Influence of glenoid wear pattern on glenoid component placement accuracy in shoulder arthroplasty

Retrospective MRI analysis of 418 adult shoulder joints to assess the physiological morphology of the glenoid in a low-grade osteoarthritic population

BACKGROUND

Due to the difference in size between the humeral head and the glenoid, the shoulder joint is prone to instability. Therefore, the reconstruction of the physiological joint morphology is of great importance in shoulder joint preservation and replacement surgery. The aim of this study was to describe physiological reference parameters for the morphology of the glenoid for the first time.

MATERIAL AND METHODS

MRI images of the shoulder joints of 418 patients (mean age: 50.6 years [± 16.3]) were retrospectively analysed in a low-grade osteoarthritic population. The glenoid distance in coronal (GDc) and axial view (GDa), glenoid inclination (GI) and version (GV) as well as scapula neck length (SNL) were measured. Parameters were studied in association for age, gender, side and degeneration grade.

RESULTS

Mean GDc was 33.4 mm (± 3.6), mean GDa 26.8 mm (± 3.2), mean GI 10.5° (± 6.4), mean GV -0.4 mm (± 5.4) and mean SNL was 33.4 mm (± 4.7). GDa was significant higher in right shoulders (p < 0.001). GDc and GDa showed significant higher mean values in older patients (p < 0.001) and in shoulders with more severe degenerative changes (p < 0.05). While GDc, GDa and SNL were significant larger in male patients (p < 0.001), GI had a higher mean value in female shoulders (p = 0.021).

CONCLUSION

Age, gender and shoulder joint degeneration influence changes in the morphological parameters of the glenoid. These findings have to be considered in shoulder diagnostics and surgery.

CLINICAL TRIAL NUMBER

Not applicable.

Planned Glenoid Implant Utilization: A Comparison of Preoperative Planning with and Without Computer-Assisted Navigation

BACKGROUND

Preoperative planning for anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) is becoming increasingly common. While preoperative planning allows surgeons to determine individualized implant types, utilization of intraoperative navigation improves the accuracy of implant placement and may increase confidence in the preoperative plan. The purpose of this study was to evaluate and compare the rate at which surgeons use a glenoid implant different than their preoperative plan with and without the use of computer navigation.

METHODS

A retrospective review of a multicenter prospectively collected shoulder arthroplasty database was conducted between 2016 and 2022. Inclusion criteria were primary aTSA or rTSA with an available preoperative plan and record of the actual implant used. Change in glenoid implant was defined as a deviation in the final implant from the preoperative plan in regard to backside shape (nonaugmented vs augment or differing augment shape).

RESULTS

We included 1,915 shoulder arthroplasties (525 aTSA, 1,390 rTSA) performed with preoperative planning and intraoperative navigation and 110 shoulder athroplasties (37 aTSA, 73 rTSA) performed with preoperative planning alone. Overall, the final glenoid implant deviated from the preoperative plan less frequently when intraoperative navigation was used compared with preoperative planning alone (1.9% [n = 36] versus 7.3% [n = 8], P = 0.002). When stratified by procedure, deviation from the preoperative plan occurred significantly less for rTSA when preoperative planning was used with intraoperative navigation versus planning alone (2% [n = 29] versus 11% [n = 8], P < 0.001; OR = 0.17 [95% CI = 0.07 to 0.46]), but not aTSA (1% [n = 7] versus 0% [n = 0], P = 1). Use of intraoperative navigation was independently associated with lower odds of deviation from the preoperative plan on multivariable logistic regression (OR = 0.25 [95% CI = 0.11 to 0.56], P = 0.001).

CONCLUSION

Use of intraoperative navigation is associated with increased adherence to the preoperative plan for primary rTSA. Use of navigation may increase surgeon confidence despite known limitations of glenoid visualization during this procedure. This may offer advantages in outpatient surgery centers and smaller hospitals where inventory space may be limited.

LEVEL OF EVIDENCE

Ⅲ, retrospective cohort study.

Metaverse, virtual reality and augmented reality in total shoulder arthroplasty: a systematic review

PURPOSE

This systematic review aims to provide an overview of the current knowledge on the role of the metaverse, augmented reality, and virtual reality in reverse shoulder arthroplasty.

METHODS

A systematic review was performed using the PRISMA guidelines. A comprehensive review of the applications of the metaverse, augmented reality, and virtual reality in in-vivo intraoperative navigation, in the training of orthopedic residents, and in the latest innovations proposed in ex-vivo studies was conducted.

RESULTS

A total of 22 articles were included in the review. Data on navigated shoulder arthroplasty was extracted from 14 articles: seven hundred ninety-three patients treated with intraoperative navigated rTSA or aTSA were included. Also, three randomized control trials (RCTs) reported outcomes on a total of fifty-three orthopedics surgical residents and doctors receiving VR-based training for rTSA, which were also included in the review. Three studies reporting the latest VR and AR-based rTSA applications and two proof of concept studies were also included in the review.

CONCLUSIONS

The metaverse, augmented reality, and virtual reality present immense potential for the future of orthopedic surgery. As these technologies advance, it is crucial to conduct additional research, foster development, and seamlessly integrate them into surgical education to fully harness their capabilities and transform the field. This evolution promises enhanced accuracy, expanded training opportunities, and improved surgical planning capabilities.

Artificial intelligence-based three-dimensional templating for total joint arthroplasty planning: a scoping review

PURPOSE

The purpose of this review is to evaluate the current status of research on the application of artificial intelligence (AI)-based three-dimensional (3D) templating in preoperative planning of total joint arthroplasty.

METHODS

This scoping review followed the PRISMA, PRISMA-ScR guidelines, and five stage methodological framework for scoping reviews. Studies of patients undergoing primary or revision joint arthroplasty surgery that utilised AI-based 3D templating for surgical planning were included. Outcome measures included dataset and model development characteristics, AI performance metrics, and time performance. After AI-based 3D planning, the accuracy of component size and placement estimation and postoperative outcome data were collected.

RESULTS

Nine studies satisfied inclusion criteria including a focus on computed tomography (CT) or magnetic resonance imaging (MRI)-based AI templating for use in hip or knee arthroplasty. AI-based 3D templating systems reduced surgical planning time and improved implant size/position and imaging feature estimation compared to conventional radiographic templating. Several components of data processing and model development and testing were insufficiently covered in the studies included in this scoping review.

CONCLUSIONS

AI-based 3D templating systems have the potential to improve preoperative planning for joint arthroplasty surgery. This technology offers more accurate and personalized preoperative planning, which has potential to improve functional outcomes for patients. However, deficiencies in several key areas, including data handling, model development, and testing, can potentially hinder the reproducibility and reliability of the methods proposed. As such, further research is needed to definitively evaluate the efficacy and feasibility of these systems.

Glenoid bone loss in shoulder arthroplasty: a narrative review

Background and Objective

Crucial to the success of any total or reverse shoulder arthroplasty (RSA) is the stability of the glenoid component fixation. Instability can lead to early implant failure and unsatisfactory results. Patients often present with varying forms of glenoid bone loss (GBL) in both the primary and revision settings, which can be a challenge for the treating surgeon. Severe cases of GBL can increase the risk of potential complications and diminish implant longevity. The use of the reverse total shoulder replacement has been particularly helpful when addressing significant glenoid bony defects. Various approaches have been proposed to deal with GBL, all of which require an individualized assessment of the specifics of the defect in order to provide maximal fixation and thereby optimize the longevity of the shoulder arthroplasty. This article aims to review the recent literature on GBL in shoulder arthroplasty to provide guidance when considering treatment based on the best available evidence.

Methods

PubMed, MEDLINE, EMBASE, AccessMedicine, ClinicalKey, DynaMed, and Micromedex were queried for publications utilizing the following keywords: "glenoid bone loss" AND "glenoid bone deficiency" AND "shoulder arthroplasty" AND "classification". The search was restricted to research published between 2004 and 2023. There were no restrictions on study type or language.

Key Content and Findings

GBL should be critically evaluated prior to undertaking total shoulder arthroplasty (TSA). The treating surgeon should be aware of various methods of addressing bone defects.

Conclusions

The use of TSA is increasing to address various shoulder pathologies. Addressing glenoid bone defects is of critical importance to maximize the longevity and outcome of TSA.

Glenoid component placement accuracy in total shoulder arthroplasty with preoperative planning and standard instrumentation is not influenced by supero-inferior glenoid erosion

PURPOSE

Accurate glenoid component placement in total shoulder arthroplasty (TSA) remains challenging even with preoperative planning, especially for variable glenoid erosion patterns in the coronal plane.

METHODS

We retrospectively reviewed 170 primary TSAs in which preoperative planning software was used. After registration of intraoperative bony landmarks, surgeons were blinded to the navigation screen and attempted to implement their plan by simulating placement of a central-axis guide pin: 230 screenshots of simulated guide pin placement were included (aTSA = 66, rTSA = 164). Displacement, error in version and inclination, and overall malposition from the preoperatively-planned target point were stratified by the Favard classification describing superior-inferior glenoid wear: E0 (n = 89); E1 (n = 81); E2 (n = 29); E3(n = 29); E4(n = 2). Malposition was considered > 10° for version/inclination errors or > 4 mm displacement from the starting point.

RESULTS

Mean displacement error was 3.5 ± 2.7 mm (aTSA = 2.7 ± 2.3 mm, rTSA = 3.8 ± 2.9 mm), version error was 5.7 ± 4.7° (aTSA = 5.8 ± 4.4°, rTSA = 5.7 ± 4.8°), inclination error was 7.1 ± 5.6 (aTSA = 4.8 ± 4.8°, rTSA = 8.1 ± 5.7°), and malposition rate was 53% (aTSA = 38%, rTSA = 59%). When compared by Favard classification, there were no differences in any measure; when stratified by TSA type, version error differed for rTSAs (P = .038), with E1 having the greatest version error (6.9 ± 5.2°) and E3 the least (4.2 ± 3.4°). When comparing glenoids without wear (E0) and glenoids with superior wear (E2 and E3), the only difference was greater version error in glenoids without wear (6.0 ± 4.9° vs. 4.6 ± 3.7°, P = .041).

CONCLUSIONS

Glenoid malposition did not differ based on coronal glenoid morphology. Although, malposition was relatively high, suggesting surgeons should consider alternate techniques beyond preoperative planning and standard instrumentation in TSA. LEVEL OF EVIDENCE III: Retrospective Cohort Study.

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.

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.

Accuracy of Blueprint software in predicting range of motion 1 year after reverse total shoulder arthroplasty

HYPOTHESIS AND BACKGROUND

Blueprint 3-dimensional computed tomography software has a functionality that predicts impingement-free range of motion (ROM) with determination of the limits of ROM at which bone and/or prosthetic impingement occurs. To our knowledge, only 1 previously published study has assessed the ability of Blueprint software to predict actual postoperative ROM after reverse total shoulder arthroplasty (RTSA). The hypotheses of this study were that (1) mean Blueprint-predicted impingement-free ROM would be statistically similar to the mean actual ROM 1 year after RTSA and (2) there would be a correlation between Blueprint-predicted impingement-free ROM and the actual ROM 1 year after RTSA.

MATERIALS AND METHODS

A retrospective review of patients who underwent Blueprint planning prior to undergoing RTSA from March 2017 through May 2021 was performed. At 1-year follow-up, flexion, external rotation at the side, abduction, external rotation in the abducted position, internal rotation in the abducted position, and internal rotation behind the back were measured. The preoperatively predicted flexion, extension, abduction, external rotation, and internal rotation were recorded using Blueprint software. The group 1 analysis examined the predicted vs. actual ROM of all 127 patients regardless of whether intraoperative component modifications were made. The group 2 analysis examined the predicted vs. actual ROM of only the patients who did not undergo intraoperative changes that would affect the preoperative ROM prediction (n = 97). The group 3 analysis examined the predicted vs. actual ROM of group 2 combined with the 30 patients who underwent post hoc Blueprint planning modifications to account for the changes made intraoperatively (combined sample size of 127).

RESULTS

Of the 141 patients, 127 (90%) were available for 1-year follow-up. When the mean values of all 3 groups were examined, the actual ROM and predicted ROM were statistically significantly different (P < .0001) for flexion, external rotation, abduction, abduction-external rotation, and abduction-internal rotation. In group 1, a very weak or poor correlation was found between predicted internal rotation and actual abducted internal rotation (r = 0.19, P = .04). For all other ROM metrics in groups 1, 2, and 3, there were no correlations between predicted and actual ROM (P ≥ .07).

CONCLUSIONS

In its current state, preoperative Blueprint 3-dimensional computed tomography planning software is unable to accurately predict ROM 1 year after RTSA.

Influence of humeral lengthening on clinical outcomes in reverse shoulder arthroplasty

BACKGROUND

Deltoid tensioning secondary to humeral lengthening after reverse shoulder arthroplasty (RSA) is commonly theorized to be crucial to improving range of motion (ROM) but may predispose patients to acromial/scapular spine fractures and neurologic injury. Clinical evidence linking patient outcomes to humeral lengthening is limited. This study assesses the relationship between humeral lengthening and clinical outcomes after RSA.

METHODS

A single institution review of 284 RSAs performed in 265 patients was performed. Humeral lengthening was defined as the difference in the subacromial height preoperatively to postoperatively as measured on Grashey radiographs. The subacromial height was measured as the vertical difference between the most inferolateral aspect of the acromion and the most superior aspect of the greater tuberosity. The relationship between humeral lengthening and clinical outcomes was assessed on a continuous basis. Secondarily, clinical outcomes were assessed using a dichotomous definition of humeral lengthening (≤25 vs. >25mm) based on prior clinical and biomechanical work purporting a correlation with clinical outcomes. Improvement exceeding the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for ROM and outcome scores after RSA were also compared.

RESULTS

Humeral lengthening demonstrated a nonlinear relationship with postoperative ROM, clinical outcome scores, and shoulder strength and their improvement preoperatively to postoperatively. Furthermore, there were minimal differences in ROM measures, outcome scores, and shoulder strength when stratified using the dichotomous definition of humeral lengthening. No difference in the proportion of patients exceeding the MCID or SCB when stratified by humeral lengthening ≤25 vs. >25mm was found. There was no difference in humeral lengthening in patients with versus without complications.

CONCLUSION

No clear relationship between humeral lengthening and clinical outcomes was identified. The previously purported 25mm threshold for humeral lengthening did not predict improved patient outcomes. Outcomes after RSA are multifactorial; the relationship between humeral lengthening and outcomes is likely confounded by other patient and surgical factors.

LEVEL OF EVIDENCE

IV; Case Series.