Background This study aimed to compare the accuracy and precision of CT-based planned central glenoid guide-pin placement among fluoroscopy-guided freehand insertion, CT-based patient-specific instrumentation (PSI), and CT-based navigation in a cadaveric reverse total shoulder arthroplasty (rTSA) model. Methods Six cadaveric shoulders were used. Three surgeons performed all three techniques in each shoulder (18 insertions per technique) under a shared preoperative plan. The sequence was fixed: fluoroscopy-guided freehand insertion, PSI, then navigation. After each insertion, guide-pin angle and entry-point position were measured by an independent assessor using the same navigation platform; recorded measurement values were not disclosed to the operating surgeon. Before the next insertion, the previous pin track was filled and visually/tactilely masked. Accuracy was assessed as deviation from the plan, and precision as the dispersion of deviations and the frequency of threshold-defined outliers. Overall successful placement was defined as angular deviations within ±5° in both inclination and retroversion and an entry-point offset magnitude ≤2.0 mm. Overall outlier status was defined as >10° deviation in either angular axis and/or an entry-point offset magnitude >4.0 mm. Results Resultant angular deviation was 6.8° (SD 4.2) for fluoroscopy, 5.7° (SD 4.6) for PSI, and 2.3° (SD 1.5) for navigation (p = 0.002). Entry-point offset magnitude was 3.2 mm (SD 1.3), 2.2 mm (SD 1.2), and 1.3 mm (SD 0.5), respectively (p < 0.001). Navigation showed smaller angular and positional deviations than both fluoroscopy and PSI. PSI improved entry-point offset magnitude versus fluoroscopy (p = 0.021) but not resultant angular deviation (p = 0.384). Overall successful placement occurred in 4/18 fluoroscopy insertions, 7/18 PSI insertions, and 17/18 navigation insertions (p < 0.001). Overall outliers occurred in 7/18, 4/18, and 0/18 insertions, respectively (p = 0.030). Conclusion In this fixed-sequence cadaveric rTSA model, navigation showed the smallest angular and entry-point deviations relative to the preoperative plan, and no threshold-defined outliers were observed. PSI improved entry-point accuracy compared with fluoroscopy-assisted freehand insertion but did not significantly improve angular accuracy. These findings characterize plan-to-pin execution at the guide-pin stage and require confirmation in studies evaluating final implant position and clinical outcomes. Level of Evidence Basic Science Study; Validation of Surgical Technique; Cadaver Model
Background Subscapularis healing is a critical determinant of successful anatomic total shoulder arthroplasty (aTSA) outcomes. Common subscapularis management techniques include tenotomy, peel, and lesser tuberosity osteotomy (LTO). However, data on subscapularis management in stemless aTSA remain limited. The purpose of this study was to evaluate clinical and functional outcomes at two-year follow-up in patients undergoing stemless aTSA with either subscapularis peel or LTO. Methods A retrospective review was performed of a prospectively maintained, multi-center database of primary RSAs performed by multiple surgeons between 2019 and 2023 with minimum two-year follow-up. A total of 122 patients met the study criteria, 88 in the LTO approach group versus 34 in the peel group. Patient-reported outcome measures (PROMs), range of motion (ROM), and strength were evaluated at baseline and at two-year follow-up, with comparisons made between groups. Results There were no significant differences between BMI, history of tobacco use, and diabetes between LTO and peel groups. There were no significant differences in PROMs, ROM, and strength testing at preoperative evaluation. Significant differences were observed in age (66.8 years old in LTO versus 62.7 in peel, p = 0.021), sex (52% of the LTO group was female versus 6% in peel, p = <0.0001), and Walch classification (p = 0.0004). At two-year follow-up, outcomes were similar between groups, with the exception of greater active external rotation at 90 degrees in the peel group, (84° vs 71°, p = <0.0001). No significant differences were observed in the magnitude of change from preoperative to two-year postoperative outcomes between the LTO and peel groups. Conclusions Both subscapularis peel and lesser tuberosity osteotomy (LTO) techniques in stemless anatomic TSA resulted in favorable outcomes at two-year follow-up. Postoperative outcomes were largely similar between groups, although a difference was observed in active external rotation at 90°. Despite baseline demographic differences, both techniques demonstrated favorable clinical and functional results. Level of Evidence Level III; Retrospective Cohort Comparison Study
Background Reverse total shoulder arthroplasty (rTSA) is an established procedure, yet the optimal timing of post-operative follow-up (FU) remains controversial. Although guidelines and clinical studies frequently define a 2-year FU to assess short-term outcomes, there is little evidence to support this practice. This study investigates longitudinal changes in patient-reported outcome measures (PROMs), range of motion (ROM) and radiographic findings over a 24-month period after primary rTSA. Methods This retrospective study included 66 primary rTSA patients (62% female; mean age 72.4 years; cuff tear arthropathy 50.0%, primary osteoarthritis 31.8%) with 3 implant designs at a single high-volume center. Assessments were performed pre-operatively and at 6, 12, and 24 months post-operatively. At each time point, the Constant Score as well as various PROMs, including the Subjective Shoulder Value, visual analog scale, European Quality of Life 5 Dimensions 5 Level Version, and the Shoulder Pain and Disability Index were assessed. ROM was measured, and standardized radiographic evaluations were performed. Longitudinal changes were analyzed using the Friedman test with post hoc correction. Additionally, mixed-effects models and Bayesian logistic regression were applied to evaluate time and group effects for both PROMs/ROM and radiographic outcomes. Results All PROMs improved significantly within the first 6 months; smaller gains in Constant Score, Subjective Shoulder Value, and the Shoulder Pain and Disability Index occurred up to 12 months, while pain and European Quality of Life 5 Dimensions 5 Level Version improvement plateaued earlier. No further PROM changes occurred beyond the first year. ROM in flexion and abduction improved markedly within the first 6 months, with only minor additional gains in flexion at 12 months and stabilization thereafter; external rotation improved more slowly, reaching significance only at 12 months, before plateauing. Model-based analysis showed no interactions between time and implant groups for any of the PROMs and only minor differences for ROM. Radiographic evaluation revealed low rates of implant loosening, scapular notching, and periprosthetic fractures, with most events occurring in the first post-operative year. Discussion rTSA leads to significant clinical and functional improvement within the first 6 to 12 months, followed by a plateau with no further changes up to 2 years. Radiographic findings and complication rates remained largely stable, with most events occurring in the first post-operative year; implant differences were minimal. These findings suggest that routine 2-year FU provides limited additional information for short-term assessment, though monitoring remains important for potential late complication. Awareness of the early plateau phase is essential for realistic patient counseling, evidence-based decision-making, and efficient resource allocation.
Background The rate of total shoulder arthroplasties (TSAs) performed in the outpatient setting is rapidly increasing. Existing data suggest comparable complication rates, readmissions, and outcomes between inpatient and outpatient TSA. Overall, the growing body of evidence comparing these procedures indicates that outpatient TSA is at least as safe as inpatient TSA. Methods This is a retrospective cohort study of all patients who underwent primary and revision TSA at a single institution between May 2021 and April 2024. Patient records were obtained for demographics, comorbidities, peri-operative factors, and post-operative course including complications, emergency department (ED) visits, and readmissions within 30 days after surgery. Patients were defined as outpatients if they discharged from the hospital on the day of surgery and as inpatients if they required hospital admission and an overnight stay of any duration. Results Data for 1,285 patients were retrospectively analyzed, including 799 (62.2%) outpatients and 486 (37.8%) inpatients. Outpatients were younger (67.9 ± 8.2 vs. 72.4 ± 8.6 years), had fewer females (47.4% vs. 57.0%), were more likely to be married (71.8% vs. 62.6%), had lower body mass index (31.4 ± 5.7 vs. 32.4 ± 6.6 kg/m2), lower Area Deprivation Index (4.3 ± 2.3 vs. 4.6 ± 2.3), and were less likely to have diabetes (15.3% vs. 20.8%) than inpatients (P < .05 for all). The rate of ED visits within 30 days post-operatively was lower in the outpatient group than the inpatient group (6.4% vs. 12.1%, P < .01). The rate of 30-day post-operative complications was lower after outpatient compared to inpatient TSA (2.9% vs. 5.3%, P = .03). There was no significant difference in the rate of 30-day hospital readmissions between outpatients and inpatients (2.9% vs. 4.5%, P = .34). There were no significant differences in any of these outcomes between outpatient and inpatient surgeries in the revision subgroup. Conclusion Patients undergoing outpatient TSA had a lower rate of total post-operative complications and ED visits within the first 30 days after surgery compared to those undergoing inpatient TSA. There was no significant difference in the post-operative 30-day hospital readmission rate between the 2 groups. These findings suggest that outpatient TSA is a safe procedure with low rates of post-operative complications and readmission rates in appropriately selected patients.
Background Computer-assisted orthopaedic surgery (CAOS) systems enhance the accuracy of implant placement in reverse total shoulder arthroplasty (rTSA), but their implementation requires a learning phase. The duration of this learning curve and its impact on surgical efficiency remain poorly quantified, particularly in large cohorts. Hypothesis This study aimed to quantify the number of cases required to exit the learning phase and achieve proficiency, as well as the duration of these phases. We hypothesized that (1) adding steps to the navigation workflow in 2019 would lengthen the learning curve, and (2) surgeons would achieve proficiency faster when navigating a greater proportion of cases and performing their first navigated cases within a shorter time frame. Methods We retrospectively analyzed 8,600 rTSA cases, comprising the first 50 cases from 172 surgeons performed between 2016–2025 using a single CAOS system (Equinoxe, Advita GPS, Blue-Ortho). Cumulative sum control chart (CUSUM) analysis was used to identify three performance phases (learning, plateau, proficiency) via automated curve segmentation. Primary outcomes included the number of cases to exit learning (N-learning), reach proficiency (N-proficiency), and navigation times during these phases (D-learning, D-proficiency). Subgroup analyses compared surgeons based on workflow changes, navigation rates (>80% vs. <80%), and time to complete the first 12 cases. Statistical comparisons used Mann-Whitney U and Kruskal-Wallis tests. Results The median N-learning was 10 cases [5–36], and N-proficiency was 25 cases [10–45]. Median navigation time decreased from 22:43 min [11:42–47:03] during learning to 17:48 min [7:54–36:50] during proficiency (p < 0.0001), a 21.6% reduction. No differences were found between workflow changes in 2019 (p > 0.405) or navigation rates (p > 0.153). However, surgeons completing their first 12 cases in less than 6 months had shorter D-learning (20:07 min) compared to those taking 12–18 months or more than 18 months (23:25, 24:09 min; p = 0.014). Conclusion This large-scale study demonstrates that 10 rTSA cases are sufficient to exit the learning phase with a single CAOS system. Proficiency is achieved by 25 cases, saving ∼5 minutes per procedure during the learning curve. Faster adoption (first 12 cases in <6 months) shortens D-learning, but not N-learning. These findings can guide training programs and hospital resource planning for rTSA navigation adoption.
Background The rotator cuff muscles are dynamic stabilizers of the glenohumeral joint and the recovery of their strength plays an important role in stabilizing the joint during postoperative rehabilitation. However, little is known about the differences in muscle strength recovery during postsurgical rehabilitation between the two principal surgical procedures used to treat shoulder instability in individuals taking part in competitive sports. Purpose To compare the strength deficit of the rotator cuff muscles between the two principal surgical techniques used to treat shoulder instability in sportspeople. Study Design Level II, Prospective Cohort Design, Treatment Study Methods We included patients who had undergone surgery for shoulder instability for whom isokinetic evaluations of maximal strength had been performed on the rotator cuff muscles more than three months after surgery in a prospective study. The evaluations were performed on a Biodex system (Biodex Medical Systems, Shirley, NY). Results 52 sportspeople who had undergone Latarjet (n=36) or Bankart (n=16) procedures were included. A comparison of the characteristics of these two groups of patients revealed no difference. The muscle strength deficit was 10.66 to 12.72% for the internal rotator cuffs and 13.65 to 14.36% for the external rotator cuffs in patients undergoing Latarjet surgery. Patients undergoing Bankart surgery presented no muscle strength deficit for the internal rotator cuffs and a 15.50 to 23.45% deficit for the external rotator cuffs. In the Latarjet group, the muscle strength deficit for the internal rotator cuff muscles of the treated shoulder was significantly greater for the concentric mode at 60°/s (p=0.037) to 180°/s (p=0.004) and the eccentric mode (p=0.025). Conclusion The Latarjet surgical technique results in a greater internal rotator cuff muscle strength deficit than the Bankart procedure. This greater deficit may result from damage to the subscapularis muscle during surgery. It would be of interest to propose a specific isokinetic concentric and eccentric protocol in addition to usual rehabilitation.
Background Multiple studies in knee and hip arthroplasty populations have reported favorable perioperative complication profiles among patients receiving glucagon-like peptide-1 receptor agonists (GLP-1 RAs). However, evidence in shoulder arthroplasty remains conflicting, and no comprehensive review has evaluated their impact in this population. This study aimed to synthesize current evidence on the association between GLP-1 RA use and short- and mid-term perioperative complications following shoulder arthroplasty. Methods A systematic review and meta-analysis was conducted in accordance with PRISMA 2020 guidelines, including studies comparing postoperative complication rates between GLP-1RA users and non-users undergoing total or reverse shoulder arthroplasty. Pooled analyses were performed with a random-effects model. Results were reported as odds ratios (ORs) with 95% confidence intervals (CIs), and between-study heterogeneity was quantified using the I2 statistic. Results Five studies (n = 40,005) met inclusion criteria, including 7,924 (19.8%) GLP-1RA users. Across 90-day outcomes, no significant differences were observed for readmission, DVT, PE, pneumonia, or surgical site infection. Sepsis was the only complication demonstrating a significant reduction among GLP-1RA users (OR 0.65; 95% CI 0.44-0.96; P = 0.03). Heterogeneity ranged from low to high across these endpoints (I2 = 21.3%-90.4%). At 2 years, no differences were observed in all-cause revision, periprosthetic joint infection, or periprosthetic fracture, with consistently low to moderate heterogeneity (I2 = 0%-36.2%). Discussion Across more than 40,000 total shoulder arthroplasty patients, GLP-1RA use was not associated with differences in 90-day or 2-year complications, except for a lower rate of sepsis among GLP-1RA users. These findings suggest that GLP-1RA continuation may not increase perioperative risk in TSA. Differences from hip and knee arthroplasty studies may reflect the lower baseline risk profile and comorbidity burden of TSA patients. Further prospective studies are needed to confirm these results and guide perioperative management as GLP-1RA use expands.
Background As shoulder arthroplasty increases, periprosthetic humeral fractures are becoming more common. However, optimal management of these fractures remains unclear. Higher stem filling ratios may contribute to stress shielding, reduced bone integrity, and fracture risk, but their influence on clinical management after fracture has not been studied. The purpose of this study is to evaluate how metaphyseal filling ratios (FRmet) and diaphyseal filling ratios (FRdia) of the implant correlate to the treatment of periprosthetic fractures. We examined whether specific filling ratios lead to performing revision arthroplasty or open reduction internal fixation (ORIF) of the humerus. Methods A retrospective case series was conducted at a single institution, including patients who underwent revision of total shoulder arthroplasty between October 2012 to August 2025. Patients were identified through electronic medical record query using Current Procedural Technology (CPT) code 23473 and Picture Archive Communication System (PACS) with search term “periprosthetic humerus fracture". Patients who had previously undergone an anatomic or reverse total shoulder arthroplasty and sustained a periprosthetic humeral fracture were included. Pre-fracture radiographs were analyzed to assess prosthesis FRmet and FRdia. Patients were divided into two groups based on treatment: revision arthroplasty and ORIF. Chi-squared and t-tests were used to assess statistical significance at p < 0.05. Results Thirty-two patients met inclusion criteria, with 17 who underwent revision arthroplasty and 15 who underwent ORIF. There were no differences in baseline demographics between the two cohorts. Patients managed with ORIF had statistically higher FRmet (0.79) compared with those treated with revision arthroplasty (0.68, p = 0.0047). FRdia and stem length did not differ statistically between cohorts. Conclusion Higher FRmet ratios were associated with an increased likelihood of undergoing ORIF compared to revision arthroplasty after periprosthetic humeral fracture. FRmet may serve as a beneficial radiographic parameter to influence surgical decision-making in the management of periprosthetic humeral fractures.
Background Walch B-type glenoids have been associated with decreased implant survival in anatomic total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA). The literature suggests that posteriorly-based eccentric glenoid wear driven by posterior humeral head subluxation may occur in conjunction with rotator cuff muscular imbalances around the shoulder. This study aims to identify existing rotator cuff and deltoid muscular imbalances in patients undergoing aTSA and rTSA and their association with different Walch-types of glenoid wear. Methods Patients with primary glenohumeral osteoarthritis (OA) or rotator cuff arthropathy who underwent preoperative computed tomography (CT) scans of the affected shoulder from 8/1/2020 to 12/31/2021 were included. Patients were included if they were over 18 years old with Walch-type A or B glenoids as identified on CT within a year of surgery and had at least two years of follow-up. Fatty infiltration was assessed using Goutallier grading, and muscle volumes were quantified using previously established methodologies. Ratios of anterior to posterior muscle volumes were established for the rotator cuff (‘RCR’), deltoid (‘DMR’), and the rotator cuff and deltoid combined (‘CMR’). Glenoid retroversion, inclination, and humeral head subluxation were recorded. Muscle volume ratios were compared between glenoid types using univariate and multivariable regression and Welch’s t-test. Results The included final cohort of 146 patients had a mean age of 64.3 (±10.6) years and mean BMI of 27.7 (±5.7) kg/m2. Glenoid retroversion was greatest in type B2 glenoids (p<0.0001). DMR (p=0.0176) and CMR (p=0.0066) were lower in B2 compared to A1 glenoids, suggesting greater posterior muscle volume in B2 glenoids. RCR was lower in B2 compared to A2 glenoids (p=0.0003); however, DMR (p=0.3809) and CMR (p=0.0569) were not significantly different between these two groups. CMR (p=0.0086), and RCR (p=0.0097) were significantly lower in B2 compared to A1 and A2 glenoids combined, further suggesting greater posterior muscle volume in B2 glenoids. Goutallier scores were not significantly different across the various glenoid types. Conclusion Patients with type B2 glenoids exhibited a higher ratio of posterior to anterior shoulder muscle volumes when accounting for both the rotator cuff and deltoid. Fatty infiltration of the rotator cuff, however, was not associated with a specific wear pattern. This study substantiates existing evidence to suggest that increased posterior muscle volume may play a role in the pathogenesis of posteriorly-based eccentric glenoid wear, warranting further longitudinal studies to confirm these findings.
Background Outpatient shoulder arthroplasty is increasing in popularity due to advancements in surgical techniques as well as intra-operative and perioperative pain management. However, complex patient selection tools and risk models limit widespread adoption. This study introduces and evaluates the Exclusion Criteria Based Eligibility (ECBE) method for selecting patients suitable for outpatient shoulder arthroplasty. Methods A retrospective analysis was conducted on a prospectively maintained cohort of all 149 patients who underwent primary shoulder arthroplasty by a single surgeon between January 2021 and September 2024. Patients were prospectively evaluated using the ECBE method, which excludes only those living alone, requiring an assistive devise for ambulation, or with serious unstable medical conditions. Those deemed eligible were prepared for same-day discharge. Outcome measures included successful same-day discharge rate, postoperative complications, emergency department visits, and 90-day readmissions. Results Of 149 patients, 107 (72%) met ECBE criteria and were scheduled for outpatient surgery. Among these, 101 patients (94%) were successfully discharged on the same day. The six patients (6%) requiring admission did so for unpredictable medical or logistical reasons, none related to surgical complications nor inadequate pain management. Within the outpatient cohort, there were no emergency department (ED) visits within 7 days postoperatively; one patient (0.9%) was admitted within 90 days for an unrelated medical issue, and one patient had a surgical complication (0.9%), a dislocation at 2 months post-op treated by closed reduction in the ED. Conclusion The ECBE method is a safe, effective, and practical tool for identifying candidates for outpatient shoulder arthroplasty. With just three exclusion criteria, it achieves high accuracy in predicting successful same-day discharge while minimizing unnecessary inpatient admissions. The simplicity of this approach supports its broad clinical applicability and has the potential to streamline outpatient selection in shoulder arthroplasty.
Background Humeral head pathomorphology is highly prevalent in glenohumeral osteoarthritis and can increase the challenge of restoration of native anatomy during anatomic total shoulder arthroplasty (aTSA). The goal of the present study was to evaluate the influence of preoperative computed tomography (CT)-based 3D humeral planning and standard transfer instrumentation on the restoration of normal humeral anatomy during aTSA with pathologic humeral specimens in a controlled laboratory setting. Methods Three experienced shoulder surgeons participated in a prospective, controlled laboratory study utilizing 3D-printed pathologic osteoarthritic humeri from CTs of existing patients, which were chosen to be -3, -1, 0, 1 and 3 size standard deviations of all patients in a large database. A realistic surgical setting was simulated. aTSA using the Arthrex Eclipse prosthesis were performed in three phases of the study. In phase 1, humeral cuts and implantations were performed without preoperative planning. In phase 2, preoperative planning was performed, and the cuts repeated on new prints of the same specimens. In phase 3, the same steps were repeated, with the additional use of standard transfer instrumentation. After digitization, deviations in the prosthetic and ideal center of rotation (COR), neck shaft angle (NSA), retrotorsion and cut thickness were assessed. Results There were no significant differences in NSA, deviation in planned resection height, or deviation in retortorsion from native between the three phases (p > 0.05). The M-L COR shift was significantly greater for Phase 1 compared to Phase 2 (2.8mm vs 1.6mm, p = 0.043). There were no other significant differences between phases for the M-L, A-P or 3D COR shifts. There were significantly fewer varus head cuts (13%) in Phase 3 compared to Phase 1 (47%) and Phase 2 (47%) (p = 0.043). Conclusions Preoperative CT-based humeral planning provides some modest improvements in medial to lateral humeral COR restoration and with the addition of standard transfer instrumentation, reduction in varus neck cuts in pathologic, osteoarthritic humeri in a controlled laboratory setting. The most important finding of the study is the avoidance of varus neck cuts with planning and transfer technology. While significant, the differences were overall modest compared to findings of previous studies for non-pathologic humeri, indicating the challenges associated with restoration of native anatomy in pathomorphologic humeri during aTSA and the need for continued development to refine planning and transfer tools.
Background The incidence of reverse total shoulder arthroplasties (RTSA) has drastically increased in recent years, but standardized implants have limitations and may not always be used in patients with extensive glenoid bone loss. The Vault Reconstruction System (VRS; Zimmer Biomet, Warsaw, IN) is a patient-specific custom glenoid implant (CuGI) derived from pre-operative CT scans in RTSA for patients with severe glenoid bone loss. However, the in vivo orientation and stability during active range of motion (ROM) have yet to be evaluated. The purpose of this study was to evaluate the in vivo kinematics and implant positioning of patients who underwent RTSA with VRS CuGI. Methods Patients with the CuGI underwent biplane video radiography while performing unrestrained scapular plane abduction. Using analogous anatomical coordinate systems, the stability of the glenoid implant on the scapula and the kinematics of patients with CuGI were compared to those of patients with healthy shoulders. Results Implant orientation closely matched the preoperative plan overall, with the largest deviation observed in retroversion (mean 5.9°). Implant–scapula motion remained minimal across all evaluated components; a small difference was observed in superior-inferior translation (maximum mean difference 1.4 mm), which was within measurement precision. Discussion Implant–scapula motion was minimal across the motion arc, with differences remaining within measurement precision. During active ROM, patients with a VRS CuGI showed similar elevation and plane of elevation mechanics to healthy controls but differed in axial rotation. Greater variability was present across all planes of motion in patients with CuGI, indicating that individuals who undergo this procedure likely employ unique compensatory strategies to achieve functional range of motion. Conclusion The VRS CuGI was shown to have increased retroversion (5.9°) in comparison to preoperative planning but maintains stable fixation to the scapula during dynamic arm elevation in patients with severe glenoid bone loss. Despite kinematic differences from healthy shoulders, participants experienced minimal functional impairment and pain, suggesting that the altered motion patterns may reflect adaptive mechanisms that support successful clinical outcomes in complex shoulder reconstructions. Level of Evidence Biomechanics Kinematic Study
Introduction Glucagon-like peptide-1 receptor agonists (GLP-1a) medications have rapidly gained popularity. However, the full impact these medications may have on the outcomes of Total Shoulder Arthroplasty (TSA) remain to be determined. The objective of this systematic review and meta-analysis is to evaluate the outcomes of patients undergoing any TSA (both anatomic or reverse) while on a GLP-1a medication versus those not on any GLP-1a medication undergoing TSA. Methods A search was conducted across MEDLINE/PubMed, Cochrane, Google Scholar, Web of Science, and Embase databases. The search used a combination of keywords and Medical Subject Headings (MeSH) terms, such as “glucagon-like-peptide-1-receptor agonists” or “total shoulder arthroplasty”, with the full search insupplementary table 1. Titles and abstracts were screened for eligibility according to the inclusion criteria. Full texts were screened, and those that met the eligibility criteria were included. Inclusion criteria included any studies that 1.) Evaluated patients undergoing any TSA (including reverse and anatomic TSA) and reported to be taking GLP-1a medication at the time of undergoing TSA, 2.) They were completed in English. Revision arthroplasty was excluded. Demographics and results of the studies were extracted from the articles that met the inclusion criteria. Meta-analysis was conducted to evaluate outcomes. Results In this systematic review, six studies met the inclusion criteria, and five studies were included for meta-analysis. No studies were deemed poor quality by the quality assessment. When compared with patients not using GLP-1a medications, patients using GLP-1a medications in the setting of TSA demonstrated no significant difference in readmissions (OR: 1.12 (95% CI: 0.86-1.44); P=0.40), infections (OR: 0.98 (95% CI: 0.53-1.80); P=0.94), or medical complications (OR: 0.89 (95% CI: 0.45-1.79); P=0.75) within 90 days of surgery. At 2 years, these patients had no significant difference in aseptic revision (OR: 1.66 (95% CI: 0.97-2.84); P=0.07), periprosthetic fractures (OR: 1.16 (95% CI: 0.65-2.05); P=0.62), or infections (OR: 1.42 (95% CI: 0.92-2.19); P=0.12). Conclusion This study supports the safe use of GLP-1a medications in patients undergoing TSA. This study found no difference in 90-day readmissions, 90-day medical complications, 90-day and 2-year infections, 2-year periprosthetic fractures, and 2-year aseptic revisions when comparing patients using GLP-1a medications when undergoing TSA to those not using GLP-1a medications. Level of Evidence III Systematic Review & MetaAnalysis
Background Preoperative expectations are increasingly recognized as a factor influencing postoperative outcomes in orthopedic surgery. The relationship of preoperative expectations and Patient-Reported Outcomes Measurement Information System (PROMIS) patient-reported outcomes (PROs) in total shoulder arthroplasty (TSA) remains understudied. This study aimed to evaluate whether higher preoperative expectations are associated with improved 2-year patient-reported outcomes (PROs). Methods Patients undergoing anatomic or reverse TSA between June 2015 and April 2022 were retrospectively identified from a prospectively enrolled orthopedic registry. Preoperative expectations were assessed using the Musculoskeletal Outcomes Data Evaluation and Management System (MODEMS). PROs were collected at baseline and 2-years postoperatively, including six domains of PROMIS, American Shoulder and Elbow Surgeons score (ASES), numeric pain scales (NPS), Tegner Activity Scale (TAS), and Marx Activity Rating Scale Upper Extremity (MARS UE). Non-parametric tests and multivariate linear regressions were performed to evaluate the relationship between preoperative expectations and 2-year PROs. Results Of 174 eligible patients, 140 (80.5%) completed 2-year follow-up. Patients with prior ipsilateral shoulder surgery had significantly lower preoperative expectations (p=.005). Higher expectations were associated with better 2-year PROs across functional, pain, and activity metrics, in addition to greater met expectations. Regression analysis demonstrated that preoperative expectations independently predicted better 2-year and greater improvement in PROMIS Physical Function, PROMIS Pain Interference, and PROMIS Social Satisfaction. Conclusion Higher preoperative expectations were significantly associated with better 2-year PROs following TSA and were independent predictors of improvements in physical function, pain, social satisfaction, and expectation fulfillment. These findings suggest that patients with higher expectations may have superior clinical outcomes after TSA.
Background Humeral implant fixation techniques for reverse total shoulder arthroplasty (rTSA) have primarily consisted of press-fit or cemented approaches. Humeral implant fixation is critical for durable rTSA outcomes, and inadequate fixation such as early subsidence or loosening, can compromise these outcomes and complicate potential revision. Limited data exist on outcomes associated with hybrid humeral stem fixation which utilizes cement distally and press-fit proximally, which may help achieve good initial fixation while allowing for bone ingrowth in patients with poor bone quality. Methods A retrospective cohort study was conducted using data from the an institutional shoulder arthroplasty clinical registry. The study included 11 patients who underwent primary rTSA with hybrid humeral stem fixation between February 1, 2016, and July 31, 2022. Data collected included patient demographics, operative details, and clinical outcomes. Patient-reported outcome measures (PROMs)—including ASES, SANE, VAS—and range of motion (ROM) were assessed preoperatively and at final follow-up. Descriptive statistics were used for analysis. Results A total of 11 patients underwent rTSA with hybrid humeral stem fixation. Average time to final PROMs was 38.7 ± 17.1 months (14.8 - 50.1 months) and the average time to final in-person follow up/radiographic imaging was 21.1 ± 11.9 months (3.8 - 38.7 months). The mean age of the cohort was 72.55 ± 4.96 years, and mean BMI was 28.73 ± 7.22. Primary diagnoses included cuff tear arthropathy (45.5%), osteoarthritis (45.5%), and avascular necrosis (9.1%). Intraoperative rotator cuff status was reported as torn (63.6%), intact (27.3%), and attenuated (9.1%) and all patients underwent biceps tenodesis. The mean ASES score improved from 46.32 ± 15.60 to 91.91 ± 9.31 (p < 0.0001). Forward elevation increased from 86.36° ± 28.05° to 142.27° ± 20.15° (p < 0.0001), and external rotation improved from 27.73° ± 15.13° to 55° ± 11.08° (p < 0.0005. VAS pain scores decreased from 6.82 ± 1.59 to 0.18 ± 0.39 (p < 0.0001). SANE scores (available for 72.7% of patients) improved from 20.63 ± 18.87 to 77.25 ± 30.86 (p < 0.0001). Conclusion Reverse total shoulder arthroplasty with hybrid humeral stem fixation resulted in significant improvements in pain relief, range of motion, and functional outcomes, with low rates of early radiographic concern at short-term follow-up. The findings support hybrid fixation as a promising alternative to fully cemented or press-fit techniques, warranting larger comparative studies with mid-term radiographic follow-up to define durability and ideal indications. Level of Evidence Level IV; Retrospective Case Series
Background Acromial fracture is a common complication after reverse total shoulder arthroplasty (rTSA) associated with poor functional outcomes. Etiologies include stress fracture, trauma, and tuberosity impingement. Several patient-specific risk factors for acromial stress fracture (ASF) have been identified, such as osteoporosis and scapular geometry. Operative factors, including implant positioning and deltoid muscle tensioning, also influence acromial stresses. However, the relative contribution of these factors to overall ASF risk remains unclear. This study incorporated both patient-specific and operative factors to simulate acromial fatigue life in patients who developed ASF after rTSA compared to controls without fracture. We hypothesized that patients with ASF would demonstrate a lower simulated fatigue life, reflecting an underlying predisposition to stress fracture. Methods Five patients with atraumatic acromial fracture after rTSA were identified and matched to five controls on age, gender, Charlson comorbidity index, and a diagnosis of osteoporosis. Pre-operative CT scans were used to segment scapular, clavicular, and humeral geometry and construct patient-specific musculoskeletal models incorporating glenohumeral and scapulothoracic kinematics. Post-operative radiographs were used to position implants. Muscle forces were calculated during a 0 to 90° abduction motion using static optimization with an active and passive force muscle model. Pre-operative and post-operative forces were applied to finite element models to assess acromial fatigue life. Material properties were assigned heterogeneously based upon pre-operative CT scans. Fatigue life was assessed using two models, a numeric model based on the highest normalized compressive stress, and a continuum-damage model of whole-bone fatigue failure. Predicted fracture locations were compared to actual locations based on the modified Levy type. Fatigue lives were normalized to the control group and compared using Wilcoxon signed-rank tests. The shapes of the fatigue curves were assessed using permutation testing. Results The predicted fracture locations were of the same modified Levy type in 3 of 5 cases accounting for 4 of 6 fractures (one type 3, two type 2A, one type 1), while the remaining two were adjacent to the actual location (predicted type 2B—actual type 2C; predicted type 2A—actual type 2B). The numeric fatigue life in cases was 98.9% of control group in the pre-operative condition, and 101.7% post-operatively (p = 0.81). The continuum-damage fatigue life in cases was 100.1% of the control group pre-operatively and 102.1% post-operatively (p = 0.81). The fatigue curves demonstrated an initially more gradual decline in cases followed by more rapid decline compared to controls (p = 0.04). Conclusion Patient-specific biomechanical simulation predicted ASF location with good accuracy using the modified Levy classification. However, this study does not support the hypothesis that patients who ultimately sustain an ASF are predisposed to fracture based upon bone quality, kinematics, and muscle forces compared to matched controls. Instead, differences in fatigue curve shape suggest a stochastic mechanism of fracture initiation and propagation possibly related to scapular geometry. Factors not accounted for in this study may additionally explain ASF, including post-operative patient activity level and bone remodeling potential.
