Locked Stem Reverse Total Shoulder Arthroplasty for Complex Proximal Humerus Fracture in the Elderly: Clinical and Radiological Short-Term Results.

Purpose: To evaluate both the short-term clinical and radiological results of reverse shoulder arthroplasty (RSA) with uncemented locked stem in the management of a proximal humerus fracture (PHFs) in the elderly. Methods: Retrospective study including 40 consecutive 3-4 part proximal humerus fractures treated with reverse shoulder arthroplasty with a minimum of 24 months follow-up. In all the cases, the greater tuberosity (GT) was reattached with a standardized suture technique and a local horseshoe bone graft. All the patients were assessed at the 24-month follow-up with Constant-Murley Score (CMS) and Visual Analog Score (VAS). Radiographic healing of the greater tuberosity was noted in addition to stem locking screws radiographic changes. Complications and revision rates were reported. Results: Mean final CMS for this cohort was 80 points. The greater tuberosity healed in the anatomic position in 90% of the cases (N = 36), obtaining an average CMS of 80 in these patients. Healing of the greater tuberosity did not occur in 10% of the cases (N = 4), obtaining an average CMS of 60. All patients scored above 100° in forward elevation with a mean of 140°. Mean active external rotation was 30°. Low-grade scapular notching was reported in <1% of the cases. Major complications were reported in one patient with an acromial fracture. No complications or loosening of stem locking screws were noted. There were no reoperations. Conclusion: In the elderly population, reverse shoulder arthroplasty utilizing a fracture-specific locking stem, low-profile metaphysis, suture-friendly groove, meticulous suture technique, and local bone grafting allows adequate fixation, variable prosthesis height adjustment, and enhances greater tuberosity healing. This approach yields positive short-term clinical outcomes without complications related to the stem's locking screws. Level of Evidence: Level IV Retrospective Case Series.

Latissimus dorsi and teres major transfer in reverse shoulder arthroplasty: A systematic review.

Background: This paper aims to conduct a systematic review of the current literature to evaluate the clinical outcomes of concurrent latissimus dorsi and teres major (LD/TM) tendon transfer in reverse shoulder arthroplasty (RSA), and to compare that to isolated RSA. Methods: A comprehensive search on PubMeb, Web of Science, Embase and CINAHL was performed from inception up to January 20, 2023, in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses. Cohort studies, case-control studies, randomized controlled trials and case series that were written in English, which involved patients who underwent RSA with LD/TM transfer were included. Quality of studies was appraised using the Cochrane Risk Of Bias In Nonrandomized Studies of Interventions tool. Systematic review of Constant-Murley Score (CMS) and range of movement (ROM) was conducted. Results: Eight studies with a total of 265 patients were included. The average mean follow-up time was 42.5 months, with a range of 6 months to 136 months. Of the studies that reported outcomes of RSA with LD/TM transfer, five reported the CMS, five reported external rotation (ER) ROM and six reported forward flexion ROM. Comparing postoperative to preoperative scores, there was an improvement above the minimal clinically important difference for CMS (mean difference (MD) range = 22.40 to 41.80), ER (MD range = 29° to 36°) and forward flexion (MD range = 50° to 75°). Three studies that compared postoperative ER between RSA with and without LD/TM reported no significant difference. Conclusion: RSA with LD/TM transfer has good clinical outcomes postoperatively, but there is insufficient comparative data to suggest that it is superior or inferior to an isolated RSA.

Systematic review on the incidence, operative treatments, and outcomes of deltoid ruptures.

Background: A deltoid rupture can result in significant losses of shoulder function, and in the setting of a rotator cuff tear, the deltoid serves as the sole abductor of the shoulder. Deltoid ruptures can be secondary to trauma, a consequence of massive rotator cuff tears, or a result of postoperative complications. There is a paucity of literature on the management of deltoid ruptures. In this systematic review, we aim to report on the incidence of deltoid ruptures, the surgical treatment options, and the outcomes following operative treatment. Methods: A literature search was conducted on February 1, 2023 on MEDLINE and Google Scholar. Titles and abstracts were screened and the full text versions of articles that met criteria were reviewed. Criteria for inclusion included peer-reviewed studies evaluating the outcomes following surgical treatment of deltoid ruptures (direct repair, mobilization, reconstruction, and pedicled pectoralis transfer, with or without a reverse total shoulder arthroplasty). Secondary outcomes included incidence and causes of deltoid ruptures. Results: A total of 101 studies were retrieved. After review and additional studies identified from reference lists, a total of 14 studies were included in the review. The incidence of deltoid ruptures ranged from 0.3% to 7%, and large, full-thickness rotator cuff tears were found to be a significant risk factor. Surgical treatment options for deltoid ruptures include direct repair, rotationplasty, and pedicelled muscle-tendon transfers; and when indicated, these procedures can be paired with a reverse total shoulder replacement. Postoperatively, the operative extremity should be immobilized in the position of least tension (forward flexion and abduction, 30°-70°) for 4-8 weeks. Most patients in this systematic review who underwent surgical treatment of their deltoid rupture had significant improvements in pain and mean postoperative forward elevation and abduction above 90°. Discussion: The current available literature demonstrates that direct deltoid repair, rotationplasty, or reconstruction (muscle tendon transfer) with or without a concomitant reverse total shoulder arthroplasty can be an acceptable treatment option in patients with deltoid defects and massive rotator cuff tear. The average shoulder flexion and abduction increased postoperatively with improvements in pain.

Machine Learning Models Can Define Clinically Relevant Bone Density Subgroups based on Patient Specific Calibrated CT Scans in Patients Undergoing Reverse Shoulder Arthroplasty.

BACKGROUND: Reduced bone density is recognized as a predictor for potential complications in reverse shoulder arthroplasty (RSA). While humeral and glenoid planning based on preoperative computed tomography (CT) scans assist in implant selection and position, reproducible methods for quantifying the patients' bone density are currently not available. The purpose of this study was to perform bone density analyses including patient specific calibration in an RSA cohort based on preoperative CT imaging. It was hypothesized that preoperative CT bone density measures would provide objective quantification of the patients' humeral bone quality. METHODS: This study consisted of three parts, (1) analysis of a patient-specific calibration method in cadaveric CT scans, (2) retrospective application in a clinical RSA cohort, and (3) clustering and classification with machine learning models. Forty cadaveric shoulders were scanned in a clinical CT and compared regarding calibration with density phantoms, air muscle, and fat (patient-specific) or standard Hounsfield unit. Post-scan patient-specific calibration was used to improve the extraction of three-dimensional regions of interest for retrospective bone density analysis in a clinical RSA cohort (n=345). Machine learning models were used to improve the clustering (Hierarchical Ward) and classification (Support Vector Machine (SVM)) of low bone densities in the respective patients. RESULTS: The patient-specific calibration method demonstrated improved accuracy with excellent intraclass correlation coefficients (ICC) for cylindrical cancellous bone densities (ICC>0.75). Clustering partitioned the training data set into a high-density subgroup consisting of 96 patients and a low-density subgroup consisting of 146 patients, showing significant differences between these groups. The SVM showed optimized prediction accuracy of low and high bone densities compared to conventional statistics in the training (accuracy=91.2%; AUC=0.967) and testing (accuracy=90.5 %; AUC=0.958) data set. CONCLUSION: Preoperative CT scans can be used to quantify the proximal humeral bone quality in patients undergoing RSA. The use of machine learning models and patient-specific calibration on bone mineral density demonstrated that multiple 3D bone density scores improved the accuracy of objective preoperative bone quality assessment. The trained model could provide preoperative information to surgeons treating patients with potentially poor bone quality.

Reverse Versus Anatomic Total Shoulder Arthroplasty for Glenohumeral Osteoarthritis with Intact Cuff: A Meta-Analysis of Clinical Outcomes.

BACKGROUND: Anatomic and reverse shoulder arthroplasty (TSA, RSA) have surged in popularity in recent years. While RSA is Food and Drug Administration (FDA) approved for cases of rotator cuff tear arthropathy, indications have expanded to include, among others, primary glenohumeral osteoarthritis (GHOA). METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) were queried through November 2023. Inclusion criteria consisted of studies that compared the utility of TSA to that of RSA for the treatment of GHOA with intact rotator cuff with respect to adverse events, patient-reported outcomes, and range of motion. The ROBINS-I tool was used to assess the risk of bias in the included non-randomized studies, and Review Manager 5.4 was used for statistical analysis. P-values <0.05 were deemed significant. RESULTS: Fourteen studies met the above inclusion criteria. Twelve studies reported adverse outcomes, with the RSA group having a lower rate of complications (odds-ratio=0.54, p=0.004) and reoperations (odds-ratio=0.31, p<.001) relative to TSA at an average follow-up of 3.4 years. Four studies reported SPADI and UCLA scores, while five reported SST scores. These studies showed superior SPADI (p=0.040), UCLA(p=0.006), and SST(p=0.040) scores among the RSA group. No significant differences were seen with regards to other patient reported outcomes. Ten studies reported on range of motion, and the RSA group had a significantly lower external rotation relative to the TSA group (p<.001) while other range of motion parameters did not show statistically significant differences. CONCLUSION: The present study provides support for RSA as a reasonable surgical option for patients with GHOA and an intact rotator cuff, with lower rates of adverse events and better outcomes relative to TSA, although at the expense of decreased external rotation. Patient education and counseling is key in order to decide optimal treatment as part of a shared decision-making process, as well as setting appropriate expectations.

Structural Bone Grafting with Reverse Shoulder Arthroplasty for Osteoarthritis with Severe Glenoid Bone Loss: outcomes using a long post.

INTRODUCTION: Severe posterior glenoid bone loss with glenohumeral osteoarthritis with an intact rotator cuff can be managed with reverse shoulder arthroplasty but requires lateralization and version correction to avoid potential complications, such as instability, notching and implant failure. Angled bone grafting with humeral head autograft can provide durable glenoid bone stock, but results have been mixed. The purpose of this study was to evaluate patient-reported and objective outcomes as well as complication and failure rates for patients who underwent angled humeral head autografting for severe retroversion. METHODS: All patients who underwent a primary RSA with angled humeral head autograft and Stryker Tornier long central post baseplate for severe glenoid bone loss in the setting of glenohumeral osteoarthritis with an intact rotator cuff at our institution between November 2018 and February of 2022 were identified. Individuals with a primary diagnosis of osteoarthritis and preoperative glenoid retroversion of ≥30° were included. Patients undergoing revision procedures, planned two-stage arthroplasty were excluded. Differences in pre- and postoperative range of motion, as well as patient-reported outcomes were assessed. Intraoperative complications, postoperative complications, and re-operation rates were analyzed. RESULTS: A total of 24 shoulders in 23 patients (61% male), with a mean age of 65.6 years were included. Average preoperative retroversion was 37.4° (range: 30° - 51°). Mean follow-up was 2.9 years (range: 2 - 4.3 years). Significant improvements were found in flexion, abduction, and external rotation. Patient-reported subjective outcomes were excellent, with average ASES score of 93.6 and average SSV 93.8%. Sixteen (67%) shoulders received postoperative CT scans and all were found to have incorporated. Complications included one shoulder hematoma requiring incision and drainage without revision, and a post-traumatic fracture of the inferior glenoid screw at 11 months, requiring revision RSA with bone grafting. No atraumatic catastrophic failures occurred due to component loosening. CONCLUSION: This study suggests that using angled humeral head bone grafting is a good solution for version correction in extreme posterior glenoid bone loss. Significant improvements are reported in ROM, pain, and subjective functional scores, with excellent graft incorporation rates and a low complication profile at early follow-up. Further work should focus on gathering higher levels of evidence, detailed radiographic analyses and exploring humeral head bone grafting for other indications.

Cemented Versus Uncemented Reverse Shoulder Arthroplasty Treatment of Proximal Humerus Fractures: National Shoulder Arthroplasty Data from Türkiye.

Background: This study evaluated national trends in cemented and uncemented reverse shoulder arthroplasty (RSA) for proximal humerus fractures using a comprehensive national surgical database. This study aimed to compare RSA used in the treatment of proximal humerus fractures with the literature and to determine the country's trend. Methods: A cross-sectional study was conducted using the health records of individuals aged ≥ 18 years who underwent RSA for proximal humerus fractures between 2016 and 2022. Patients were divided into cemented and uncemented groups, and demographic data (age, sex), duration of hospital stay, transfusions, revisions, mortality, and Charlson Comorbidity Index (CCI) scores were analyzed. Results: A total of 618 cemented RSA and 1,364 uncemented RSA procedures were reviewed. Patients who underwent cemented RSA were significantly older than those who had uncemented RSA (p = 0.002). Transfusion rates were higher in the cemented RSA group (p = 0.006). The frequency of revision surgery was 6.1%. Younger age and male sex were associated with revision (p < 0.001). CCI scores were higher among transfused patients than non-transfused patients (p < 0.001). The incidence of cemented RSA was 11.7% and 49% in 2016 and 2022, respectively. Differences were found among hospital types and geographical regions. Conclusions: While cemented RSA has been gaining attention and increased application in recent years for proximal humerus fractures, uncemented RSA still predominates. The choice between these 2 methods is largely influenced by regional and hospital-level factors. The type of RSA and high CCI scores were found to have no significant impact on the risk of surgical revision.

Preventing Infections in Reverse Shoulder Arthroplasty.

PURPOSE OF REVIEW: Reverse shoulder arthroplasty (rTSA) is a commonly performed procedure to treat degenerative conditions of the shoulder. With its growing utilization, techniques to reliably diagnose and treat prosthetic joint infection (PJI) have become increasingly important. In this review we outline the current research and prevention methods of prosthetic joint infection in rTSA. This includes preoperative considerations, intraoperative, and postoperative treatment algorithms. RECENT FINDINGS: There is currently no established standardized protocol for preoperative infection prevention or post operative management. However, recent studies have identified risk factors for infection, as well as successful prevention techniques that can be implemented to minimize infection risk. Although there is no standardized protocol currently utilized to diagnose and treat shoulder PJI, we outline a potential set of preventative measures and postoperative management strategies that clinicians can use to properly diagnose and treat patients with this difficult condition.

Predictors of inpatient mortality following reverse shoulder arthroplasty.

INTRODUCTION: The number of reverse shoulder arthroplasties (RSA) performed each year is growing rapidly, especially in elderly patients and with expanded indications including geriatric proximal humerus fractures. As the elderly population grows and the number of RSA's annually continues to rise, there will be a proportionate number of adverse events and mortality. However, the rate of early mortality has consistently shown to be less than 1%, so a large-scale analysis of possible risk factors for post-operative mortality is warranted. METHODS: A retrospective multivariate analysis of 59,915 patients from the National Inpatient Sample database between 2016 and 2019 was performed. Patients who underwent RSA were identified based on ICD-10 code. Patients were divided into two groups, early mortality and no mortality. Early mortality was defined as those who died within the same admission. Patient demographics and medical comorbidities were evaluated. Hospital admission status was classified as elective or non-elective. Odds ratios for predictive variables were measured as a ratio of incidence between the early mortality and no mortality groups. RESULTS: The overall incidence of inpatient mortality was 0.07%. The incidence of mortality for elective admissions was 0.04% and for non-elective admissions was 0.34%. On univariate analysis, age greater than 75 years (p < 0.001), octogenarians (p < 0.001), nonagenarians (p < 0.001), and non-elective admission (p < 0.001) were associated with early mortality following RSA. Upon multivariate analysis, age greater than 75 years old had 4 times the odds of early mortality following RSA (OR 4.20; 95%CI (1.67, 10.60); p < 0.001) while non-elective admission had about 5 times the odds (OR 5.38; 95%CI (2.75, 10.53); p < 0.001). DISCUSSION: Age greater than 75 years old has 4-fold higher odds and non-elective admission has 5-fold higher odds of early mortality following RSA. Appropriate pre-operative counseling should be performed with elderly patients and those undergoing non-elective indications for RSA.

A high hospital frailty risk score indicates an increased risk for complications following surgical treatment of proximal humerus fractures.

BACKGROUND: Approximately 70 % of proximal humerus fractures (PHF) occur after the age of 60. High complication rates have been described in correlation with the treatment of PHF. Major risk factors for the outcome might be frailty, mobility and comorbidities of patients at the time of hospital admission. The aim of this study was to create risk adjusted quality indicators for surgical treatment of proximal humerus fractures based on German claims data and to evaluate the impact of the Hospital Frailty Risk Score (HFRS) on risk adjustment. METHODS: Retrospective claims data (2015-2021) were used to create risk adjusted quality indicators for eight outcomes by clustered multivariable logistic regression. The comparison of different risk adjustment model performances was done by ROC-AUC and Standardized Mortality/Morbidity Ratios. RESULTS: In total, N = 34,912 patients (median age 75 years, 80.3 % female) were included. The most common surgical procedure was open reduction and internal fixation with plate osteosynthesis with 39.7 %, followed by reverse shoulder arthroplasty with 25.3 %. The most influential risk factor for all outcomes was a high HFRS with an Odds Ratio of 2.0 (95 %-Confidence Interval 1.8-2.3) for any secondary surgery (365 days) up to an Odds Ratio of 17.6 (95 %-Confidence Interval 14.9-20.8) for general complications during the index stay. CONCLUSION: Comparative quality reporting for the surgical treatment of PHF appears feasible with the developed models for risk adjustment using claims data. Preoperative evaluation of HFRS in PHF can contribute to risk assessment, and individual patient management. It therefore enables personalized treatment decisions.

High Delta Angle after Reverse Total Shoulder Arthroplasty increases stresses of the acromion: Biomechanical study of different implant positions.

BACKGROUND: Acromial fractures after Reverse Total Shoulder Arthroplasty (RTSA) are a common complication. Nevertheless, only a few studies have identified risk factors for acromial fractures after RTSA. High delta angle (combination of inferiorization and medialization of the center of rotation) after RTSA was identified as a risk factor in recent studies. The aim of this study was the biomechanical exploration of different delta angles and implant configurations with regard to the acromial stress. METHODS: In a rigid body model of the upper extremity muscle, forces of the deltoid muscle were calculated before and after implanting RTSA in different arm and implant positions. The deltoid muscle was divided into an anterior, middle, and posterior part. Implant positions of the glenoid components were changed in the medialization, lateralization and inferiorization of the center of rotation (COR) as well as lateralization of the humeral component. Further, in a finite element model of the upper extremity, the stresses of the acromion in the same implant design configurations were measured. RESULTS: Differences in acromial stress between different delta angle model configurations were observed. Lateralization (5 mm, 10 mm) of the glenosphere reduced maximal acromial stress by 21% (1.5 MPa) and 31% (1.3 MPa), respectively. Inferiorization (5 mm, 10 mm) of the glenosphere increased maximal acromial stress by 5% (2.0 MPa) and 15% (2.2MPa), respectively. Changes in positioning the humeral component was found to have the highest impact in this model configuration. A 10 mm lateralized humeral component reduced acromial stress by 37% (1.2 MPa) while in the 6 mm medialized configuration, an increase in acromial stress by 83% (3.48 MPa) was observed. There was a high correlation between delta angle and acromial stress (R-squared = 0.967). CONCLUSION: Implant design configuration has an impact on the acromial stress. High delta angles correlate with an increase in acromial stress. Both lateralization of the COR and the humerus decreased the acromial stress in our study. The lateralization of the humerus has the highest impact in influencing acromial stress. Due to contrary results in the current literature, further studies with focus on the acromial stress influenced by different anatomical variants of the shoulder and the acromion are needed before a clinical recommendation can be made.

Operative Treatment of Acromial and Scapular Spine Fracture Nonunions Complicating Reverse Total Shoulder Arthroplasty.

BACKGROUND: Fractures of the acromion and spine can have a major impact on the outcome of reverse shoulder arthroplasty (RSA) with respect to pain, motion, and function. Reports on internal fixation for these fractures are isolated to small series or case reports with variable outcomes. The purpose of this study was to report on the outcome of open reduction and internal fixation (ORIF) of acromion or spine fractures encountered before or after RSA and describe our evolution of fixation techniques. METHODS: Between 2011 and 2023, 22 fractures or nonunions of the acromion or spine of the scapula underwent ORIF at a single institution and were followed for a minimum of 1 year. In 16 shoulders, fractures occurred after RSA, whereas 5 shoulders underwent ORIF prior to RSA. One shoulder had undergone prior failed ORIF elsewhere and revision ORIF was performed at our institution. There were 10 males and 12 females with a mean age of 67 (SD=15.1) years. Fixation strategies included single (n=11) and double plate fixation (n=11). Kruskal-Wallis one-way analyses of variance were used to analyze continuous variables and Chi-square tests employed for categorical variables. RESULTS: Of the 5 fractures treated with ORIF pre-RSA, 1 shoulder suffered an additional fracture medial to the hardware and 1 required additional bone grafting for incomplete union at the time of RSA. These 5 shoulders all underwent RSA uneventfully, but one fracture experienced late displacement of the scapular spine nonunion, leading to plate removal. Of the 16 post-RSA ORIF shoulders, radiographic union was confirmed in 14 and substantial residual inferior angulation identified in 3. New fractures occurred after ORIF in 5 shoulders. For patients who underwent ORIF after RSA, pain scores improved from a mean of 8 to 1.9 points, with more modest elevation gains (58.2° to 91.3° pre- and postoperatively, respectively). CONCLUSIONS: ORIF of acromion and scapular spine fractures or nonunions in the setting of RSA have the potential to lead to union. When these fractures and nonunions are encountered prior to RSA, ORIF allows for uneventful RSA implantation, but secondary displacement may occur. ORIF seems to lead to improvements in pain, but more modest improvements in motion and function. Our fixation strategy has evolved to (1) dual plating, (2) spanning the whole length of the spine with one of the plates, (3) use of hook features under the acromion or os trigonum if possible, and (4) liberal use of bone graft.

Stemless reverse shoulder arthroplasty neck shaft angle influences humeral component time-zero fixation and survivorship: a cadaveric biomechanical assessment.

Background: Stemless humeral components are being clinically investigated for reverse shoulder arthroplasty (RSA) procedures. There is, however, a paucity of basic science literature on the surgical parameters that influence the success of these procedures. Therefore, this cadaveric biomechanical study evaluated the neck shaft angle (NSA) of implantation on the survivability and performance of stemless RSA humeral components during cyclical loading. Methods: Twelve paired cadaveric humeri were implanted with stemless RSA humeral components at NSAs of 135° and 145°. Implant-bone motion at the periphery of the implant was measured with 3 optical machine vision USB3 cameras outfitted with c-mount premium lenses and quantified with ProAnalyst software. A custom 3-dimensional loading apparatus was used to cyclically apply 3 loading directions representative of physiological states at 5 progressively increasing loading magnitudes. Stemless 135° and 145° implants were compared based on the maximum implant-bone relative distraction detected, as well as the survivorship of the implants throughout the loading protocol. Results: Primary fixation and implant biomechanical survivorship were substantially better in the 145° NSA implants. The 135° NSA implants elicited significantly higher implant-bone distractions during cyclical loading (P = .001), and implant survivorship was considerably lower in the 135° NSA specimens when compared to the 145° NSA specimens (135° NSA: 0%, 145° NSA: 50%) (P < .001). Conclusion: NSA is a modifiable parameter that influences time-zero implant stability, as well as the early survivorship of the stemless RSA humeral components tested in this study. NSA resections of 145° appear to promote better stability than those utilizing 135° NSAs during early postoperative eccentric loads. Further studies are required to assess if other stemless reversed humeral implant designs have improved time-zero fixation at higher NSAs.

Radial and median nerves distal peripheral tension after reverse shoulder arthroplasty: a cadaveric study.

Background: Peripheral nerve injury is a recognized complication after reverse shoulder arthroplasty (RSA) that has mainly been studied at the level of the brachial plexus and its proximal branches. However, the impact of RSA on distal peripheral nerves and the influence of elbow and wrist position is not known. This cadaveric study aimed to analyze the effect of RSA implantation and upper limb position on tension in the distal median and radial nerves. The hypothesis was that RSA increased distal nerve tension, which could be further affected by elbow and wrist position. Methods: 12 upper limbs in 9 full fresh-frozen cadavers were dissected. Nerve tension was measured in the median nerve at the level of the proximal arm, elbow, and distal forearm, and in the radial nerve at the level of the elbow, using a customized three-point tensiometer. Measurements were carried out before and after RSA implantation, using a semi-inlay implant (Medacta, Castel San Pietro, Switzerland). Two different configurations were tested, using the smallest and largest available implant sizes. Three upper-limb key positions were considered (plexus at risk, plexus relief, and neutral), from which the effect of elbow and wrist position was further tested. Results: RSA implantation significantly increased median and radial nerve tension throughout the upper limb. The distal nerve segments were particularly dependent on elbow and wrist position. The plexus at risk position induced the most tension in all nerve segments, especially with the large implant configuration. On the other hand, the plexus relief position induced the least amount of tension. Flexing the elbow was the most efficient way to decrease nerve tension in all tested nerve segments and key positions. Wrist flexion significantly decreased nerve tension in the median nerve, whereas wrist extension decreased tension in the radial nerve. Conclusion: RSA significantly increases tension in the median and radial nerves and makes them more susceptible to wrist and elbow positioning. The mechanism behind distal peripheral neuropathy after RSA may thus result from increased compression of tensioned nerves against anatomical fulcrums rather than nerve elongation alone. Elbow flexion was the most effective way to decrease nerve tension, while elbow extension should be avoided when implanting the humeral component. Further studies are needed to assess the ulnar nerve.

Glenoid lateralization in reverse shoulder arthroplasty: metal vs. bone offset in different implant designs.

Background: Higher bone or metal glenoid offset in reverse shoulder arthroplasty (RSA) reduces scapular notching, improves range of motion (ROM), and reduces postoperative instability. This retrospective multicenter study compared two implant designs to evaluate the short-term clinical and radiologic results of bone increased offset RSA (BIO-RSA) and metal increased offset RSA (MIO-RSA) in reverse shoulder. We hypothesized no difference between groups. Methods: This study analyzed n = 62 BIO-RSA and n = 90 MIO-RSA cases with a mean follow-up of 29.7 ± 6.0 months (BIO-RSA, range 24-49 months) and 24.0 ± 1.1 months (MIO-RSA, range 22-28 months). A 145°-onlay humeral stem was utilized in BIO-RSA cases, while a 135°-semi-inlay humeral stem was implanted in all MIO-RSA cases. Preoperative and postoperative radiologic imaging was reviewed to identify signs of scapular notching. Additionally, lateralization was evaluated according to Erickson et al. The constant score, subjective shoulder value, and ROM were evaluated during the baseline and follow-up consultations, and the findings of both groups were subsequently compared. Results: Scapular notching was observed in 7.0% (n = 8) of MIO-RSA cases and 8.1% (n = 5) of BIO-RSA cases (P = .801). MIO-group had a higher lateralization angle (P = .020) and the BIO-group had a higher distalization angle (P = .005). At baseline, mean constant score in the MIO-RSA group was higher than in the BIO-RSA group (P < .001), and it significantly increased to 67.8 ± 12.1P (MIO-RSA) and 69.5 ± 12.3P (BIO-RSA) to a similar level (P = .399). ROM improved in both groups with no significant difference between the two groups at follow-up. Conclusion: BIO-RSA and MIO-RSA in two distinct implant designs provide comparable short-term outcomes with a similar increase in shoulder function with notable variations in the lateralization and distalization angles between both implants. Scapular notching was rarely seen and unaffected by the method of glenoid lateralization. Follow-up investigations of both techniques are necessary to complement and track changes in the long-term outcome.

Shoulder Arthroplasty: A Bibliometric Analysis Using the Scopus Database.

Primary joint replacements are performed increasingly often worldwide, driven by an aging population, improvement in surgical techniques, and advancements in implant designs. While more attention has traditionally been focused on weight-bearing joints such as the hip and knee, shoulder replacement surgeries have gained increasing attention in recent years due to the population's demand for a better quality of life. Thus far, a comprehensive bibliometric analysis of shoulder arthroplasty-related publications using the Scopus database has not yet been conducted. This bibliometric analysis aims to fill this gap by reviewing the Scopus database from its inception until 2023 to examine the literature on shoulder arthroplasty. A total of 5300 publications meeting the selection criteria were included in this analysis. The turn of the century marked a significant turning point for the field of shoulder arthroplasty, with an increasing number of publications produced annually. This trend can be attributed to the improvement of implant designs, which have become more consistent and reliable over time. While the majority of articles were authored by researchers and clinicians from the United States of America (USA), publications by French authors had a higher scholarly impact in the field. There is a noticeable gap in research on shoulder arthroplasty in developing countries, possibly due to the prohibitively high cost of implants and the prioritization of other healthcare sectors. This bibliometric analysis, utilizing Scopus data, serves as a guiding light for researchers, clinicians, and policymakers, potentially fostering collaborative projects and guiding the development of future studies to further advance the field of shoulder arthroplasty, particularly in developing countries.

The lateralization and distalization index is more reliable than angular radiographic measurements in reverse shoulder arthroplasty.

BACKGROUND: The lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) are used to reproducibly measure lateralization and distalization after reverse shoulder arthroplasty (RSA). However, LSA and DSA may not offer a precise measurement of humeral lateralization and distalization and this relationship has not been explored. The aim of this study was to evaluate the validity of these measurements and to propose new measurement methods to estimate implant lateralization and distalization. METHODS: 3D models were constructed from computed tomography (CT) scans of 30 patients using a software platform. For each patient 24 different RSA modifications were created, resulting in 720 different RSA configurations. For each configuration LSA and DSA angles as well as lateralization and distalization distances were measured. Moreover, for each configuration two new measurements were done: the lateralization index (LI) and distalization index (DI). Correlations of the lateralization and distalization parameters were evaluated between measurements. RESULTS: Weak correlations were founded between LSA and lateralization (r = 0.36, p < 0.01), whereas moderate correlations were observed between LI and lateralization (r = 0.72, p < 0.01). No significant correlations were found between DSA and distalization (r = 0.17, p = 0.113). In contrast, moderate correlations were identified between DI and distalization (r = 0.69, p < 0.01). CONCLUSION: LI and DI are more reliable methods to estimate implant lateralization and distalization compared to angular radiographic measurements. However, the prognostic significance in predicting clinical outcomes after RSA remains unknown.

EFFECTIVENESS OVER TIME OF THE REVERSE SHOULDER PROSTHESIS FOR ACUTE PROXIMAL HUMERAL FRACTURE.

BACKGROUND: Reverse shoulder arthroplasty (RSA) has proven to be an effective surgical procedure for irreparable rotator cuff tears, comminuted fractures of the proximal humerus and shoulder arthroplasty revision surgeries. We know from the literature that the functional results are good in the short term, but not whether these results remain stable in the long term or, on the contrary, show a deterioration in functionality. OBJECTIVE: This study aims to analyze the functionality, degree of satisfaction, complications, and prosthesis survival at different cut-off points in patients with complex proximal humerus fractures treated with RSA, with a minimum postoperative follow-up of 7 years. MATERIAL AND METHODS: Analytical, longitudinal and prospective observational study of a cohort of patients treated for a fracture of the proximal humerus with PIH. Functional outcome was assessed using the Constant scale and the Constant adjusted for age and gender of the patients. Quality of life was measured using the University of California at Los Angeles Shoulder Assessment scale (UCLA) and the Disability of the Arm, Shoulder and Hand score scale (QuickDASH). In addition, range of motion, pain and radiological variables of loosening, scapular notching and tuberosity consolidation were assessed. RESULTS: Thirty-three patients were included with a mean postoperative follow-up of 8.3 years (range 7-12 years). There was a progressive and significant decrease in Constant score at 5and7years follow-up compared to the baseline assessment 2 years after surgery, although the effect size was not significant. The age- and sex-adjusted Constant as well as the UCLA scale did not show statistically significant variations at follow-up. Both shoulder abduction and anterior shoulder flexion correlated well with the final QuickDASH score. Radiological variables did not influence any of the study outcome variables. CONCLUSION: The functionality and quality of life of patients with complex proximal humerus fractures treated with RSA decreased significantly compared to the 2-year evaluation, although this change was not clinically relevant. Survival of RSA was satisfactory in the medium to long term with a low complication rate.