How Fellowship Training Affects Complication Rate After Shoulder Arthroplasty: A Nationwide Assessment.

BACKGROUND: Total shoulder arthroplasty is performed by orthopedic surgeons with various fellowship training backgrounds. Whether surgeons performing shoulder arthroplasty with different types of fellowship training have differing rates of complications and reoperation remains unknown. METHODS: The PearlDiver Mariner database was retrospectively queried from the years 2010-2022. Patients undergoing shoulder arthroplasty were selected using the CPT code 23472. Those undergoing revision arthroplasty and those with a history of fracture, infection, or malignancy were excluded. Fellowship was determined and verified via online search. Only surgeons who performed a minimum of 10 cases were selected; and PearlDiver was queried using their provider ID codes. Primary outcome measures included 90-day, 1-year, and 5-year rates of complication and reoperation. A Bonferroni correction was utilized in which the significance threshold was set at p≤0.00023 RESULTS: In total, 150,385 patients met the inclusion criteria and were included in the study. Analysis of surgical trends revealed that Sports Medicine and Shoulder and Elbow fellowship- trained surgeons are performing an increasing percentage of all shoulder arthroplasty over time, with each cohort exhibiting am 11.3% and 4.2% increase from 2010 to 2022, respectively. The geographic region with the highest proportion of cases performed by Sports Medicine surgeons was the West, while the Northeast has the highest proportion of cases performed by Shoulder and Elbow surgeons. Shoulder and Elbow surgeons operated on patients that were significantly younger and had fewer comorbidities. Both Shoulder and Elbow and Sports Medicine surgeons had lower rates of postoperative complications at 90 days, 1 year and 5 years in comparison to surgeons who completed another type of fellowship or no fellowship. Across each time point, the rates of individual complications between Sports Medicine and Shoulder and Elbow were comparable, but the pooled complication rate was lowest in the Shoulder and Elbow cohort. CONCLUSION: Surgeons who have completed either a Sports Medicine or Shoulder and Elbow fellowship are performing an increasing proportion of shoulder arthroplasty over time. Sports Medicine and Shoulder and Elbow-trained surgeons have significantly lower complication rates at 90 days, 1 year and 5 years postoperatively. The individual complication rates between Sports Medicine and Shoulder and Elbow are comparable, but Shoulder and Elbow has the lowest pooled complication rates overall.

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

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

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.

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

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

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

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

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

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

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

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

Do total shoulder arthroplasty implants corrode?

BACKGROUND: Total shoulder arthroplasty (TSA) has become the gold-standard treatment to relieve joint pain and disability in patients with glenohumeral osteoarthritis who do not respond to conservative treatment. An adverse reaction to metal debris released due to fretting corrosion has been a major concern in total hip arthroplasty. To date, it is unclear how frequently implant corrosion occurs in TSA and whether it is a cause of implant failure. This study aimed to characterize and quantify corrosion and fretting damage in a single anatomic TSA design and to compare the outcomes to the established outcomes of total hip arthroplasty. METHODS: We analyzed 21 surgically retrieved anatomic TSAs of the same design (Tornier Aequalis Pressfit). The retrieved components were microscopically examined for taper corrosion, and taper damage was scored. Head and stem taper damage was quantitatively measured with a non-contact optical coordinate-measuring machine. In selected cases, damage was further characterized at high magnifications using scanning electron microscopy. Energy-dispersive x-ray spectroscopy and metallographic evaluations were performed to determine underlying alloy microstructure and composition. Comparisons between groups with different damage features were performed with independent-samples t tests; Mann-Whitney tests and multivariate linear regression were conducted to correlate damage with patient factors. The level of statistical significance was set at P < .05. RESULTS: The average material loss for head and stem tapers was 0.007 mm3 and 0.001 mm3, respectively. Material loss was not correlated with sex, age, previous implant, or time in situ (P > .05). We observed greater volume loss in head tapers compared with stem tapers (P = .002). Implants with evidence of column damage had larger volumetric material loss than those without such evidence (P = .003). Column damage aligned with segregation bands within the alloy (preferential corrosion sites). The average angular mismatch was 0.03° (standard deviation, 0.0668°), with negative values indicating distal engagement and positive values indicating proximal engagement. Implants with proximal engagement were significantly more likely to have column damage than those with distal engagement (P = .030). DISCUSSION: This study has shown not only that the metal components of TSA implants can corrode but also that the risk of corrosion can be reduced by (1) eliminating preferential corrosion sites and (2) ensuring distal engagement to prevent fluid infiltration into the modular junction.

Does native glenoid anatomy predispose to shoulder instability? An MRI analysis.

BACKGROUND: It is unclear if native glenohumeral anatomic features predispose young patients to instability and if such anatomic risk factors differ between males and females. The purpose of this study was to compare glenoid and humeral head dimensions between patients with a documented instability event without bone loss to matched controls and to evaluate for sex-based differences across measurements. The authors hypothesized that a smaller glenoid width and glenoid surface area would be significant risk factors for instability, whereas humeral head width would not. METHODS: A prospectively maintained database was queried for patients aged <21 years who underwent magnetic resonance imaging (MRI) for shoulder instability. Patients with prior shoulder surgery, bony Bankart, or glenoid or humeral bone loss were excluded. Patients were matched by sex and age to control patients who had no history of shoulder instability. Two blinded independent raters measured glenoid height, glenoid width, and humeral head width on sagittal MRI. Glenoid surface area, glenoid index (ratio of glenoid height to width), and glenohumeral mismatch ratio (ratio of humeral head width to glenoid width) were calculated. RESULTS: A total of 107 instability patients and 107 controls were included (150 males and 64 females). Among the entire cohort, there were no differences in glenoid height, glenoid width, glenoid surface area, humeral head width, or glenoid index between patients with instability and controls. Overall, those with instability had a greater glenohumeral mismatch ratio (P = .029) compared with controls. When stratified by sex, female controls and instability patients showed no differences in any of the glenoid or humerus dimensions. However, males with instability had a smaller glenoid width by 3.5% (P = .017), smaller glenoid surface area by 5.2% (P = .015), and a greater glenohumeral mismatch ratio (P = .027) compared with controls. CONCLUSION: Compared with controls, males with instability were found to have smaller glenoid width and surface area, and a glenoid width that was proportionally smaller relative to humeral width. In contrast, bony glenohumeral morphology did not appear to be a significant risk factor for instability among females. These sex-based differences suggest that anatomic factors may influence risk of instability for male and female patients differently.

Characteristics and risk factors for 90-day readmission following shoulder arthroplasty.

BACKGROUND: Anatomic total shoulder arthroplasty (TSA) and reverse TSA are the standard of care for end-stage shoulder arthritis. Advancements in implant design, perioperative management, and patient selection have allowed shorter inpatient admissions. Unplanned readmissions remain a significant complication. Identification of risk factors for readmission is prudent as physicians and payers prepare for the adoption of bundled care reimbursement models. The purpose of this study was to identify characteristics and risk factors associated with readmission following shoulder arthroplasty using a large, bi-institutional cohort. METHODS: A total of 2805 anatomic TSAs and 2605 reverse TSAs drawn from 2 geographically diverse, tertiary health systems were examined for unplanned inpatient readmissions within 90 days following the index operation (primary outcome). Forty preoperative patient sociodemographic and comorbidity factors were tested for their significance using both univariable and multivariable logistic regression models, and backward stepwise elimination selected for the most important associations for 90-day readmission. Readmissions were characterized as either medical or surgical, and subgroup analysis was performed. A short length of stay (discharge by postoperative day 1) and discharge to a rehabilitation or skilled nursing facility were also examined as secondary outcomes. Parameters associated with increased readmission risk were included in a predictive model. RESULTS: Within 90 days of surgery, 175 patients (3.2%) experienced an unanticipated readmission, with no significant difference between institutions (P = .447). There were more readmissions for surgical complications than for medical complications (62.9% vs. 37.1%, P < .001). Patients discharged to a rehabilitation or skilled nursing facility were significantly more likely to be readmitted (13.1% vs. 8.8%, P = .049), but a short inpatient length of stay was not associated with an increased rate of 90-day readmission (42.9% vs. 41.3%, P = .684). Parameter selection based on predictive ability resulted in a multivariable logistic regression model composed of 16 preoperative patient factors, including reverse TSA, revision surgery, right-sided surgery, and various comorbidities. The area under the receiver operator characteristic curve for this multivariable logistic regression model was 0.716. CONCLUSION: Risk factors for unplanned 90-day readmission following shoulder arthroplasty include reverse shoulder arthroplasty, surgery for revision and fracture, and right-sided surgery. Additionally, there are several modifiable and nonmodifiable risk factors that can be used to ascertain a patient's readmission probability. A shorter inpatient stay is not associated with an increased risk of readmission, whereas discharge to post-acute care facilities does impose a greater risk of readmission. As scrutiny around health care cost increases, identifying and addressing risk factors for readmission following shoulder arthroplasty will become increasingly important.

Short stay after shoulder arthroplasty does not increase 90-day readmissions in Medicare patients compared with privately insured patients.

BACKGROUND: As of January 1, 2021, total shoulder arthroplasty was removed from the Medicare inpatient-only list, reflecting a growing belief in the potential merits of same-day discharge regardless of insurance type. It is yet unknown whether Medicare populations, which frequently have more severe comorbidity burdens, would experience higher complication rates relative to privately insured patients, who are often younger with fewer comorbidities. Given the limited number of true outpatient cohorts available to study, discharge at least by postoperative day 1 may serve as a useful proxy for true same-day discharge, and we hypothesized that these Medicare patients would have increased 90-day readmission rates compared with their privately insured counterparts. METHODS: Data on 4723 total shoulder arthroplasties (anatomic in 2459 and reverse in 2264) from 2 large, geographically diverse health systems in patients having either Medicare or private insurance were collected. The unplanned 90-day readmission rate was the primary outcome, and patients were stratified into those who were discharged at least by postoperative day 1 (short inpatient stay) and those who were not. Patients with private insurance (n = 1845) were directly compared with those with Medicare (n = 2878), whereas cohorts of workers' compensation (n = 198) and Medicaid (n = 58) patients were analyzed separately. Forty preoperative variables were examined to compare overall health burden, with the χ2 and Wilcoxon rank sum tests used to test for statistical significance. RESULTS: Medicare patients undergoing short-stay shoulder arthroplasty were not significantly more likely than those with private insurance to experience an unplanned 90-day readmission (3.6% vs. 2.5%, P = .14). This similarity existed despite a substantially worse comorbidity burden in the Medicare population (P < .05 for 26 of 40 factors). Furthermore, a short inpatient stay did not result in an increased 90-day readmission rate in either Medicare patients (3.6% vs. 3.4%, P = .77) or their privately insured counterparts (2.5% vs. 2.4%, P = .92). Notably, when the analysis was restricted to a single insurance type, readmission rates were significantly higher for reverse shoulder arthroplasty compared with total shoulder arthroplasty (P < .001 for both), but when the analysis was restricted to a single procedure (anatomic or reverse), readmission rates were similar between Medicare and privately insured patients, whether undergoing a short or extended length of stay. CONCLUSIONS: Despite a substantially more severe comorbidity profile, Medicare patients undergoing short-stay shoulder arthroplasty did not experience a significantly higher rate of unplanned 90-day readmission relative to privately insured patients. A higher incidence of reverse shoulder arthroplasty in Medicare patients does increase their overall readmission rate, but a similar increase also appears in privately-insured patients undergoing a reverse indicating that Medicare populations may be similarly appropriate for accelerated-care pathways.

Appropriate patient selection for outpatient shoulder arthroplasty: a risk prediction tool.

BACKGROUND: The transition from inpatient to outpatient shoulder arthroplasty critically depends on appropriate patient selection, both to ensure safety and to counsel patients preoperatively regarding individualized risk. Cost and patient demand for same-day discharge have encouraged this transition, and a validated predictive tool may help decrease surgeon liability for complications and help select patients appropriate for same-day discharge. We hypothesized that an accurate predictive model could be created for short inpatient length of stay (discharge at least by postoperative day 1), potentially serving as a useful proxy for identifying patients appropriate for true outpatient shoulder arthroplasty. METHODS: A multicenter cohort of 5410 shoulder arthroplasties (2805 anatomic and 2605 reverse shoulder arthroplasties) from 2 geographically diverse, high-volume health systems was reviewed. Short inpatient stay was the primary outcome, defined as discharge on either postoperative day 0 or 1, and 49 patient outcomes and factors including the Elixhauser Comorbidity Index, sociodemographic factors, and intraoperative parameters were examined as candidate predictors for a short stay. Factors surviving parameter selection were incorporated into a multivariable logistic regression model, which underwent internal validation using 10,000 bootstrapped samples. RESULTS: In total, 2238 patients (41.4%) were discharged at least by postoperative day 1, with no difference in rates of 90-day readmission (3.5% vs. 3.3%, P = .774) between cohorts with a short length of stay and an extended length of stay (discharge after postoperative day 1). A multivariable logistic regression model demonstrated high accuracy (area under the receiver operator characteristic curve, 0.762) for discharge by postoperative day 1 and was composed of 13 variables: surgery duration, age, sex, electrolyte disorder, marital status, American Society of Anesthesiologists score, paralysis, diabetes, neurologic disease, peripheral vascular disease, pulmonary circulation disease, cardiac arrhythmia, and coagulation deficiency. The percentage cutoff maximizing sensitivity and specificity was calculated to be 47%. Internal validation showed minimal loss of accuracy after bias correction for overfitting, and the predictive model was incorporated into a freely available online tool to facilitate easy clinical use. CONCLUSIONS: A risk prediction tool for short inpatient length of stay after shoulder arthroplasty reaches very good accuracy despite requiring only 13 variables and was derived from an underlying database with broad geographic diversity in the largest institutional shoulder arthroplasty cohort published to date. Short inpatient length of stay may serve as a proxy for identifying patients appropriate for same-day discharge, although perioperative care decisions should always be made on an individualized and holistic basis.

A validated preoperative risk prediction tool for discharge to skilled nursing or rehabilitation facility following anatomic or reverse shoulder arthroplasty.

BACKGROUND: As bundled payment models continue to spread, understanding the primary drivers of cost excess helps providers avoid penalties and ensure equal health care access. Recent work has shown discharge to rehabilitation and skilled nursing facilities (SNFs) to be a primary cost driver in total joint arthroplasty, and an accurate preoperative risk calculator for shoulder arthroplasty would not only help counsel patients in clinic during shared decision-making conversations but also identify high-risk individuals who may benefit from preoperative optimization and discharge planning. METHODS: Anatomic and reverse total shoulder arthroplasty cohorts from 2 geographically diverse, high-volume centers were reviewed, including 1773 cases from institution 1 (56% anatomic) and 3637 from institution 2 (50% anatomic). The predictive ability of a variety of candidate variables for discharge to SNF/rehabilitation was tested, including case type, sociodemographic factors, and the 30 Elixhauser comorbidities. Variables surviving parameter selection were incorporated into a multivariable logistic regression model built from institution 1's cohort, with accuracy then validated using institution 2's cohort. RESULTS: A total of 485 (9%) shoulder arthroplasties overall were discharged to post-acute care (anatomic: 6%, reverse: 14%, P < .0001), and these patients had significantly higher rates of unplanned 90-day readmission (5% vs. 3%, P = .0492). Cases performed for preoperative fracture were more likely to require post-acute care (13% vs. 3%, P < .0001), whereas revision cases were not (10% vs. 10%, P = .8015). A multivariable logistic regression model derived from the institution 1 cohort demonstrated excellent preliminary accuracy (area under the receiver operating characteristic curve [AUC]: 0.87), requiring only 11 preoperative variables (in order of importance): age, marital status, fracture, neurologic disease, paralysis, American Society of Anesthesiologists physical status, gender, electrolyte disorder, chronic pulmonary disease, diabetes, and coagulation deficiency. This model performed exceptionally well during external validation using the institution 2 cohort (AUC: 0.84), and to facilitate convenient use was incorporated into a freely available, online prediction tool. A model built using the combined cohort demonstrated even higher accuracy (AUC: 0.89). CONCLUSIONS: This validated preoperative clinical decision tool reaches excellent predictive accuracy for discharge to SNF/rehabilitation following shoulder arthroplasty, providing a vital tool for both patient counseling and preoperative discharge planning. Further, model parameters should form the basis for reimbursement legislation adjusting for patient comorbidities, ensuring no disparities in access arise for at-risk populations.

Cost-effectiveness analyses in shoulder arthroplasty: a critical review using the Quality of Health Economic Studies (QHES) instrument.

HYPOTHESIS: The purpose of this study was to perform a systematic review to identify cost-analysis studies pertaining to shoulder arthroplasty, provide a comprehensive review of published studies, and critically evaluate the quality of the available literature using the Quality of Health Economic Studies (QHES) instrument. METHODS: A systematic review of the literature was performed to identify cost analyses examining shoulder arthroplasty. The inclusion criteria included studies pertaining to either shoulder hemiarthroplasty (HA), total shoulder arthroplasty (TSA), or reverse TSA. Articles were excluded based on the following: nonoperative studies, nonclinical studies, studies not based in the United States, and studies in which no cost analysis was performed. The quality of studies was assessed using the QHES instrument. One-sided Fisher exact testing was performed to identify predictors of both low-quality (ie, QHES score < 25th percentile) and high-quality (ie, QHES score > 75th percentile) cost analyses based on items within the QHES checklist. RESULTS: Of the 196 studies screened, 9 were included. Seven studies conducted cost analyses comparing reverse TSA vs. arthroscopic rotator cuff repair, HA, or total hip arthroplasty, and 2 studies examined TSA vs. HA for primary glenohumeral arthritis. The average QHES score among all studies was 86.22 ± 13.39 points. Failure to include an annual cost discounting rate was associated with a low-quality QHES score (P = .03). In addition, including a discussion of the magnitude and direction of potential biases was associated with a high-quality score (P = .03). CONCLUSIONS: Shoulder arthroplasty is a cost-effective procedure when used to treat a multitude of shoulder pathologies. The overall quality of cost analysis in shoulder arthroplasty is relatively good, with an average QHES score of 86.22 points. Studies failing to include an annual cost discounting rate are more likely to score below the 25th percentile, whereas those including a discussion of the magnitude and direction of potential biases are more likely to achieve a score in excess of the 75th percentile.

Efficacy of the modified Frailty Index and the modified Charlson Comorbidity Index in predicting complications in patients undergoing operative management of proximal humerus fracture.

BACKGROUND: Comorbidity indices such as the 5-factor modified Frailty Index (mFI-5) and modified Charlson Comorbidity Index (mCCI) are widely used in outcomes research. METHODS: A total of 3893 patients who underwent total shoulder arthroplasty (n=975), hemiarthroplasty (n=495), or open reduction and internal fixation (n=2423) for the treatment of proximal humerus fracture from 2005-2017 were identified from the National Surgical Quality Improvement Program database. Data regarding demographics, comorbidities, American Society of Anesthesiologists class, and postoperative complications were collected, and the mFI-5 and mCCI were calculated for each case. Multivariate logistic regression models and receiver operating characteristic curve analyses were performed. RESULTS: The patient population had a mean age of 68.0 ± 13.2 years, body mass index of 29.1 ± 8.1 and mean operative time of 119.9 ± 55.5 minutes. The most common complications within this cohort were extended length of stay (4 days or more) (1085/3893; 27.87%), transfusion (377/3893; 9.68%), unplanned reoperation (97/3893; 2.49%), urinary tract infection (43/3893; 1.10%), death (42/3893; 1.08%), and deep vein thrombosis (40/3893; 1.03%). After accounting for patient demographics, the mFI-5 (odds ratio [OR] = 1.105, P < .001) and mCCI (OR = 1.063, P < .001) were significantly associated with incidence of any adverse event. Both comorbidity indices had low positive predictive value and high negative predictive value for all adverse events. CONCLUSION: The comorbidity indices mCCI and mFI-5 are both strongly associated with adverse events but have moderate ability to predict complications following surgical treatment of proximal humerus fractures.

Development of supervised machine learning algorithms for prediction of satisfaction at 2 years following total shoulder arthroplasty.

BACKGROUND: Patient satisfaction after primary anatomic and reverse total shoulder arthroplasty (TSA) represents an important metric for gauging patients' perception of their care and surgical outcomes. Although TSA confers improvement in pain and function for most patients, inevitably some will remain unsatisfied postoperatively. The purpose of this study was to (1) train supervised machine learning (SML) algorithms to predict satisfaction after TSA and (2) develop a clinical tool for individualized assessment of patient-specific risk factors. METHODS: We performed a retrospective review of primary anatomic and reverse TSA patients between January 2014 and February 2018. A total of 16 demographic, clinical, and patient-reported outcomes were evaluated for predictive value. Five SML algorithms underwent 3 iterations of 10-fold cross-validation on a training set (80% of cohort). Assessment by discrimination, calibration, Brier score, and decision-curve analysis was performed on an independent testing set (remaining 20% of cohort). Global and local model behaviors were evaluated with global variable importance plots and local interpretable model-agnostic explanations, respectively. RESULTS: The study cohort consisted of 413 patients, of whom 331 (82.6%) were satisfied at 2 years postoperatively. The support vector machine model demonstrated the best relative performance on the independent testing set not used for model training (concordance statistic, 0.80; calibration intercept, 0.20; calibration slope, 2.32; Brier score, 0.11). The most important factors for predicting satisfaction were baseline Single Assessment Numeric Evaluation score, exercise and activity, workers' compensation status, diagnosis, symptom duration prior to surgery, body mass index, age, smoking status, anatomic vs. reverse TSA, and diabetes. The support vector machine algorithm was incorporated into an open-access digital application for patient-level explanations of risk and predictions, available at https://orthopedics.shinyapps.io/SatisfactionTSA/. CONCLUSION: The best-performing SML model demonstrated excellent discrimination and adequate calibration for predicting satisfaction following TSA and was used to create an open-access, clinical decision-making tool. However, rigorous external validation in different geographic locations and patient populations is essential prior to assessment of clinical utility. Given that this tool is based on partially modifiable risk factors, it may enhance shared decision making and allow for periods of targeted preoperative health-optimization efforts.

Return to sport following Latarjet glenoid reconstruction for anterior shoulder instability.

BACKGROUND: Latarjet coracoid transfer reconstruction is the gold standard for the treatment of recurrent shoulder instability with anterior-inferior glenoid bone loss, and return to sport is often a primary outcome of interest in this patient population. The purpose of this study was to determine the rate of return to sport in patients undergoing the Latarjet procedure and variables that are associated with a higher likelihood of a successful return to sport. METHODS: A prospectively maintained institutional registry was retrospectively queried between August 2012 and August 2016 for all patients who underwent the Latarjet procedure. Patients were contacted electronically and via telephone to administer a previously validated and standardized return-to-sport survey. Patients self-reported return to sport, varying sports participation, recurrence of instability, and time to return to sport. Multivariate analysis was performed to determine variables associated with each outcome. RESULTS: Of 83 patients, 66 (75.3%) were available for final follow-up, of whom 60 participated in sports prior to surgery and were eligible for inclusion. The average follow-up period was 53.8 ± 11.8 months. The average age at surgery was 26.7 ± 11.3 years, and the average body mass index was 26.2 ± 4.0 kg/m2. There were 54 patients (90%) who were able to return to sport at an average of 8.6 ± 4.1 months following surgery. In total, 36 patients (60%) were able to return to sport at the same level or a better level of intensity, 19 of 28 patients (67.9%) were able to return to throwing sports without difficulty, and 31 of 60 patients (51.7%) reported that their shoulder was a hindrance to some activity. An increased likelihood of returning to sport was associated with increased body mass index (P = .016), male sex (P = .028), and decreased humeral bone loss volume (P = .034). An increased likelihood of returning to sport at the same level or a better level of intensity was associated with reduced humeral bone loss volume (P = .026). Recurrent instability was associated with humeral bone loss (P = .038). CONCLUSION: Although a large majority of patients were able to return to sport following the Latarjet procedure, some patients experienced limitation with throwing and return to sport at the preinjury level. Greater humeral bone loss was associated with inferior outcomes. These findings should be discussed with patients in the preoperative setting to manage expectations appropriately.

Malnutrition in elective shoulder arthroplasty: a multi-institutional retrospective study of preoperative albumin and adverse outcomes.

BACKGROUND: Malnutrition is associated with poor postoperative outcomes after knee, hip, and spine surgery. However, whether albumin labs should be part of the routine preoperative workup for shoulder arthroplasty remains understudied. This study investigated the role of preoperative albumin levels in predicting common postoperative adverse outcomes in patients undergoing shoulder arthroplasty. METHODS: All shoulder arthroplasty cases performed at 2 tertiary referral centers between July 2013 and May 2019 (institution 1) and between June 2007 and Feb 2020 (institution 2) were reviewed. A total of 421 primary and 71 revision elective shoulder arthroplasty cases had preoperative albumin levels recorded. Common demographic variables and relevant Elixhauser comorbidities were pulled. Outcomes gathered included extended (>3 days) postoperative inpatient length of stay (eLOS), 90-day readmission, and discharge to rehab or skilled nursing facility (SNF). RESULTS: The prevalence of malnutrition (albumin <3.5 g/dL) was higher in the revision group compared with the primary group (36.6% vs. 19.5%, P = .001). Reverse shoulder arthroplasty (P = .013) and increasing American Society of Anesthesiologists score (P = .016) were identified as independent risk factors for malnutrition in the primary group. In the revision group, liver disease was associated with malnutrition (P = .046). Malnourished primary shoulder arthroplasty patients had an increased incidence of eLOS (26.8% vs. 13.6%, P = .003) and discharge to rehab/SNF (18.3% vs. 10.3%, P = .045). On univariable analysis, low albumin had an odds ratio (OR) of 2.34 for eLOS (P = .004), which retained significance in a multivariable model including age, American Society of Anesthesiologists score, sex, and body mass index (OR 2.11, P = .03). On univariable analysis, low albumin had an OR of 1.94 for discharge to SNF/rehab (P = .048), but this did not reach significance in the multivariable model. Among revisions, malnourished patients had an increased incidence of eLOS (30.8% vs. 6.7%, P = .014) and discharge to rehab/SNF (26.9% vs. 4.4%, P = .010). In both the primary and revision groups, there was no difference in 90-day readmission rate between patients with low or normal albumin. CONCLUSION: Malnutrition is more prevalent among revision shoulder arthroplasty patients compared with those undergoing a primary procedure. Primary shoulder arthroplasty patients with low preoperative albumin levels have an increased risk of eLOS and may have an increased need for postacute care. Low albumin was not associated with a risk of 90-day readmissions. Albumin level merits further investigation in large, prospective cohorts to clearly define its role in preoperative risk stratification.

Patients undergoing anatomic total shoulder arthroplasty achieve clinically significant outcomes faster than those undergoing reverse shoulder arthroplasty.

BACKGROUND: Clinically significant outcome (CSO) benchmarks have been previously established for outcome assessment after total shoulder arthroplasty. However, the time required to achieve CSO improvement is not well understood. The purpose of this study was to (1) determine the time-dependent achievement of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) in patients undergoing either anatomic total shoulder (TSA) or reverse total shoulder arthroplasty (RTSA) and compare the results of the 2 populations and (2) identify variables associated with earlier or delayed achievement of each CSO. METHODS: A prospectively maintained institutional registry was retrospectively queried for all patients receiving a primary TSA or RTSA between September 2, 2016-October 31, 2017. The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) was administered to all patients preoperatively and at standardized postoperative time periods: 5-7 months (6-month time point), 11-13 months (1-year time point), and 23-25 months (2-year time point). Cumulative percentages of CSO achievement were calculated using Kaplan-Meier survival curve analysis with interval censoring. A Weibull parametric survival regression analysis was used to investigate the influence of demographic and clinical variables on delayed or earlier CSO achievement. RESULTS: A total of 153 patients (157 shoulders) undergoing TSA (n = 76) and RTSA (n = 81) were included in the study population. The RTSA cohort was older (70.2 ± 7.5 vs. 61.0 ± 8.4, P < .001), had a lower BMI (28.8 ± 5.9 vs. 31.5 ± 6.5, P = .006), and a greater proportion of females (53.1% vs. 32.9%, P = .017) relative to TSA. For SCB, there was a significant difference in the cumulative percentage of TSA and RTSA patients reaching this threshold at both the 6-month (77.3% vs. 59.0%, P = .024) and 2-year (92.0% vs. 79.5%, P = .048) time periods, with similar findings demonstrated for PASS. There was a significant difference in the average time required to achieve the PASS (TSA: 6.1 months vs. rTSA: 11.6 months, P = .009), but not the MCID (P = .407) or SCB (P = .153). Factors significantly associated with earlier achievement of more than 1 of the CSO benchmarks were regular preoperative physical exercise and diagnosis of rotator cuff tear without osteoarthritis. CONCLUSION: Patients undergoing RTSA had lower rates of achieving SCB and PASS at both 6 months and 2 years compared to patients undergoing TSA. Patients undergoing RTSA on average required nearly double the time to achieve PASS compared with those undergoing TSA. In both groups, clinically significant improvement continued for the entire 2-year duration of study follow-up.

Return to sport and weightlifting analysis following distal biceps tendon repair.

BACKGROUND: Rupture of the distal biceps tendon is an increasingly frequent injury sustained predominantly by middle-aged men. Despite the prevalence of sport in this age group, little is known regarding return to sport outcomes following surgery. METHODS: Patients undergoing distal biceps tendon repair (DBR) between January 2015 and January 2017 were contacted electronically via e-mail and via telephone to administer a previously validated and standard return to sport survey. Patients self-reported preinjury and current level of sport and activity as well as preinjury and current level of select weightlifts. RESULTS: A total of 77 of 124 patients were available for follow-up (62.1%). Of these patients, 61 endorsed preoperative sport and were included for analysis. Average follow-up was 38.7 ± 6.7 months. The mean age at surgery was 47.5 ± 8.8 years, and the mean body mass index was 30.3 ± 5.1. The dominant side was affected in 25 of 61 cases. Of the 61 included patients, 57 (93.4%) were able to return to sport at any level (lower, same, or higher intensity than preinjury activity level). Forty of the patients (65.6%) were able to return to sport at same or higher intensity. Mean time to return to sport was 6.0 ± 2.8 months. Days from injury to surgery (odds ratio [OR] 0.999, 95% confidence interval [CI] 0.998-0.999), suture anchor fixation in comparison to suture button (OR 0.602, 95% CI 0.427-0.850), and dominant-side surgery (OR 0.749, 95% CI 0.582-0.963) were associated with a decreased likelihood to return to sport at same or higher level of duty. Single-sided incision in comparison to double (OR 5.209, 95% CI 1.239-20.903) and dominant-side surgery (OR 6.370, 95% CI 1.639-24.762) were associated with increased duration to return to sport. CONCLUSION: Distal biceps tendon rupture is a significant injury; however, patients can expect high levels of return to sport following DBR with some residual impairment compared with baseline. It is important to counsel patients on their expectations while taking into account the results of this study: that there will be a small but appreciable decrease in strength compared with preinjury levels.