Outcomes after arthroscopically assisted lower trapezius transfer with Achilles tendon allograft.

BACKGROUND: Lower trapezius tendon transfer is 1 option to improve pain and function with massive irreparable rotator cuff tears. Magnetic resonance imaging (MRI) evaluation of tendon healing with the procedure has not yet been reported. The purpose of this study was to evaluate early tendon transfer healing using postoperative MRI scans and to assess early clinical outcomes in patients after arthroscopically assisted lower trapezius tendon transfer (AALTT) for massive irreparable rotator cuff tears. METHODS: This was a single institution retrospective review of consecutive patients with massive irreparable rotator cuff tears who underwent AALTT with a single surgeon from January 2017 to July 2020 with a minimum 6-month follow-up. Patient information including age, sex, follow-up, prior surgical history, and type of work (sedentary or labor-intensive) was recorded. Preoperative and postoperative range of motion, external rotation strength, presence of a lag sign, and pain visual analog scale data were extracted from medical records. Patient-reported outcomes were extracted from patient charts. Six-month postoperative MRIs were reviewed for tendon transfer healing at both the greater tuberosity and the trapezius-allograft interface. RESULTS: A total of 19 patients met inclusion criteria with average age 56.7 (range, 29-72 years). Of these patients, 17 (89.5%) were male. The average follow-up was 14.6 (range, 6-45) months. Fifteen (78.9%) patients had unsuccessful previous rotator cuff repair. Six-month MRI demonstrated complete healing of the transferred tendon in 17 of 19 patients (89.5%). There were significant improvements in postoperative pain visual analog scale (5.9 ± 2 vs. 1.8 ± 2), ASES score (44.6 ± 18 vs. 71.2 ± 24), and Patient Reported Outcomes Measurement Information System Physical (46.3 ± 6 vs. 51.3 ± 11) and in external rotation motion (10.5 ± 17° vs. 40.5 ± 13°) and strength (2.8/5 ± 1 vs. 4.7/5 ± 0.5) at final follow-up. All patients with a preoperative external rotation lag sign had reversal of their lag sign at final follow-up (15/15). Of 17 work-eligible patients, 13 (76.4%) were able to return to work. CONCLUSION: In this series, AALTT showed a high rate of healing of the transferred tendon on MRI by 6 months postoperatively. The current findings of a high rate of early tendon transfer healing are consistent with the good early and mid-term outcomes that have been observed in AALTT and provide support for surgeon and patient expectations, postoperative rehabilitation, and return to work following AALTT for massive posterior superior rotator cuff tears.

Funding bias in shoulder arthroplasty research.

BACKGROUND: Prior research has shown that industry funding can impact the outcomes reported in medical literature. Limited data exist on the degree of bias that industry funding may have on shoulder arthroplasty literature outside of the Journal of Shoulder and Elbow Surgery. The purpose of this study is to characterize the type and frequency of funding for recently published shoulder arthroplasty studies and the impact of industry funding on reported outcomes. We hypothesized that studies with industry funding are more likely to report positive outcomes than those without. MATERIALS AND METHODS: We performed a retrospective study searching all articles with the term "shoulder arthroplasty," "reverse shoulder arthroplasty," "anatomic total shoulder arthroplasty," or "total shoulder arthroplasty" on PubMed from the years January 2020 to December 2022. The primary outcome of studies was coded as either positive, negative, or neutral. A positive result was defined as one in which the null hypothesis was rejected. A negative result was defined as one in which the result did not favor the group in which the industry-funded implant was used. A neutral result was defined as one in which the null hypothesis was confirmed. Article funding type, subcategorized as National Institutes of Health funding or industry funding was recorded. Author disclosures were recorded to determine conflicts of interest. Statistical analysis was conducted using the χ2 test and Fisher exact test. RESULTS: A total of 750 articles reported on either conflict of interest or funding source and were included in the study. Of the total number of industry-funded studies, the majority were found to have a positive primary endpoint (58.1%, 104 of 179), as compared to a negative (7.8%, 14 of 179) or neutral endpoint (33.5%, 60 of 179) (P = .004). Overall, 363 articles reported an author conflict of interest, and the majority of these studies had positive primary endpoint (55.6%, 202 of 363) as compared to negative (9.1%, 33 of 363) or neutral endpoints (34.4%, 125 of 363) (P = .002). CONCLUSION: The results of this study suggest that there is a significant relationship between conflicts of interest and the primary outcome of shoulder arthroplasty studies, beyond the overall positive publication bias. Studies with industry funding and author conflicts of interest both report positive outcomes more frequently than negative outcomes. Shoulder surgeons should be aware of this potential bias when choosing to base clinical practice on published data.

Home health care is associated with an increased risk of readmission and cost of care without reducing risk of complication following shoulder arthroplasty: a propensity-score analysis.

BACKGROUND: Home health services provide patients with additional professional care and supervision following discharge from the hospital to theoretically reduce the risk of complication and reduce health care utilization. The aim of this investigation was to determine if patients assigned home health services following total shoulder arthroplasty (anatomic [TSA] and reverse [RSA]) exhibited lower rates of medical complications, lower health care utilization, and lower cost of care compared with patients not receiving these services. METHODS: A national insurance database was retrospectively reviewed to identify all patients undergoing primary TSA and RSA from 2010 to 2019. Patients who received home health services were matched using a propensity score algorithm to a set of similar patients who were discharged home without services. We compared medical complication rates, emergency department (ED) visits, readmissions, and 90-day cost of care between the groups. Multivariate regression analysis was performed to determine the independent effect of home health services on all outcomes. RESULTS: A total of 1119 patients received home health services and were matched to 11,190 patients who were discharged home without services. There was no significant difference in patients who received home health services compared with those who did not receive home health services with respect to rates of ED visits within 30 days (OR 1.293; P = .0328) and 90 days (OR 1.215; P = .0378), whereas the home health group demonstrated increased readmissions within 90 days (OR 1.663; P < .001). For all medical complications, there was no difference between cohorts. Episode-of-care costs for home health patients were higher than those discharged without these services ($12,521.04 vs. $9303.48; P < .001). CONCLUSION: Patients assigned home health care services exhibited higher cost of care and readmission rates without a reduction in the rate of complication or early return to the ED. These findings suggest that home health care services should be strongly analyzed on a case-by-case basis to determine if a patient may benefit from its implementation.

Gender differences among shoulder arthroplasty surgeons: past, present, and future.

BACKGROUND: Reducing differences in the gender representation of shoulder arthroplasty surgeons may help optimize patient care. This work aimed to determine (1) the current gender distribution of surgeons performing shoulder arthroplasty, (2) how gender relates to practice patterns among shoulder arthroplasty surgeons, and (3) how gender distribution has been changing over time. METHODS: The Medicare Provider Utilization and Payment Data for the years 2012-2020 were used to identify orthopedic surgeons performing anatomic and reverse total shoulder arthroplasty (Current Procedural Terminology code 23472). The data set provides self-reported gender, credentials, National Provider Identifier, annual volume of all procedures (based on Current Procedural Terminology codes) that were performed ≥11 times in the calendar year, and location for all included providers. The data set was linked to the Medicare Physician Compare data set using National Provider Identifiers to determine hospital affiliations, year of medical school graduation, and graduating medical school. All included hospitals were queried to determine academic status (affiliated orthopedic residency or fellowship program). The American Shoulder and Elbow Surgeons (ASES) directory was reviewed to determine the gender breakdown of current members. RESULTS: The number of surgeons performing ≥11 shoulder arthroplasties annually increased from 821 (13 women [1.6%]) in 2012 to 1840 (53 women [2.9%], P = .05) in 2019. One female surgeon ranked in the top 100 surgeons by shoulder arthroplasty volume in 2012 and in 2020. Female surgeons graduated more recently from medical school (mean, 2005) compared with male surgeons (mean, 1997; P < .001). About 10% of female surgeons (10.8%, 12 of 111) and male surgeons (9.1%, 229 of 2528) practiced at hospitals with orthopedic residents (P = .50). Female surgeons performing shoulder arthroplasty were less likely than male surgeons to perform total knee arthroplasty (29.4% vs. 54.1%, P < .001) and total hip arthroplasty (12.6% vs. 34.7%, P < .001). There were 86 female members of ASES (6.7%, 86 of 1275), with a significant difference in the proportion of women in differing membership categories (P = .017). DISCUSSION AND CONCLUSION: A diverse cohort of high-volume shoulder replacement surgeons is integral to delivering high-quality shoulder arthroplasty. Currently, the proportion of women performing high-volume shoulder replacement in the United States is small, with little improvement in recent years. However, women performing shoulder arthroplasty are younger and are often involved in academic practices, and the membership of ASES is increasingly female. Continued efforts to promote orthopedics-and to mentor female residents and medical students interested in shoulder surgery-may bring real change to the gender differences among shoulder replacement surgeons over the coming years.

Biomechanics of subscapularis V-shaped tenotomy compared to standard tenotomy.

BACKGROUND: Subscapularis function is critical after anatomic total shoulder arthroplasty (aTSA). Recently, however, a technique has been described that features a chevron or V-shaped subscapularis tendon cut (VT). This biomechanical study compared repair of the standard tenotomy (ST), made perpendicular to the subscapularis fibers, to repair of the novel VT using cyclic displacement, creep, construct stiffness, and load to failure. METHODS: This biomechanical study used 6 pairs of fresh frozen paired cadaveric shoulder specimens. One specimen per each pair underwent VT, the other ST. Subscapularis tenotomy was performed 1 cm from the insertion onto the lesser tuberosity. For VT, the apex of the V was 3 cm from the lesser tuberosity. After tenotomy, each humerus underwent humeral head arthroplasty. Eight figure-of-8 sutures were used to repair the tenotomy (Ethibond Excel; Ethicon, US LLC). Specimens were cyclically loaded from 2 to 100 N at 45 degrees abduction at a rate of 1 Hz for 3000 cycles. Cyclic displacement, creep, and stiffness and load to failure were measured. RESULTS: Cyclic displacement did not differ significantly between the ST and VT from 1 to 3000 cycles. The difference in displacement between the V-shaped and standard tenotomy at 3000 cycles was 1.57 mm (3.66 ± 1.55 mm vs. 5.1 ± 2.8 mm, P = .31, respectively). At no point was the V-shape tenotomy (VT) >3 mm of average displacement, whereas the standard tenotomy (ST) averaged 3 mm of displacement after 3 cycles. Creep was significantly lower for VT in cycles 1 through 3. For all cycles, stiffness was not significantly different in the VT group compared with the ST group. Load to failure was not statistically significant in the VT compared to the standard tenotomy throughout all cycles (253.2 ± 27.7 N vs. 213.3 ± 76.04 N; P = .25, respectively). The range of load to failure varied from 100 to 301 N for standard tenotomy compared with 216 to 308 N for VT. CONCLUSION: This study showed that VT and ST demonstrated equivalent stiffness, displacement, and load to failure. VT had the benefit of less creep throughout the first 3 cycles, although there was no difference from cycle 4 to 3000. The VT had equivalent biomechanical properties to the ST at time zero, an important first step in our understanding of the technique. The VT technique warrants further clinical study to determine if the technique has clinical benefits over ST following aTSA.

Effect of vitamin E-enhanced highly cross-linked polyethylene on wear rate and particle debris in anatomic total shoulder arthroplasty: a biomechanical comparison to ultrahigh-molecular-weight polyethylene.

BACKGROUND: Particle-induced osteolysis resulting from polyethylene wear remains a source of implant failure in anatomic total shoulder designs. Modern polyethylene components are irradiated in an oxygen-free environment to induce cross-linking, but reducing the resulting free radicals with melting or heat annealing can compromise the component's mechanical properties. Vitamin E has been introduced as an adjuvant to thermal treatments. Anatomic shoulder arthroplasty models with a ceramic head component have demonstrated that vitamin E-enhanced polyethylene show improved wear compared with highly cross-linked polyethylene (HXLPE). This study aimed to assess the biomechanical wear properties and particle size characteristics of a novel vitamin E-enhanced highly cross-linked polyethylene (VEXPE) glenoid compared to a conventional ultrahigh-molecular-weight polyethylene (UHMWPE) glenoid against a cobalt chromium molybdenum (CoCrMo) head component. METHODS: Biomechanical wear testing was performed to compare the VEXPE glenoid to UHMWPE glenoid with regard to pristine polyethylene wear and abrasive endurance against a polished CoCrMo alloy humeral head in an anatomic shoulder wear-simulation model. Cumulative mass loss (milligrams) was recorded, and wear rate calculated (milligrams per megacycle [Mc]). Under pristine wear conditions, particle analysis was performed, and functional biologic activity (FBA) was calculated to estimate particle debris osteolytic potential. In addition, 95% confidence intervals for all testing conditions were calculated. RESULTS: The average pristine wear rate was statistically significantly lower for the VEXPE glenoid compared with the HXLPE glenoid (0.81 ± 0.64 mg/Mc vs. 7.00 ± 0.45 mg/Mc) (P < .05). Under abrasive wear conditions, the VEXPE glenoid had a statistically significant lower average wear rate compared with the UHMWPE glenoid comparator device (18.93 ± 5.80 mg/Mc vs. 40.47 ± 2.63 mg/Mc) (P < .05). The VEXPE glenoid demonstrated a statistically significant improvement in FBA compared with the HXLPE glenoid (0.21 ± 0.21 vs. 1.54 ± 0.49 (P < .05). CONCLUSIONS: A new anatomic glenoid component with VEXPE demonstrated significantly improved pristine and abrasive wear properties with lower osteolytic particle debris potential compared with a conventional UHMWPE glenoid component. Vitamin E-enhanced polyethylene shows early promise in shoulder arthroplasty components. Long-term clinical and radiographic investigation needs to be performed to verify if these biomechanical wear properties translate to diminished long-term wear, osteolysis, and loosening.

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.

Payor type is associated with increased rates of reoperation and health care utilization after rotator cuff repair: a national database study.

BACKGROUND: Despite strong evidence supporting the efficacy of rotator cuff repair (RCR), previous literature has demonstrated that socioeconomic disparities exist among patients who undergo surgery. There is a paucity of literature examining whether payor type, including Medicare, Medicaid, and commercial insurance types, impacts early medical complications and rates of reoperation after RCR. METHODS: Patients with Medicare, Medicaid, or commercial payor-type insurance who underwent primary open or arthroscopic RCR between 2010 and 2019 were identified using a large national database. Ninety-day incidence of medical complications, emergency department (ED) visit, and hospital readmission, as well as 1-year incidence of revision repair, revision to arthroplasty, and cost of care were evaluated. Propensity-score matching was used to control for patient demographic factors and comorbidities as covariates. RESULTS: A total of 113,257 Medicare, 23,074 Medicaid, and 414,447 commercially insured patients were included for analysis. Medicaid insurance was associated with an increased 90-day risk of various medical complications, ED visit (odds ratio [OR]: 2.87; P < .001), and 1-year revision RCR (OR: 1.60; P < .001) compared with Medicare insurance. Medicaid insurance was also associated with an increased risk of various medical complications, ED visit (OR: 2.98; P < .001), and hospital readmission (OR: 1.56; P = .002), as well as 1-year risk of revision RCR (OR: 1.60; P < .001) and conversion to arthroplasty (OR: 1.4358; P < .001) compared with commercially insured patients. Medicaid insurance was associated with a decreased risk of conversion to arthroplasty compared with Medicare patients (OR: 0.6887; P < .001). Medicaid insurance was associated with higher 1-year cost of care compared with patients with both Medicare (P < .001) and commercial insurance (P < .001). DISCUSSION: Medicaid insurance is associated with increased rates of medical complications, health care utilization, and reoperation after rotator cuff surgery, despite controlling for covariates. Medicaid insurance is also associated with a higher 1-year cost of care. Understanding the complex relationship between sociodemographic factors, such as insurance status, medical comorbidities, and outcomes, is necessary to ensure optimal health care access for all patients and to allow for appropriate risk stratification.

The long head of the biceps tendon: a valuable tool in shoulder surgery.

ANATOMY AND FUNCTION: The long head of the biceps tendon (LHBT) has different properties and characteristics that render it a valuable tool in the hands of shoulder surgeons. Its accessibility, biomechanical strength, regenerative capabilities, and biocompatibility allow it to be a valuable autologous graft for repairing and augmenting ligamentous and muscular structures in the glenohumeral joint. SHOULDER SURGERY APPLICATIONS: Numerous applications of the LHBT have been described in the shoulder surgery literature, including augmentation of posterior-superior rotator cuff repair, augmentation of subscapularis peel repair, dynamic anterior stabilization, anterior capsule reconstruction, post-stroke stabilization, and superior capsular reconstruction. Some of these applications have been described meticulously in technical notes and case reports, whereas others may require additional research to confirm clinical benefit and efficacy. CONCLUSION: This review examines the role of the LHBT as a source of local autograft, with biological and biomechanical properties, in aiding outcomes of complex primary and revision shoulder surgery procedures.

Effect of reverse shoulder arthroplasty humeral component retroversion on acromial strain.

INTRODUCTION: Acromion and scapular spine stress fractures can be catastrophic complications following reverse shoulder arthroplasty (RSA). A variety of host, implant, and technical factors have been identified that increase the risk of this complication. The glenoid component in particular has been closely evaluated for its impact on rates of stress fractures following RSA. The goal of this biomechanical study is to evaluate if humeral stem version has an impact on acromion and scapular spine strain after RSA. METHODS: Eight cadaveric specimens were tested on a custom dynamic shoulder frame. Commercially available RSA components were implanted with the humeral component inserted in 0° of retroversion. Acromion and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes secured to the acromion and scapular spine in the typical locations for Levy type II and type III stress fractures, respectively. The humeral stem was then removed and reimplanted in 30° of retroversion and the measurements were repeated. Student t test was performed to analyze the relationship between humeral stem version and acromion and scapular spine strain at various abduction angles. RESULTS: Strain at the both the acromion and scapular spine were found to have no significant difference at any abduction angle when comparing 0° and 30° version of the humeral stem. With 0° and 30° versions pooled together, there is significantly lower acromion and scapular spine strain at 60° of abduction when compared to 0° of abduction (strain at 0° abduction - strain at 60° abduction: acromion 313.1 µêœª; P = .0409, Scapular spine 304.9 µêœª; P = .0407). There was no significant difference in strain at either location when comparing 0° of abduction to 30° of abduction and when comparing 30° of abduction to 60° of abduction. CONCLUSIONS: This biomechanical study found no significant difference in scapular spine and acromion strain after RSA when comparing variations in humeral stem version. There does appear to be lower strain at both the acromion and scapular spine at 60° of abduction when compared to 0° of abduction regardless of stem version.

Impact of radiocapitellar interposition arthroplasty on ulnohumeral joint biomechanics.

BACKGROUND: Radial head excision (RHE) has been shown to increase contact pressures within the ulnohumeral joint. Radiocapitellar interposition arthroplasty (RCIA) with the use of a soft tissue graft is an alternative for the treatment of isolated radiocapitellar arthritis or with failure of radial head replacement. We investigated contact pressures and contact area within the ulnohumeral joint after RHE compared to RCIA with dermal autograft. METHODS: Six fresh-frozen cadaver elbows were tested on a custom dynamic elbow frame. A pressure sensor was inserted into the intact elbow joint, and mean contact pressure, peak contact pressure, contact area, and force within the ulnohumeral joint were recorded at 0°, 30°, 60°, 90°, and 120° of flexion as a valgus load was applied to the elbow. The radial head was then excised and specimens were retested. Finally, a dermal graft matched to the size of the resected radial head was inserted in the radiocapitellar space and the specimens were tested a third time. RESULTS: At 90° of flexion, contact pressure within the ulnohumeral joint was significantly lower with RCIA compared with RHE (110.8 kPa vs 216.8 kPa; P = .013). The mean peak contact pressure was also significantly lower with RCIA compared with RHE at 90° (279.4 vs 626.7 kPa; P = .025). No statistically significant differences were seen in mean contact area or force between the 3 testing conditions at any flexion position. CONCLUSION: RCIA with a dermal graft reduced contact pressures within the ulnohumeral joint compared to RHE at 90° of flexion without a significant change in contact area or contact force.

Predicting successful outpatient total shoulder arthroplasty.

BACKGROUND: Total shoulder arthroplasty (TSA) is increasingly performed safely and efficiently as an outpatient procedure in certain patients. Patient selection is often based on surgeon choice, surgeon expertise, or institutional guidelines. One orthopedic research group released a publicly available shoulder arthroplasty outpatient appropriateness risk calculator that considers patient demographic characteristics and comorbidities with the aim of helping surgeons to predict successful outpatient TSA. This study aimed to retrospectively assess the utility of this risk calculator at our institution. METHODS: Records were obtained for patients undergoing procedure code 23472 at our institution between January 1, 2018, and March 31, 2021. Patients undergoing anatomic TSA in the hospital setting were included. Records were reviewed for demographic characteristics, comorbidities, American Society of Anesthesiologists classification, and surgery duration. These data were entered into the risk calculator to calculate the likelihood of discharge by postoperative day 1. Charlson Comorbidity Index, complications, reoperations, and readmissions were also collected from patient records. Statistical analyses assessed the model's fit with our patient cohort and compared outcome measures between inpatient and outpatient groups. RESULTS: Of the 792 patients whose records were initially obtained, 289 met the inclusion criteria of anatomic TSA performed in the hospital setting. Of these patients, 7 were excluded because of missing data, leaving 282 patients: 166 (58.9%) in the inpatient group and 116 (41.1%) in the outpatient group. We found no significant differences in mean age (66.4 years in inpatient group vs. 65.1 years in outpatient group, P = .28), Charlson Comorbidity Index (3.48 vs. 3.06, P = .080), or American Society of Anesthesiologists class (2.58 vs. 2.66, P = .19). Surgery time was longer in the inpatient group than the outpatient group (85 minutes vs. 77 minutes, P = .001). Overall complication rates were low (4.2% in inpatient group vs. 2.6% in outpatient group, P = .07). Readmissions and reoperations did not differ between groups. There was no difference in the average percentage likelihood of same-day discharge (55.4% in inpatient group vs. 52.4% in outpatient group, P = .24), and a receiver operating characteristic curve to assess fit with the risk calculator demonstrated an area under the curve of 0.55. DISCUSSION: The shoulder arthroplasty risk calculator performed similarly to chance when retrospectively predicting discharge within 1 day after TSA in our patients. Complications, readmissions, and reoperations were not higher after outpatient procedures. Risk calculators for determining whether a patient should be admitted after TSA should be used cautiously because they may not provide measurable benefit over the use of surgeon experience and expertise in discharge decision making, and other factors may be relevant in the decision to perform outpatient TSA.

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.

Long head of biceps transfer to augment Bankart repair in chronic anterior shoulder instability with and without subcritical bone loss: a biomechanical study.

BACKGROUND: Treating recurrent anterior shoulder instability in participants in collision sports, patients with capsulolabral defects, and patients with bipolar bone loss remains challenging. The study purpose was to investigate the effect of long head of the biceps transfer (LHBT) on load-to-dislocation biomechanics in a repetitive serial shoulder dislocation cadaveric model comparing LHBT with the Latarjet and Bankart procedures-the first-line treatment methods for chronic traumatic anterior shoulder instability with and without anterior glenoid bone loss, respectively. METHODS: In this controlled laboratory study, 8 fresh-frozen cadaveric shoulders with different conditions were dislocated in sequence using a custom test frame. The muscle loading configuration simulated the arm in the apprehension position, and biceps loads of 20 N and 40 N were used for the static glenohumeral position analysis to evaluate the sling effect. Sequential experimental conditions consisted of the intact state, second and third dislocations, chronic instability, Bankart repair, first LHBT, subcritical glenoid bone loss, second LHBT, and Latarjet procedure. RESULTS: The pectoralis major and joint reaction loads to dislocation sequentially decreased with serial dislocations in all specimens, with the lowest value in the subcritical glenoid bone defect condition. In the setting of chronic instability, the pectoralis load to dislocation was significantly higher with the Bankart repair (P = .031) and LHBT (P < .001), at 71% and 85% of the intact value, respectively. Direct comparison of the pectoralis load to dislocation favored LHBT over Bankart repair (P = .015). In the subcritical defect scenario, LHBT did not significantly increase the load to dislocate, and the Latarjet procedure demonstrated a higher load to dislocate than LHBT (P < .001). All 3 surgical procedures tested significantly increased the angle of horizontal abduction at the time of dislocation and restored the glenohumeral position to closer to the intact state. Doubling the biceps load leveraged the sling effect, pulling the humeral head farther posterior-superiorly, but this was not enough to overcome the effect of a 20% subcritical glenoid bone defect. CONCLUSIONS: In a serial dislocation model, LHBT effectively stabilized the glenohumeral joint in a simulated chronic instability scenario, increasing the pectoralis major load-to-dislocate and glenohumeral joint reaction force components at the time of dislocation and restoring relative glenohumeral positioning to close to the intact state. The Latarjet procedure outperformed LHBT in stabilizing shoulders in the 20% subcritical glenoid bone defect condition.

Fragility of randomized controlled trials on treatment of proximal humeral fracture.

BACKGROUND: Proximal humeral fracture represents an increasingly common pathology with evaluation and treatment often guided by evidence from randomized controlled trials (RCTs), but the strength of an RCT must be considered in this process. The purpose of this study was to evaluate the strength of outcomes in RCTs on the management of proximal humeral fractures using the fragility index (FI), a method used with statistically significant dichotomous outcomes to assess the number of patients that would change an outcome measure from significant (P ≤ .05) to nonsignificant if the patient outcome changed. We also aimed to correlate the FI with other measures of study strength. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to evaluate RCTs on the management of proximal humeral fractures. The PubMed, Ovid MEDLINE, Web of Science, and Embase databases were searched from database inception to May 2021. RCTs with at least 1 statistically significant (P ≤ .05) dichotomous outcome were included. The FI was calculated for each included trial using the Fisher exact test. The FI was correlated with the study sample size and journal impact factor. RESULTS: Ten RCTs reporting on 656 patients and published between 2011 and 2020 were included. The median patient sample size was 67 (mean, 65.6; range, 40-86). Complications were the most commonly reported dichotomous statistically significant outcome. The median FI was 1 (mean, 2.6; range, 0-18), with 4 studies having an FI of 0. A median FI of 1 indicates that 1 patient experiencing an alternative outcome or having not been lost to follow-up could have changed the pertinent conclusions of the trial for a given outcome. The median number of patients lost to follow-up was 3 (mean, 4.9; range, 0-16) and exceeded the FI in 50% of studies. There was no correlation between the FI and sample size (Spearman coefficient = 0.0592, P = .865) or between the FI and journal impact factor (Spearman coefficient = -0.0229, P = .522). CONCLUSION: In most studies of proximal humeral fractures, only 1 or 2 patients experiencing an alternative outcome or lost to follow-up would change the conclusions for the dichotomous outcome studied. Although the FI cannot be used to assess continuous variables, which are often the primary outcome variables of RCTs, it does offer an additional unique measure of study strength that surgeons should consider when evaluating RCTs.

Evaluation of clinical and radiographic outcomes after total shoulder arthroplasty with inset Trabecular Metal-backed glenoid.

BACKGROUND: Trabecular Metal (TM)-backed glenoid implants were introduced for their theoretical ability to increase osseointegration while minimizing wear and the risk of loosening in total shoulder arthroplasty (TSA). Initial follow-up studies of TM-backed glenoids demonstrated high rates of metallic debris formation around the implant site, raising concerns about longevity. More recent data suggest that metallic debris formation may be less prevalent than previously reported and that the implants may have positive long-term outcomes regardless of debris. The goal of our study was to assess the clinical and radiographic outcomes at mid-term follow-up of TSA using a TM-backed glenoid implant placed with full backside support using an inset technique. We hypothesized that our clinical and radiographic outcomes would be good using this technique. METHODS: We retrospectively reviewed the charts of 39 patients who underwent 41 TSA procedures with a Zimmer Biomet TM-backed glenoid component performed by a single surgeon between January 2010 and March 2016. After exclusions for death unrelated to surgery and loss to follow-up, 35 patients (37 shoulders) with minimum 2-year clinical follow-up were included in the study. The glenoids were all placed in an inset fashion with full backside support. Clinical, patient-reported, and radiographic outcomes were analyzed. RESULTS: The average follow-up period was 7.2 years (range, 2-11 years). At final follow-up, average shoulder elevation was 153° ± 22° and average external rotation was 53° ± 12°. The average American Shoulder and Elbow Surgeons score was 86.8 ± 19.0, and the average visual analog scale score was 1.3 ± 2.4. Metallic debris was found in 9 shoulders (27%), and radiolucency was observed around the glenoid components in 13 shoulders (39%) on the final postoperative radiographs. Metallic debris and radiolucency findings were low in severity, with average grades of 0.32 (standard deviation, 0.54) and 0.39 (standard deviation, 0.50), respectively. There were no reoperations. CONCLUSION: This study of 37 shoulders undergoing TSA with a TM-backed glenoid demonstrated 100% implant survivorship at an average follow-up of 7 years. Clinical outcomes were excellent despite the occurrence of some metallic debris formation. The findings suggest that a TM-backed glenoid component implanted in an inset fashion to achieve full backside support can provide good clinical and patient-reported outcomes in TSA patients at mid-term follow-up and suggest that continued consideration of the role of TM-backed glenoids and the optimal technique for implantation may be warranted.

The relationship between academic influence, NIH funding, and industry payments among academic shoulder and elbow surgeons.

BACKGROUND: The effect of academic influence, or the volume and quality of a surgeon's publications, on industry payments and National Institutes of Health (NIH) funding has recently been studied in some academic orthopedic subspecialities. The purpose of this study is to evaluate the relationship between academic influence, industry payments, and NIH funding among American Shoulder and Elbow Surgeons accredited shoulder and elbow fellowship faculty. METHODS: Shoulder and elbow fellowships and affiliated faculty members were identified from the American Shoulder and Elbow Surgeons website. Academic influence, measured by the Hirsch (h)-index, and the number of articles published were determined for faculty members using the Scopus Database Author Identifier tool. Industry payments were derived from the Centers for Medicare and Medicaid Services Open Payments database. NIH funding was determined using the NIH's Research Portfolio Online Reporting tool. Statistical analysis used Spearman correlations and the Mann-Whitney U-test with an alpha value of 0.05 (P < .05). RESULTS: A total of 146 faculty members were included. Twenty-two percent (42 of 146) received nonresearch payments, whereas 78% (114 of 146) received industry research funding averaging $6364 (standard deviation = $21,213). NIH funding averaged $272,589 (standard deviation = $224,635), and 5% received NIH funding (7 of 146). Faculty members who received NIH funding had a higher average h-index than those who did not (38 ± 22 vs. 22.64 ± 22.7, P = .02), whereas those receiving industry research payments had a greater number of publications than those who did not (127.97 ± 127.2 vs. 100.3 ± 122.3, P = .03). Industry nonresearch payments did not impact the number of publications or the h-index. DISCUSSION/CONCLUSION: This study demonstrated that academic influence among academic shoulder and elbow surgeons is not greater in those who receive nonresearch industry funding. However, surgeons with industry research funding did produce more publications, whereas NIH funding is associated with greater academic influence.

Gender disparities in shoulder and elbow publications.

HYPOTHESIS/BACKGROUND: Female representation in orthopedics, and specifically shoulder and elbow surgery, lags behind other surgical subspecialities. There has been a growing interest in recent years to better characterize, and address, gender disparities in the field. The purpose of this investigation was to characterize gender trends in authorship in the shoulder and elbow literature from 2002 to 2020. METHODS: Articles published from January 2002 to December 2020 in 15 clinical orthopedic and shoulder- and elbow-specific journals were extracted from the online PubMed database. Articles that included the first name of the first and senior authors and contained keywords related to the shoulder and elbow subspecialty were included. The Genderize algorithm was used to determine each author's gender. Gender-based publication trends from 2002 to 2020 were analyzed using descriptive and significance testing as well as logistic regression. RESULTS: 34,695 articles met inclusion criteria and 52,497 unique authors were identified. Of these unique authors, 10,175 (19.4%) were female and 42,322 (80.6%) were male. On average, each unique female author published 1.7 ± 0.1 manuscripts since 2002 and each male author published 2.5 ± 0.2 (P < .001). Female representation in shoulder and elbow publications began at 10.2% in 2002 and rose to 15.9% in 2020 (P < .001). Female representation in the lead author position began at 4.1% in 2002 and rose to 5.8% in 2020 (P = .009). Female representation in the senior author position began at 6.0% in 2002 and rose to 9.1% in 2020 (P < .001). CONCLUSION: Although female representation in first, senior, and general authorship lags behind male representation in the shoulder and elbow literature, female authorship has significantly increased since 2002. The same men tend to publish more frequently while the number of unique female authors surpasses the annual representation of female authorship. Efforts to improve female representation in the field of orthopedic surgery should include efforts directed at improving female representation in academic literature.

An investigation into gender bias in the evaluation of orthopedic trainee arthroscopic skills.

BACKGROUND: Women surgeons receive lower compensation, hold fewer academic positions, and hold fewer leadership positions than men, particularly in orthopedic surgery. Gender bias at the trainee level has been demonstrated in various surgical subspecialties, but there is a lack of information on gender bias within the orthopedic training environment. This study investigated whether implicit gender bias is present in the subjective evaluation of orthopedic trainee arthroscopic skills. METHODS: After institutional review board approval, a web-based survey was sent to American Shoulder and Elbow Surgeons (ASES) members via the society's email listserve. Study participants were informed that the study was being done to develop a systematic evaluation method for trainees. The survey randomized participants to view and evaluate a prefellowship and a postfellowship video of "Rachel" (she/her) or "Charles" (he/him) performing a 15-point diagnostic shoulder arthroscopy. The videos for Rachel and Charles were identical except for the pronouns used in the video. Participants evaluated the trainee's skill level using questions from the Arthroscopic Surgical Skill Evaluation Tool (ASSET). Blinded and deidentified additional comments regarding the trainee's skill were classified as positive, negative, or neutral. Statistical analyses were used to compare scores and comments between Rachel and Charles. RESULTS: Of 1115 active ASES members, 181 ASES members started the survey and 106 watched both videos and were included in the analysis. Of the 106 participants completing the survey, 96 (91%) were men and 10 (9%) were women with a median (interquartile range) age of 44 (38-51). A teaching role was reported by 84 of 106 participants (79%). There was no significant difference between prefellowship scores (P = .87) or between postfellowship scores (P = .84) for the woman and man fellow. The numbers of comments classified as positive, negative, or neutral were not significantly different between the man and woman fellow (P = .19). Participants in teaching roles gave significantly lower scores to both fellows at both time points (P = .04), and participants who had fellow trainees were more likely to give negative comments to both fellows (P = .02). DISCUSSION: Trainee gender did not influence the ratings and comments participants gave for trainee arthroscopic skills, suggesting that gender bias may not play a major role in the evaluation of arthroscopic skill during orthopedic training.

Biomechanical comparison of zoned-conformity glenoid versus standard glenoid in total shoulder arthroplasty: impact on rotator cuff strain and glenohumeral translation.

BACKGROUND: Current standard total shoulder arthroplasty glenoid implants allow for high levels of glenohumeral mismatch and associated high levels of humeral head translation to improve range of motion and reduce rim stresses on the glenoid. However, high levels of glenohumeral mismatch could also increase glenoid edge loading, eccentric wear, and rotator cuff strain. A zoned-conformity glenoid may be able to reduce the forces on the rotator cuff and glenoid. We compared rotator cuff strain and glenohumeral translation between a standard glenoid (SG) with moderate glenohumeral mismatch and a zoned-conformity glenoid (conforming glenoid [CG]) that limits mismatch. We hypothesized that the CG would have lower levels of strain on the rotator cuff and lower levels of humeral head translation compared with the SG. METHODS: Eight fresh frozen cadaveric shoulders, aged 72 years (range, 67-76 years), were used in this biomechanical study. The specimens were first tested in the intact state. We cycled them 3 times from 0° to 60° of abduction and measured the superiorly-inferiorly and anteriorly-posteriorly directed forces at the joint, compressive forces applied to the glenoid, and humeral head translation. The specimens were then implanted with a standard press-fit humeral component and a polyethylene glenoid with 3 peripherally cemented pegs and a central press-fit peg. Testing was repeated. Finally, the SG was removed, the CG was implanted, and each specimen was tested a third time. RESULTS: The average superiorly directed force at the glenohumeral joint was significantly lower in the intact and CG groups (18.1 ± 18.6 N and 19.8 ± 16.2 N, respectively) than in the SG group (29.3 ± 21.9 N, P = .024). The maximum force directed against the glenoid was also significantly lower in the CG group (87.6 ± 11.7 N) than in the SG (96.0 ± 7.3 N) and intact (98.9 ± 16.5 N) groups (P = .035). No difference was observed in humeral head translation in the anterior-posterior plane from 0° to 60° of abduction (P = .998) or in the superior-inferior plane (P = .999). CONCLUSION: A zoned-conformity glenoid was associated with similar humeral head translation but significantly lower superior forces against the rotator cuff and a significantly lower maximum force against the glenoid compared with an SG implant. These biomechanical findings suggest that a zoned-conformity implant warrants further study in the effort to maintain humeral head translation while reducing rotator cuff and glenoid forces for successful outcomes of total shoulder arthroplasty.