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Background: Proximal humerus fractures (PHF) are common with approximately 30% requiring surgical intervention. This ranges from open reduction internal fixation (ORIF) to shoulder arthroplasty (including hemiarthroplasty, total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA)). The aim of this study was to assess trends in operative interventions for PHF in an Australian population. Methods: Data was retrospectively collected for private patients with a PHF and requiring surgical intervention (2001–2020). Data for patients undergoing ORIF were extracted from the Medicare database, while those receiving arthroplasty for PHF were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Results: Across the study period, ORIF was the most common surgical procedure for management of PHFs. While the number of RTSA procedures for PHF has increased, shoulder hemiarthroplasty has significantly reduced since 2008 (p < 0.001). Patients aged < 65 years were more likely to receive ORIF. Patients aged ≥ 65 years were more likely to receive RTSA or hemiarthroplasty compared to patients aged < 65 years. Conclusions: While the number of ORIF procedures has increased during the period of interest, it has diminished slightly as a proportion of overall procedure volume. RTSA is becoming increasingly popular, with decreasing utilization of hemiarthroplasty, and TSA for fracture remaining uncommon. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Prosthetic arthroplasty has emerged as a major contributor to the management of shoulder disorders. This paper outlines the situation in Australia regarding the process by which shoulder replacement devices are made available. Although entry of joint replacement devices to the Australian market is relatively unrestricted, they must be first approved by the Therapeutic Goods Administration—based on safety and efficacy—to be legally used. In addition, to obtain a private insurance rebate (Prescribed List) and thus be commercially viable, the Federal Department of Health and Aged Care requires a more stringent benchmark of comparative clinical effectiveness and value for money. The AOANJRR (Australian Orthopaedic Associate National Joint Replacement Registry) records the implantation and possible revision of virtually all (>98%) major joint arthroplasties in Australia and plays an important role in informing surgeons about their implant selection, but also in identifying and highlighting devices with a higher than anticipated rate of revision. Although the increased cost of health care is placing pressure on health care systems around the world, in Australia, access to shoulder arthroplasty remains relatively unrestricted—but carefully controlled and monitored. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the relationship between multiple radiographic measures of lateralization and distalization and clinical outcome scores after a reverse total shoulder arthroplasty (RTSA). We retrospectively evaluated all RTSAs performed by the senior author between January 1, 2007, and November 1, 2017. We then evaluated the visual analog scale for pain (VAS pain), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) scores and complication and reoperation rates at a minimum of 2-year follow-up. We measured preoperative and postoperative (2-week) radiographs for the lateralization shoulder angle (LSA), the distalization shoulder angle (DSA), lateral humeral offset, and the distance from the glenoid to the lateral aspect of the greater tuberosity. A multivariable analysis was performed to evaluate the effect of the postoperative radiographic measurements on final patient-reported outcomes (ASES scores, SST, and VAS pain). The cohort included 216 shoulders from unique patients who had patient-reported outcome scores available at a minimum of 2-year follow-up (average, 4.0 ± 1.9 years) for a total follow-up rate of 70%. In the multivariable models, more lateralization (LSA) was associated with worse final ASES scores −0.52 (95% confidence interval [CI]: −0.88, −0.17; P =.004), and more distalization (DSA) was associated with better final ASES scores 0.40 (95% CI: 0.11, 0.69; P =.007). More lateralization (LSA) was associated with worse final SST scores −0.06 (95% CI: −0.11, −0.003; P =.039). Finally, greater distalization (DSA) was associated with lower final VAS pain scores, ratio = 0.98 (95% CI: 0.96, 1.00; P =.021). Greater distalization and less lateralization are associated with better function and less pain after a Grammont-style RTSA. When using a Grammont-style implant, remaining consistent with Grammont's principles of implant placement will afford better final clinical outcomes. [ABSTRACT FROM AUTHOR]

Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (−1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (−21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (−3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (−44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies. [ABSTRACT FROM AUTHOR]

John Twomey-Kozak, Kwabena Adu-Kwarteng,&ast; Kiera Lunn,&ast; Damon Vernon Briggs, Eoghan Hurley, Oke A Anakwenze, Christopher S Klifto Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA&ast;These authors contributed equally to this workCorrespondence: John Twomey-Kozak, Duke University Medical Center, Department of Orthopaedic Surgery, Durham, NC, USA, Email jnt25@duke.eduPurpose of Review: This narrative review comprehensively aims to analyze recent advancements in shoulder arthroplasty, focusing on implant systems and their impact on patient outcomes. The purpose is to provide a nuanced understanding of the evolving landscape in shoulder arthroplasty, incorporating scientific, regulatory, and ethical dimensions.Recent Findings: The review synthesizes recent literature on stemless implants, augmented glenoid components, inlay vs onlay configurations, convertible stems, and associated complications. Notable findings include improved patient-reported outcomes with stemless implants, variations in outcomes between inlay and onlay configurations, and the potential advantages of convertible stems. Additionally, the regulatory landscape, particularly the FDA’s 510(k) pathway, is explored alongside ethical considerations, emphasizing the need for standardized international regulations.Summary: Recent innovations in shoulder arthroplasty showcase promising advancements, with stemless implants demonstrating improved patient outcomes. The review underscores the necessity for ongoing research to address unresolved aspects and highlights the importance of a standardized regulatory framework to ensure patient safety globally. The synthesis of recent findings contributes to a comprehensive understanding of the current state of shoulder arthroplasty, guiding future research and clinical practices.Keywords: shoulder arthroplasty, rTSA, stemless implants, glenoid components, patient outcomes, innovations in arthroplasty

BACKGROUND: Glenoid wear secondary to primary osteoarthritis or rotator cuff arthropathy is an obstacle commonly encountered by surgeons performing reverse shoulder arthroplasty, with numerous techniques devised to address this finding. The most recent of such techniques is the introduction of augmented glenoid baseplates to fill these glenoid defects. The objectives of this systematic review are to analyze clinical outcomes of augmented baseplates in patients with glenoid wear, including pain, range of motion, patient-reported functional scores, radiographic outcome measures, complication rates, and revision rates. METHODS: Three online databases (Ovid Medline, EMBASE, Pubmed) were searched for studies publishing clinical and functional outcomes of augmented baseplates in primary reverse shoulder arthroplasty. Findings were aggregated and frequency-weighted means of these variables were calculated when applicable. RESULTS: Seven studies comprising 810 patients were included in this review. The mean patient age was 72.1 ± 8.1 years with an average follow-up time of 41.4 months. Frequency-weighted means of improvement in forward elevation, abduction, and active external rotation were 53°, 47°, and 19°, respectively. Patients experienced American Shoulder and Elbow Surgeons, Simple Shoulder Test, and Constant score improvements of 45.9, 5.9, and 33.7, respectively. Pooled complicated rate was 6.4%, with 10 cases of baseplate loosening and 3 cases of instability. Five (0.6%) patients required reoperation. Subdividing among augment type (posterior, superior, posterosuperior), there were no apparent differences in outcomes or complication rates between directional augments. CONCLUSION: This systematic review demonstrates that augmented baseplates for reverse shoulder arthroplasty provide positive outcomes both clinically and functionally at early follow-up. Complications are within an acceptable range for primary reverse shoulder arthroplasty, with a low rate of revision. Augmented baseplates should serve as a viable option for surgeons seeking to address glenoid wear during reverse shoulder arthroplasty.

The aim of the present study was to individuate and compare specific machine learning algorithms that could predict postoperative anterior elevation score after reverse shoulder arthroplasty surgery at different time points. Data from 105 patients who underwent reverse shoulder arthroplasty at the same institute have been collected with the purpose of generating algorithms which could predict the target. Twenty-eight features were extracted and applied to two different machine learning techniques: Linear regression and support vector regression (SVR). These two techniques were also compared in order to define to most faithfully predictive. Using the extracted features, the SVR algorithm resulted in a mean absolute error (MAE) of 11.6° and a classification accuracy (PCC) of 0.88 on the test-set. Linear regression, instead, resulted in a MAE of 13.0° and a PCC of 0.85 on the test-set. Our machine learning study demonstrates that machine learning could provide high predictive algorithms for anterior elevation after reverse shoulder arthroplasty. The differential analysis between the utilized techniques showed higher accuracy in prediction for the support vector regression. Level of Evidence III: Retrospective cohort comparison; Computer Modeling. [ABSTRACT FROM AUTHOR]

Reverse total shoulder arthroplasty (RTSA) is increasingly used as a treatment modality for various pathologies. The purpose of this review is to identify preoperative risk factors associated with loss of internal rotation (IR) after RTSA. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Ovid MEDLINE, Ovid Embase, and Scopus were queried. The inclusion criteria were as follows: articles in English language, minimum 1-year follow-up postoperatively, study published after 2012, a minimum of 10 patients in a series, RTSA surgery for any indication, and explicitly reported IR. The exclusion criteria were as follows: articles whose full text was unavailable or that were unable to be translated to English language, a follow-up of less than 1 year, case reports or series of less than 10 cases, review articles, studies in which tendon transfers were performed at the time of surgery, procedures that were not RTSA, and studies in which the range of motion in IR was not reported. The search yielded 3792 titles, and 1497 duplicate records were removed before screening. Ultimately, 16 studies met the inclusion criteria with a total of 5124 patients who underwent RTSA. Three studies found that poor preoperative functional IR served as a significant risk factor for poor postoperative IR. Eight studies addressed the impact of subscapularis, with 4 reporting no difference in IR based on subscapularis repair and 4 reporting significant improvements with subscapularis repair. Among studies with sufficient power, BMI was found to be inversely correlated with degree of IR after RTSA. Preoperative opioid use was found to negatively affect IR. Other studies showed that glenoid retroversion, component lateralization, and individualized component positioning affected postoperative IR. This study found that preoperative IR, individualized implant version, preoperative opioid use, increased body mass index and increased glenoid lateralization were all found to have a significant impact on IR after RTSA. Studies that analyzed the impact of subscapularis repair reported conflicting results. [ABSTRACT FROM AUTHOR]

Background: Archery, a popular recreational activity, puts strain on the shoulder girdle. rTSA indications are expanding, thus it is necessary to further understand return to sports such as archery. Methods: A retrospective chart review was performed on patients undergoing primary rTSA with a minimum of 6-month follow-up. Demographic and surgical data was collected. Return to archery metrics included utilization of vertical vs. crossbow, ability to return to archery, presence of pain and instability during archery, modification of archery technique, and reason for lack of return to sport. VAS and ASES scores were obtained. Results: 13 patients self-reported routinely participating in archery before undergoing rTSA. Seven participants (53.8 %) with a mean age of 69.7 years ( ± 6.32 years), returned to sport postoperatively. Four of these seven participants indicated that they switched to using a crossbow to return to the sport. Average VAS score was 1.85 ( ± 0.34, range 0–6). Only one participant returning to the sport had surgery on their dominant arm. Conclusion: Return to archery following rTSA is possible and more likely if the surgery is performed on the bow arm. Switching from a vertical to a crossbow alongside targeted physical therapy to strengthen the deltoid may help facilitate return to archery postoperatively. Level of evidence: III.

Purpose: Clinical decision support tools (CDSTs) are software that generate patient-specific assessments that can be used to better inform healthcare provider decision making. Machine learning (ML)-based CDSTs have recently been developed for anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty to facilitate more data-driven, evidence-based decision making. Using this shoulder CDST as an example, this external validation study provides an overview of how ML-based algorithms are developed and discusses the limitations of these tools. Methods: An external validation for a novel CDST was conducted on 243 patients (120F/123M) who received a personalized prediction prior to surgery and had short-term clinical follow-up from 3 months to 2 years after primary aTSA (n = 43) or rTSA (n = 200). The outcome score and active range of motion predictions were compared to each patient's actual result at each timepoint, with the accuracy quantified by the mean absolute error (MAE). Results: The results of this external validation demonstrate the CDST accuracy to be similar (within 10%) or better than the MAEs from the published internal validation. A few predictive models were observed to have substantially lower MAEs than the internal validation, specifically, Constant (31.6% better), active abduction (22.5% better), global shoulder function (20.0% better), active external rotation (19.0% better), and active forward elevation (16.2% better), which is encouraging; however, the sample size was small. Conclusion: A greater understanding of the limitations of ML-based CDSTs will facilitate more responsible use and build trust and confidence, potentially leading to greater adoption. As CDSTs evolve, we anticipate greater shared decision making between the patient and surgeon with the aim of achieving even better outcomes and greater levels of patient satisfaction. [ABSTRACT FROM AUTHOR]

Patients are increasingly undergoing bilateral total shoulder arthroplasty (TSA). At present, it is unknown whether success after the first TSA is predictive of success after contralateral TSA. We aimed to determine whether exceeding clinically important thresholds of success after primary TSA predicts similar outcomes for subsequent contralateral TSA. We performed a retrospective review of a prospectively collected shoulder arthroplasty database for patients undergoing bilateral primary anatomic (aTSA) or reverse (rTSA) total shoulder arthroplasty since January 2000 with preoperative and 2- or 3-year clinical follow-up. Our primary outcome was whether exceeding clinically important thresholds in the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score for the first TSA was predictive of similar success of the contralateral TSA; thresholds for the ASES score were adopted from prior literature and included the minimal clinically important difference (MCID), the substantial clinical benefit (SCB), 30% of maximal possible improvement (MPI), and the patient acceptable symptomatic state (PASS). The PASS is defined as the highest level of symptom beyond which patients consider themselves well, which may be a better indicator of a patient's quality of life. To determine whether exceeding clinically important thresholds was independently predictive of similar success after second contralateral TSA, we performed multivariable logistic regression adjusted for age at second surgery, sex, BMI, and type of first and second TSA. Of the 134 patients identified that underwent bilateral shoulder arthroplasty, 65 (49%) had bilateral rTSAs, 45 (34%) had bilateral aTSAs, 21 (16%) underwent aTSA/rTSA, and 3 (2%) underwent rTSA/aTSA. On multivariable logistic regression, exceeding clinically important thresholds after first TSA was not associated with greater odds of achieving thresholds after second TSA when success was evaluated by the MCID, SCB, and 30% MPI. In contrast, exceeding the PASS after first TSA was associated with 5.9 times greater odds (95% confidence interval 2.5-14.4, P <.001) of exceeding the PASS after second TSA. Overall, patients who exceeded the PASS after first TSA exceeded the PASS after second TSA at a higher rate (71% vs. 29%, P <.001); this difference persisted when stratified by type of prosthesis for first and second TSA. Patients who achieve the ASES score PASS after first TSA have greater odds of achieving the PASS for the contralateral shoulder regardless of prostheses type. [ABSTRACT FROM AUTHOR]

Reversed total shoulder arthroplasty (RTSA) is a standard surgical procedure for the treatment of rotator cuff tear arthropathy (CTA), aimed at restoring active arm elevation. Shoulder elevation relies on both scapulothroacic (ST) and glenohumeral (GH) motion, but RTSA computer planning primarily focuses on the GH joint due to challenges in visualizing scapulothroacic (ST) motion. Does the scapulohumeral rhythm, by means of the relative contributions of ST rotation and GH elevation per degree of arm elevation, in a longitudinal setting for up to two years postoperatively after RTSA for CTA change? In a prospective longitudinal study, shoulder kinematics were studied in 20 patients (22 shoulders) before and at three, six, 12, and 24 months after RTSA implantation for CTA. Skin markers were tracked using 3D motion analysis. The relative ST and GH contributions per degree of arm elevation were assessed and were compared using statistical non-parametric mapping with Bayesian inference. Mean arm elevation was 89 ± 33° preoperatively, 135 ± 28° at 3 months, 161 ± 20° at 6 months, 169 ± 18° at 12 months, and 165 ± 19° at 24 months. Between 48–66°, 62–93°, 53–94°, 60–97° and 72–104° of arm elevation at the measurement time points pre, 3-months, 6-months, 12-months and 24-months postoperatively, respectively, the ST rotation had a significantly greater contribution to arm elevation compared to GH elevation; a pattern that was not found in controls. While RTSA successfully restored active arm elevation through improved GH and ST motion, the scapulohumeral rhythm exhibited a consistent pattern up to two years postoperatively, resembling the preoperative state. In the midrange of motion, ST rotation dominated over GH elevation, potentially contributing to muscular fatigue and explaining the documented decline in functional outcomes over time after RTSA. The findings highlight the importance of incorporating ST kinematics into modern computer planning for RTSA. • Arm elevation was restored after reversed total shoulder arthroplasty. • Normal scapulohumeral rhythm was not restored within two years after RTSA. • In the midrange or arm elevation: scapulothoracic > glenohumeral contribution. • Modern computer planning of RTSA should consider scapulothoracic rotation. [ABSTRACT FROM AUTHOR]

The incidence of proximal humerus fractures (PHF) is continuing to rise due to shifts towards a more aged population as well as advancements in surgical treatment options. The purpose of this study is to examine and compare trends in the treatment of PHFs (nonoperative vs. operative; different surgical treatments) across different age groups over the last decade (2010-2020). The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried using International Classification of Diseases and Current Procedural Terminology codes to identify all patients presenting with or undergoing surgery for PHF between 2010 and 2020. Treatment trends, demographics, and insurance information were analyzed during the study period. Comparisons were made between operative and nonoperative trends with respect to the number and type of surgeries performed among 3 age groups: ≤49 years, 50-64 years, and ≥65 years. The rate of postoperative complications and reoperations was evaluated and compared among different surgical treatments for patients with a minimum 1-year postoperative follow-up. A total of 92,308 patients with a mean age of 67.8 ± 16.8 years were included. Over the last decade, there was no significant increase in the percentage of PHFs treated with surgery. A total of 15,523 PHFs (16.82%) were treated operatively, and these patients, compared with the nonoperative cohort, were younger (64.9 years vs. 68.4 years, P <.001), more likely to be White (80.2% vs. 74.7%, P <.001), and more likely to have private insurance (41.4% vs. 32.0%, P <.001). For patients ≤49 years old, trends in operative treatment have remained stable with internal fixation (IF) as the most used surgical modality. For patients 50-64 years old, we observed a gradual decline in the use of hemiarthroplasty (HA), with a corresponding increase in the use of reverse total shoulder arthroplasty (rTSA), but IF continued to be the most used operative modality. In patients over 65 years, a steep decline in the use of IF and HA was noted during the first half of the decade along with a significant exponential increase in the use of rTSA, which surpassed the use of IF in 2019. Despite the increase in the use of rTSA, no differences in rate of surgical complications were noted between rTSA and IF (χ2 = 0.245, P =.621) or reoperations (χ2 = 0.112, P =.730). Nonsurgical treatment remains the mainstay treatment of PHFs. Although there is no increase in the prevalence of operative treatment in patients ≥50 years in the last decade, there is an exponential increase in the use of rTSA with a corresponding decrease in HA and IF, a trend more substantial in patients ≥65 years compared with patients between 50 and 64 years. [ABSTRACT FROM AUTHOR]

Background: Although substantial motion at the acromioclavicular joint (ACJ) occurs during overhead shoulder motion, the influence of ACJ arthritis on postoperative outcomes of patients undergoing reverse total shoulder arthroplasty (rTSA) is unclear. We assessed the influence of ACJ arthritis, defined by degenerative radiographic changes, and its severity on clinical outcomes after primary rTSA. Methods: We conducted a retrospective review of a prospectively collected shoulder arthroplasty database of patients that underwent primary rTSA with a minimum 2-year clinical follow-up. Imaging studies of included patients were evaluated to assess ACJ arthritis classified by radiographic degenerative changes of the ACJ; severity was based upon size and location of osteophytes. Both the Petersson classification and the King classification (a modified Petersson classification addressing superior osteophytes and size of the largest osteophyte) were used to evaluate the severity of degenerative ACJ radiographic changes. Severe ACJ arthritis was characterized by large osteophytes (≥2 mm). Active range of motion (ROM) in abduction, forward elevation, and external and internal rotation as well as clinical outcome scores (American Shoulder and Elbow Surgeons Shoulder, Constant, Shoulder Pain and Disability Index, simple shoulder test, University of California, Los Angeles scores) were assessed both preoperatively and at the latest follow-up; outcomes were compared based on severity of ACJ arthritis. Multivariable linear regression models were used to determine whether increasing severity of ACJ arthritis was associated with poorer outcomes. Results: A total of 341 patients were included with a mean age of 71 ± 8 years and 55% were female. The mean follow-up was 5.1 ± 2.4 years. Preoperatively, there were no differences in outcomes based on the severity of ACJ pathology. Postoperatively, there were no differences in outcomes based upon the severity of ACJ arthritis except for greater preoperative to postoperative improvement in active internal rotation in patients with normal or grade 1 ACJ arthritis vs. grade 2 and 3 (3 ± 2 vs. 1 ± 2 and 1 ± 3, P = .029). Patients with ACJ arthritis and osteophytes ≥2 mm had less favorable Shoulder Pain and Disability Index scores, corresponding to greater pain (−49.3 ± 21.5 vs. −41.3 ± 26.8, P = .015). On multivariable linear regression, increased severity of ACJ arthritis was not independently associated with poorer postoperative ROM or outcome scores. Conclusion: Overall, our results demonstrate that greater ACJ arthritis severity score is not associated with poorer outcome scores and has minimal effect on ROM. However, patients with the largest osteophytes (≥2 mm) did have slightly worse pain postoperatively. Radiographic presence of high-stage ACJ arthritis should not alter the decision to undergo rTSA.

Introduction: Reverse total shoulder arthroplasty (RTSA) is a well-establish procedure with increasing incidence. Depending on the medical history, many patients undergo multiple soft-tissue procedures before RTSA. The role of acromioclavicular pathology as well as the consequences of a distal clavicle resection (DCR) before RTSA has not been evaluated yet. Material and methods: A retrospective single-center review was performed on all patients undergoing primary RTSA with or without DCR with a minimum follow-up of 2 years. We compared patient-reported outcome measures (Constant score (CS), subjective shoulder values (SSV), and range of motion (ROM)) with a matched control group. The control group consisted of patients treated with a RTSA without DCR and matching was performed for age, sex, operating side, American Society of Anesthesiologists (ASA), body mass index (BMI), and indication. Surgical time and complication rate were recorded. Results: Thirty-nine patients with a mean follow-up of 63 months (SD 33) were enrolled in the study group. Mean age was 67 years (SD 7) with 44% male patients for both groups. The mean relative CS improved from 43% (SD 17) to 73% (SD 20) in the study group, and from 43% (18) to 73% (22) in the control group. The SSV improved from 29% (SD 17) to 63% (SD 29) in the study group, and from 28% (SD 16) to 69% (SD 26) in the control group (both n.s.). The postoperative ROM did not significantly differ between the two groups. Five patients in the study group and six in the control group had reoperations. Conclusion: Patients who received a DCR before RTSA showed equivalent clinical outcomes compared to a match-control group with RTSA only. Surgical time was not different, and no complication related to the open DCR was observed in the study group. Therefore, we conclude that a prior DCR does not influence the postoperative outcome after RTSA. Level of evidence: Level III: Retrospective comparative study. [ABSTRACT FROM AUTHOR]

We compared the 2-year clinical outcomes of both anatomic and reverse total shoulder arthroplasty (ATSA and RTSA) using intraoperative navigation compared to traditional positioning techniques. We also examined the effect of glenoid implant retroversion on clinical outcomes. In both ATSA and RTSA, computer navigation would be associated with equal or better outcomes with fewer complications. Final glenoid version and degree of correction would not show outcome differences. A total of 216 ATSAs and 533 RTSAs were performed using preoperative planning and intraoperative navigation with a minimum of 2-year follow-up. Matched cohorts (2:1) for age, gender, and follow-up for cases without intraoperative navigation were compared using all standard shoulder arthroplasty clinical outcome metrics. Two subanalyses were performed on navigated cases comparing glenoids positioned greater or less than 10° of retroversion and glenoids corrected more or less than 15°. For ASTA, no statistical differences were found between the navigated and non-navigated cohorts for postoperative complications, glenoid implant loosening, or revision rate. No significant differences were seen in any of the ATSA outcome metrics besides higher internal and external rotation in the navigated cohort. For RTSA, the navigated cohort showed an ARR of 1.7% (95% CI 0%, 3.4%) for postoperative complications and 0.7% (95% CI 0.1%, 1.2%) for dislocations. No difference was found in the revision rate, glenoid implant loosening, acromial stress fracture rates, or scapular notching. Navigated RTSA patients demonstrated significant improvements over non-navigated patients in internal rotation, external rotation, maximum lifting weight, the Simple Shoulder Test (SST), Constant, and Shoulder Arthroplasty Smart (SAS) scores. For the navigated subcohorts, ATSA cases with a higher degree of final retroversion showed significant improvement in pain, Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), SST, University of California–Los Angeles shoulder score (UCLA), and Shoulder Pain and Disability Index (SPADI) scores. No significant differences were found in the RTSA subcohort. Higher degrees of version correction showed improvement in external rotation, SST, and Constant scores for ATSA and forward elevation, internal rotation, pain, SST, Constant, ASES, UCLA, SPADI, and SAS scores for RTSA. The use of intraoperative navigation shoulder arthroplasty is safe, produces at least equally good outcomes at 2 years as standard instrumentation does without any increased risk of complications. The effect of final implant position above or below 10° of glenoid retroversion and correction more or less than 15° does not negatively impact outcomes. [ABSTRACT FROM AUTHOR]

There is a lack of gender-specific research after reverse total shoulder arthroplasty (RTSA). Although previous studies have documented worse outcomes in women, a more thorough understanding of why outcomes may differ is needed. We therefore asked: (1) Are there gender-specific differences in preoperative and postoperative clinical scores, complications, surgery-related parameters, and demographics? (2) Is female gender an independent risk factor for poorer clinical outcomes after RTSA? (3) If so, why is female gender associated with poorer outcomes after RTSA? Between 2005 and 2019, 987 primary RTSAs were performed in our institution. After exclusion criteria were applied, data of 422 female and 271 male patients were analyzed. Clinical outcomes (absolute/relative Constant Score [a/rCS] and Subjective Shoulder Value [SSV]), complications (intra- and/or postoperative fracture, loosening), surgery-related parameters (indication, implant-related characteristics), and demographics (age, gender, body mass index, and number of previous surgeries) were evaluated. Preoperative and postoperative radiographs were analyzed (critical shoulder angle, deltoid-tuberosity index, reverse shoulder angle, lateralization shoulder angle, and distalization shoulder angle). Preoperative clinical scores (aCS, rCS, SSV, and pain level) and postoperative clinical outcomes (aCS and rCS) were significantly worse in women. However, the improvement between preoperative and postoperative outcomes was significantly higher in female patients for rCS (P =.037), internal rotation (P <.001), and regarding pain (P <.001). Female patients had a significantly higher number of intraoperative and postoperative fractures (24.9% vs. 11.4%, P <.001). The proportion of female patients with a deltoid-tuberosity index <1.4 was significantly higher than males (P =.01). Female gender was an independent negative predictor for postoperative rCS (P =.047, coefficient −0.084) and pain (P =.017, coefficient −0.574). In addition to female sex per se being a predictive factor of worse outcomes, females were significantly more likely to meet 2 of the 3 most significant predictive factors: (1) significantly worse preoperative clinical scores and (2) higher rate of intra- and/or postoperative fractures. Female sex is a very weak, but isolated, negative predictive factor that negatively affects the objective clinical outcome (rCS) after RTSA. However, differences did not reach the minimal clinically important difference, and it is not a predictor for the subjective outcome (SSV). The main reason for the worse outcome in female patients seems to be a combination of higher preoperative disability and higher incidence of fractures. To improve the outcome of women, all measures that contribute to the reduction of perioperative fracture risk should be used. [ABSTRACT FROM AUTHOR]

Purpose: Functional internal rotation (IR) is a combination of extension and IR. It is clinically often limited after reverse total shoulder arthroplasty (RTSA) either due to loss of extension or IR in extension. It was the purpose of this study to determine the ideal in‐vitro combination of glenoid and humeral components to achieve impingement‐free functional IR. Methods: RTSA components were virtually implanted into a normal scapula (previously established with a statistical shape model) and into a corresponding humerus using a computer planning program (CASPA). Baseline glenoid configuration consisted of a 28 mm baseplate placed flush with the posteroinferior glenoid rim, a baseplate inclination angle of 96° (relative to the supraspinatus fossa) and a 36 mm standard glenosphere. Baseline humeral configuration consisted of a 12 mm humeral stem, a metaphysis with a neck shaft angle (NSA) of 155° (+ 6 mm medial offset), anatomic torsion of ‐20° and a symmetric PE inlay (36mmx0mm). Additional configurations with different humeral torsion (‐20°, + 10°), NSA (135°, 145°, 155°), baseplate position, diameter, lateralization and inclination were tested. Glenohumeral extension of 5, 10, 20, and 40° was performed first, followed by IR of 20, 40, and 60° with the arm in extension of 40°—the value previously identified as necessary for satisfactory clinical functional IR. The different component combinations were taken through simulated ROM and the impingement volume (mm3) was recorded. Furthermore, the occurrence of impingement was read out in 5° motion increments. Results: In all cases where impingement occurred, it occurred between the PE inlay and the posterior glenoid rim. Only in 11 of 36 combinations full functional IR was possible without impingement. Anterosuperior baseplate positioning showed the highest impingement volume with every combination of NSA and torsion. A posteroinferiorly positioned 26 mm baseplate resulting in an additional 2 mm of inferior overhang as well as 6 mm baseplate lateralization offered the best impingement‐free functional IR (5/6 combinations without impingement). Low impingement potential resulted from a combination of NSA 135° and + 10° torsion (4/6 combinations without impingement), followed by NSA 135° and ‐20° torsion (3/6 combinations without impingement) regardless of glenoid setup. Conclusion: The largest impingement‐free functional IRs resulted from combining a posteroinferior baseplate position, a greater inferior glenosphere overhang, 90° of baseplate inclination angle, 6 mm glenosphere lateralization with respect to baseline setup, a lower NSA and antetorsion of the humeral component. Surgeons can employ and combine these implant configurations to achieve and improve functional IR when planning and performing RTSA. Level of evidence: Basic Science Study, Biomechanics. [ABSTRACT FROM AUTHOR]

Patient satisfaction after reverse shoulder arthroplasty (RSA) partly relies on restoring functional internal rotation (IR). Although postoperative assessment of IR includes objective appraisal by the surgeon and subjective report from the patient, these evaluations may not vary together uniformly. We assessed the relationship between objective, surgeon-reported assessments of IR and subjective, patient-reported ability to perform IR-related activities of daily living (IRADLs). Our institutional shoulder arthroplasty database was queried for patients undergoing primary RSA with a medialized-glenoid lateralized-humerus design between 2007-2019 and minimum 2-year follow-up. Patients who were wheelchair bound or had a preoperative diagnosis of infection, fracture, and tumor were excluded. Objective IR was measured to the highest vertebral level reached with the thumb. Subjective IR was reported based on patients' rating (normal, slightly difficult, very difficult, or unable) of their ability to perform 4 IRADLs (tuck in shirt with hand behind back, wash back or fasten bra, personal hygiene, and remove object from back pocket). Objective IR was assessed preoperatively and at latest follow-up and reported as median and interquartile ranges. A total of 443 patients were included (52% female) at a mean follow-up of 4.4 ± 2.3 years. Objective IR improved pre- to postoperatively from L4-L5 (buttocks to L1-L3) to L1-L3 (L4-L5 to T8-T12) (P <.001). Preoperatively reported IRADLs of "very difficult" or "unable" significantly decreased postoperatively for all IRADLs (P ≤.004) except those unable to perform personal hygiene (3.2% vs. 1.8%, P >.99). The proportions of patients who improved, maintained, and lost objective and subjective IR was similar between IRADLs; 14%-20% improved objective IR but lost or maintained subjective IR and 19%-21% lost or maintained the same objective IR but improved subjective IR depending on the specific IRADL assessed. When ability to perform IRADLs improved postoperatively, objective IR also increased (P <.001). In contrast, when subjective IRADLs worsened postoperatively, objective IR did not significantly worsen for 2 of 4 IRADLs assessed. When examining patients who reported no change in ability to perform IRADLs pre- vs. postoperatively, statistically significant increases in objective IR were found for 3 of 4 IRADLs assessed. Objective improvement in IR parallels improvements in subjective functional gains uniformly. However, in patients with worse or equivalent IR, the ability to perform IRADLs postoperatively does not uniformly correlate with objective IR. When attempting to elucidate how surgeons can ensure patients will have sufficient IR after RSA, future investigations may need to use patient-reported ability to perform IRADLs as the primary outcome measure rather than objective measures of IR. [ABSTRACT FROM AUTHOR]

Background: Glenoid wear secondary to primary osteoarthritis or rotator cuff arthropathy is an obstacle commonly encountered by surgeons performing reverse shoulder arthroplasty, with numerous techniques devised to address this finding. The most recent of such techniques is the introduction of augmented glenoid baseplates to fill these glenoid defects. The objectives of this systematic review are to analyze clinical outcomes of augmented baseplates in patients with glenoid wear, including pain, range of motion, patient-reported functional scores, radiographic outcome measures, complication rates, and revision rates. Methods: Three online databases (Ovid Medline, EMBASE, Pubmed) were searched for studies publishing clinical and functional outcomes of augmented baseplates in primary reverse shoulder arthroplasty. Findings were aggregated and frequency-weighted means of these variables were calculated when applicable. Results: Seven studies comprising 810 patients were included in this review. The mean patient age was 72.1 ± 8.1 years with an average follow-up time of 41.4 months. Frequency-weighted means of improvement in forward elevation, abduction, and active external rotation were 53°, 47°, and 19°, respectively. Patients experienced American Shoulder and Elbow Surgeons, Simple Shoulder Test, and Constant score improvements of 45.9, 5.9, and 33.7, respectively. Pooled complicated rate was 6.4%, with 10 cases of baseplate loosening and 3 cases of instability. Five (0.6%) patients required reoperation. Subdividing among augment type (posterior, superior, posterosuperior), there were no apparent differences in outcomes or complication rates between directional augments. Conclusion: This systematic review demonstrates that augmented baseplates for reverse shoulder arthroplasty provide positive outcomes both clinically and functionally at early follow-up. Complications are within an acceptable range for primary reverse shoulder arthroplasty, with a low rate of revision. Augmented baseplates should serve as a viable option for surgeons seeking to address glenoid wear during reverse shoulder arthroplasty.

Background: To optimize patients' functional external rotation outcomes, reverse total shoulder arthroplasties (rTSAs) including a latissimus dorsi tendon transfer were undertaken with promising early results and no significant increase in complications in comparison to traditional rTSAs. This was especially utilized for patients with a pronounced combined loss of elevation and external rotation. The purpose of this study is to evaluate and synthesize the findings of all relevant publications assessing the outcomes of rTSAs with associated latissimus dorsi transfer. Methods: We thoroughly searched the literature within the PubMed database using a standardized methodology. For our inclusion criteria, we included any study regarding rTSAs that contained functional outcome scores for postoperative range of motion (such as elevation, external rotation, etc.) or postoperative outcomes such as complications (reoperation, infection, etc.) and patient satisfaction. For the extraction of data, we used pilot-tested Google Forms to record extracted data. These data were then converted to spreadsheets (Microsoft Excel [Microsoft, Redmond, WA, USA]). This was done on 2 separate scenarios by 2 authors to ensure accuracy. We used the modified Coleman Methodology Score to assess the methodological quality of the studies in our samples. Meta-analysis mathematics and statistical analysis were performed using Stata software 17 (StataCorp, College Station, TX, USA). Results: Our search returned a total of 12 studies containing data of 213 shoulders receiving RTSAs with a latissimus dorsi transfer. Functional outcomes were available for 160 shoulders. The mean preoperative elevation of the affected shoulder was 73.57 degrees, and the mean postoperative elevation was 141.80 degrees. For external rotation, the mean preoperative average was −6.71 degrees, and the mean postoperative average was 22.73 degrees. The absolute Constant score average was 31.56 preoperatively, while the postoperative value was 68.93. In our sample, 25 patients (11.73%) required a revision of the RTSA implant due to complications. Discussion: Combined loss of elevation and external rotation can be a severely debilitating condition for those with a glenohumeral pathology. Latissimus dorsi transfer for this condition has been proven to be an effective modality. The reoperation and complication rate appears to be sizable, and as such surgeons should consider this when considering this modality for their patients.

Hypothesis/Background: There is no consensus on whether to repair the subscapularis in the setting of reverse total shoulder arthroplasty (rTSA). There have been an assortment of studies showing mixed results regarding shoulder stability and postoperative strength outcomes when looking at subscapularis repair in rTSA. The purpose of this systematic review was to investigate differences in biomechanical strength outcomes of cadaveric subscapularis repair vs. no repair in rTSA.Increased force will be required to move the shoulder through normal range of motion (ROM) in cadaveric rTSA shoulders with the subscapularis repaired when compared with no subscapularis repair. Methods: A comprehensive literature review was conducted in accordance with the 2009 Preferred Reporting Items for Systematic Review and Meta-Analysis statement. The databases used to search the keywords used for the concepts of subscapularis, reverse total shoulder arthroplasty, and muscle strength were PubMed (includes MEDLINE), Embase, Web of Science, Cochrane Reviews and Trials, and Scopus. Original, English-language cadaveric studies evaluating rTSA and subscapularis management were included, with subscapularis repair surgical techniques and strength outcomes being evaluated for each article meeting inclusion criteria. Results: The search yielded 4113 articles that were screened for inclusion criteria by 4 authors. Two articles met inclusion criteria and were subsequently included in the final full-text review. A total of 11 shoulders were represented between these 2 studies. Heterogeneity of the data across the 2 studies did not allow for meta-analysis. Hansen et al found that repair of the subscapularis with rTSA significantly increased the mean joint reaction force and the force required by the posterior deltoid, total deltoid, infraspinatus, teres minor, total posterior rotator cuff, and pectoralis major muscles. Giles et al found that rotator cuff repair and glenosphere lateralization both increased total joint load. Conclusion: The present review of biomechanical literature shows that repair of the subscapularis in the setting of rTSA can effectively restore shoulder strength by increasing joint reactive forces and ROM force requirements of other rotator cuff muscles and of the deltoid muscle. Available biomechanical evidence is limited, and further biomechanical studies evaluating the strength of various subscapularis repair techniques are needed to evaluate the effects of these techniques on joint reactive forces and muscle forces required for ROM.

Lateralization in reverse total shoulder arthroplasty (RTSA) has been used to theoretically offer the potential benefits of reduced scapular notching rates and improved stability and range of motion (ROM), particularly external rotation. The aim of this study was to compare ROM and clinical and radiographic outcomes between patients who underwent RTSA with a lateralized vs. a nonlateralized and distalized glenosphere. A single-surgeon randomized control trial was conducted comparing 27 patients with a lateralized glenosphere and 26 patients with a nonlateralized and distalized glenosphere. A total of 66 patients were enrolled, 2 patients died before 2-year follow-up, 4 patients withdrew from the study, and 7 patients were lost to follow-up. All patients in the lateralized group received 6 mm of lateralization through the glenosphere. Participants represented a population presenting to an orthopedics sports medicine clinic with any indication for RTSA including revision arthroplasty. Patients completed preoperative and routine postoperative functional outcome measures 3, 6, 12, and a minimum of 24 months postoperatively, including American Shoulder and Elbow Surgeons, Patient-Reported Outcomes Measurement Information System Physical Function Upper Extremity, and Activities of Daily Living Requiring Active External and Internal Rotation assessments. Patients were also evaluated with ROM and radiographic measurements. The primary outcome of interest in this study was ROM, particularly external rotation. At 2-year follow-up, both groups had significant improvement in their American Shoulder and Elbow Surgeons, Patient-Reported Outcomes Measurement Information System Physical Function Upper Extremity, and Activities of Daily Living Requiring Active External and Internal Rotation scores with no significant difference observed between the groups. There were no statistically significant differences in incidence of scapular notching or acromial stress fractures. ROM in both groups improved significantly at their 2-year assessment with the only exception to this being external rotation at 90° of abduction in the nonlateralized and distalized group (39° ± 31° vs. 48° ± 24°, P =.379). Regardless of glenosphere lateralization status, patients in both groups had significant improvement in functional outcome scores and ROM, and there were no significant differences observed between the groups at 2-year follow-up. Longer follow-up is needed to determine the effect of implant design on late complications, long-term outcomes, and implant retention. [ABSTRACT FROM AUTHOR]

Reverse total shoulder arthroplasty (RTSA) alters the line of action of muscles around the glenohumeral joint. The effects of these changes have been well characterized for the deltoid, but there is limited information regarding the biomechanical changes to the coracobrachialis (CBR) and short head of biceps (SHB). In this biomechanical study, we investigated the changes to the moment arms of the CBR and SHB due to RTSA using a computational model of the shoulder. The Newcastle Shoulder Model, a pre-validated upper-extremity musculoskeletal model, was used for this study. The Newcastle Shoulder Model was modified with bone geometries obtained from 3-dimensional reconstructions of 15 nondiseased shoulders, constituting the native shoulder group. The Delta XTEND prosthesis, with a glenosphere diameter of 38 mm and polyethylene thickness of 6 mm, was virtually implanted in all the models, creating the RTSA group. Moment arms were measured using the tendon excursion method, and muscle length was calculated as the distance between the muscle's origin and insertion points. These values were measured during 0°-150° of abduction, forward flexion, scapular-plane elevation, and –90° to 60° of external rotation–internal rotation with the arm at 20° and 90° of abduction. Statistical comparisons between the native and RTSA groups were analyzed using 1-dimensional statistical parametric mapping (spm1D). Forward flexion moment arms showed the greatest increase between the RTSA group (CBR, 25.3 ± 4.7 mm; SHB, 24.7 ± 4.5 mm) and native group (CBR, 9.6 ± 5.2 mm; SHB, 10.2 ± 5.2 mm). The CBR and SHB were longer in the RTSA group by maximum values of 15% and 7%, respectively. Both muscles had larger abduction moment arms in the RTSA group (CBR, 20.9 ± 4.3 mm; SHB, 21.9 ± 4.3 mm) compared with the native group (CBR, 19.6 ± 6.6 mm; SHB, 20.0 ± 5.7 mm). Abduction moment arms occurred at lower abduction angles in the RTSA group (CBR, 50°; SHB, 45°) than in the native group (CBR, 90°; SHB, 85°). In the RTSA group, both muscles had elevation moment arms until 25° of scapular-plane elevation motion, whereas in the native group, the muscles only had depression moment arms. Both muscles had small rotational moment arms that were significantly different between RTSA and native shoulders during different ranges of motion. Significant increases in elevation moment arms for the CBR and SHB were observed in RTSA shoulders; these increases were most pronounced during abduction and forward elevation motions. RTSA also increased the lengths of these muscles. [ABSTRACT FROM AUTHOR]

The expansion of indications for reverse total shoulder arthroplasty (RTSA) has resulted in a rapid increase in the incidence of subsequent revision procedures. The purpose of this study was to identify the incidence and risk factors for re-revision shoulder arthroplasty after first revision RTSA. We retrospectively queried our institutional shoulder arthroplasty database of prospectively collected data from 2003 to 2019. To assess revision implant survival, patients were censored on the date of re-revision surgery or, if the revision arthroplasty was not revised, at the most recent follow-up or their date of death. Patients with a prior infection, concern for infection at the time of revision, antibiotic spacer, or oncologic indication for primary arthroplasty were excluded. A total of 186 revision RTSAs were included, with 32 undergoing re-revision shoulder arthroplasty. The Kaplan–Meier method and bivariate Cox regression were used to assess the relationship of patient and surgical characteristics on implant survivorship. Multivariate Cox regression was performed to identify independent predictors of re-revision. Re-revision shoulder arthroplasty was most commonly performed for instability (34%), infection (28%), and glenoid loosening (19%). Overall re-revision rates at 6 months (7%), 1 year (9%), and 2 years (13%) were relatively low; however, the rate of re-revision increased at 5 years (35%). Men underwent re-revision more often than women within the first 6 months after revision RTSA (12% vs. 2%; P =.025), but not thereafter. On multivariate analysis, increased estimated blood loss was associated with a greater risk of undergoing re-revision shoulder arthroplasty (hazard ratio: 41.16 [3.34-506.50]; P =.004). The rate of re-revision after revision RTSA is low in the first 2 years postoperatively (13%) but increases to 35% at 5 years. Increased estimated blood loss, which may reflect greater operative complexity, was identified as a risk factor that may confer an increased chance of re-revision after revision RTSA. Knowledge of risk factors for re-revision after revision RTSA can aid surgeons and patients in preoperative counseling. [ABSTRACT FROM AUTHOR]

Outpatient shoulder arthroplasty is advantageous in appropriately selected patients, and tools for performing selection are available. Whether vulnerable populations benefit from outpatient surgery despite being appropriate candidates clinically is unclear. We hypothesized that patient travel distance and resource level impact the ability to complete accelerated care pathways. A retrospective cohort of patients undergoing anatomic/reverse total shoulder arthroplasty at 2 geographically diverse, high-volume tertiary referral centers was created; 5406 cases were stratified into cohorts based on travel distance (0-49, 50-99, 100-150, and >150 miles). Sociodemographic, median income, and comorbidity data were collected. Short inpatient stay was utilized as a proxy for appropriateness for same-day discharge. Overall length of stay (LOS) and unplanned 90-day readmissions were collected as secondary outcomes. Four thousand one hundred one patients traveled 0-49 miles, 695 traveled 50-99 miles, 313 traveled 100-149 miles, and 297 traveled >150 miles for shoulder arthroplasty. Few significant differences in sociodemographic/comorbidity burdens were observed between distance cohorts. Increased distance outside of the immediate area (>50 miles) was significantly associated with decreased likelihood of short inpatient stay (P <.001) and increased LOS (P =.027) for Institution #1. For Institution #2, those in the shortest and longest distance groups had the shortest LOS (P =.018). Overall, patients living <50 miles had the highest income levels. A bi-modal income distribution was observed for Institution #1, while income decreased as distance increased for Institution #2. Unplanned 90-day readmission rates were not significantly different for either institution. Overall, when examining demographic variables for the entire cohort representing both institutions, patient travel distance to a high-volume tertiary orthopedic center did not appear to be the primary driver for variability in early postoperative outcomes (ie, 90-day readmissions, short stay, LOS). For Institution 1, patients living further from surgery centers underwent short inpatient stay at lower rates relative to those nearby. Importantly, lower resource levels were seen as distance increased for both institutions, potentially limiting the ability to manage same-day discharge without additional assistance despite being clinically appropriate candidates for outpatient arthroplasty. Therefore, providing overnight lodging options and perioperative support for vulnerable populations may minimize disparities in access, while serving as a lower-cost-option. [ABSTRACT FROM AUTHOR]

Indications for reverse total shoulder arthroplasty (RSA) have expanded to include individuals with intact rotator cuffs such as patients with severe glenoid deformity or with concern of future rotator cuff insufficiency. The purpose of this study was to compare outcomes of RSA with an intact rotator cuff to RSA for cuff arthropathy and anatomic total shoulder arthroplasty (TSA). We hypothesized that outcomes of RSA with an intact rotator cuff would be comparable to RSA for cuff arthropathy and TSA but with diminished range of motion (ROM) compared with TSA. Patients at one institution who underwent RSA and TSA between 2015 and 2020 with minimum 12-month follow-up were identified. RSA with preservation of the rotator cuff (+rcRSA) was compared to RSA for cuff arthropathy (–rcRSA) and anatomic TSA (TSA). Demographics and glenoid version/inclination were obtained. Pre- and postoperative ROM; patient-reported outcomes including visual analog scale (VAS), Subjective Shoulder Value (SSV), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores; and complications were obtained. Twenty-four patients underwent +rcRSA, 69 underwent –rcRSA, and 93 underwent TSA. There were more women in the +rcRSA cohort (75.8%) than in the –rcRSA (37.7%, P =.001) and TSA (37.6%, P =.001) cohorts. Mean age of the +rcRSA cohort (71.1) was greater than that of TSA (66.0, P =.021) but similar to that of –rcRSA (72.4, P =.237). Glenoid retroversion was greater in +rcRSA (18.2°) compared with –rcRSA (10.5°, P =.011) but was similar to TSA (14.7°; P =.244). Postoperatively, there were no differences in VAS or ASES between +rcRSA vs. –rcRSA and +rcRSA vs. TSA. SSV was lower in +rcRSA (83.9) compared with –rcRSA (91.8, P =.021), but was similar to TSA (90.5, P =.073). Similar ROM was achieved in forward flexion, external rotation, and internal rotation at final follow-up between +rcRSA and –rcRSA, but TSA had greater external rotation (44° vs. 38°, P =.041) and internal rotation (6.5° vs. 5.0°, P =.001) compared with +rcRSA. There were no differences in complication rates. At short-term follow-up, preservation of the rotator cuff in RSA demonstrated similarly excellent outcomes and low complication rates compared with RSA with a deficient rotator cuff and TSA, except for slightly lower internal and external rotation compared with TSA. Although multiple factors deserve consideration when choosing between RSA and TSA, RSA with preservation of the posterosuperior cuff is a viable treatment option for glenohumeral osteoarthritis, particularly in patients with severe glenoid deformity or those at risk for future rotator cuff insufficiency. [ABSTRACT FROM AUTHOR]

Purpose: There is a common belief among some shoulder surgeons that the increased utilization of reverse shoulder arthroplasty (RSA) is driven by the operation being performed in younger patients. The primary purpose of this study was to evaluate the change in patient age at the time of primary RSA in the USA. Methods: All patients undergoing primary RSA (January 2011–June 2018) were identified in the Mariner database. The mean age at the time of primary RSA was evaluated for each patient and assessed in 6-month intervals. A longitudinal comparison over time was performed for all patients. Results: A total of 56,141 primary RSA were evaluated, with the mean age increasing from 69 in the 2011 to 71 in 2018 (p < 0.001). The largest increase in RSA utilization occurred in patients > 70 (1092 in 2011 to 3499 in 2018), with patients < 50 years demonstrating the slowest growth (13 in 2011 to 65 in 2018). However, when evaluated by percentage increase from 2011 to 2018, RSA volumes for patients < 60 have increased 390% compared to 220% for those > 70 years (p < 0.001). Conclusion: RSA continues to be performed at a similar mean age despite expanded indications and surgeon comfort. However, patients < 60 years have had a greater increase in utilization compared to patients > 70 years. The volumetric growth of RSA has largely been driven by the older population, but younger patients have shown a higher percentage of growth, which may explain the generalized observation that RSA is performed in younger patients. Level of Evidence: Level III; Retrospective comparative study; Treatment study. [ABSTRACT FROM AUTHOR]

Background: With the increase in utility and popularity of the reverse total shoulder arthroplasty (RTSA) within the last decades, indications for RTSA have expanded. As well as the established indications such as cuff tear arthropathy and massive irreparable rotator cuff tears, RTSA for complex proximal humeral fractures in elderly patients has been proven to be a reliable treatment option. Methods: A prospectively enrolled RTSA database of 1457 RTSAs implanted between September 2005 and November 2020 was reviewed. Patients treated with RTSA for a complex proximal humerus fracture and fracture sequalae (F-RTSA) were 1:1 matched with a group of patients who were treated electively with RTSA for indications other than a fracture (E-RTSA). Matching criteria included sex, age, length of follow-up and body mass index. Evaluation after a minimum of 2 years follow-up included evaluation of the absolute and relative Constant–Murley score (aCS; rCS), subjective shoulder value (SSV), range of motion (ROM) assessment and complications. Results: Each of the matched cohorts comprised 134 patients with a mean follow-up of 58 ± 41 months for the fracture group and 58 ± 36 months for the elective group. The mean age for both groups was 69 ± 11 years in the F-RTSA and 70 ± 9 years for the E-RTSA group. There were no significant differences in clinical outcome measures including aCS, rCS and SSV (p > 0.05). There was a significant difference in mean active external rotation with 20° ± 18° in the F-RTSA group compared with 25° ± 19° in the E-RTSA group (p = 0.017). The complication rate was not significantly different, with 41 complications in 36 shoulders in the F-RTSA and 40 complications in 32 shoulders in the E-RTSA group (p = 0.73). The main complication for the F-RTSA group was dislocation of the greater tuberosity (6%), whereas acromial fractures (9%) were the leading complication in the E-RTSA group. There was also no significant difference in revision rate comparing F-RTSA with E-RTSA (10% vs. 14%; p = 0.25). Conclusions: RTSA for complex proximal humeral fractures and its sequalae leads to a comparable clinical outcome as that for patients treated electively with RTSA for indications other than fracture. There was, however, a significant difference in active external rotation, with inferior rotation in patients undergoing RTSA for fracture. This valuable information can help in requesting informed consent of patients with proximal humeral fractures. [ABSTRACT FROM AUTHOR]

Background and hypothesis: The impact of preoperative fatty infiltration of specific rotator cuff muscles on the outcomes of reverse total shoulder arthroplasty (rTSA) has not been well defined. Preoperative fatty infiltration of the shoulder musculature will negatively affect rTSA outcomes. Methods: A comprehensive literature review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses using PubMed, Embase, OVID Medline, Scopus, Cinahl, Web of Science, and Cochrane databases for original, English-language studies evaluating effect of fatty infiltration of shoulder musculature on rTSA outcomes published from January 1, 2000 to present. Blinded reviewers conducted multiple screens. All included studies were graded based on the level of evidence, and data concerning patient demographics and postoperative outcomes were extracted. Results: A total of 11 articles were included, including one level I article, three level III articles, and seven level IV articles. The review consisted of 720 patients and 731 shoulders (320 women and 157 men), with a mean age of 72.4 years. A single deltopectoral approach was performed for a majority of studies (627/731 shoulders), followed by a superolateral approach (70/731 shoulders) and a single transdeltoid approach (4/731 patients). Eleven studies reported data specifically about preoperative fatty infiltration of the rotator cuff musculature; the teres minor was studied most widely (298/731 shoulders), followed by the subscapularis (256/731 shoulders) and infraspinatus (232/731 shoulders). The Constant score (562/731 shoulders) and American Shoulder and Elbow Surgeons score (284/731 shoulders) were the most common recorded outcome scores. Fatty infiltration of the teres minor, supraspinatus, and infraspinatus was associated with worse range of motion after rTSA. Conclusion: Preoperative fatty infiltration of the rotator cuff, particularly of the teres minor and infraspinatus, has a negative impact on subjective patient outcomes and restoration of range of motion, especially external rotation, after rTSA. The impact of fatty infiltration of the other rotator cuff muscles remains unclear, which may be due to intersurgeon differences in the handling of the remaining rotator cuff muscles or differences in implant design. The evaluated literature provides information on which patients can be educated about probable outcomes and restoration of function after rTSA.

Hypothesis and Background: There is no differences in abduction, internal rotation, or external rotation strength after reverse total shoulder arthroplasty (rTSA) with or without subscapularis repair. Repair of the subscapularis can be effective in the setting of rTSA. However, consensus has yet to be reached on whether postoperative strength after rTSA differs based on subscapularis management. The purpose of this review is to evaluate shoulder strength outcomes after rTSA with and without subscapularis tendon repair. Methods: A comprehensive literature review was conducted using the key terms “subscapularis” AND “reverse total shoulder arthroplasty” AND “muscle strength” in PubMed, Embase, Web of Science, Cochrane Reviews and Trials, and Scopus. Original, English-language studies evaluating shoulder strength outcomes after rTSA published from January 1, 2000, to present were evaluated. Strength outcomes reported included abduction strength (kg) and internal rotation strength (kg) using an electric spring balance and external rotation strength (lb) using a handheld dynamometer. Heterogeneity of data in the included studies did not allow for meta-analysis. Resuts: The search yielded 4253 unique results, which were screened for inclusion according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two articles met eligibility criteria and were included in the final full-text review. A total of 267 shoulders were represented, 111 with subscapularis repair and 156 without subscapularis repair. No significant differences in abduction (P = .39), internal rotation (P = .09), and external rotation (P = .463) strength were observed between subscapularis repair and nonrepair groups. Conclusion: There were no differences in abduction, internal rotation, or external rotation strength after rTSA with or without subscapularis repair. The literature on postoperative strength outcomes after rTSA is limited, and further study in this area is warranted.

Introduction: Indications for reverse shoulder arthroplasties (rTSA) have increased since their development by Paul Grammont in 1985. Prosthesis design was enhanced over time, but the management of the tendon of the M. subscapularis (SSC-tendon) in primary rTSA is still a controversial subject with regard to perform a refixation or not. Methods: 50 patients were randomized in a refixation group (A) and a non-refixation-group (B) of the SSC-tendon in a double-blinded fashion. SSC-function was assessed at baseline before surgery, such as 3 and 12 months after surgery. Constant–Murley-Shoulder Score (CS), American Shoulder and Elbow Surgeons Score (ASES), strength, range of motion (ROM), and pain on numeric rating scale (NRS) were measured in all examinations. An ultrasound examination of the shoulder was performed for evaluation of subscapularis tendon integrity at 3 and 12 month follow-up visits. Pain was evaluated on NRS via phone 5 days after surgery. Surgery was performed by a single experienced senior surgeon in all patients. Results: Patients with a refixation of the SSC-tendon and primary rTSA had improved internal rotation [40° (20°–60°) vs. 32° (20°–45°); p = 0.03] at 12 months of follow-up. Additionally, the A-group had increased CS [74 (13–90) vs. 69.5 (40–79); p = 0.029] 1 year after surgery. Results were strengthened by subgroup analysis of successful refixation in ultrasound examination vs. no refixation. No differences were seen in ASES and NRS 1 year after rTSA. Conclusion: SSC-tendon repair in rTSA improves CS and internal rotation 12 months after surgery. [ABSTRACT FROM AUTHOR]

Since the introduction of the Grammont-style reverse total shoulder arthroplasty, the humeral stem design has been modified with improved clinical outcomes. Two distinct humeral designs have been used extensively: the inlay design, in which the humeral tray is seated within the metaphysis, and the onlay design, in which the humeral tray sits on the metaphysis at the level of the humeral neck cut. The purpose of this systematic review was to determine whether there are differences in clinical outcomes and complication rates between these designs. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used to perform this systematic review. A search of MEDLINE, PubMed, and Embase was performed to identify all studies comparing the clinical results of both humeral designs. Primary outcomes included patient-reported outcome measures, shoulder range of motion, and incidence of complications. From the 156 identified publications, 12 studies were included in the final review. A total of 1447 patients were included, with a minimum follow-up period of 12 months. At final follow-up, both implants demonstrated significant improvements in comparison to preoperative baseline. On comparison of the inlay vs. onlay groups, the American Shoulder and Elbow Surgeons score was higher in the inlay group (mean difference, 2.53 [95% confidence interval, 0.27-4.78]; P =.03). Postoperative motion, even if statistically greater in the onlay group (differences of 5° in forward flexion [ P <.001], 3° in abduction [ P =.003], and 4° in external rotation [ P <.001]), was not clinically different. On comparison of complications, the inlay group showed more instances of scapular notching (93 of 322 patients vs. 70 of 415 patients; odds ratio, 0.35; P <.001) but fewer scapular spine fractures (26 of 727 patients vs. 21 of 559 patients, P =.09). Inlay and onlay humeral tray designs in reverse total shoulder arthroplasty demonstrate similar clinical improvements postoperatively. Onlay implants have a low rate of scapular notching but a higher rate of scapular spine fracture. Understanding the strengths and weaknesses of the 2 humeral tray designs is important to provide surgeons with options to tailor surgical plans for high-risk patients. [ABSTRACT FROM AUTHOR]

Background: Proximal humerus fractures (PHF) are common with approximately 30% requiring surgical intervention. This ranges from open reduction internal fixation (ORIF) to shoulder arthroplasty (including hemiarthroplasty, total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA)). The aim of this study was to assess trends in operative interventions for PHF in an Australian population., Methods: Data was retrospectively collected for private patients with a PHF and requiring surgical intervention (2001-2020). Data for patients undergoing ORIF were extracted from the Medicare database, while those receiving arthroplasty for PHF were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)., Results: Across the study period, ORIF was the most common surgical procedure for management of PHFs. While the number of RTSA procedures for PHF has increased, shoulder hemiarthroplasty has significantly reduced since 2008 (p < 0.001). Patients aged < 65 years were more likely to receive ORIF. Patients aged ≥ 65 years were more likely to receive RTSA or hemiarthroplasty compared to patients aged < 65 years., Conclusions: While the number of ORIF procedures has increased during the period of interest, it has diminished slightly as a proportion of overall procedure volume. RTSA is becoming increasingly popular, with decreasing utilization of hemiarthroplasty, and TSA for fracture remaining uncommon., Level of Evidence: Level III., Competing Interests: Declarations. Conflict of interests: The authors declare that they have no conflict of interests. Ethical approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent: Informed consent was obtained from all individual participants included in the study., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Since the introduction of stemless anatomic shoulder arthroplasty, many studies have been published on anatomic implants. For reverse stemless implants, however, there are only a few clinical follow-up studies available. The current clinical case series aims to present clinical and radiological outcomes of a new stemless reverse prosthesis system (Lima Shoulder Modular Replacement stemless). Methods: We prospectively evaluated the outcome of 56 stemless total shoulder arthroplasties in 56 patients with a mean age of 61.2 years (46-76 years) at the time of implantation at a minimum follow-up of 24 months (range 24-41 months). All patients were physically and radiologically examined. Clinical outcomes were evaluated by using the Constant-Murley Score and the Subjective Shoulder Value. Results: The mean Subjective Shoulder Value was 84.27% at the latest follow-up. Significant improvements from preoperative to latest follow-up were documented for Constant-Murley Score (34.9 pts to 74.43 pts, P

Abstract Purpose Functional internal rotation (IR) is a combination of extension and IR. It is clinically often limited after reverse total shoulder arthroplasty (RTSA) either due to loss of extension or IR in extension. It was the purpose of this study to determine the ideal in‐vitro combination of glenoid and humeral components to achieve impingement‐free functional IR. Methods RTSA components were virtually implanted into a normal scapula (previously established with a statistical shape model) and into a corresponding humerus using a computer planning program (CASPA). Baseline glenoid configuration consisted of a 28 mm baseplate placed flush with the posteroinferior glenoid rim, a baseplate inclination angle of 96° (relative to the supraspinatus fossa) and a 36 mm standard glenosphere. Baseline humeral configuration consisted of a 12 mm humeral stem, a metaphysis with a neck shaft angle (NSA) of 155° (+ 6 mm medial offset), anatomic torsion of ‐20° and a symmetric PE inlay (36mmx0mm). Additional configurations with different humeral torsion (‐20°, + 10°), NSA (135°, 145°, 155°), baseplate position, diameter, lateralization and inclination were tested. Glenohumeral extension of 5, 10, 20, and 40° was performed first, followed by IR of 20, 40, and 60° with the arm in extension of 40°—the value previously identified as necessary for satisfactory clinical functional IR. The different component combinations were taken through simulated ROM and the impingement volume (mm3) was recorded. Furthermore, the occurrence of impingement was read out in 5° motion increments. Results In all cases where impingement occurred, it occurred between the PE inlay and the posterior glenoid rim. Only in 11 of 36 combinations full functional IR was possible without impingement. Anterosuperior baseplate positioning showed the highest impingement volume with every combination of NSA and torsion. A posteroinferiorly positioned 26 mm baseplate resulting in an additional 2 mm of inferior overhang as well as 6 mm baseplate lateralization offered the best impingement‐free functional IR (5/6 combinations without impingement). Low impingement potential resulted from a combination of NSA 135° and + 10° torsion (4/6 combinations without impingement), followed by NSA 135° and ‐20° torsion (3/6 combinations without impingement) regardless of glenoid setup. Conclusion The largest impingement‐free functional IRs resulted from combining a posteroinferior baseplate position, a greater inferior glenosphere overhang, 90° of baseplate inclination angle, 6 mm glenosphere lateralization with respect to baseline setup, a lower NSA and antetorsion of the humeral component. Surgeons can employ and combine these implant configurations to achieve and improve functional IR when planning and performing RTSA. Level of evidence Basic Science Study, Biomechanics.

To evaluate the cost-effectiveness of surgical treatment with reverse total shoulder arthroplasty (RTSA) compared with open reduction and internal fixation (ORIF) with a locking plate for patients 65-85 years old with a displaced proximal humerus fracture. A cost-utility analysis was conducted alongside a multicenter randomized controlled trial, taking a health care perspective. A total of 124 patients with displaced proximal humerus fractures were randomized to treatment with RTSA (n = 64) or ORIF (n = 60) during a 2-year period. The outcome measure was quality-adjusted life years derived from the generic questionnaire 15D in an intention to treat population. The results were expressed as incremental cost-effectiveness ratios, and a probabilistic sensitivity analysis was performed to account for uncertainty in the analysis. At 2 years, 104 patients were eligible for analyses. The mean quality-adjusted life year was 1.24 (95% confidence interval: 1.21-1.28) in the RTSA group and 1.26 (95% confidence interval: 1.22-1.30) in the ORIF group. The mean cost in the RTSA group (€36.755 [€17,654-€55,855]) was higher than that in the ORIF group (€31.953 [€16,226-€47,279]). Using incremental cost-effectiveness ratio, ORIF was the dominant treatment. When using a probabilistic sensitivity analysis with 1000 replications, the plots were centered around origo. This indicates that there is no significant difference in cost or effect. In the cost-utility analysis of treatment of displaced proximal humeral fractures, there were no differences between RTSA and ORIF. [ABSTRACT FROM AUTHOR]

Peripheral nerve injuries associated with reverse total shoulder arthroplasty (rTSA) are rarely reported and are often dismissed as neuropraxias, particularly in the setting of perioperative nerve blocks. The purpose of this study was to evaluate nerve injuries following rTSA to determine if there is a pattern of injury and to evaluate outcomes of patients who sustain an intraoperative nerve injury. A retrospective review was performed identifying patients who underwent rTSA and had a concomitant major nerve injury who were referred to a multidisciplinary peripheral nerve injury clinic. Demographic data, preoperative nerve block use, physical examination, electrodiagnostic studies, injury pattern, and time from injury to referral was collected. Radiographs, Quick Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) score, and outcomes surveys were obtained at final follow-up. Twenty-two patients were identified with postoperative nerve injuries. Average time from injury to referral was 9.0 months, with 18.8 months' follow-up. Eight patients had undergone prior shoulder surgery, and 11 patients had prior shoulder trauma. Injury patterns were variable and involved diffuse pan-plexopathies with severity localized to the posterior and medial cords (11), the upper trunk (5), lateral cord (2), and axillary nerve (4). The average postoperative acromiohumeral distance (AHD) was 3.7 cm, with an average change of 2.9 cm. The average postoperative lateral humeral offset (LHO) was 1.1 cm, with an average change of 0.2 cm. Seventeen patients were confirmed to have undergone preoperative nerve blocks, which were initially attributed as the etiology of nerve injury. Eighteen patients were initially treated with observation: 11 experienced residual debilitating neuropathic pain and/or disability, and 7 had substantial improvement. One patient underwent nerve transfers, whereas the others underwent procedures for hand dysfunction improvement. The average QuickDASH score was 53.5 at average of 4 years post rTSA. Although uncommon, permanent peripheral nerve injuries following rTSA do occur with debilitating effects. Preoperative regional blocks were used in most cases, but none of the blocks could be directly attributed to the nerve injuries. Nerve injuries were likely secondary to traction at the time of arthroplasty and/or substantial distalization and lateralization of the implants. Patients with medial cord injuries had the most debilitating loss of hand function. Surgeons should be cognizant of these injuries and make a timely referral to a peripheral nerve specialist. [ABSTRACT FROM AUTHOR]

Background: Functional internal rotation (fIR) of the shoulder is frequently limited after reverse shoulder arthroplasty (RTSA). The objective of this study was to study a cohort of satisfied patients after RTSA who had comparable active mobility except for fIR and to identify factors associated with selective loss of fIR. Methods: A retrospective cohort study was conducted to compare 2 patient groups with either poor (≤ 2 points in the Constant-Murley score [CS]) or excellent (≥8 points in CS) fIR after RTSA at a minimum follow-up of 2 years. Influencing factors (demographic, surgical or implant related, radiographic parameters) and clinical outcome were analyzed. Results: Fifty-two patients with a mean age of 72.8 (±9.3) and a mean follow-up of 41 months were included in the IR≤2 group and 63 patients with a mean age of 72.1 (±8.0) and a mean follow-up of 59 months in the IR≥8 group. All patients had undergone RTSA with the same implant type and only 2 different glenosphere sizes (36 and 40) for comparable indications. A multivariate analysis identified the following significant risk factors for poor postoperative fIR: poor preoperative fIR (pts in CS: 3 [range: 2-6] vs. 6 [range: 4-8], P

Objectives: Low health literacy is both pervasive in the United States and a substantial barrier to satisfactory patient care and the appropriate utilization of healthcare resources. This prospective study aims to evaluate the factors that contribute to limited musculoskeletal literacy in patients who undergo shoulder arthroplasty. Methods: Ninety patients undergoing shoulder replacement surgery completed demographics and Literacy in Musculoskeletal Problems (LiMP) surveys. Scores of less than six were considered indicative of limited musculoskeletal literacy. Results: The overall percentage of participants with limited musculoskeletal literacy was 38.8%. Multivariable logistic regression analysis with multiple imputation modeling demonstrated a significant positive relationship between patient income and adequate LiMP scores (p = 0.009) with an odds ratio of 1.15 (CI: 1.04; 1.28) while level of education (p = 0.173) and patient ethnicity (p = 0.830) among other patient characteristics did not have a significant relationship with LiMP scores. Conclusion: In patients undergoing shoulder replacement surgery, low income was the only variable found to be predictive of limited musculoskeletal health literacy scores. Therefore, when discussing the risks and benefits of shoulder arthroplasty, orthopaedic surgeons should be cognizant of the possibility that any given patient may not meet the threshold of adequate musculoskeletal literacy. [ABSTRACT FROM AUTHOR]

Shoulder function in wheelchair-dependent patients is critical for preserving independence and quality of life due to lower extremity impairment. The purpose of this study was to report the revision rate, as well as clinical and radiological outcome in wheelchair-dependent patients treated with reverse total shoulder arthroplasty (RTSA) and to compare them to an ambulating population. Prospectively obtained data of 21 primary RTSAs in 17 wheelchair-dependent patients (5 male, 12 female) with a median age of 72.4 years (range: 49-80) and a minimum follow-up of 2 years were analyzed retrospectively. Revision rate, clinical (Subjective Shoulder Value = SSV, relative Constant-Murley Score = rCS, wheelchair user's shoulder pain index = WUSPI) and radiological (glenoid loosening, scapular notching, glenoid inclination) outcome, as well as implant-related parameters (baseplate peg length, glenosphere size, bony augmentation), were compared with a 2:1 matching cohort of 42 ambulating patients (10 male, 32 female) with a median age of 72.5 years (range: 56-78). The revision rate was 9.5% in both cohorts. In the wheelchair cohort, two shoulders had to be revised due to a complete baseplate dislocation. In the matching cohort, four shoulders had to be revised due to one prosthetic dislocation, one traumatic and one atraumatic scapular spine fracture with glenoid baseplate dislocation, and one fracture of the greater tuberosity. Median preoperative SSV and rCS did not differ significantly between cohorts. Postoperative SSV was also comparable (wheelchair: median 70 (range: 10-99) vs. matching: median 70 (30-100), p = n.s.). Relative CS was significantly lower in the wheelchair cohort (65% vs. 81.4%, P =.004). Median postoperative WUSPI was 35 points (range: 13-40) for difficulty and 0 points for pain (range: 0-29). The highest difficulty and pain were found for 'hygiene behind the back' and 'propulsion of wheelchair up a ramp or on uneven surface'. Glenoid loosening, scapular notching, and postoperative baseplate inclination did not differ significantly between cohorts. In the wheelchair cohort, glenoid autograft augmentation (38.1% vs. 7.1%, P =.002) and implantation of baseplates with longer pegs were performed more often (≥ 25mm: 38.1% vs. 7.1%, P =.004). RTSA is a valuable therapeutic option for the treatment of advanced OA or irreparable rotator cuff tears in wheelchair-bound patients with high patient satisfaction. Postoperatively, poorer function and a higher rate of baseplate dislocations might be anticipated compared to ambulating patients. [ABSTRACT FROM AUTHOR]

Disabling loss of functional internal rotation (fIR) after reverse total shoulder arthroplasty (RTSA) is frequent but not well understood. This study tested the hypothesis that limitation of fIR after RTSA is not primarily related to a deficit in internal rotation. Fifty patients (mean age at RTSA, 74 ± 11.7 years) who were consecutively seen at a yearly follow-up visit at 1-10 years (median, 4 years) after RTSA were prospectively examined with special attention to fIR. Patients with axillary nerve or deltoid dysfunction were excluded. Relative (age- and sex-adjusted) Constant-Murley scores (CSs) and Subjective Shoulder Values were assessed preoperatively and at final follow-up. In addition, active extension and 4 postoperative activities of daily living (ADLs) requiring fIR were tested at follow-up. Rotator cuff fatty infiltration and notching were evaluated radiographically. For analysis, patients were divided into a group with poor fIR (fIR–, n = 19), defined as ≤2 internal-rotation points in the CS, and a group with good fIR (fIR+, n = 31), defined as ≥4 internal-rotation points in the CS. Active extension of the contralateral shoulders was comparable in the fIR– group (mean, 60.3° [standard deviation (SD), 11.2°]) and fIR+ group (66.1° [SD, 14.2°]). Postoperatively, a difference in active extension between the unaffected and operated sides was present in both groups and averaged 16° (55° [SD, 14.3°] in fIR+ group and 39.1° [SD, 10.8°] in fIR– group; P <.001). No patient in the fIR+ group had active extension < 40° (range, 40°-85°). Shoulders with extension ≥ 40° but unsatisfactory fIR had restricted passive internal rotation in extension. The ability to perform ADLs behind the back correlated better with shoulder extension than with so-called fIR measurements in the CS. Functional internal rotation after RTSA requires at least 40° of shoulder extension. If fIR is unsatisfactory despite 40° of extension, passive restriction of internal rotation in full extension is the limiting factor. It is crucial to preserve or restore active shoulder extension to allow ADLs involving internal rotation. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) preoperative planning software for reverse total shoulder arthroplasty (rTSA) has been implemented in recent years in order to increase accuracy, improve efficiency, and add value to the outcome. A comprehensive literature review is required to determine the utility of preoperative 3D planning software in guiding orthopedic surgeons for implant placement in rTSA. We hypothesize that implementation of 3D preoperative planning software in the setting of rTSA leads to high concordance with minimal deviation from the preoperative plan. A comprehensive and iterative literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) using the PubMed, Embase, OVID Medline, Scopus, Cinahl, Web of Science, and Cochrane databases for original English-language studies evaluating the impact of preoperative planning software usage on rTSA outcomes published from January 1, 2000, to present. Blinded reviewers conducted multiple screens. All included studies were graded based on level of evidence, and data concerning patient demographics and postoperative outcomes were extracted. Nine articles met inclusion criteria (1 level II, 3 level III, and 5 level IV articles), including 415 patients and 422 shoulders. Of the patients who underwent rTSA, 235 were female and 140 were male, although 3 studies (n = 40) did not report sex breakdowns for rTSA patients. The average age was 72.7 years. Four studies (79 shoulders) reported implant final position as mean deviation from planned version and planned inclination. Six studies (n = 236) reported screw angle deviation, fixation, length, and concordance. Concordance with the preoperative plan was measured in 3 studies (n = 178), resulting in complete concordance of 90% (n = 100), arthroplasty type concordance (rTSA vs. TSA) of 100% (n = 100), and glenosphere size concordance between 93% (n = 100) and 88% (n = 76). For screw length concordance, baseplate screw matched by 81% (n = 76) and 100% (n = 2), and upper (n = 35) and lower (n = 35) screw length concordance was observed as 74% and 69%, respectively. The use of preoperative planning (n = 178) was associated with low deviation from preoperative plan, more 2-screw fixations, and longer average screw length in comparison with an unplanned cohort. The use of preoperative planning software in the setting of rTSA results in minimal deviation from preoperative plan. High levels of concordance in screw angle, screw length, and glenosphere size were observed. Further prospective studies should be conducted to further substantiate these results. [ABSTRACT FROM AUTHOR]

Improvement in internal rotation (IR) after anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty is difficult to predict, with rTSA patients experiencing greater variability and more limited IR improvements than aTSA patients. The purpose of this study is to quantify and compare the IR score for aTSA and rTSA patients and create supervised machine learning that predicts IR after aTSA and rTSA at multiple postoperative time points. Clinical data from 2270 aTSA and 4198 rTSA patients were analyzed using 3 supervised machine learning techniques to create predictive models for internal rotation as measured by the IR score at 6 postoperative time points. Predictions were performed using the full input feature set and 2 minimal input feature sets. The mean absolute error (MAE) quantified the difference between actual and predicted IR scores for each model at each time point. The predictive accuracy of the XGBoost algorithm was also quantified by its ability to distinguish which patients would achieve clinical improvement greater than the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient satisfaction thresholds for IR score at 2-3 years after surgery. rTSA patients had significantly lower mean IR scores and significantly less mean IR score improvement than aTSA patients at each postoperative time point. Both aTSA and rTSA patients experienced significant improvements in their ability to perform activities of daily living (ADLs); however, aTSA patients were significantly more likely to perform these ADLs. Using a minimal feature set of preoperative inputs, our machine learning algorithms had equivalent accuracy when predicting IR score for both aTSA (0.92-1.18 MAE) and rTSA (1.03-1.25 MAE) from 3 months to >5 years after surgery. Furthermore, these predictive algorithms identified with 90% accuracy for aTSA and 85% accuracy for rTSA which patients will achieve MCID IR score improvement and predicted with 85% accuracy for aTSA patients and 77% accuracy for rTSA which patients will achieve SCB IR score improvement at 2-3 years after surgery. Our machine learning study demonstrates that active internal rotation can be accurately predicted after aTSA and rTSA at multiple postoperative time points using a minimal feature set of preoperative inputs. These predictive algorithms accurately identified which patients will, and will not, achieve clinical improvement in IR score that exceeds the MCID and SCB patient satisfaction thresholds. [ABSTRACT FROM AUTHOR]