Clinical management of bone loss in cervical total disc arthroplasty: literature review and treatment recommendations.

PURPOSE: Cervical total disc replacement (cTDR) has been established as an alternative treatment for degenerative cervical radiculopathy and myelopathy. While the rate of complications for cTDR is reasonably low, recent studies have focused on bone loss after cTDR. The purpose of this work is to develop a clinical management plan for cTDR patients with evidence of bone loss. To guide our recommendations, we undertook a review of the literature and aimed to determine: (1) how bone loss was identified/imaged, (2) whether pre- or intraoperative assessments of infection or histology were performed, and (3) what decision-making and revision strategies were employed. METHODS: We performed a search of the literature according to PRISMA guidelines. Included studies reported the clinical performance of cTDR and identified instances of cervical bone loss. RESULTS: Eleven case studies and 20 cohort studies were reviewed, representing 2073 patients with 821 reported cases of bone loss. Bone loss was typically identified on radiographs during routine follow-up or by computed tomography (CT) for patients presenting with symptoms. Assessments of infection as well as histological and/or explant assessment were sporadically reported. Across all reviewed studies, multiple mechanisms of bone loss were suspected, and severity and progression varied greatly. Many patients were reportedly asymptomatic, but others experienced symptoms like progressive pain and paresthesia. CONCLUSION: Our findings demonstrate a critical gap in the literature regarding the optimal management of patients with bone loss following cTDR, and treatment recommendations based on our review are impractical given the limited amount and quality evidence available. However, based on the authors' extensive clinical experience, close follow-up of specific radiographic observations and serial radiographs to assess the progression/severity of bone loss and implant changes are recommended. CT findings can be used for clinical decision-making and further follow-up care. The pattern and rate of progression of bone loss, in concert with patient symptomatology, should determine whether non-operative or surgical intervention is indicated. Future studies involving implant retrieval, histopathological, and microbiological analysis for patients undergoing cTDR revision for bone loss are needed.

Identification of ChatGPT-Generated Abstracts Within Shoulder and Elbow Surgery Poses a Challenge for Reviewers.

PURPOSE: To evaluate the extent to which experienced reviewers can accurately discern between artificial intelligence (AI)-generated and original research abstracts published in the field of shoulder and elbow surgery and compare this with the performance of an AI detection tool. METHODS: Twenty-five shoulder- and elbow-related articles published in high-impact journals in 2023 were randomly selected. ChatGPT was prompted with only the abstract title to create an AI-generated version of each abstract. The resulting 50 abstracts were randomly distributed to and evaluated by 8 blinded peer reviewers with at least 5 years of experience. Reviewers were tasked with distinguishing between original and AI-generated text. A Likert scale assessed reviewer confidence for each interpretation, and the primary reason guiding assessment of generated text was collected. AI output detector (0%-100%) and plagiarism (0%-100%) scores were evaluated using GPTZero. RESULTS: Reviewers correctly identified 62% of AI-generated abstracts and misclassified 38% of original abstracts as being AI generated. GPTZero reported a significantly higher probability of AI output among generated abstracts (median, 56%; interquartile range [IQR], 51%-77%) compared with original abstracts (median, 10%; IQR, 4%-37%; P < .01). Generated abstracts scored significantly lower on the plagiarism detector (median, 7%; IQR, 5%-14%) relative to original abstracts (median, 82%; IQR, 72%-92%; P < .01). Correct identification of AI-generated abstracts was predominately attributed to the presence of unrealistic data/values. The primary reason for misidentifying original abstracts as AI was attributed to writing style. CONCLUSIONS: Experienced reviewers faced difficulties in distinguishing between human and AI-generated research content within shoulder and elbow surgery. The presence of unrealistic data facilitated correct identification of AI abstracts, whereas misidentification of original abstracts was often ascribed to writing style. CLINICAL RELEVANCE: With rapidly increasing AI advancements, it is paramount that ethical standards of scientific reporting are upheld. It is therefore helpful to understand the ability of reviewers to identify AI-generated content.

Posterior Shoulder Instability, Part I-Diagnosis, Nonoperative Management, and Labral Repair for Posterior Shoulder Instability-An International Expert Delphi Consensus Statement.

PURPOSE: To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability. METHODS: A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization. CONCLUSIONS: The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required. LEVEL OF EVIDENCE: Level V, expert opinion.

Infection in Shoulder Arthroplasty: Prevention, Diagnosis, and Treatment.

Prosthetic joint infection is a devastating complication following shoulder arthroplasty that can lead to pain, poor function, and poor quality of life. With the increasing number of shoulder arthroplasties performed annually, recognition of prosthetic infection and treatment is necessary. The skin surrounding the shoulder has a unique microbiome, and Cutibacterium acnes is the most commonly encountered bacteria causing prosthetic joint infection. C acnes is a low-virulence organism that resides in the subcutaneous layer of the skin. As a result, the clinical presentation is typically less obvious than prosthetic infections seen in other joints such as the hip and knee. Therefore, diagnosis is not always straightforward, and optimal treatment strategy is unclear. Guidance on prevention, diagnosis, and treatment of shoulder prosthetic joint infection with special emphasis on the consensus definition established at the 2018 International Consensus Meeting is provided.

Job satisfaction and practice characteristics of shoulder and elbow surgeons: a survey of American Shoulder and Elbow Surgeons society members.

BACKGROUND: The purpose of this study is to assess the current trends in fellowship training, career satisfaction, practice characteristics, and surgical case volume among shoulder and elbow surgeons. METHODS: A web-based, anonymous 25-item survey was sent to the membership of the American Shoulder and Elbow Surgeons (ASES) in October of 2022. Questions posed included respondent demographics, fellowship training, career satisfaction, practice characteristics, and surgical case characteristics. Descriptive statistics were performed to report demographic information, assess job and training satisfaction rates, and evaluate practice characteristics. Chi-squared and independent samples t-tests were performed to analyze satisfaction rates, job applications, and surgical case volume with regard to years in practice and practice setting. RESULTS: Twenty percent (243/1248) of ASES members satisfactorily completed the survey. Of the 243 ASES member respondents, 97% (236/243) stated that they would pursue their fellowship training again. Ninety-eight percent (239/243) of respondents were satisfied with their specialty choice. One-hundred percent (242/243) were satisfied with their training in shoulder. Seventy-two percent (176/243) were satisfied with their training in elbow. Seventy-four percent (179/243) were satisfied with their job availability and 85% (207/243) were satisfied with their job location. The mean total number of orthopedic surgical cases per year was 393 ± 171. The mean total number of shoulder cases per year was 253 ± 149. The mean total number of elbow cases per year was 41 ± 41. Physicians who have been in practice for 11 years or more were comparatively more satisfied (90% vs. 80%) with their job location (P value = .008) and job availability (81% vs. 64%, P value < .001). Additionally, senior surgeons completed more orthopedic (431 vs. 347, P value < .001) and shoulder (279 vs. 220, P value = .002) cases annually than surgeons earlier in their careers. Satisfaction rates, job applications, and surgical case volume did not associate with practice setting. CONCLUSIONS: The majority of ASES member shoulder and elbow surgeons are satisfied with their training, their case volume and complexity, and their specialty choice. Fewer surgeons are satisfied with their elbow training and overall elbow case volume remains low among shoulder and elbow surgeons. Shoulder and elbow surgeons earlier in their careers perform fewer surgical cases, are less satisfied with their job availability and location, and completed more job applications for their first job after fellowship when compared to more senior surgeons.

How to avoid baseplate failure: the effect of compression and reverse shoulder arthroplasty baseplate design on implant stability.

BACKGROUND: Failure to achieve fixation of the glenoid baseplate will lead to clinical failure. The fixation of the baseplate to the scapula must be able to withstand sufficient shear forces to allow bony ingrowth. The importance of compression to neutralize the forces at the baseplate-bone interface has been assumed to be critical in limiting excessive micromotion. The purpose of this study is to determine the effect of compression on implant stability with different baseplate designs. METHODS: Various baseplate designs (1-piece monolithic central screw [1P], 2-piece locking central screw [2PL], and 2-piece nonlocking center screw [2PNL]) were investigated at 3 different compressive forces (high [810 N], medium [640 N], and low [530 N]). Synthetic bone cylinders were instrumented, and peripheral screws were used in all models. The combination of 1 locking and 3 nonlocking peripheral screw fixation was selected as worst-case scenario. Dynamic testing protocol followed the ASTM F2028-17 standard. The baseplate micromotion at high compression was compared to low compression. Additionally, the baseplate micromotion for each design was compared at baseline (first 50 cycles) and at 10,000 cycles for the 3 different compressive forces where motion above 150 µm was defined as failure. RESULTS: Baseplate micromotion was found to negatively correlate with compression (rpb = -0.83, P < .0001). At baseline, all baseplate designs were considered stable, regardless of compression. With high compression, average micromotion at the glenoid baseplate-bone interface remained below the 150-µm threshold for all baseplate designs at 10,000 cycles (1P: 50 ± 10 µm; 2PL: 78 ± 32 µm; 2PNL: 79 ± 8 µm; P = .060). With medium compression, average micromotion at 10,000 cycles for all 3 designs remained below the 150-µm threshold (1P: 88 ± 22 µm; 2PL: 132 ± 26 µm; 2PNL: 107 ± 39 µm). The 2PL design had the highest amount of micromotion (P = .013). With low compression, both 2-piece designs had an average micromotion above the 150-µm threshold whereas the 1-piece design did not (1P: 133 ± 35 µm; 2PL: 183 ± 21 µm; 2PNL: 166 ± 39 µm). The 2PL design had significantly higher micromotion when compared to 1P design (P = .041). DISCUSSION: The stability of a central screw baseplate correlates with the amount of compression obtained and is affected by implant design. For the same amount of compression, more micromotion is observed in a 2-piece design than a 1-piece design.

WITHDRAWN: On the Concerning Early Failure of a Short Stem Press-Fit Humeral Component.

This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause.

How fellowship training affects complication rate after shoulder arthroplasty: a nationwide assessment.

BACKGROUND: Total shoulder arthroplasty is performed by orthopedic surgeons with various fellowship training backgrounds. Whether surgeons performing shoulder arthroplasty with different types of fellowship training have differing rates of complications and reoperation remains unknown. METHODS: The PearlDiver Mariner database was retrospectively queried from the years 2010 to 2022. Patients undergoing shoulder arthroplasty were selected using the CPT code 23472. Those undergoing revision arthroplasty and those with a history of fracture, infection, or malignancy were excluded. Fellowship was determined and verified via online search. Only surgeons who performed a minimum of 10 cases were selected; and PearlDiver was queried using their provider ID codes. Primary outcome measures included 90-day, 1-year, and 5-year rates of complication and reoperation. A Bonferroni correction was utilized in which the significance threshold was set at P ≤ .00023. RESULTS: In total, 150,385 patients met the inclusion criteria and were included in the study. Analysis of surgical trends revealed that Sports Medicine and Shoulder and Elbow fellowship-trained surgeons are performing an increasing percentage of all shoulder arthroplasty over time, with each cohort exhibiting an 11.3% and 4.2% increase from 2010 to 2022, respectively. The geographic region with the highest proportion of cases performed by Sports Medicine surgeons was the West, while the Northeast has the highest proportion of cases performed by Shoulder and Elbow surgeons. Shoulder and Elbow surgeons operated on patients that were significantly younger and had fewer comorbidities. Both Shoulder and Elbow and Sports Medicine surgeons had lower rates of postoperative complications at 90 days, 1 year, and 5 years in comparison to surgeons who completed another type of fellowship or no fellowship. Across each time point, the rates of individual complications between Sports Medicine and Shoulder and Elbow were comparable, but the pooled complication rate was lowest in the Shoulder and Elbow cohort. CONCLUSION: Surgeons who have completed either a Sports Medicine or Shoulder and Elbow fellowship are performing an increasing proportion of shoulder arthroplasty over time. Sports Medicine and Shoulder and Elbow-trained surgeons have significantly lower complication rates at 90 days, 1 year, and 5 years postoperatively. The individual complication rates between Sports Medicine and Shoulder and Elbow are comparable, but Shoulder and Elbow have the lowest pooled complication rates overall.

The Effect of Surgeon Volume on Complications Following Total Shoulder Arthroplasty: A Nationwide Assessment.

BACKGROUND: Increased surgeon volume has been demonstrated to correlate with improved outcomes after orthopedic surgery. However, there is a lack of data demonstrating the effect of surgeon volume on outcomes after total shoulder arthroplasty. METHODS: The PearlDiver Mariner database was retrospectively queried from the years 2010-2022. Patients undergoing shoulder arthroplasty were selected using the CPT code 23472 (Total Shoulder Arthroplasty). Patients under 40 years of age, those undergoing revision arthroplasty and cases of bilateral arthroplasty were excluded. Additionally, cases with a history of fracture, infection, or malignancy prior to surgery were excluded. Only surgeons who performed a minimum of 10 cases were selected and PearlDiver was queried using their provider ID codes. Primary outcome measures included 90 day, 1-year, and 2-year rates of complication and reoperation. A Bonferroni correction was utilized in which the significance threshold was set at p≤0.00082 RESULTS: A total of 155,560 patients met inclusion criteria and were retained for analysis. The 90th percentile for surgeon volume was determined to be 112 cases during the study period. Surgeons above the 90th percentile (n=340) operated on 68,531 patients whereas surgeons below the 90th percentile (n=3,038) operated on 87,029 patients. Surgeons in the high-volume group were significantly more likely to have completed a Shoulder and Elbow fellowship (p<0.001) and less likely to have no fellowship training or fellowship training outside of Shoulder and Elbow or Sports Medicine (p<0.001). Low-volume surgeons operated on patients with higher baseline comorbidities (CCI: 2.01 vs 1.85, p<0.001). After adjusting for age, gender, CCI, obesity, and tobacco use, high-volume surgeons experienced lower rates of medical complications including renal failure (p<0.001), anemia (p<0.001), and UTI (p<0.001). All cause readmission (0.90, p<0.001), reoperation at 90 days (OR 0.75, p<0.001) and reoperation at 1 year (OR: 0.86, p<0.001) were significantly lower among high-volume surgeons. High-volume surgeons exhibited lower rates of various complications including prosthetic joint infection (90d: p<0.001; 1yr: p<0.001; 2yr: p<0.001), periprosthetic fracture (90d: p<0.001; 1yr: p<0.001; 2yr: p<0.001) and all complications (90d: p<0.001; 1yr: p<0.001). CONCLUSION: Surgeons who perform a high volume of total shoulder arthroplasty are more likely to operate on healthier patients than surgeons who perform a lower volume of cases. When compared to low-volume surgeons, and after adjusting for age, gender, and CCI, high-volume surgeons have a significantly lower overall complication rate. Despite this lower complication rate, high-volume surgeons are responsible for a decreasing portion of shoulder arthroplasty since 2016.

Anatomic or Reverse Total Shoulder Arthroplasty? How Fellowship Training Affects Selection of Arthroplasty Type.

BACKGROUND: While both anatomic (ATSA) and reverse total shoulder arthroplasty (RTSA) have been popularized as a means of treating individuals with degenerative shoulder conditions, the indications for each can vary widely amongst providers. While surgeons with differing fellowship training commonly perform these procedures, it is not understood how fellowship training influences choice of implant. METHODS: A national database was queried to identify surgeons performing anatomic and reverse total shoulder arthroplasty. For all surgeons who performed more than 10 cases between 2010-2022, fellowship data was individually collected via online search. For each fellowship group, rates of anatomic and reverse total shoulder arthroplasty were identified using International Classification of Diseases (ICD) procedural codes. Those undergoing revision arthroplasty and those with a history of fracture, infection, or malignancy were excluded. Primary outcome measures included the proportion of primary and revision ATSA and RTSA by fellowship in addition to the rate of RTSA performed for a primary diagnosis of glenohumeral osteoarthritis. RESULTS: A total of 131,974 patients met the inclusion criteria and were retained for this study. RTSA increased from 50.1% of all primary shoulder arthroplasty cases in 2011 to 72.0% in 2022. After adjusting for age and comorbidities, Sports Medicine fellowship-trained (Sports) surgeons opted for primary RTSA over ATSA at a significantly higher rate than Shoulder and Elbow fellowship-trained (Shoulder) surgeons and surgeons who completed another type of fellowship or no fellowship (Other). Sports surgeons also chose RTSA more frequently for the diagnosis of glenohumeral osteoarthritis compared to Shoulder surgeons. Surgeons in the Other cohort were more likely to perform primary ATSA rather than RTSA in comparison to surgeons in the Shoulder and Sports cohorts. Sports surgeons were responsible for the greatest increase in percentage of all shoulder arthroplasty procedures from 2010-2022 (28.4% to 40.4%) while the Other group decreased by a comparable amount (45.9% to 32.4%) over the same period. CONCLUSION: Surgeons who have completed a Sports Medicine fellowship choose RTSA over ATSA at a higher rate than Shoulder and Elbow surgeons, both for all indications and also for a primary diagnosis of glenohumeral osteoarthritis. Those who have no fellowship training or fellowship training outside of Sports Medicine and Shoulder and Elbow surgery have the highest percentage of ATSA in their arthroplasty practice. Revision anatomic and revision reverse total shoulder arthroplasty represents a larger percentage of overall case volume for Shoulder and Elbow surgeons.

3-dimensionally printed patient-specific glenoid drill guides vs. standard nonspecific instrumentation: a randomized controlled trial comparing the accuracy of glenoid component placement in anatomic total shoulder arthroplasty.

BACKGROUND: Traditional, commercially sourced patient-specific instrumentation (PSI) systems for shoulder arthroplasty improve glenoid component placement but can involve considerable cost and outsourcing delays. The purpose of this randomized controlled trial was to compare the accuracy of glenoid component positioning in anatomic total shoulder arthroplasty (aTSA) using an in-house, point-of-care, 3-dimensionally (3D) printed patient-specific glenoid drill guide vs. standard nonspecific instrumentation. METHODS: This single-center randomized controlled trial included 36 adult patients undergoing primary aTSA. Patients were blinded and randomized 1:1 to either the PSI or the standard aTSA guide groups. The primary endpoint was the accuracy of glenoid component placement (version and inclination), which was determined using a metal-suppression computed tomography scan taken between 6 weeks and 1 year postoperatively. Deviation from the preoperative 3D templating plan was calculated for each patient. Blinded postoperative computed tomography measurements were performed by a fellowship-trained shoulder surgeon and a musculoskeletal radiologist. RESULTS: Nineteen patients were randomized to the patient-specific glenoid drill guide group, and 17 patients were allocated to the standard instrumentation control group. There were no significant differences between the 2 groups for native version (P = .527) or inclination (P = .415). The version correction was similar between the 2 groups (P = .551), and the PSI group was significantly more accurate when correcting version than the control group (P = .042). The PSI group required a significantly greater inclination correction than the control group (P = .002); however, the 2 groups still had similar accuracy when correcting inclination (P = .851). For the PSI group, there was no correlation between the accuracy of component placement and native version, native inclination, or the Walch classification of glenoid wear (P > .05). For the control group, accuracy when correcting version was inversely correlated with native version (P = .033), but accuracy was not correlated with native inclination or the Walch classification of glenoid wear (P > .05). The intraclass correlation coefficient was 0.703 and 0.848 when measuring version and inclination accuracy, respectively. CONCLUSION: When compared with standard instrumentation, the use of in-house, 3D printed, patient-specific glenoid drill guides during aTSA led to more accurate glenoid component version correction and similarly accurate inclination correction. Additional research should examine the influence of proper component position and use of PSI on clinical outcomes.

Artificial intelligence in shoulder and elbow surgery: overview of current and future applications.

Artificial intelligence (AI) is amongst the most rapidly growing technologies in orthopedic surgery. With the exponential growth in healthcare data, computing power, and complex predictive algorithms, this technology is poised to aid providers in data processing and clinical decision support throughout the continuum of orthopedic care. Understanding the utility and limitations of this technology is vital to practicing orthopedic surgeons, as these applications will become more common place in everyday practice. AI has already demonstrated its utility in shoulder and elbow surgery for imaging-based diagnosis, predictive modeling of clinical outcomes, implant identification, and automated image segmentation. The future integration of AI and robotic surgery represents the largest potential application of AI in shoulder and elbow surgery with the potential for significant clinical and financial impact. This editorial's purpose is to summarize common AI terms, provide a framework to understand and interpret AI model results, and discuss current applications and future directions within shoulder and elbow surgery.

Predictors of dislocations after reverse shoulder arthroplasty: a study by the ASES complications of RSA multicenter research group.

BACKGROUND: Instability after reverse shoulder arthroplasty (RSA) is one of the most frequent complications and remains a clinical challenge. Current evidence is limited by small sample size, single-center, or single-implant methodologies that limit generalizability. We sought to determine the incidence and patient-related risk factors for dislocation after RSA, using a large, multicenter cohort with varying implants. METHODS: A retrospective, multicenter study was performed involving 15 institutions and 24 American Shoulder and Elbow Surgeons members across the United States. Inclusion criteria consisted of patients undergoing primary or revision RSA between January 2013 and June 2019 with minimum 3-month follow-up. All definitions, inclusion criteria, and collected variables were determined using the Delphi method, an iterative survey process involving all primary investigators requiring at least 75% consensus to be considered a final component of the methodology for each study element. Dislocations were defined as complete loss of articulation between the humeral component and the glenosphere and required radiographic confirmation. Binary logistic regression was performed to determine patient predictors of postoperative dislocation after RSA. RESULTS: We identified 6621 patients who met inclusion criteria with a mean follow-up of 19.4 months (range: 3-84 months). The study population was 40% male with an average age of 71.0 years (range: 23-101 years). The rate of dislocation was 2.1% (n = 138) for the whole cohort, 1.6% (n = 99) for primary RSAs, and 6.5% (n = 39) for revision RSAs (P < .001). Dislocations occurred at a median of 7.0 weeks (interquartile range: 3.0-36.0 weeks) after surgery with 23.0% (n = 32) after a trauma. Patients with a primary diagnosis of glenohumeral osteoarthritis with an intact rotator cuff had an overall lower rate of dislocation than patients with other diagnoses (0.8% vs. 2.5%; P < .001). Patient-related factors independently predictive of dislocation, in order of the magnitude of effect, were a history of postoperative subluxations before radiographically confirmed dislocation (odds ratio [OR]: 19.52, P < .001), primary diagnosis of fracture nonunion (OR: 6.53, P < .001), revision arthroplasty (OR: 5.61, P < .001), primary diagnosis of rotator cuff disease (OR: 2.64, P < .001), male sex (OR: 2.21, P < .001), and no subscapularis repair at surgery (OR: 1.95, P = .001). CONCLUSION: The strongest patient-related factors associated with dislocation were a history of postoperative subluxations and having a primary diagnosis of fracture nonunion. Notably, RSAs for osteoarthritis showed lower rates of dislocations than RSAs for rotator cuff disease. These data can be used to optimize patient counseling before RSA, particularly in male patients undergoing revision RSA.

Biphasic Interpositional Allograft for Rotator Cuff Repair Augmentation Is Safe in an Ovine Model.

PURPOSE: To perform a preclinical histologic assessment of a biphasic acellular interpositional cancellous allograft in an ovine model of rotator cuff repair (RCR) designed to better understand its safety profile and effects on tendon healing after RCR. METHODS: Thirty skeletally mature sheep with clinically normal shoulders with an artificially created degenerative infraspinatus tendon tear were randomized to control and treatment groups. Animals were euthanized at 3 weeks, 6 weeks, and 12 weeks. After gross dissection, rotator cuff specimens were fixed with formalin and polymerized for sectioning and staining. Blinded histologic scores evaluated inflammatory cell infiltrates, signs of degradation, particulate debris, collagen arrangement, neovascularization, and enthesis qualitative measures. RESULTS: There were no treatment specimens that exhibited histologic signs of a significant infection, inflammatory infiltrate, or foreign body reaction such as granuloma or fibrous capsule formation. Histologic scores in all categories were not significantly different at all time points, including the primary end point mean cumulative inflammatory score (control: 3.66 ± 1.21 vs treated: 4.33 ± 1.51, P = .42), when comparing the treatment and control RCR groups. In general, the degree of tendon healing and host tissue response was essentially equivalent between the 2 groups with observation of low overall levels of inflammation and progressive improvements in collagen organization, reduced tenocyte activity, and fibrocartilaginous enthesis reformation. CONCLUSIONS: This histologic study demonstrated the use of a biphasic interpositional allograft for RCR augmentation in an ovine model does not generate an inflammatory response or foreign body reaction. Use of the biphasic interpositional allograft resulted in a histological profile that was essentially equivalent to that of a standard RCR at 3-, 6-, and 12-week postoperative timepoints. These findings suggest that a biphasic interpositional allograft is safe for further clinical investigation in humans before broader clinical application. CLINICAL RELEVANCE: Patch augmentation of RCR is a popular technique that has shown clinical success in improving the likelihood of a successful repair in patients at elevated risk for retear. Newer augmentation technologies are being developed to address the biology at the interface between the bone and soft tissue where failure typically occurs.

Shoulder Arthroplasty Management in the Young Patient With Posterior Glenoid Erosion.

Osteoarthritic shoulders with posterior glenoid erosion present a unique challenge to shoulder arthroplasty surgeons. Although numerous treatment options and techniques have been described, a consensus regarding the optimal surgical management strategy has not been reached. It is important to summarize the best available evidence regarding these different treatment options, with a particular focus on the young patient.

Clinical and radiographic outcomes following anatomic total shoulder arthroplasty utilizing an inset glenoid component at 2-year minimum follow-up: a dual center study.

BACKGROUND: Anatomic total shoulder arthroplasty (aTSA) is a successful and reproducible treatment for patients with painful glenohumeral arthritis. However, long-term outcomes using traditional onlay glenoid components have been tempered by glenoid loosening. Inset components have been proposed to minimize glenoid loosening by reducing edge-loading and opposite-edge lift-off forces with humeral translation. Successful short- and long-term outcomes have been reported while using inset glenoid implants. The current study is the largest study presenting a minimum of 2-year follow-up data following aTSA with an all-polyethylene inset glenoid component (Shoulder Innovations, Holland, MI, USA). METHODS: A dual center, retrospective review of patients undergoing aTSA using an Inset glenoid component by 2 fellowship-trained shoulder surgeons at 2 separate institutions from August, 2016, to August, 2019, was performed. Minimum follow-up was 2 years. Range of motion (ROM), visual analog scale (VAS) pain scores, Single Assessment Numeric Evaluation (SANE), and American Shoulder and Elbow Surgeons (ASES) scores were obtained. Radiographic outcomes, including central peg lucency and glenoid loosening, were assessed by 3 independent reviewers on the postoperative Grashey and axillary radiographs obtained at the final follow-up. RESULTS: Seventy-five shoulders were included for the final analysis. The mean age of the entire cohort was 64 (±11.4) years. Twenty-one (28%) glenoids were type A1, 10 (13.3%) were type A2, 13 (17.3%) were type B1, 22 (29.3%) were type B2, 6 (8%) were type B3, and 3 (4%) were type D. At a minimum follow-up of 24 months (mean: 28.7 months), a significant improvement in ROM in all planes was observed. Significant improvements in VAS (5.1-0.9, P < .001), SANE (39.5-91.2, P < .001), and ASES (43.7-86.6, P < .001) scores were observed. There were 4 (5.3%) cases of central peg lucency about the inset glenoid component and one (1.3%) case of glenoid loosening. No revisions were performed for glenoid loosening. CONCLUSION: At a minimum of 2 years postoperatively, there were significant improvements in ROM, VAS, SANE, and ASES scores with very low rates of central peg lucency and glenoid loosening in patients undergoing aTSA with an inset glenoid component. Further work is needed to determine the long-term benefit of this novel implant.

Minimal inter-surgeon agreement on the diagnosis of pseudoparalysis in patients with massive rotator cuff tears.

BACKGROUND: Pseudoparalysis is commonly used to describe patients with severe loss of active elevation associated with advanced rotator cuff disease, but its definition in the literature has been variable. This study aimed to determine how 15 expert shoulder surgeons use the term "pseudoparalysis" when presented with clinical cases and assess clinical agreement on the diagnosis of pseudoparalysis. METHODS: Fifteen expert shoulder surgeons were surveyed regarding 18 patients with magnetic resonance imaging-diagnosed massive rotator cuff tears, restricted active range of motion (ROM), full passive ROM, and without advanced rotator cuff arthropathy (Hamada grade <3). The survey included 18 patient vignettes with key clinical details and a deidentified video demonstrating the physical examination of the patient. For all patients, surgeons were instructed to assume that the patient has a full passive ROM. An anteroposterior radiograph and T2 sequences of the patient's coronal, axial, and sagittal magnetic resonance imaging were also provided. After each case, the surgeons were asked: (1) does the patient have pseudoparalysis, and (2) if so, how severe it is. At the end of the patient vignettes, surgeons were asked to define pseudoparalysis using a checklist with predefined options. Surgeons were also asked if there was a difference between the term pseudoparalysis and pseudoparesis. Fleiss' kappa (κ) correlation coefficient was used to determine intersurgeon agreement. RESULTS: There was minimal inter-rater agreement on the diagnosis of pseudoparalysis (κ = 0.360) and no agreement on describing the severity of pseudoparalysis (κ = -0.057). Although 80% of surgeons stated that an active glenohumeral elevation less than 90° was a diagnostic feature of pseudoparalysis, there was disagreement on the remaining criteria, leading to no agreement on a set of universal criteria that defines pseudoparalysis. A total of 67% included maintained full passive elevation, 33% included the absence of pain, 67% included elevation causing anterosuperior escape, and 27% included an additional unlisted factor. There was minimal agreement among the 15 surgeons on the diagnostic criteria of pseudoparalysis (κ = 0.092). Finally, 7 surgeons stated that pseudoparalysis and pseudoparesis are identical, whereas 8 surgeons stated that they are 2 different clinical diagnoses. CONCLUSION: Among this panel of expert shoulder surgeons, there was a lack of consensus on the definition of pseudoparalysis and minimal agreement on the diagnosis of pseudoparalysis based on clinical scenarios. In addition, half the surgeons believed that pseudoparalysis and pseudoparesis are identical, whereas the other half believed that they represent 2 separate clinical entities. A standardized definition of pseudoparalysis would be of value to facilitate communication and research efforts.

Costs of shoulder and elbow procedures are significantly reduced in ambulatory surgery centers compared to hospital outpatient departments.

BACKGROUND: Recent literature has shown the advantages of outpatient surgery for many shoulder and elbow procedures, including cost savings with equivalent safety in appropriately selected patients. Two common settings for outpatient surgeries are ambulatory surgery centers (ASCs), which function as independent financial and administrative entities, or hospital outpatient departments (HOPDs), which are owned and operated by hospital systems. The purpose of this study was to compare shoulder and elbow surgery costs between ASCs and HOPDs. METHODS: Publicly available data from 2022 provided by the Centers for Medicare & Medicaid Services (CMS) was accessed via the Medicare Procedure Price Lookup Tool. Current Procedural Terminology (CPT) codes were used to identify shoulder and elbow procedures approved for the outpatient setting by CMS. Procedures were grouped into arthroscopy, fracture, or miscellaneous. Total costs, facility fees, Medicare payments, patient payment (costs not covered by Medicare), and surgeon's fees were extracted. Descriptive statistics were used to calculate means and standard deviations. Cost differences were analyzed using Mann-Whitney U tests. RESULTS: Fifty-seven CPT codes were identified. Arthroscopy procedures (n = 16) at ASCs had significantly lower total costs ($2667 ± $989 vs. $4899 ± $1917; P = .009), facility fees ($1974 ± $819 vs. $4206 ± $1753; P = .008), Medicare payments ($2133 ± $791 vs. $3919 ± $1534; P = .009), and patient payments ($533 ± $198 vs. $979 ± $383; P = .009) compared with HOPDs. Fracture procedures (n = 10) at ASCs had lower total costs ($7680 ± $3123 vs. $11,335 ± $3830; P = .049), facility fees ($6851 ± $3033 vs. $10,507 ± $3733; P = .047), and Medicare payments ($6143 ± $2499 vs. $9724 ± $3676; P = .049) compared with HOPDs, although patient payments were not significantly different ($1535 ± $625 vs. $1610 ± $160; P = .449). Miscellaneous procedures (n = 31) at ASCs had lower total costs ($4202 ± $2234 vs. $6985 ± $2917; P < .001), facility fees ($3348 ± $2059 vs. $6132 ± $2736; P < .001), Medicare payments ($3361 ± $1787 vs. $5675 ± $2635; P < .001), and patient payments ($840 ± $447 vs. $1309 ± $350; P < .001) compared with HOPDs. The combined cohort (n = 57) at ASCs had lower total costs ($4381 ± $2703 vs. $7163 ± $3534; P < .001), facility fees ($3577 ± $2570 vs. $6539.1 ± $3391; P < .001), Medicare payments ($3504 ± $2162 vs. $5892 ± $3206; P < .001), and patient payments ($875 ± $540 vs. $1269 ± $393; P < .001) compared with HOPDs. CONCLUSION: Shoulder and elbow procedures performed at HOPDs for Medicare recipients were found to have average total cost increase of 164% compared with those performed at ASCs (184% savings for arthroscopy, 148% for fracture, and 166% for miscellaneous). ASC use conferred lower facility fees, patient payments, and Medicare payments. Policy efforts to incentivize migration of surgeries to ASCs may translate into substantial health care cost savings.

A validated preoperative risk prediction tool for extended inpatient length of stay following anatomic or reverse total shoulder arthroplasty.

BACKGROUND: Recent work has shown inpatient length of stay (LOS) following shoulder arthroplasty to hold the second strongest association with overall cost (after implant cost itself). In particular, a preoperative understanding for the patients at risk of extended inpatient stays (≥3 days) can allow for counseling, optimization, and anticipating postoperative adverse events. METHODS: A multicenter retrospective review was performed of 5410 anatomic (52%) and reverse (48%) total shoulder arthroplasties done at 2 large, tertiary referral health systems. The primary outcome was extended inpatient LOS of at least 3 days, and over 40 preoperative sociodemographic and comorbidity factors were tested for their predictive ability in a multivariable logistic regression model based on the patient cohort from institution 1 (derivation, N = 1773). External validation was performed using the patient cohort from institution 2 (validation, N = 3637), including area under the receiver operator characteristic curve (AUC), sensitivity, specificity, and positive and negative predictive values. RESULTS: A total of 814 patients, including 318 patients (18%) in the derivation cohort and 496 patients (14%) in the validation cohort, experienced an extended inpatient LOS of at least 3 days. Four hundred forty-five (55%) were discharged to a skilled nursing or rehabilitation facility. Following parameter selection, a multivariable logistic regression model based on the derivation cohort (institution 1) demonstrated excellent preliminary accuracy (AUC: 0.826), with minimal decrease in accuracy under external validation when tested against the patients from institution 2 (AUC: 0.816). The predictive model was composed of only preoperative factors, in descending predictive importance as follows: age, marital status, fracture case, ASA (American Society of Anesthesiologists) score, paralysis, electrolyte disorder, body mass index, gender, neurologic disease, coagulation deficiency, diabetes, chronic pulmonary disease, peripheral vascular disease, alcohol dependence, psychoses, smoking status, and revision case. CONCLUSION: A freely-available, preoperative online clinical decision tool for extended inpatient LOS (≥ 3 days) after shoulder arthroplasty reaches excellent predictive accuracy under external validation. As a result, this tool merits consideration for clinical implementation, as many risk factors are potentially modifiable as part of a preoperative optimization strategy.

Risk factors of acromial and scapular spine stress fractures differ by indication: a study by the ASES Complications of Reverse Shoulder Arthroplasty Multicenter Research Group.

BACKGROUND: Both patient and implant related variables have been implicated in the incidence of acromial (ASF) and scapular spine fractures (SSF) following reverse shoulder arthroplasty (RSA); however, previous studies have not characterized nor differentiated risk profiles for varying indications including primary glenohumeral arthritis with intact rotator cuff (GHOA), rotator cuff arthropathy (CTA), and massive irreparable rotator cuff tear (MCT). The purpose of this study was to determine patient factors predictive of cumulative ASF/SSF risk for varying preoperative diagnosis and rotator cuff status. METHODS: Patients consecutively receiving RSA between January 2013 and June 2019 from 15 institutions comprising 24 members of the American Shoulder and Elbow Surgeons (ASES) with primary, preoperative diagnoses of GHOA, CTA and MCT were included for study. Inclusion criteria, definitions, and inclusion of patient factors in a multivariate model to predict cumulative risk of ASF/SSF were determined through an iterative Delphi process. The CTA and MCT groups were combined for analysis. Consensus was defined as greater than 75% agreement amongst contributors. Only ASF/SSF confirmed by clinical and radiographic correlation were included for analysis. RESULTS: Our study cohort included 4764 patients with preoperative diagnoses of GHOA, CTA, or MCT with minimum follow-up of 3 months (range: 3-84). The incidence of cumulative stress fracture was 4.1% (n = 196). The incidence of stress fracture in the GHOA cohort was 2.1% (n = 34/1637) compared to 5.2% (n = 162/3127) (P < .001) in the CTA/MCT cohort. Presence of inflammatory arthritis (odds ratio [OR] 2.90, 95% confidence interval [CI] 1.08-7.78; P = .035) was the sole predictive factor of stress fractures in GHOA, compared with inflammatory arthritis (OR 1.86, 95% CI 1.19-2.89; P = .016), female sex (OR 1.81, 95% CI 1.20-2.72; P = .007), and osteoporosis (OR 1.56, 95% CI 1.02-2.37; P = .003) in the CTA/MCT cohort. CONCLUSION: Preoperative diagnosis of GHOA has a different risk profile for developing stress fractures after RSA than patients with CTA/MCT. Though rotator cuff integrity is likely protective against ASF/SSF, approximately 1/46 patients receiving RSA with primary GHOA will have this complication, primarily influenced by a history of inflammatory arthritis. Understanding risk profiles of patients undergoing RSA by varying diagnosis is important in counseling, expectation management, and treatment by surgeons.