical outcome measure or complication rate in this series.

Avoiding Glenoid Baseplate Fixation Failure by Altering Surgical Technique for Varying Bone Densities

Glenoid baseplate failure is one of the causes of revision and poor outcomes in reverse shoulder arthroplasty (RSA). The objective of this study was to determine whether alterations in surgical technique can improve time-zero fixation of the baseplate in varying bone densities. A secondary objective was to identify whether preoperative radiographic glenoid sclerosis width was associated with the implementation of these techniques.

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.

Intermediate to long term results of stemless metaphyseal reverse shoulder arthroplasty: A five to nine year follow-up

BACKGROUND

Shoulder arthroplasty incidence is increasing as is the volume of revision surgeries. Revision surgery is easier if humeral bone stock is preserved with minimal bone defects and osteolysis. This has led to an increased focus on the development of various short stemmed and stemless implants which provides stable fixation whilst preserving humeral bone stock.

PURPOSE

To review the medium to long term clinical and radiological outcomes, complications and survival rates of a stemless reverse shoulder prosthesis.

PATIENTS AND METHOD

Patients with a minimum follow-up of 60 months following a reverse stemless shoulder arthroplasty were deemed eligible. Clinical and radiological data on twenty-one patients operated between 2009 and 2014 were recorded prospectively. Survivorship and patient recorded symptoms with the end point of revision surgery were recorded.

RESULTS

Mean follow-up of 78 months (60-114 months). Mean range of active elevation was 136° (80-170°). Mean range of active abduction and active external rotation was 122° (70-170°) and 47° (10-75°) respectively. Mean Oxford score improved from 12 pre-operatively to 44 at final follow up (p < 0.0001). Mean Constant Murley Score improved from 18 to 72 (p < 0.0001). Mean ADLEIR score of 13 pre-operatively increased to 32 post-operatively (p < 0.0001). Notching was seen in 23.5% of cases and no radiolucent areas were observed around the glenoid component. There were two cases of post traumatic peri-prosthetic fractures that were managed conservatively and one case of deep-seated infection that required a washout. The survivorship at the most recent follow-up was 100%.

CONCLUSION

The advantages of bone preservation with the stemless metaphyseal prosthesis combined with encouraging medium to long term clinical and radiological results are very promising, particularly with the improved post-operative patient satisfaction scores. This is the first study that reports the results with a minimum of 5 year follow-up and has the longest mean follow-up period.

CLINICAL RELEVANCE

The reverse stemless shoulder prosthesis is an effective and reliable option for elective shoulder arthroplasty.

The in vivo impact of computer navigation on screw number and length in reverse total shoulder arthroplasty

BACKGROUND

Little information exists regarding the benefit of computer navigation in shoulder arthroplasty in the clinical setting. This study aimed to quantify how computer navigation affects the number and length of screws used during in vivo reverse total shoulder arthroplasty (RSA) placement.

METHODS

We performed a retrospective review of a research database to identify patients who underwent primary RSA before and after the use of computer navigation between January 1, 2015, and December 31, 2019. One hundred consecutive RSAs were selected from the computer navigation implantation date; then, 100 consecutive sex-matched RSAs were chosen prior to navigation implantation in reverse chronologic order. Baseplate augmentations were chosen based on surgeon discretion, with the goal of restoring version to within 10° of neutral and inclination to neutral or slightly inferior with removal of the smallest amount of subchondral bone possible. Screws were placed with the goal of ≥3 screws with good purchase and were added as needed, with up to 5 screws used. We compared demographic factors, comorbidities, preoperative diagnosis, number of screws, screw length, number of wasted screws, and number of cases with bone graft used behind the baseplate between the 2 groups. We used the χ² test for bivariate analysis and the Student t test for continuous variables.

RESULTS

A total of 200 RSAs were included, with 100 primary RSAs (mean age, 69.3 years) performed prior to computer navigation compared with 100 primary RSAs (mean age, 69.7 years) performed using computer navigation. The total number of screws used in RSAs without computer navigation was 414; the total used in the computer navigation cases was 344. RSAs placed with computer navigation used significantly fewer screws per case (3.4 screws vs. 4.1 screws, P < .001) and had a significantly greater average screw length (35.0 mm vs. 32.6 mm, P < .001). Three screws were implanted in 61% of computer navigation cases vs. 1% of cases without computer navigation (P < .001). Screws ≥ 30 mm in length were more commonly used in patients undergoing RSA using computer navigation (84.6% vs. 73.7%, P < .001).

CONCLUSION

This study shows that computer navigation in RSA leads to longer and fewer glenoid baseplate screws being implanted. Computer navigation appears to assist with better screw placement, which may have similar clinical benefits of better glenoid fixation. Additionally, using fewer screws can save glenoid bone stock, avoid added glenoid stress risers, and decrease operative time.

Minimum five-year outcomes of reverse total shoulder arthroplasty using a trabecular metal glenoid base plate

AIMS

Reverse total shoulder arthroplasty (RTSA) using trabecular metal (TM)-backed glenoid implants has been introduced with the aim to increase implant survival. Only short-term reports on the outcomes of TM-RTSA have been published to date. We aim to present the seven-year survival of TM-backed glenoid implants along with minimum five-year clinical and radiological outcomes.

METHODS

All consecutive elective RTSAs performed at a single centre between November 2008 and October 2014 were reviewed. Patients who had primary TM-RTSA for rotator cuff arthropathy and osteoarthritis with deficient cuff were included. A total of 190 shoulders in 168 patients (41 male, 127 female) were identified for inclusion at a mean of 7.27 years (SD 1.4) from surgery. The primary outcome was survival of the implant with all-cause revision and aseptic glenoid loosening as endpoints. Secondary outcomes were clinical, radiological, and patient-related outcomes with a five-year minimum follow-up.

RESULTS

The implant was revised in ten shoulders (5.2%) with a median time to revision of 21.2 months (interquartile range (IQR) 9.9 to 41.8). The Kaplan-Meier survivorship estimate at seven years was 95.9% (95% confidence interval (CI) 91.7 to 98; 35 RTSAs at risk) for aseptic mechanical failure of the glenoid and 94.8% (95% CI 77.5 to 96.3; 35 RTSAs at risk) for all-cause revision. Minimum five-year clinical and radiological outcomes were available for 103 and 98 RTSAs respectively with a median follow-up time of six years (IQR 5.2 to 7.0). Median postoperative Oxford Shoulder Score was 38 (IQR 31 to 45); median Constant and Murley score was 60 (IQR 47.5 to 70); median forward flexion 115° (IQR 100° to 125°); median abduction 95° (IQR 80° to 120°); and external rotation 25° (IQR 15° to 40°) Scapular notching was seen in 62 RTSAs (63.2%).

CONCLUSION

We present the largest and longest-term series of TM-backed glenoid implants demonstrating 94.8% all-cause survivorship at seven years. Specifically pertaining to glenoid loosening, survival of the implant increased to 95.9%. In addition, we report satisfactory minimum five-year clinical and radiological outcomes. Cite this article: Bone Joint J 2021;103-B(8):1333-1338.

Humeral osteolysis after reverse shoulder arthroplasty using cemented or cementless stems comparative retrospective study with a mean follow-up of 9 years

INTRODUCTION

The cause of proximal humeral osteolysis after reverse shoulder arthroplasty (RSA) remains controversial. The primary objective of our study was to compare the radiographic outcomes of Grammont-type RSA when a cemented stem is used versus when a cementless stem is used. The secondary objective was to identify the cause of these radiographic changes, especially for the cementless stems.

HYPOTHESIS

More proximal humerus bone loss occurs when a cementless humeral stem is used.

METHODS

With a minimum follow-up of 5 years, two paired cohorts were compared retrospectively: 70 RSA with cemented stem and 70 RSA with cementless stem. Using the radiographs made at the final follow-up visit, we looked for tuberosity resorption, signs of stress shielding, the presence of periprosthetic radiolucent lines and scapular notching.

RESULTS

At a mean follow-up of 9 years (5.0-20.6), the RSA revision rate was 1.8% in the cemented group and 3.6% in the cementless group (p=1). Tuberosity resorption was twice as common in the cementless group: 59% versus 30% (p<0.001). Signs of stress shielding such as osteopenia were only present in the cementless group. In both groups, tuberosity resorption was often associated with scapular notching. In the shoulders with tuberosity resorption, stage≥3 scapular notching was more common in the cementless group (p=0.001).

DISCUSSION

For the cementless stems, proximal humeral osteolysis can in part be attributed to stress shielding. The relationship between notching and tuberosity resorption in the two groups also suggests a secondary biological cause.

LEVEL OF EVIDENCE

III; Comparative retrospective study.

Does preoperative diagnosis impact patient outcomes following reverse total shoulder arthroplasty? A systematic review

BACKGROUND

The indications for reverse total shoulder arthroplasty (rTSA) have expanded to include the treatment of a wide variety of shoulder pathologies, and there may be significant differences in patient outcomes based on preoperative diagnosis.

METHODS

A systematic review of the orthopedic literature contained in the PubMed, Cochrane, and Embase databases was performed on November 14, 2019. Studies investigating rTSA indicated for 7 distinct preoperative diagnoses (massive rotator cuff tear [MCT] without glenohumeral osteoarthritis [GHOA], MCT with GHOA or cuff tear arthropathy, primary GHOA, inflammatory arthritis with MCT, failed shoulder arthroplasty, proximal humeral fracture [PHF], and sequelae following PHF) were included. The main outcomes of interest included functional outcomes (abduction, external rotation, and forward flexion) and patient-reported outcome measures (American Shoulder and Elbow Surgeons shoulder score and Constant-Murley score). Because of significant variation in measurement and reporting, data on internal rotation were not extracted. In addition, radiographic outcomes and complication rates were extracted and recorded for each of the included studies.

RESULTS

In total, 47 studies, comprising 2280 patients, met the inclusion criteria. Significant improvements in functional outcomes and patient-reported outcome measures were found across the preoperative diagnostic groups. There were no significant differences between the diagnostic groups regarding improvement between preoperative and postoperative values for the outcomes of interest, with the exception that the inflammatory arthropathy group had significantly less improvement in the Constant-Murley score than the primary GHOA and revision arthroplasty groups. Although there were few differences in improvement between groups, there were significant differences regarding the level of postoperative functional performance, which was not as consistent in the context of trauma or revision operations (ie, complex PHF, fracture sequela, and revision arthroplasty groups).

CONCLUSION

Reverse total shoulder arthroplasty can provide reliable improvement in clinical outcomes regardless of preoperative diagnosis, with few differences across diagnostic groups regarding preoperative to postoperative improvement. The groups with primary GHOA and MCTs with or without GHOA demonstrated the most reliable postoperative functional outcomes of the examined diagnostic groups. Postoperative outcomes were not as consistent in the context of trauma or revision operations, and these groups may benefit from a variety of modern advancements in rTSA, although further research into these modalities for these groups is needed. Finally, rTSA remains an important treatment option in the context of rheumatoid arthritis, with similar outcomes and complication rates compared with the 6 other operative indications.

Glenoid bony morphology of osteoarthritis prior to shoulder arthroplasty: what the surgeon wants to know and why

Shoulder arthroplasty is performed with increasing frequency, and osteoarthritis is the most common indication for this procedure. However, the glenoid side of the joint is widely recognized as a limiting factor in the long-term durability of shoulder replacement, and osteoarthritis leads to characteristic bony changes at the glenoid which can exacerbate this challenge by reducing the already limited glenoid bone stock, by altering biomechanics, and by interfering with operative exposure. This article reviews the Walch classification system for glenoid morphology. Several typical findings of osteoarthritis at the glenoid are discussed including central bone loss, posterior bone loss, retroversion, biconcavity, inclination, osteophyte formation, subchondral bone quality, and bone density. The three primary types of shoulder arthroplasty are reviewed, along with several techniques for addressing glenoid deformity, including eccentric reaming, bone grafting, and the use of augmented glenoid components. Ultimately, a primary objective at shoulder arthroplasty is to correct glenoid deformity while preserving bone stock, which depends critically on characterizing the glenoid at pre-operative imaging. Understanding the surgical techniques and the implications of glenoid morphology on surgical decision-making enables the radiologist to provide the morphologic information needed by the surgeon.

Effects of implant rotational malposition on contact surface area after implantation of the augmented glenoid baseplate in the setting of glenoid bone loss

AIM OF THE STUDY

Augmented glenoid baseplates are utilized in reverse total shoulder arthroplasty in the setting of glenoid bone loss. These implants permit lateralization of the joint line and correction of bony version abnormalities. To allow bone preservation in the setting of abnormal bony version or deficiency, the backside of the augmented glenoid baseplate is not perpendicular to the axis of the central post/screw. Thus, if the baseplate is implanted with any rotational malposition, this could affect the backside contact area available for ingrowth. The purpose of this study was to assess if rotational malpositioning of a full-wedge augmented baseplate alongside the axis of the central screw significantly affects the glenoid implant backside contact area.

METHODS

Seven synthetic scapulas (Sawbones, Vashon, WA) were used to implant a 15° full-wedge glenoid baseplate (Wright Medical, Memphis, TN) according to the manufacturer's technique. The contact pressure between the baseplate and the glenoid surface at rotational positions 5°, 10°, and 15° clockwise (CW) and counterclockwise (CCW) from the central axis was measured with Extreme Low Fujifilm Prescale (Tekscan, Boston, MA). The data was analyzed digitally to obtain a percentage of contact surface area. To evaluate gross contact, a computed tomography (CT) scan was performed and manual measurements of contact between the glenoid and the baseplate were conducted using a standardized axial CT slice.

RESULTS

The average contact area at zero degrees of malrotation was 37.26 ± 3.27%. Average contact areas for the simulated malposition cases were 13.99 ± 9.39% at 15° CCW, 24.89 ± 5.11% at 10° CW, and 19.32 ± 3.13% at 15° CW. Each of these results was significant (p < 0.003). On computed tomography, at 15° CCW, the contact area decreased by 39%; at 15° CW, the contact area decreased by 38%.

DISCUSSION

The use of augmented glenoid baseplates presents a technical challenge. It is difficult to avoid implant malrotation along the axis of the central peg/screw, because the final rotation of the baseplate must be chosen while the implant is several centimeters away from the bone. This study found that 10° and 15° malrotation about the glenoid baseplate's central axis leads to significant decreases in the implant-bone contact area.

CONCLUSIONS

When implanting an augmented baseplate for total shoulder arthroplasty, it is important to minimize baseplate malrotation to decrease the risk of baseplate loosening.

Reverse Total Shoulder Arthroplasty without Bone-Grafting for Severe Glenoid Bone Loss in Patients with Osteoarthritis and Intact Rotator Cuff: A Concise 5-Year Follow-up of a Previous Report

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

An update on reverse total shoulder arthroplasty: current indications, new designs, same old problems

Reverse total shoulder arthroplasty (RTSA) was originally developed because of unsatisfactory results with anatomic shoulder arthroplasty options for the majority of degenerative shoulder conditions and fractures.

After initial concerns about RTSA longevity, indications were extended to primary osteoarthritis with glenoid deficiency, massive cuff tears in younger patients, fracture, tumour and failed anatomic total shoulder replacement.

Traditional RTSA by Grammont has undergone a number of iterations such as glenoid lateralization, reduced neck-shaft angle, modular, stemless components and onlay systems.

The incidence of complications such as dislocation, notching and acromial fractures has also evolved.

Computer navigation, 3D planning and patient-specific implantation have been in use for several years and mixed-reality guided implantation is currently being trialled.

Controversies in RTSA include lateralization, stemless humeral components, subscapularis repair and treatment of acromial fractures.

Cite this article: EFORT Open Rev 2021;6:189-201. DOI: 10.1302/2058-5241.6.200085

Percutaneous cementoplasty of periprosthetic loosening: can interventional radiologists offer an alternative to revision surgery?

OBJECTIVE

To evaluate feasibility and validate both safety and efficiency of radiological percutaneous periprosthetic bone cementoplasty (RPPBC) performed under local anesthesia as an alternative minimally invasive treatment of aseptic implant loosening.

METHODS

In this case series, seven patients (mean age 81 years, range 73 to 89 years, 2 men and 5 women) were enrolled between February 2011 and January 2020 with confirmed aseptic loosening of orthopedic implants. One patient presented with tibial component loosening of an unicompartmental knee arthroplasty, one with glenoid component loosening from a reverse shoulder arthroplasty, one femoral gamma nail, and four presented with pedicle screw loosening after staged posterior lumbar interbody fusion. All patients underwent clinical, biochemical, and imaging assessments to confirm the diagnosis of aseptic loosening. All benefited from RPPBC under dual CT and fluoroscopic guidance. All procedures were performed under local anesthesia by an experienced radiologist. Preprocedural, immediate and 6-month post-cementoplasty pain levels on a visual analogue scale (VAS), and functional outcomes were evaluated. Immediate and 6-month postprocedural CTs were performed to evaluate the treated region.

RESULTS

All RPPBC were well tolerated by patients throughout the procedure. None of the patients suffered from local or systemic infection post-RPPBC, or periprosthetic fractures. No recurrent implant loosening was observed. Six patients were pain free at 6 months. All patients expressed functional improvements during validated outcome score evaluations.

CONCLUSION

RPPBC appears to be an efficient and reliable treatment strategy for aseptic loosening of orthopedic implants in elderly patients deemed unfit for revision surgery.

KEY POINTS

• Radiological percutaneous periprosthetic bone cementoplasty offers immediate and long-lasting pain relief in elderly frail patients, or those deemed unfit for revision surgery despite presenting with symptomatic aseptic loosening of orthopedic implants. • Radiological percutaneous periprosthetic bone cementoplasty brings quick and long-lasting improvements in clinical functional outcomes and offer effective pain reduction, thereby improving the overall quality of life. • Radiological percutaneous periprosthetic bone cementoplasty is a safe, quick, reliable, and well-tolerated minimally invasive procedure which can be easily performed under simple locoregional anesthesia and requires short-term hospital stay.

Complications and implant survivorship following primary reverse total shoulder arthroplasty in patients younger than 65 years: a systematic review

BACKGROUND

Concerns exist regarding the complication rates and implant survivorship of reverse total shoulder arthroplasty (RTSA) in younger patients.

METHODS

A systematic review of the literature regarding the existing evidence on RTSA in patients younger than 65 years was performed using the CENTRAL (Cochrane Central Register of Controlled Trials), PubMed, and Embase databases on June 9, 2019. Articles published between 1995 and 2019 with combinations of the following keywords were identified: "reverse shoulder arthroplasty" and "65," "60," and/or "55." Complications, reoperations, and revisions were recorded. Reoperation-free survival and implant survival rates were grouped at 2, 5, and 10 years. Range of motion and clinical outcomes, along with postoperative radiographic results, were recorded.

RESULTS

Data from 7 studies with a total of 286 shoulders were obtained for quantitative analysis. The mean patient age was 58.4 years (mean age range, 48.9-60.4 years), and the mean follow-up period was 4.7 years (mean follow-up range, 3.0-7.8 years). The overall rate of complications was 18.6%; reoperations, 14.4%; and revisions, 11.2%. The reoperation-free survival rate was 97% at 2 years, 88%-90% at 5 years, and 76% at 10 years. The implant survival rate was 99% at 2 years, 91%-98% at 5 years, and 88% at 10 years. Active abduction, forward elevation, and external rotation significantly improved from preoperatively to postoperatively. All clinical outcome measures significantly improved from preoperatively to postoperatively, with no decline seen over time. The overall rate of infrascapular notching was 22.7% at final follow-up.

CONCLUSION

RTSA is safe and effective in patients younger than 65 years. Complication, reoperation, and revision rates were similar to those seen in older patient cohorts, without an increase in revisions owing to aseptic loosening. Clinical outcome scores showed significant and lasting improvements.

Catastrophic Failure of Reverse Shoulder Arthroplasty from a Broken Screw: A Case Report

CASE

A 63-year-old woman presented with pain and limited range of motion 2 years after undergoing reverse shoulder arthroplasty (RSA). She underwent revision RSA for catastrophic implant failure caused by central screw breakage, subsequent polyethylene wear, and glenosphere loosening, and achieved excellent outcomes.

CONCLUSION

This is a unique case of a salvage procedure with satisfactory outcomes for a rare complication of RSA. It demonstrates the importance of clinical vigilance notwithstanding the absence of radiographic abnormalities in long-term monitoring of patient implant failure.

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.