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.

Acromion fractures after reverse shoulder arthroplasty occur in predictable clusters.

BACKGROUND: Acromion and scapular spine fractures (ASFs) following reverse total shoulder arthroplasty (RSA) have been reported at a rate of 3.9%. The location of the fracture has been shown to be an important factor in determining the outcomes of nonoperative treatment, with medial fractures having worse outcomes than lateral fractures. As the debate between operative and nonoperative treatment continues, a more precise understanding of the location of the fracture is necessary for effective management. The purpose of this study was to use 3-dimensional computed tomography (CT) reconstruction to characterize the exact location of ASFs after RSA. METHODS: A retrospective review of 2 separate institutional shoulder and elbow repositories was performed. Patients with post-RSA ASFs documented by post-fracture CT scans were included. The query identified 48 patients who sustained postoperative ASFs after RSA between July 2008 and September 2021. CT scans of patients with ASFs were segmented using Mimics software. Eight patients were excluded because of poor image quality. Each bone model was manipulated using 3-Matic Medical software to align the individual scapula with an idealized bone model to create a view of scapular fracture locations on a normalized bone model. This model was used to classify the fractures using the modified Levy classification. RESULTS: The study cohort consisted of 40 patients with a diagnosis of postoperative ASF after RSA. The median age at the time of surgery was 76 years (interquartile range, 73-79 years). The cohort comprised 32 women (80%) and 8 men (20%), with a median body mass index of 27.8. Only 10 patients (25%) had a previous diagnosis of osteoporosis and 6 (13%) had a diagnosis of inflammatory arthritis; 53% of patients underwent RSA owing to rotator cuff tear arthropathy. The distribution of fracture locations was similar within the cohort. However, lateral fractures were slightly more prevalent. The most common fracture location was the type I zone, with 12 fracture lines (29%). There were 11 fracture lines (26%) in the type IIa zone, 10 (23%) in the type IIb zone, 0 in the type IIc zone, and 9 (21%) in the type III zone. CONCLUSION: ASFs after RSA occur in 4 predictable clusters. No fractures appeared to distinctly cluster in the type IIc zone, which may not represent a true fracture zone. Understanding the distribution of these fractures will help to enable the future design of implants and devices to stabilize the fractures that require fixation.

Functional composite spacer (antibiotic cement around a hemiarthroplasty) for the treatment of shoulder infections: minimum 5-year outcomes.

BACKGROUND: Periprosthetic infections remain a challenging complication after shoulder arthroplasty, and an ideal treatment protocol has yet to be established. Two-stage revision is a common approach. Historically, the first stage entails placement of an all-cement antibiotic spacer. Although prior studies have reported on cement spacers as definitive management, persistent pain and inadequate function often lead many to later request a second-stage procedure. The functional composite spacer consists of a humeral hemiarthroplasty implant with antibiotic cement coated around the stem alone to preserve the metallic humeral head-glenoid articulation. Functional composite spacers have demonstrated improvements in function and motion with high patient satisfaction at 25 months, but longer-term follow-up is needed to better understand the role it may play in the management of shoulder infections. The purpose of this study is to evaluate outcomes at a minimum of 5 years in patients who initially planned to undergo 2-stage revision but elected to retain the functional spacer. METHODS: A retrospective review of a single institution's shoulder surgery repository from 2007 to 2018 identified 30 patients who underwent placement of a composite spacer. Overall, 5 patients underwent second-stage reimplantation and 12 patients did not have 5-year follow-up (6 lost to follow-up and 6 deceased). A total of 13 patients were included who maintained a functional composite spacer and had minimum 5-year follow-up. Patient-reported outcome measures (American Shoulder and Elbow Surgeons score, Simple Shoulder Test, Single Assessment Numeric Evaluation, visual analog scale function, and visual analog score pain), satisfaction, range of motion, and radiographic estimation of glenoid wear were evaluated. RESULTS: Two of 13 patients (15%) required additional surgery: 1 secondary closure for early superficial wound dehiscence and 1 revision spacer for pain. There were no reinfections. At most recent follow-up, patient satisfaction was high and significant improvements were noted for American Shoulder and Elbow Surgeons score (45.4; P < .001), Simple Shoulder Test (5.3; P = .003), Single Assessment Numeric Evaluation (47.3; P = .002), visual analog scale function (4.9; P = .004), and visual analog score pain (-4.4; P = .007) as well as range of motion including abduction (39.2°; P = .005) and elevation (65.9°; P = .005). There was no significant change in humeral head medialization (P = .11). CONCLUSIONS: Patients who do not undergo an early revision and retain a functional composite spacer maintain good function and range of motion with minimal pain at midterm follow-up.

Improvement in sleep disturbance following arthroscopic rotator cuff repair.

BACKGROUND: Approximately 90% of patients express concerns with sleep shortly after developing shoulder-related symptoms. Previous small cohort studies have demonstrated the impact of rotator cuff repair (RCR) on sleep, but none have characterized the observed benefits. The purpose of this study is to evaluate sleep improvement after rotator cuff repair including the speed of sleep recovery, the time at which improvement plateaus, and the longer-term maintenance of improved sleep. METHODS: A retrospective review of our institution's shoulder and elbow repository identified patients who underwent primary arthroscopic rotator cuff repair from 2012 to 2021 and reported sleep disturbance preoperatively. Patients were evaluated using sleep-related questions from the Simple Shoulder Test and American Shoulder and Elbow Surgeons score. Sleep outcomes were compared from a preoperative visit to 3-month, 6-month, 12-month, and most recent follow-ups to evaluate efficacy of treatment, speed of recovery, and improvement plateaus. RESULTS: Among 677 RCR patients, 95.7% (648/677) reported sleep disturbance preoperatively. A total of 474 met inclusion criteria with median follow-up of 4.1 years (IQR, 2.1-6.1). At most recent follow-up, 81.8% were able to sleep comfortably and 65.7% were able to sleep on the affected side. A plateau in the ability to sleep comfortably was seen at 6 months while no plateau was observed in the ability to sleep on the affected side. More rapid improvement in the ability to sleep comfortably occurred during the first 3 months and from 3-6 months for the ability to sleep on the affected side. CONCLUSION: The majority of patients with sleep disturbance who undergo RCR, report significant, rapid, and lasting improvement in the ability to sleep comfortably and the ability to sleep on the affected side.

Functional and radiographic results of anatomic total shoulder arthroplasty in the setting of subscapularis dysfunction: 5-year outcomes analysis.

BACKGROUND: Subscapularis management is a critical component to the success of anatomic total shoulder arthroplasty (TSA). Failure to heal the subscapularis can result in pain, weakness, loss of function, and revision. However, not all patients have poor outcomes. The purpose of this study is to compare patients with normal and dysfunctional subscapularis function following TSA in regard to (1) patient-reported outcome measures (PROMs); (2) range of motion (ROM) and strength; (3) achievement of minimal clinically important differences (MCIDs); and (4) specific functional internal rotation tasks. METHODS: A retrospective review of patients treated with TSA for osteoarthritis with a minimum 2-year follow-up was performed to identify patients with subscapularis dysfunction. Subscapularis dysfunction was diagnosed when any degree of weakness in internal rotation was detected on physical examination (positive belly press sign). These patients were case controlled matched on a 1:3 ratio to patients with normal subscapularis function based on age and sex. PROMs, measured active motion, revision rates, patient satisfaction, and postoperative radiographic findings were compared. Population-specific institutional anchor-based MCID values were used to compare the improvement in PROM. RESULTS: Of the 668 patients included, 34 patients (5.1%) demonstrated evidence of subscapularis dysfunction. Mean follow-up for the normal subscapularis function cohort was 63.4 ± 29.7 and 58.7 ± 26.8 for the dysfunctional subscapularis cohort. Patients with subscapularis dysfunction demonstrated significantly worse postoperative Simple Shoulder Test, Single Assessment Numerical Evaluation, visual analog scale (VAS) function, VAS pain, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores with higher rates of unsatisfactory results when compared to patients with normal subscapularis function. Abduction, elevation, internal rotation ROM, along with supraspinatus and external rotation strength were also significantly worse in the dysfunctional group. Similarly, these patients were more likely to have decreased ability to perform functional internal rotation tasks, with only 47% of the patients being able to reach the small of their back compared to 85% with normal subscapularis function. Radiographically, the dysfunctional cohort demonstrated higher rates of anterior subluxation (56% vs. 7%; P < .001) and glenoid loosening (24% vs. 5%; P = .004). Similarly, revision rates were significantly higher for patients with subscapularis dysfunction (8 patients, 23.5%). Nonetheless, the dysfunctional subscapularis cohort demonstrated improvements in VAS pain (4.0 ± 3.7) and ASES (46.4 ± 35.9) scores that exceeded MCID thresholds. CONCLUSION: Patients who develop subscapularis dysfunction after TSA have significantly worse PROMs, ROM, functional tasks of internal rotation, and radiographic outcomes, as well as increased rates of revision. Although patients show worse outcomes and high revision rates compared with their normal-functioning counterparts, these patients maintained improvement above MCID thresholds for pain and function at a mean 5-year follow-up.

Impact of humeral stem length on calcar resorption in anatomic total shoulder arthroplasty.

BACKGROUND: Use of standard-length anatomic total shoulder (TSA) humeral stems has been associated with high rates of medial calcar bone loss. Calcar bone loss has been attributed to stress shielding, debris-induced osteolysis, and undiagnosed infection. Short stem and canal-sparing humeral components may provide more optimal stress distribution and thus lower rates of calcar bone loss related to stress shielding. The purpose of this study is to determine whether implant length will affect the rate and severity of medial calcar resorption. METHODS: A retrospective review was performed on TSA patients treated with three different-length humeral implants (canal-sparing, short, and standard-length designs). Patients were matched 1:1:1 based on both gender and age (±4 years), resulting in 40 patients per cohort. Radiographic changes in medial calcar bone were evaluated and graded on a 4-point scale, from the initial postoperative radiographs to those at 3 months, 6 months, and 12 months. RESULTS: The presence of any degree of medial calcar resorption demonstrated an overall rate of 73.3% at one year. At 3 months, calcar resorption was observed in 20% of the canal-sparing cohort, while the short and standard designs demonstrated resorption in 55% and 52.5%, respectively (P = .002). At 12 months, calcar resorption was seen in 65% of the canal-sparing design, while both the short and standard designs had a 77.5% rate of resorption (P = .345). The severity of calcar resorption for the canal-sparing cohort was significantly lower at all time points when compared to the short stem (3 months, P = .004; 6 months, P = .003; 12 months, P = .004) and at 3 months when compared to the standard-length stem (P = .009). CONCLUSION: Patients treated with canal-sparing TSA humeral components have significantly lower rates of early calcar resorption with less severe bone loss when compared to patients treated using short and standard-length designs.

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.

Radiographic and anatomic variations on postoperative acromion fractures after inlay and lateralized reverse shoulder arthroplasty.

INTRODUCTION: Postoperative fracture of the acromion is a complication uniquely more common after reverse shoulder arthroplasty (RSA) than other forms of shoulder arthroplasty. There is limited knowledge regarding the etiology of these fractures or the anatomic risk factors. The purpose of this study is to identify associations of the acromioclavicular (AC) joint and relative humeral and glenoid positioning on the occurrence of acromial fractures after RSA. METHODS: A retrospective case-controlled study was performed on primary RSA patients treated by a single surgeon from September 2009 to September 2019. Patients with a postoperative acromion fracture were matched in a 3:1 ratio based on gender, indication, and age to those without a fracture and with a 2-year minimum follow-up. Preoperative and the immediate postoperative radiographs were reviewed by 2 investigators to measure critical shoulder angle, acromion-humeral interval, global lateralization, delta angle, preoperative glenoid height, and the level of inlay or onlay of the humeral stem. The morphology, width, and stigmata of osteoarthritis in the AC joint were assessed using computed tomography scans taken preoperatively. RESULTS: Of a total of 920 RSAs performed, 47 (5.1%) patients suffered a postoperative acromion fracture. These patients were compared with a control group of 141 patients, with a mean age of 76.4 years and similar distributions of gender and surgical indication. Patients in both groups had similar preoperative glenoid height (P = .953) and postoperative degree of inset or offset of humeral implant relative to the anatomic neck (P = .413). There were no differences in critical shoulder angle, acromion-humeral interval, global lateralization, and delta angle both preoperatively and postoperatively between the fracture and nonfracture groups. Computed tomography analysis also showed no differences in AC joint morphology (P = .760), joint space (P = .124), and stigma of osteoarthritis (P = .161). CONCLUSION: There was no relation between the features of the AC joint and the anatomic parameters of the humerus relative to the glenoid and acromion on postoperative acromion fractures after RSA.

Iron deficiency anemia is associated with increased medical and implant-related complications and length of stay for patients undergoing total shoulder arthroplasty.

BACKGROUND: Iron deficiency anemia (IDA) is associated with decreased bone mineral density and osteoporosis; however, studies investigating the effects of IDA in patients undergoing primary total shoulder arthroplasty (TSA) have not been well studied. The purpose of this study is to utilize a nationwide administrative claims database to investigate whether patients with diagnosed IDA undergoing primary TSA have higher rates of 1) in-hospital length of stay (LOS); 2) medical complications; and 3) implant-related complications. METHODS: A retrospective review from 2005 to 2014 was conducted using the Medicare Standard Analytical Files. Patients with IDA undergoing primary TSA were identified and matched to controls without IDA, in a 1:5 ratio by age, sex, and medical comorbidities. Outcomes analyzed included in-hospital LOS and 90-day medical and implant-related complications. Mann-Whitney U tests compared in-hospital LOS, and multivariate logistic regression was used to calculate odds ratios (ORs) on the effects of IDA on postoperative complications after adjusting for age, sex, and Elixhauser Comorbidity Index. RESULTS: A total of 17,689 patients with IDA and 88,445 without IDA participated in the matched-cohort analysis, with no differences in age, gender, and comorbidities (P = .99). IDA patients were found to have significantly longer in-hospital LOS (3-days vs. 2-days, P < .0001). IDA patients were also found to have significantly higher odds of 90-day implant-related complications (OR: 1.65, P < .0001), such as periprosthetic joint infections (OR: 1.80, P < .0001) and 90-day medical complications (OR: 2.87, P < .0001), including blood transfusions (OR: 10.37, P < .0001). CONCLUSION: Patients with IDA undergoing primary TSA have significantly longer in-hospital LOS, and medical and implant-related complications. Patients were 10 times more likely to undergo a blood transfusion and 2 times more likely to have a periprosthetic fracture.

Comparison of reverse shoulder arthroplasty and total shoulder arthroplasty for patients with inflammatory arthritis.

BACKGROUND: End-stage glenohumeral joint arthritis is common in patients with inflammatory arthritis. Reverse shoulder arthroplasty (RSA) and anatomic total shoulder arthroplasty (TSA) are both indicated in this setting. RSA is often considered based on the impacts of long-standing inflammatory arthritis including glenoid and humeral bone erosion and rotator cuff insufficiency. However, acromial and scapular spine fractures following RSA have been reported more commonly in these patients, which can have a significant impact on outcomes. Currently, no study has directly compared the efficacy and complication rates of RSA vs. TSA in patients with inflammatory arthritis. This study aimed to investigate differences in clinical outcomes and complications in patients undergoing RSA vs. TSA with glenohumeral inflammatory arthritis. METHODS: We performed a retrospective review of 86 patients with inflammatory arthritis treated with primary RSA (n = 43) or TSA (n = 43) with a minimum of 2 years' follow-up. American Shoulder and Elbow Surgeons scores, Simple Shoulder Test scores, visual analog scale scores for pain and function, active range of motion, and patient self-ratings of upper-extremity normality (Subjective Assessment of Normal Evaluation [SANE]) were collected preoperatively and at minimum 2-year follow-up. Radiographic classification of preoperative glenoid and humeral bone loss was performed, and postoperative complications were observed. Revision and complication details were compared. RESULTS: The study cohort had an average age of 72.1 years (range, 31-92 years) and average follow-up period of 51.6 months (range, 22-159 months). Both the RSA and TSA cohorts demonstrated improvements in patient-reported outcome measures and ranges of motion; however, patients treated with TSA showed a greater postoperative final Simple Shoulder Test score (P < .001), visual analog scale score for function (P = .0347), active elevation (P = .0331), active external rotation (P < .001), active internal rotation (P = .005), and Single Assessment Numeric Evaluation (SANE) score (P = .0161). Analysis of complication rates demonstrated no statistically significant difference between cohorts. Four acromial fractures occurred in the RSA group. When RSA patients who sustained acromial fractures were removed from the analysis, there were minimal differences in outcomes between the RSA and TSA cohorts. CONCLUSION: TSA in patients with inflammatory arthritis leads to improved clinical outcomes but higher early revision rates when compared with RSA. RSA outcomes are negatively impacted by a high rate of postoperative acromial fractures.

Anatomic and reverse shoulder arthroplasty for management of type B2 and B3 glenoids: a matched-cohort analysis.

BACKGROUND: Severe glenohumeral osteoarthritis (GHOA) with posterior glenoid erosion remains challenging to address for shoulder surgeons. Whereas anatomic total shoulder arthroplasty (TSA) has historically been the treatment of choice, reverse shoulder arthroplasty (RSA) offers an alternative option. Limited evidence exists directly comparing these 2 treatments in a similar patient population. The purpose of this study was to compare the clinical outcomes of patients with GHOA and Walch type B2 and B3 glenoid morphologies treated with TSA vs. RSA. METHODS: We performed a multicenter retrospective cohort study of patients with GHOA who were treated with primary shoulder arthroplasty and had a minimum follow-up period of 2 years. Preoperative computed tomography was used to determine type B2 and B3 glenoid morphology as described by the modified Walch classification. Three-dimensional perioperative planning software was used to characterize glenoid retroversion and humeral subluxation. Patients were categorized based on type of arthroplasty (TSA or RSA) and were matched 1:1 by sex, Walch classification, and age. Patient-reported outcome measures, active range of motion, presence and severity of glenoid loosening, and complications were compared. The percentage of patients who reached previously established clinically significant thresholds of the minimal clinically important difference and substantial clinical benefit for the American Shoulder and Elbow Surgeons score was also comparatively assessed. RESULTS: In total, 202 patients (101 per group) with GHOA and type B2 or B3 glenoids were included in the 1:1 matched analysis. The mean length of follow-up (± standard deviation) was 39 ± 18.7 months. The cohorts were well matched, with no differences in sex, age, American Society of Anesthesiologists score, body mass index, preoperative glenoid morphology (Walch classification), glenoid retroversion, or posterior subluxation (P > .05). RSA was associated with a lower postoperative visual analog scale pain score (0.5 in RSA group vs. 1.2 in TSA group, P = .036); however, no other no other significant differences in patient-reported significant differences in patient-reported outcome measures were found. Most patients in both groups (95.0% in TSA group vs. 98.0% in RSA group, P = .436) reached the minimal clinically important difference, and 82% of TSA patients and 90% of RSA patients reached the substantial clinical benefit value (P = .292). No significant differences in the overall complication rate (P = .781) and active range of motion were found, with the exception of internal rotation (scored on a numeric scale) being worse in the RSA group (2.7 preoperatively and 5.2 postoperatively in RSA group vs. 3.9 and 6.5, respectively, in TSA group; P < .001). Baseplate loosening occurred in 2 RSA cases, and 29 TSA cases had glenoid radiolucencies (P < .001), with 3 grossly loose glenoid components. CONCLUSION: Primary RSA results in short-term outcomes largely comparable to those of TSA in patients with Walch type B2 or B3 glenoid morphology. Both TSA and RSA provide substantial clinical benefit to patients with significant posterior glenoid wear.

Indication matters: effect of indication on clinical outcome following reverse total shoulder arthroplasty-a multicenter study.

BACKGROUND: As the utilization and success of reverse total shoulder arthroplasty (RTSA) have continued to grow, so have its surgical indications. Despite the adoption of RTSA for the treatment of glenohumeral osteoarthritis (GHOA) with an intact rotator cuff and irreparable massive rotator cuff tears (MCTs) without arthritis, the literature remains sparse regarding the differential outcomes after RTSA among these varying indications. Thus, the purpose of this study was to examine the postoperative clinical outcomes of RTSA based on indication. METHODS: A retrospective review of 2 large institutional databases was performed to identify all patients who underwent RTSA between 2015 and 2019 with minimum 2-year follow-up. Patients were stratified by indication into 3 cohorts: GHOA, rotator cuff tear arthropathy (CTA), and MCT. Baseline demographic characteristics were collected to determine differences between the 3 cohorts. Clinical outcomes were measured preoperatively and postoperatively, including active range of motion, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation score, and visual analog scale pain score. Multivariate linear regression was performed to determine the factors independently predictive of the postoperative ASES score. RESULTS: A total of 625 patients (383 with GHOA, 164 with CTA, and 78 with MCTs) with a mean follow-up period of 33.4 months were included in the analysis. Patients with GHOA had superior ASES scores (85.6 ± 15.7 vs. 76.6 ± 20.8 in CTA cohort [P < .001] and 75.9 ± 19.9 in MCT cohort [P < .001]), Single Assessment Numeric Evaluation scores (86 ± 20.9 vs. 76.7 ± 24.1 in CTA cohort [P < .001] and 74.2 ± 25.3 in MCT cohort [P < .001]), and visual analog scale pain scores (median [interquartile range], 0.0 [0.0-1.0] vs. 0.0 [0.0-2.0] in CTA cohort [P < .001] and 0.0 [0.0-2.0] in MCT cohort [P < .001]) postoperatively. Postoperative active forward elevation (P < .001) and improvement in active external rotation (P < .001) were greatest in the GHOA cohort compared with other indications. Multivariate linear regression demonstrated that the factors independently associated with the postoperative ASES score included a diagnosis of GHOA (ß coefficient, 7.557 [P < .001]), preoperative ASES score (ß coefficient, 0.114 [P = .009]), female sex (ß coefficient, -4.476 [P = .002]), history of surgery (ß coefficient, -3.957 [P = .018]), and postoperative complication (ß coefficient, -13.550 [P < .001]). CONCLUSION: RTSA for the treatment of GHOA generally has superior patient-reported and functional outcomes when compared with CTA and MCTs without arthritis. Long-term follow-up is needed to identify the lasting implications of such outcome differences.

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.

Nonoperative treatment of acromial fractures following reverse shoulder arthroplasty: clinical and radiographic outcomes.

BACKGROUND: Acromion/scapular spine fractures (ASFs) remain a challenging complication following reverse shoulder arthroplasty (RSA). Historically, nonoperative management has been the treatment of choice, with variable results. The purpose of this study is to report on both clinical and radiographic outcomes of nonoperative treatment. A new subclassification of Levy type II acromion fractures will be proposed, and outcomes will be evaluated in relation to the modified Levy classification. METHODS: Forty-four patients diagnosed with ASF following RSA were matched 1:3 to a control group based on gender, age, and preoperative function. All ASF patients were treated nonoperatively. Patient-reported outcome measures, consisting of American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, Single Assessment Numerical Evaluation, visual analog scale pain and function scores, satisfaction, and active range of motion were gathered preoperatively and at the most recent follow-up. Outcomes were stratified based on fracture type. Radiographic findings including fracture union, scapular rotation, progressive notching, and osteolysis were reviewed from latest follow-up and compared with initial postoperative films. RESULTS: ASFs were identified at a median of 2 months following RSA (8 type I; 22 type II; 14 type III), followed for a median of 37 months and compared to 108 matched controls. Patients with ASF had inferior clinical outcomes with a higher rate of dissatisfaction (27.8%) when compared to controls. Lateral fracture subtypes (I and IIA) were similar to controls and had little impact on outcomes. However, medial fracture subtypes (type IIB, IIC, and III) demonstrated inferior outcomes when compared to controls, with type III fracture patients demonstrating no improvement from baseline. The overall nonunion rate was 61.4%, with high rates of scapular rotation and osteolysis in medial fracture subtypes. Nonunion was associated with a higher incidence of secondary radiographic findings, including scapular rotation, progressive notching, and osteolysis. CONCLUSION: Results of nonoperative treatment of ASF following RSA differs based on fracture location. Fractures that occur at or medial to the glenoid face (IIB, IIC, III) demonstrate high rates of unsatisfactory results and worse clinical outcomes. Concerning radiographic findings of scapular tilt, progressive scapular notching and osteolysis were seen at a higher rate with medial fracture types and fracture nonunions.

Functional internal rotation is similar between lesser tuberosity osteotomy and subscapularis peel in total shoulder arthroplasty: short-term follow-up.

INTRODUCTION: Lesser tuberosity osteotomy (LTO) and subscapularis peel (Peel) are 2 common techniques used to mobilize the subscapularis tendon during anatomic total shoulder arthroplasty (TSA). The literature is inconclusive over which technique is optimal; thus, controversy exists over which technique should be performed. The purpose of this study was to compare specific functional internal rotation tasks and general outcome scores in TSA patients who received either an LTO or Peel. METHODS: A retrospective review of 563 patients treated with primary TSA using either an LTO (n = 358) or Peel (n = 205) with a minimum 2-year follow-up was performed. Subjective internal rotation, active internal rotation, and specific questions related to functional internal rotation isolated from the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgeons functional questionnaires were reviewed. Other outcome scores including visual analog scale pain and function, Single Assessment Numerical Evaluation, SST, American Shoulder and Elbow Surgeons, and revision rates were compared between the 2 groups. RESULTS: The study found no difference in postoperative functional internal rotation and range of motion between LTO and Peel. Patients who received a Peel were shown to have a slightly greater improvement in the ability to perform toileting and a higher average change in SST score that did not reach clinical significance. There was no difference in the percentage of maximal improvement, revision rate, or need for revision between the 2 groups. CONCLUSION: No difference was found between the LTO and Peel techniques in regard to functional tasks of internal rotation at short-term follow-up.

Periprosthetic humerus fractures after shoulder arthroplasty: an evaluation of available classification systems.

BACKGROUND: Periprosthetic proximal humerus fractures (PPHFs) are a detrimental complication of shoulder arthroplasty, yet their characterization and management have been poorly studied. We aimed to determine the intra- and interobserver reliability of 4 previously described PPHF classification systems to evaluate which classifications are the most consistent. METHODS: We retrospectively reviewed 32 patients (34 fractures) that were diagnosed with a PPHF between 1990 and 2017. Patient electronic medical records and research electronic data capture (REDCap) were used for data collection. Post-PPHF radiographs in multiple views for all 34 cases were organized into an encrypted, randomized Qualtrics survey. Four blinded fellowship-trained shoulder and elbow surgeons graded each fracture using previously reported classification systems by (1) Wright and Cofield (1995), (2) Campbell et al (1998), (3) Worland et al (1999), and (4) Groh et al (2008), along with selecting a preferred management strategy for each fracture. Grading was performed twice with at least 2 weeks between each randomized attempt. Intraobserver reliability was calculated as an unweighted Cohen kappa coefficient between attempt 1 and attempt 2 for each surgeon. Interobserver reliability and agreeability between surgeons' preferred management strategies were calculated for each classification system using Fleiss kappa coefficient. The kappa coefficients were interpreted using the Landis and Koch criteria. RESULTS: The average intraobserver kappa coefficient for each classification was as follows: Wright and Cofield = 0.703, Campbell = 0.527, Worland = 0.637, Groh = 0.699. The overall Fleiss kappa coefficient for interobserver reliability for each classification was as follows: Wright and Cofield = 0.583, Campbell = 0.488, Worland = 0.496, Groh = 0.483. Interobserver reliability was significantly greater with the Wright and Cofield classification. Using Landis and Koch criteria, all the classification systems assessed demonstrated only moderate interobserver agreement. Additionally, the mean interobserver agreeability kappa coefficient for preferred management strategy was 0.490, indicating only moderate interobserver agreement. CONCLUSION: There is only moderate interobserver reliability among the 4 PPHF classification systems and the preferred management strategy for the fractures assessed. Of the 4 PPHF classification systems, Wright and Cofield demonstrated the greatest mean intraobserver reliability and overall interobserver reliability. Our study highlights a need for the development of a PPHF classification system that can achieve high intra- and interobserver reliability and that can allow for a standardized treatment algorithm in the management of PPHFs.

A comparison of patient same-day discharge selection after shoulder arthroplasty before and after the COVID-19 pandemic.

Background: Early discharge has been a target of cost control efforts, given the growing demand for joint replacement surgery. Select patients are given the choice for same-day discharge (SDD) or overnight stay after shoulder arthroplasty. The COVID-19 pandemic changed patient perspectives regarding hospital visitation and admission. The purpose of this study was to determine if the COVID-19 pandemic impacted the utilization of SDD after shoulder arthroplasty. We hypothesize that patients undergoing shoulder arthroplasty after the start of the COVID-19 pandemic will have higher rates of SDD. Methods: A retrospective continuous review was performed on 370 patients who underwent a primary anatomic (total shoulder arthroplasty) or reverse shoulder arthroplasty between August 2019 and December 2020 by a single surgeon. This group of patients represent the 185 arthroplasty cases completed before the COVID-19 pandemic and the first 185 patients after the start of the pandemic. April 1, 2020, was chosen as the cutoff for pre-COVID patients, as this represents the date a statewide ban on elective surgery was declared. All patients were counseled preoperatively regarding SDD and given the choice to stay overnight, unless medically contraindicated. Demographics, medical history, length of stay, 30- and 90-day readmissions, and 90-day emergency room (ER) and urgent care visits were obtained from medical records and compared. Two-tailed student t-tests, chi-square tests, and Fischer's exact were performed where appropriate. Results: The 2 groups were similar in age, body mass index, gender distribution, and Outpatient Arthroplasty Risk Assessment score. During the collection period, there were more anatomic shoulder arthroplasties performed after (54%) than before (44%) the COVID-19 pandemic (P = .029). Patients treated after the start of the COVID-19 pandemic were almost 3 times more likely to have an SDD (P < .001), with 85.4% (158/185) of patients being discharged the same day after COVID-19, compared with 34.6% (64/185) before COVID-19. Discharge disposition (location of discharge) was significantly different, as 99% (183/185) of patients undergoing surgery after the start of the COVID-19 pandemic were discharged home, compared with 94% (174/185) of patients before COVID-19. There was no difference in 30-day readmissions, 90-day readmissions, and 90-day (ER) and urgent care visits between the 2 groups. Conclusion: Our study suggests that the COVID-19 pandemic has dramatically impacted patient choices for SDD within a single surgeon's practice, with nearly 3 times as many patients electing for SDD. Readmissions and ER visits were similar, indicating that SDD remains a safe alternative for patients after total shoulder arthroplasty and reverse shoulder arthroplasty. Level of evidence: Level III; Retrospective Comparative Study.

The Basic Shoulder Arthroplasty: Simple Shoulder Replacement for the Generalist.

Shoulder arthroplasty was first introduced through the developments of Dr. Charles Neer and over the past decade has seen several advancements. Improved recognition and training have heightened the awareness of arthroplasty as a treatment alternative both for surgeons and patients. The addition of reverse shoulder arthroplasty has been the driving force behind the explosive growth of arthroplasty and is now performed more often than anatomic shoulder arthroplasty. Although revision shoulder arthroplasty is primarily of interest to the subspecialist, it is a skill sought by the general orthopaedic surgeon. It is important for the orthopaedic surgeon to be knowledgeable about the planning, necessary skills, and management of basic shoulder arthroplasty.

Mid-term outcomes of reverse shoulder arthroplasty using the alternative center line for glenoid baseplate fixation: a case-controlled study.

BACKGROUND: A critical step in reverse shoulder arthroplasty (RSA) is glenoid baseplate fixation. In cases of glenoid bone loss, use of the anatomic glenoid center line may not provide sufficient bone support for fixation. Anteversion along the alternative center line is a described method for achieving baseplate fixation in these cases. However, concern remains regarding negative consequences in functional outcomes and complications. The purpose of this study was to compare the outcomes of RSA using the anatomic or alternative center line. METHODS: We performed a retrospective case-controlled study of patients who underwent RSA between November 2006 and August 2017, performed by a single surgeon, with a minimum of 2 years' follow-up. Patients treated with the anatomic center-line technique for baseplate fixation were matched 3:1 based on sex, indication for surgery, and age with patients treated with the alternative center-line technique. Patient-reported outcome measures (PROMs), active range of motion, and the ability to perform functional tasks of internal rotation were compared. Evaluations of the most recently obtained radiographs focused on acromial fractures, scapular notching, and glenoid loosening. RESULTS: A total of 88 patients (66 in anatomic center-line group and 22 in alternative group) participated in the matched analysis, with a mean age of 74.2 years (range, 58-89 years) and mean follow-up period of 53 months (range, 24-130 months). At the final follow-up, we found no significant differences in PROMs, including the Simple Shoulder Test score (P = .829), American Shoulder and Elbow Surgeons score (P = .601), visual analog scale pain score (P = .068), and Single Assessment Numeric Evaluation score (P = .674). Moreover, both the overall improvements in these PROMs and all active motions and functional tasks of internal rotation were not different. No radiographic evidence of glenoid loosening was found in either group, and 2 patients in each cohort (3% of the anatomic group and 9% of the alternative group) experienced an acromial fracture. Low-grade scapular notching developed in 15.2% of the anatomic group and 18.2% of the alternative center line group (P = .736). CONCLUSION: The alternative center line can be used for baseplate fixation in the setting of glenoid bone loss and leads to similar patient outcomes and functional tasks of internal rotation, as well as a low rate of complications, compared with the anatomic center line following RSA.

Reverse total shoulder arthroplasty for patients with minimal preoperative pain: a matched-cohort analysis.

BACKGROUND: Profound improvements in function have been described in patients following reverse total shoulder arthroplasty (RSA). Previous studies have demonstrated young age, high preoperative function, and neurologic dysfunction to be predictors of poor functional improvement. However, no study to date has focused on patients electing to undergo RSA for function more than pain. The purpose of this study was to compare the outcomes of RSA in patients with minimal preoperative pain with those in patients who have higher baseline pain. METHODS: We performed a retrospective matched-cohort study of RSA patients treated by a single surgeon with a minimum of 2 years' follow-up. Patients with at least moderate baseline pain (function-pain group), predefined by existing literature as a visual analog scale pain score > 3, were matched 3:1 based on sex, indication, and age to patients with minimal pain (function group), defined as a visual analog scale score ≤ 3. Patient-reported outcome measures, active range of motion, and overall satisfaction were compared. The percentage of maximal improvement in outcomes and the proportion of patients exceeding the established threshold that predicts excellent satisfaction were also compared. RESULTS: A total of 260 patients (195 in function-pain group and 65 in function group) were selected for matched analysis with a similar sex distribution; the mean age was 73.1 years, and the mean follow-up period was 50 months. No differences in most recent postoperative function, overall improvement in functional scores, and active motion were found between patients in the 2 groups (P > .05). However, pain scores improved only in patients with at least moderate baseline pain (P < .0001). Patient satisfaction was significantly different (P = .035), as 10.8% of patients who elected to undergo RSA for function were unsatisfied. The function cohort also had worse percentage of maximal Simple Shoulder Test score (P = .034) and American Shoulder and Elbow Surgeons score (P < .0001) improvement, and a lower proportion of these patients exceeded the threshold for the percentage of maximal improvement that predicts an "excellent" outcome (P < .0001). CONCLUSION: RSA patients with minimal preoperative pain achieve significant improvements in function and motion similar to those who choose to undergo RSA for both pain and function, but they are less satisfied and are less likely to achieve an excellent outcome. Patients electing to proceed with RSA with minimal pain should be counseled accordingly.