Management of glenoid bone defects with reverse shoulder arthroplasty-surgical technique and clinical outcomes

Pre-operative planning for reverse shoulder arthroplasty in low-resource centres: A modified Delphi study in South Africa

BACKGROUND

Pre-operative planning for reverse shoulder arthroplasty (RSA) poses challenges, particularly when dealing with glenoid bone loss. This modified Delphi study aimed to assess expert consensus on RSA planning processes and rationale, specifically targeting low-resourced institutions. Our objective was to offer pre-operative decision-making algorithms tailored for surgeons practising in resource-constrained hospitals with limited access to computed tomography (CT) scans.

METHODS

A working group generated statements on pre-operative imaging and glenoid of glenoid morphology and intra-operative decision-making. The study was conducted in three stages, with virtual consensus meetings in between. Stages 2 and 3 consisted only of closed questions/statements. The statements with over 70% were considered consensus achieved and those with less than 10% were considered disagreement consensus achieved.

RESULTS

Twelve shoulder surgeons participated, with 67% having over five years of experience in shoulder arthroplasty. In the absence of glenoid bone loss, the sole use of plain radiographs for pre-operative planning reached consensus and is recommended by these groups, while 100% advise using CT scans when bone loss is present. Most surgeons (70%) recommend using patient-specific instrumentation (PSI) in cases of structural bone loss. Most of the statements on intra-operative decision-making related to component placement and enhancing stability failed to reach consensus.

CONCLUSION

While consensus was achieved on most aspects of pre-operative imaging and planning, technical aspects of surgery lacked consensus. Planning for patients with structural glenoid bone loss necessitates CT scans and planning tools.

Both angled bony-increased offset and metal-augmented baseplates provide satisfactory bone incorporation to the glenoid in reverse total shoulder arthroplasty: a radiographic evaluation using tomosynthesis

BACKGROUND

Angled bony-increased offset and metal-augmented baseplate have recently been used to achieve neutral to inferior inclination of the glenoid implant. Nonetheless, bone incorporation is difficult to evaluate using computed tomography or other conventional methods owing to the presence of metal artifacts; therefore, whether bone incorporation between the grafted bone and glenoid or between the graft and baseplate implant can be achieved remains unclear. Several studies have reported the effectiveness of tomosynthesis in reducing metal artifacts for the evaluation of implant loosening, bone resorption, and spot welds. We aimed to evaluate and compare the bone incorporation rates between angled bony-increased offset and metal-augmented implants using tomosynthesis with metal artifact reduction technology. We hypothesized that a high bone incorporation rate would be obtained with angled bony-increased offset and a metal-augmented baseplate.

METHODS

A total of 52 patients who underwent reverse total shoulder arthroplasty (TSA) with angled bony-increased offset and 42 patients who underwent reverse total shoulder arthroplasty with metal-augmented baseplate were assessed and followed up for a minimum of 2 years. The bone incorporation and implant loosening rates were compared between the 2 groups, and the sites of spot welds and trabeculation were recorded according to zones. Bone incorporation between the bone and prosthesis was defined as a confirmation of spot welds connecting the porous area and bone in more than three zones. Bone incorporation between the native bone and grafted bone was defined as an observation of trabeculation. Glenoid loosening was defined as the presence of at least 1 mm radiolucency around the prosthesis in more than 2 zones.

RESULTS

Both the angled bony-increased offset and metal-augmented baseplate groups achieved sufficient bone incorporation rates (98% [51/52 cases] vs. 100% [42/42 cases], P = 1.0) and low implant loosening rates (2% [1/52 cases] vs. 0% [0/42 cases], P = 1.0). Spot welds and trabeculation were likely to be confirmed in the lower parts of the glenoid.

CONCLUSION

The two groups did not show any significant differences regarding bone incorporation rates. Considering the complexity of performing the procedure with angled bony-increased offset, the use of a metal-augmented baseplate can serve as an alternative treatment to avoid superior inclination in reverse total shoulder arthroplasty.

The Value of Computed Tomography-Based Planning in Shoulder Arthroplasty Compared to Intra-/Interobserver Reliability of X-ray Planning

Background: Reversed total shoulder arthroplasty (RTSA) is an established surgery for many pathologies of the shoulder and the demand continues to rise with an aging population. Preoperative planning is mandatory to support the surgeon's understanding of the patient's individual anatomy and, therefore, is crucial for the patient's outcome. Methods: In this observational study, we identified 30 patients who underwent RTSA with two- and three-dimensional preoperative planning. Each patient underwent new two-dimensional planning from a medical student and an orthopedic resident as well as through a mid-volume and high-volume shoulder surgeon, which was repeated after a minimum of 4 weeks. The intra- and interobserver reliability was then analyzed and compared to the 3D planning and the implanted prosthesis. The evaluated parameters were the size of the pegged glenoid baseplate, glenosphere, and humeral short stem. Results: The inter-rater reliability showed higher deviations in all four raters compared to the 3D planning of the base plate, glenosphere, and shaft. The intra-rater reliability showed a better correlation in more experienced raters, especially in the planning of the shaft. Conclusions: Our study shows that 3D planning is more accurate than traditional planning on plain X-rays, despite experienced shoulder surgeons showing better results in 2D planning than inexperienced ones.

The Use of Glenoid Structural Allografts for Glenoid Bone Defects in Reverse Shoulder Arthroplasty

Background: The use of reverse shoulder arthroplasty as a primary and revision implant is increasing. Advances in implant design and preoperative surgical planning allow the management of complex glenoid defects. As the demand for treating severe bone loss increases, custom allograft composites are needed to match the premorbid anatomy. Baseplate composite structural allografts are used in patients with eccentric and centric defects to restore the glenoid joint line. Preserving bone stock is important in younger patients where a revision surgery is expected. The aim of this article is to present the assessment, planning, and indications of femoral head allografting for bony defects of the glenoid. Methods: The preoperative surgical planning and the surgical technique to execute the plan with a baseplate composite graft are detailed. The preliminary clinical and radiological results of 29 shoulders which have undergone this graft planning and surgical technique are discussed. Clinical outcomes included visual analogue score of pain (VAS), American Shoulder and Elbow Surgeons score (ASES), Constant-Murley score (CS), satisfaction before and after operation, and active range of motion. Radiological outcomes included graft healing and presence of osteolysis or loosening. Results: The use of composite grafts in this series has shown excellent clinical outcomes, with an overall graft complication rate in complex bone loss cases of 8%. Conclusion: Femoral head structural allografting is a valid and viable surgical option for glenoid bone defects in reverse shoulder arthroplasty.

Patient-specific implants in reverse shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) is widely popular among shoulder surgeons and patients, and its prevalence has increased dramatically in recent years. With this increased use, the indicated pathologies associated with RTSA are more likely to be encountered, and challenging patient presentations are more likely to be seen. One prominent challenging presentation is RTSA patients with severe glenoid bone loss. Several techniques with varying degrees of invasiveness, including excessive reaming, alternate centerline, bone grafting, and patient-specific implants (PSIs), have been developed to treat patients with this presentation. PSI treatment uses a three-dimensional reconstruction of a computed tomography scan to design a prosthetic implant or component customized to the patient's glenoid morphology, allowing compensation for any significant bone loss. The novelty of this technology implies a paucity of available literature, and although many studies show that PSIs have good potential for solving challenging shoulder problems, some studies have reported questionable and equivocal outcomes. Additional research is needed to explore the indications, outcomes, techniques, and cost-efficiency of this technology to help establish its role in current treatment guidelines and strategies.

Mid-term results of the use of structural humeral head autograft to correct glenoid bone loss in reverse total shoulder arthroplasty

Background

Native glenoid bone loss presents technical challenges in shoulder arthroplasty. The purpose of this study is to report the mid-term clinical and radiographic outcomes of patients treated with structural humeral head autograft reconstruction of glenoid bone loss in the setting of reverse total shoulder arthroplasty (rTSA).

Methods

Retrospective review of 30 shoulders in 28 patients undergoing rTSA with a structural humeral head autograft to correct glenoid bone loss. Demographics, comorbidities, anatomic details, and patient-reported outcome measures were collected for analysis.

Results

Range of motion and patient-reported outcome measures were all significantly improved postoperatively (P < .001). Bone grafts were found to incorporate into 100% of shoulders, with no protheses displaying signs of loosening or other structural concerns. No revision procedures were performed, and all patients were satisfied with their shoulder postoperatively. Two patients developed scapular notching on follow-up.

Discussion

The use of a humeral head autograft to reconstruct glenoid bone loss in patients undergoing rTSA is a safe and effective procedure. It allows for a local graft source to be utilized thus avoiding potential comorbidity and complications associated with the use of alternative site autografts or allografts and has the advantage of nearly congruent fit within the defect.

Augmented baseplates in reverse shoulder arthroplasty: a systematic review of outcomes and complications

Background

Glenoid wear secondary to primary osteoarthritis or rotator cuff arthropathy is an obstacle commonly encountered by surgeons performing reverse shoulder arthroplasty, with numerous techniques devised to address this finding. The most recent of such techniques is the introduction of augmented glenoid baseplates to fill these glenoid defects. The objectives of this systematic review are to analyze clinical outcomes of augmented baseplates in patients with glenoid wear, including pain, range of motion, patient-reported functional scores, radiographic outcome measures, complication rates, and revision rates.

Methods

Three online databases (Ovid Medline, EMBASE, Pubmed) were searched for studies publishing clinical and functional outcomes of augmented baseplates in primary reverse shoulder arthroplasty. Findings were aggregated and frequency-weighted means of these variables were calculated when applicable.

Results

Seven studies comprising 810 patients were included in this review. The mean patient age was 72.1 ± 8.1 years with an average follow-up time of 41.4 months. Frequency-weighted means of improvement in forward elevation, abduction, and active external rotation were 53°, 47°, and 19°, respectively. Patients experienced American Shoulder and Elbow Surgeons, Simple Shoulder Test, and Constant score improvements of 45.9, 5.9, and 33.7, respectively. Pooled complicated rate was 6.4%, with 10 cases of baseplate loosening and 3 cases of instability. Five (0.6%) patients required reoperation. Subdividing among augment type (posterior, superior, posterosuperior), there were no apparent differences in outcomes or complication rates between directional augments.

Conclusion

This systematic review demonstrates that augmented baseplates for reverse shoulder arthroplasty provide positive outcomes both clinically and functionally at early follow-up. Complications are within an acceptable range for primary reverse shoulder arthroplasty, with a low rate of revision. Augmented baseplates should serve as a viable option for surgeons seeking to address glenoid wear during reverse shoulder arthroplasty.

[Bony glenoid reconstruction in revision arthroplasty]

Glenoid pathologies are one of the main indications for shoulder arthroplasty revisions. In most cases, the glenoid bone defect is associated with insufficiency of the rotator cuff, so that only reverse total shoulder arthroplasty can be considered as a revision implant. For stable permanent fixation of the reverse glenoid component, to avoid inferior glenoid notching, and to achieve optimal function, physiological restoration of three-dimensional glenoid anatomy is necessary. In order to approach the individual glenoid pathologies in a differentiated and optimal manner, it is important to classify the defects. A basic distinction must be made between centric contained and eccentric uncontained defects. Combinations often occur. It is also important to consider the severity, depth, and three-dimensional orientation of the defect. Therefore, a CT analysis of the glenoid is essential preoperatively. The data obtained should serve as the basis for computer-assisted planning to determine the optimal position of the glenoid baseplate and the type and shape of the bone graft for the reconstruction. For patients with good bone quality, we recommend defect reconstruction with autologous iliac crest. The type of graft configuration and fixation and the decision between a one- and two-stage procedure depend on the type and severity of the defect. With technically correct reconstruction and proper prosthesis implantation, sufficient integration of the bone graft and durable fixation of the glenoid component can be expected with satisfactory clinical results. After bony reconstruction of the defects, repeated treatment with a reverse arthroplasty is possible in the long term in the event of renewed glenoid problems.

Single-Stage Revision Reverse Shoulder Arthroplasty: Preoperative Planning, Surgical Technique, and Mixed Reality Execution

Revision shoulder arthroplasty is increasing with the number of primary shoulder replacements rising globally. Complex primary and revisions of shoulder arthroplasties pose specific challenges for the surgeon, which must be addressed preoperatively and intraoperatively. This article aimed to present strategies for the management of revision of shoulder arthroplasties through a single-stage approach. Preoperatively, patient factors, such as age, comorbidities, and bone quality, should be considered. The use of planning software can aid in accurately evaluating implants in situ and predict bony anatomy that will remain after explantation during the revision surgery. The planning from such software can then be executed with the help of mixed reality technology to allow accurate implant placement. Single-stage revision is performed in two steps (debridement as first step, implantation and reconstruction as the second step), guided by the following principles: adequate debridement while preserving key soft tissue attachments (i.e., rotator cuff, pectoralis major, latissimus dorsi, deltoid), restoration of glenoid joint line using bone grafting, restoration of humeral length, reconstruction and/or reattachment of soft tissues, and strict compliance with the postoperative antibiotic regimen. Preliminary results of single-stage revision shoulder arthroplasty show improvement in patient outcomes (mean 1 year), successful treatment of infection for those diagnosed with periprosthetic joint infection, and improved cost-benefit parameters for the healthcare system.

Features of reverse arthroplasty of the shoulder joint in orthopedic pathology of the glenoid (literature review)

The reverse shoulder arthroplasty in the conditions of the modified anatomy of the glenoid is complex and often excludes the possibility of using the standard tactics of installing the glenoid component. There are no identical glenoids, each articular cavity of the scapula differs in height, width, angle of inclination, density of bone tissue, absence or presence of various defects of bone tissue. Given the variety of options for changing the structure and quality of the glenoid bone tissue in injuries and diseases of the shoulder joint, each case of endoprosthetics should be considered individually. In order to perform an adequate metaglen installation, these parameters must be normalized or standardized. The purpose of this work is to review the domestic and foreign literature devoted to the features of reversible shoulder joint replacement during deformation of the articular cavity of the scapula. Based on the analysis of literature data, the percentage of complications associated with unsatisfactory treatment results due to the instability of the glenosphere is quite large, which indicates the lack of elaboration of this topic and its relevance for practical traumatology and orthopedics. The paper considers eccentric non-standard methods of rimming the articular cavity of the scapula, methods of its bone grafting, the use of metaglens made taking into account the deformation of the glenoid, as well as indications for the use of technology for the individual manufacture of scapular components. The study and analysis of indications for the use of various types of techniques for solution glenoid deformities made it possible to systematize and differentially approach the issue of preoperative planning and choosing the correct, right treatment tactics in complex cases of reversible shoulder joint replacement.

Clinical and Radiological Outcomes after Total Shoulder Arthroplasty Using Custom-Made Glenoid Components: A Systematic Review

Reverse total shoulder arthroplasty presents itself sometimes as challenging when it comes to addressing massive bone loss, either in primary or revision settings. Custom components recently have made their way into shoulder prosthetics and are meant to help in the case of extensive glenoid bone destruction. Because of strict indication and the fairly recent introduction of these implants, the usage of custom-made glenoid implants is not very common yet. However, the early results are promising. The purpose of this review was to summarize and analyze the available literature. Therefore, a systematic review was performed according to PRISMA guidelines. A comprehensive search of the databases PubMed, Cochrane, and Livivo was performed to screen for studies reporting on clinical and radiological outcomes of custom glenoid implants. Four studies with a total of 46 shoulders were included in this review. The mean patient age was 68.8 years and the mean time of follow-up was 24.3 months. The weighted means showed an increase in CMS (32.7 points), in ASES (39.8 points), in anteversion (67.4 degrees), and in abduction (51.9 degrees) and a decrease in VAS (5.4 points). Custom-made glenoid implants are therefore a viable option in cases of large combined glenoid bone loss, both in primary and revision shoulder arthroplasty.

Management of glenoid bone loss in primary reverse shoulder arthroplasty

Aims

Rates of reverse total shoulder arthroplasty (rTSA) continue to grow. Glenoid bone loss and deformity remains a technical challenge to the surgeon and may reduce improvements in patients’ outcomes. However, there is no consensus as to the optimal surgical technique to best reconstruct these patients’ anatomy. This review aims to compare the outcomes of glenoid bone grafting versus augmented glenoid prostheses in the management of glenoid bone loss in primary reverse total shoulder arthroplasty.

Methods

This systematic review and meta-analysis evaluated study-level data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We performed searches of Medline (Ovid), Embase (Ovid), and PubMed from their dates of inception to January 2022. From included studies, we analyzed data for preoperative and postoperative range of motion (ROM), patient-reported functional outcomes, and complication rates.

Results

A total of 13 studies (919 shoulders) were included in the analysis. The mean age of patients at initial evaluation was 72.2 years (42 to 87), with a mean follow-up time of 40.7 months (24 to 120). Nine studies with 292 rTSAs evaluated the use of bone graft and five studies with 627 rTSAs evaluated the use of augmented glenoid baseplates. One study was analyzed in both groups. Both techniques demonstrated improvement in patient-reported outcome measures and ROM assessment, with augmented prostheses outperforming bone grafting on improvements in the American Shoulder and Elbow Surgeons Score. There was a higher complication rate (8.9% vs 3.5%; p < 0.001) and revision rate among the bone grafting group compared with the patients who were treated with augmented prostheses (2.4% vs 0.6%; p = 0.022).

Conclusion

This review provides strong evidence that both bone graft and augmented glenoid baseplate techniques to address glenoid bone loss give excellent ROM and functional outcomes in primary rTSA. The use of augmented base plates may confer fewer complications and revisions. Cite this article: Bone Joint J 2022;104-B(12):1334–1342.

Hemi-reverse revision arthroplasty in the setting of severe glenoid bone loss

BACKGROUND

Glenoid bone loss is one of the main challenges in revision of failed shoulder arthroplasties. The concept of a hemi-reverse procedure is to implant a glenoid baseplate and glenosphere to protect the glenoid reconstruction to allow it to heal and to preserve the joint space for a potential second-stage humeral component implantation. The purpose of this study was to report the results of hemi-reverse procedures.

METHODS

Revision to a hemi-reverse procedure was performed in 15 patients: 8 with a failed anatomic total shoulder arthroplasty, 3 with a failed reverse shoulder arthroplasty, 3 with a failed humeral hemiarthroplasty, and 1 with placement of a cement spacer owing to sepsis after a total shoulder arthroplasty. After complete removal of the initial prosthesis, all patients underwent glenoid reconstruction with bone grafting and implantation of a reverse arthroplasty baseplate and glenosphere. A humeral implant was not placed in any case. The patients were prospectively followed up and underwent complete clinical and radiologic studies preoperatively and postoperatively at a minimum of 2 years after the surgical procedure.

RESULTS

Thirteen hemi-reverse implants and glenoid bone grafts healed (86%) and remained radiographically stable. One hemi-reverse construct migrated and became mechanically loose, which was attributed to absent fixation of the central post in the native glenoid bone. In 1 patient, an implant-related infection developed; irrigation and debridement were performed, in addition to revision to a resection arthroplasty. After documented radiographic healing of the hemi-reverse glenoid reconstruction, 5 patients underwent a second-stage revision to a reverse procedure with insertion of a humeral component at a median of 6 months (interquartile range [IQR], 6-8 months). In this group, the median follow-up period was 73 months (IQR, 45-153 months), the median Constant score was 48 (IQR, 41-56), median active forward elevation was 135° (IQR, 100°-150°), and the median Subjective Shoulder Value was 50% (IQR, 50%-60%). In the group of 9 patients with remaining hemi-reverse implants, the median follow-up period was 38 months (IQR, 29-60 months), the median Constant score was 41 (IQR, 38-46), median active forward elevation was 100° (IQR, 80°-100°), and the median Subjective Shoulder Value was 50% (IQR, 40%-60%).

CONCLUSION

The hemi-reverse procedure is an effective revision procedure to reconstruct a severely deficient glenoid. The hemi-reverse procedure may function as the definitive procedure, with satisfactory outcomes. Additionally, in patients who undergo the hemi-reverse procedure, second-stage revision to a total reverse procedure can be performed once imaging confirms bone graft and construct stability.

Identifying areas of screw fixation in glenoids with severe bone loss in shoulder arthroplasty

BACKGROUND

Severe glenoid bone loss (SGBL) poses significant technical challenges. Adequate fixation of glenoid implants may require the use of alternative screw placement. Although bone volumes for the spine and lateral pillars have previously been defined, insufficient evidence exists regarding the distribution of screw placement for fixation in such regions for cases with SGBL. The purpose of this study is to evaluate the variability of screw placement. We hypothesize that determining this variability and establishing common patterns of glenoid bone loss will allow for recommendations for preoperative planning, and implant design and selection.

METHODS

An internal registry of 2 high-volume shoulder and elbow surgeons was queried, and 65 three-dimensional scapulae models exhibiting SGBL were identified. A fellowship-trained shoulder and elbow surgeon simulated the placement of two 3.5 mm × 30 mm screws, one in the scapular spine (CS) bone volume and one in the inferior column (IS) bone volume. Three orthogonal reference planes were created using anatomic reference points: the scapula trigonum, estimated glenoid center, and inferior pole. Screw positions were mapped, and deviations from the reference planes were calculated. Mutual positions of the IS to CS were also computed. Intraobserver reliability was assessed using 10 randomly selected samples. Median and 25th and 75th percentiles were reported for screw orientation distributions. Means and standard deviations were reported for screw head positions.

RESULTS

We demonstrated excellent intraobserver reliability (intraclass correlation coefficients, 0.90-0.98). Fifty percent of CS were oriented 10° ± 5° of retroversion from the scapula plane, with 5° ± 5° of inclination. For IS, 50% were positioned 0° ± 4° from the scapula plane, with -33° ± 7° of inclination. The relationship of the IS with the CS was medial and posterior in 49% of cases, lateral and posterior in 45%, and lateral and anterior in 6% of cases. On average, the distance between the CS and IS heads was 25 mm ± 4 mm.

DISCUSSION

For SGBL, adequate fixation of glenoid implants can be achieved by placing screws in the spine and lateral columns, with excellent reproducibility. Future implant designs should accommodate CS positioned -16° to -5° from the scapula plane, with 0° to 12° of inclination, and IS positioned -6° to 4° from the scapula plane, with -40° to -25° of inclination. Moreover, mutual screw positions suggested bone loss distributions anteriorly and inferiorly. Future implant designs should consider the potential benefits of augmentation to accommodate interscrew distances of 21-29 mm and anatomic locations of the IS relative to the CS.

Preoperative planning of baseplate position in reverse shoulder arthroplasty: Still no consensus on lateralization, version and inclination

INTRODUCTION

In the context of reverse shoulder arthroplasty, some parameters of glenoid baseplate placement follow established golden rules, while other parameters still have no consensus. The assessment of glenoid wear in the future location of the glenoid baseplate varies among surgeons. The objective of this study was to analyze the inter-observer reproducibility of glenoid baseplate 3D positioning during virtual pre-operative planning.

METHOD

Four shoulder surgeons planned the glenoid baseplate position of a reverse arthroplasty in the CT scans of 30 degenerative shoulders. The position of the glenoid guide pin entry point and the glenoid baseplate center was compared between surgeons. The baseplate's version and inclination were also analyzed.

RESULTS

The 3D positioning of the pin entry point was achieved within ± 4 mm for nearly 100% of the shoulders. The superoinferior, anteroposterior and mediolateral positions of the baseplate center were achieved within ± 2 mm for 77.2%, 67.8% and 39.4% of the plans, respectively. The 3D orientation of the glenoid baseplate within ± 10° was inconsistent between the four surgeons (weak agreement, K=0.31, p=0.17).

DISCUSSION

The placement of the glenoid guide pin was very consistent between surgeons. Conversely, there was little agreement on the lateralization, version and inclination criteria for positioning the glenoid baseplate between surgeons. These parameters need to be studied further in clinical practice to establish golden rules. Three-dimensional information from pre-operative planning is beneficial for assessing the glenoid deformity and for limiting its impact on the baseplate position achieved by different surgeons.

LEVEL OF EVIDENCE

III. Case control study.

[3D printing in the field of shoulder surgery]

The 3D printing technology is a relatively new procedure with a high potential, especially in the field of shoulder surgery. The 3D printing procedures are increasingly being developed and also gaining new users. Principally, 3D printing procedures can be applied preoperatively in planning the surgical procedure, patient clarification and in teaching; however, the technology is increasing being used intraoperatively. In addition to intraoperative visualization of the models, 3D printing permits the use of individual and specific instruments and implants. This allows the precise transfer of the preoperative planning to the surgical procedure. Inaccuracies are mainly caused by soft tissues. The 3D printing can be beneficial in the fields of arthroplasty, shoulder instability as well as orthopedic trauma. The literature shows promising results in relation to duration of surgery, blood loss and clinical results of the procedure. On the other hand, it is still unclear which indications warrant the use of 3D printing. Other aspects that raise questions are the time of planning, the production time and the additional cost that the use of 3D printing entails. Nonetheless, 3D printing represents a meaningful enhancement of the portfolio of surgeons, which becomes highly beneficial and useful in complex situations. Furthermore, this procedure enables a certain amount of flexibility when reacting to certain circumstances.

Reverse Shoulder Arthroplasty with Bony and Metallic versus Standard Bony Reconstruction for Severe Glenoid Bone Loss. A Retrospective Comparative Cohort Study

There are different techniques to address severe glenoid erosion during reverse shoulder arthroplasty (RSA). This study assessed the clinical and radiological outcomes of RSA with combined bony and metallic augment (BMA) glenoid reconstruction compared to bony augmentation (BA) alone. A review of patients who underwent RSA with severe glenoid bone loss requiring reconstruction from January 2017 to January 2019 was performed. Patients were divided into two groups: BMA versus BA alone. Clinical outcome measurements included two years postoperative ROM, Constant score, subjective shoulder value (SSV), and the American Shoulder and Elbow Surgeons Shoulder (ASES) score. Radiological outcomes included radiographic evidence of scapular complications and graft incorporation. The BMA group had significantly different glenoid morphology (p < 0.001) and greater bone loss thickness than the BA group (16.3 ± 3.8 mm vs. 12.0 ± 0.0 mm, p = 0.020). Both groups had significantly improved ROM (anterior forward flexion and external rotation) and clinical scores (Constant, SSV and ASES scores) at 2 years. Greater improvement was observed in the BMA group in terms of anterior forward flexion (86.3° ± 27.9° vs. 43.8° ± 25.6°, p = 0.013) and Constant score (56.6 ± 10.1 vs. 38.3 ± 16.7, p = 0.021). The BA group demonstrated greater functional and clinical improvements with higher postoperative active external rotation and ASES results (active external rotation, 49.4° ± 17.0° vs. 29.4° ± 14.7°, p = 0.017; ASES, 89.1 ± 11.3 vs. 76.8 ± 11.0, p = 0.045). The combination use of bone graft and metallic augments in severe glenoid bone loss during RSA is safe and effective and can be considered in cases of severe glenoid bone loss where bone graft alone may be insufficient.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Management of Humeral and Glenoid Bone Defects in Reverse Shoulder Arthroplasty

Bone loss of either the glenoid or the humerus is a challenging problem in reverse total shoulder arthroplasty. When left unaddressed, it can lead to early failure of the implant and poor outcomes. Humeral bone loss can be addressed with the use of an endoprosthesis or allograft prosthetic implant. Glenoid bone loss can be treated with a variety of grafting options, such as augmented implants, patient-specific navigation, and implantation systems.

Is bone grafting always necessary in revision reverse total shoulder arthroplasty with uncontained glenoid bone defects?

BACKGROUND

Patients with an uncontained glenoid bone defect can still successfully undergo a reverse total shoulder arthroplasty (RTSA). Currently, there is a tendency toward reconstruction of the premorbid glenoid plane with bone grafts, which is technically demanding. We investigated whether central peg positioning in the spine pillar (CPPSP) is a more feasible alternative to the use of bone grafts.

METHODS

This study included 60 revisions to an RTSA with uncontained glenoid bone defects. Patients were treated with bone grafts in 29 cases and with the CPPSP technique in 31 cases. We assessed clinical results using the Constant score and assessed the complication rate.

RESULTS

The Constant score changed from 42 to 69 points in the CPPSP group and from 47 to 60 points in the bone graft group. This difference in the increase in the Constant score was significant (P = .031) owing to a significant difference in strength in favor of the CPPSP group. The overall complication rate was 37.7% (20 of 53 patients), with a reoperation rate of 18.9% (10 of 53). Dislocations occurred only in the CPPSP group (n = 3), and loosening of the glenoid occurred only in the bone graft group (n = 3).

CONCLUSION

Patients with uncontained glenoid bone defects undergoing revision to an RTSA obtain similar clinical results with the CPPSP technique compared with the use of bone grafts. The CPPSP technique is a valid alternative but results in different complications.

Revision Reverse Shoulder Arthroplasty for Anatomical Glenoid Component Loosening Was Not Universally Successful: A Detailed Analysis of 127 Consecutive Shoulders

BACKGROUND

Glenoid component loosening is a primary cause of failure of anatomical total shoulder arthroplasty (TSA) and is commonly associated with glenoid bone loss. The purpose of the present study was to evaluate the outcome and survival following revision to a reverse total shoulder arthroplasty (RSA) for the treatment of loosening of a polyethylene cemented glenoid component in the setting of failed TSA.

METHODS

Between 2010 and 2017, 151 shoulders underwent revision to RSA for the treatment of loosening of an anatomical polyethylene glenoid component. Shoulders with staged reconstruction for the treatment of infection were excluded. One hundred and twenty-seven patients (67 women and 60 men) had a single-stage reconstruction and were available for follow-up. The mean age at the time of surgery was 70 years (range, 41 to 93 years). In all cases, the humeral component was revised and a standard glenoid baseplate was utilized. Bone graft was used at the discretion of the treating surgeon. Medical records and radiographs were reviewed to collect demographic, intraoperative, and postoperative data; to quantify glenoid bone loss; and to determine the radiographic outcome. The mean duration of follow-up was 35 months (range, 24 to 84 months).

RESULTS

Revision to RSA resulted in significant improvements in terms of pain and motion. Sixteen shoulders (13%) underwent revision surgery for the treatment of baseplate loosening. Radiographic baseplate loosening was present in 6 additional shoulders (overall rate of baseplate loosening, 17%). Intraoperative fracture or fragmentation of the greater tuberosity occurred in 30 shoulders (24%). Other reoperations included resection for deep infection (3 shoulders), arthroscopic biopsies for unexplained persistent pain (2 shoulders), humeral tray exchange for dislocation (2 shoulders), revision for humeral loosening (1 shoulder), irrigation and debridement for hematoma (1 shoulder), and internal fixation of periprosthetic fracture (1 shoulder) (overall reoperation rate, 20%). Among shoulders with surviving implants at the time of the most recent follow-up, pain was rated as none or mild in 83 shoulders (65.4%) and the average active elevation and external rotation were 132° and 38°, respectively. With the numbers available, no risk factors for failure could be identified.

CONCLUSIONS

Revision RSA for the treatment of loosening of an anatomical polyethylene component was associated with a 17% glenoid mechanical failure rate. Although this procedure resulted in improvements in terms of pain and function, it was not universally successful and thus needs further refinement in order to improve outcomes.

LEVEL OF EVIDENCE

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

Mid-term outcomes of reverse shoulder arthroplasty using the alternative center line for glenoid baseplate fixation: a case-controlled study

BACKGROUND

A critical step in reverse shoulder arthroplasty (RSA) is glenoid baseplate fixation. In cases of glenoid bone loss, use of the anatomic glenoid center line may not provide sufficient bone support for fixation. Anteversion along the alternative center line is a described method for achieving baseplate fixation in these cases. However, concern remains regarding negative consequences in functional outcomes and complications. The purpose of this study was to compare the outcomes of RSA using the anatomic or alternative center line.

METHODS

We performed a retrospective case-controlled study of patients who underwent RSA between November 2006 and August 2017, performed by a single surgeon, with a minimum of 2 years' follow-up. Patients treated with the anatomic center-line technique for baseplate fixation were matched 3:1 based on sex, indication for surgery, and age with patients treated with the alternative center-line technique. Patient-reported outcome measures (PROMs), active range of motion, and the ability to perform functional tasks of internal rotation were compared. Evaluations of the most recently obtained radiographs focused on acromial fractures, scapular notching, and glenoid loosening.

RESULTS

A total of 88 patients (66 in anatomic center-line group and 22 in alternative group) participated in the matched analysis, with a mean age of 74.2 years (range, 58-89 years) and mean follow-up period of 53 months (range, 24-130 months). At the final follow-up, we found no significant differences in PROMs, including the Simple Shoulder Test score (P = .829), American Shoulder and Elbow Surgeons score (P = .601), visual analog scale pain score (P = .068), and Single Assessment Numeric Evaluation score (P = .674). Moreover, both the overall improvements in these PROMs and all active motions and functional tasks of internal rotation were not different. No radiographic evidence of glenoid loosening was found in either group, and 2 patients in each cohort (3% of the anatomic group and 9% of the alternative group) experienced an acromial fracture. Low-grade scapular notching developed in 15.2% of the anatomic group and 18.2% of the alternative center line group (P = .736).

CONCLUSION

The alternative center line can be used for baseplate fixation in the setting of glenoid bone loss and leads to similar patient outcomes and functional tasks of internal rotation, as well as a low rate of complications, compared with the anatomic center line following RSA.

Custom-made reverse shoulder arthroplasty for severe glenoid bone loss: review of the literature and our preliminary results

The treatment of severe glenoid bone loss in shoulder arthroplasty represents a challenge, and the results of current prosthetic designs with only glenoid fixation still remain unsatisfactory. In the past decade, customized glenoid prostheses have been developed to address severe glenoid arthritis and in the revision setting. In this review, we analyzed the current surgical options, the classification limits, past literature evidence, and our preliminary results of 6 patients (3 male, 3 female) treated with a reverse implant and custom-made glenoid implant (ProMade; LimaCorporate, Italy). Computer analysis of the residual shape and the amount of glenoid bone stock in association with new classifications could help the surgeon to obtain good clinical and radiological outcomes. The development of navigation systems could improve the adequacy of the implant and, thus, the reliability and longevity of the implant itself.

Reverse Total Shoulder Arthroplasty with a Superior Augmented Glenoid Component for Favard Type-E1, E2, and E3 Glenoids

BACKGROUND

Uncorrected superior glenoid wear in patients managed with reverse total shoulder arthroplasty (rTSA) can result in increased complications, including baseplate failure. The present study quantifies the clinical and radiographic outcomes of patients with Favard type-E1, E2, and E3 glenoid deformity who were managed with rTSA with use of a superior or superior/posterior augmented glenoid baseplate.

METHODS

We retrospectively reviewed the records for 68 patients with shoulder arthritis and Favard type-E1, E2, or E3 glenoid deformity who were managed with primary rTSA and a 10° superior augmented or 10° superior/8° posterior augmented baseplate. The mean duration of follow-up was 40 months (range, 24 to 85 months). Outcomes were assessed preoperatively and at the latest follow-up with shoulder range of motion and use of outcome scores including the Simple Shoulder Test (SST), University of California Los Angeles (UCLA) score, American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Shoulder Pain and Disability Index (SPADI) score. Radiographs were evaluated preoperatively and at the time of the latest follow-up. Differences in preoperative and postoperative range of motion and outcome metrics were assessed with use of a 2-tailed Student t test.

RESULTS

The majority of patients experienced clinically meaningful improvements in terms of pain and function following rTSA with a superior or superior/posterior augment, with 94% of patients rating themselves as "much better" (73.5%) or "better" (20.5%) at the time of the latest follow-up. At least 88% of the patients exceeded the minimum clinically important difference (MCID) threshold, and 75% of patients exceeded the substantial clinical benefit (SCB) threshold, for each of the clinical outcome metrics and range of motion. Five complications were reported (prevalence, 7.4%), including acromial stress fracture (2 patients), posttraumatic scapular neck fracture (1 patient), chronic shoulder pain (1 patient), and aseptic glenoid loosening (1 patient).

CONCLUSIONS

The present short-term clinical and radiographic study demonstrated that shoulder arthropathy with superior glenoid wear patterns (Favard types E1, E2, and E3) can be successfully treated with rTSA with a superior or superior/posterior augmented baseplate. Longer-term clinical and radiographic follow-up is necessary to confirm that these promising short-term results are durable.

LEVEL OF EVIDENCE

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

Allograft-Composite Reverse Shoulder Arthroplasty for Malignant Tumor of the Proximal Humerus

Composite-allograft reverse shoulder arthroplasties are a surgical alternative in malignant tumor reconstructions following segmental bone resection of the proximal humerus. They allow reinsertion of the rotator cuff tendons and reliable restoration of humeral height, increasing prosthetic stability and mobility. Preoperative local tumor extension assessment must be thorough and a strict surgical technique must be followed to obtain satisfactory functional results. The indications for this procedure include a strictly intraosseous tumor of the proximal humerus corresponding to an S3-S4 A resection following criteria provided by the Musculoskeletal Tumor Society as described by Enneking and colleagues in 1990. Certain conditions must question the procedure such as extended S3-S4-S5 bone resections, partial sacrifice of the deltoid muscle, preoperative deltoid impairment, and glenohumeral arthrectomy. Here, we report technical details and indications of composite-allograft reverse shoulder arthroplasty in the context of tumor segmental resection of the proximal humerus, especially in the humeral preparation.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Clinical relevance of augmented statistical shape model of the scapula in the glenoid region

OBJECTIVE

To illustrate (a) whether a statistical shape model (SSM) augmented with anatomical landmark set(s) performs better fitting and provides improved clinical relevance over non-augmented SSM and (b) which anatomical landmark set provides the best augmentation strategy for predicting the glenoid region of the scapula.

METHODS

Scapula SSM was built using 27 dry bone CT scans and augmented with three anatomical landmark sets (16 landmarks each) resulting in three augmented SSMs (aSSM_proposed, aSSM_set1, aSSM_set2). The non-augmented and three augmented SSMs were then used in a non-rigid registration (regression) algorithm to fit to six external scapular shapes. The prediction error by each type of SSM was evaluated in the glenoid region for the goodness of fit (mean error, root mean square error, Hausdorff distance and Dice similarity coefficient) and for four anatomical angles (critical shoulder angle, lateral acromion angle, glenoid inclination, glenopoar angle).

RESULTS

Inter- and intra-observer reliability for landmark selection was moderate to excellent (ICC>0.74). Prediction error was significantly lower for SSM_{non-augmented} for mean (0.9 mm) and root mean square (1.15 mm) distances. Dice coefficient was significantly higher (0.78) for aSSM_proposed compared to all other SSM types. Prediction error for anatomical angles was lowest using the aSSM_proposed for critical shoulder angle (3.4°), glenoid inclination (2.6°), and lateral acromion angle (3.2°).

CONCLUSION AND SIGNIFICANCE

The conventional SSM robustness criteria or better goodness of fit do not guarantee improved anatomical angle accuracy which may be crucial for certain clinical applications in pre-surgical planning. This study provides insights into how SSM augmented with region-specific anatomical landmarks can provide improved clinical relevance.

Reverse Shoulder Arthroplasty for B2 Glenoid Deformity

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

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

Purpose

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

Methods

The PubMed and Cochrane databases were searched for relevant papers.

Results

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

Conclusions

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

Reverse Total Shoulder Arthroplasty: Biomechanics and Indications

PURPOSE OF REVIEW

Over the past decade, our understanding of the biomechanics of the reverse total shoulder arthroplasty (RTSA) has advanced, resulting in design adjustments, improved outcomes, and expanding indications. The purpose of this review is to summarize recent literature regarding the biomechanics of RTSA and the evolving indications for its use.

RECENT FINDINGS

While Grammont's principles of RTSA biomechanics remain pillars of contemporary designs, a number of modifications have been proposed and trialed in later generations to address complications such as impingement and glenoid failure. Clinical and biomechanical literature suggest that less medialized, more inferior glenospheres result in less impingement and notching. On the humerus, a more vertical neck cut is associated with less impingement. Indications for RTSA continue to expand beyond the classic indication of cuff tear arthropathy (CTA). Patients without a functional cuff but no arthritis now have a reliable option in the RTSA. RTSA has also replaced hemiarthroplasty as the implant of choice for displaced three- and four-part proximal humerus fractures in the elderly. Finally, updated design options and modular components now allow for treatment of glenoid bone loss, failed arthroplasty, and proximal humerus tumors with RTSA implants. Reverse total shoulder arthroplasty design has been modernized on both the glenoid and humerus to address biomechanical challenges of early implants. As outcomes improve with these modifications, RTSA indications are growing to address complex bony pathologies such as tumor and bone loss. Longitudinal follow-up of patients with updated designs and novel indications is essential to judicious application of RTSA technology.