The gene expression profile and cell of origin of canine peripheral T-cell lymphoma.

BACKGROUND: Peripheral T-cell lymphoma (PTCL) refers to a heterogenous group of T-cell neoplasms with poor treatment responses and survival times. Canine PTCL clinically and immunophenotypically resembles the most common human subtype, PTCL-not otherwise specified (PTCL-NOS), leading to interest in this canine disease as a naturally occurring model for human PTCL. Gene expression profiling in human PTCL-NOS has helped characterize this ambiguous diagnosis into distinct subtypes, but similar gene expression profiling in canine PTCL is lacking. METHODS: Bulk RNA-sequencing was performed on tumor samples from 33 dogs with either CD4+ (26/33), CD8+ (4/33), or CD4-CD8- (3/33) PTCL as diagnosed by flow cytometry, and sorted CD4+ and CD8+ lymphocytes from healthy control dogs. Following normalization of RNA-seq data, we performed differential gene expression and unsupervised clustering methods. Gene set enrichment analysis was performed to determine the enrichment of canine CD4+ PTCL for human PTCL-NOS, oncogenic pathways, and various stages of T-cell development gene signatures. We utilized gene set variation analysis to evaluate individual canine CD4+ PTCLs for various human and murine T-cell and thymocyte gene signatures. Cultured canine PTCL cells were treated with a pan-PI3K inhibitor, and cell survival and proliferation were compared to DMSO-treated controls. Expression of GATA3 and phosphorylated AKT was validated by immunohistochemistry. RESULTS: While the canine CD4+ PTCL phenotype exhibited a consistent gene expression profile, the expression profiles of CD8+ and CD4-CD8- canine PTCLs were more heterogeneous. Canine CD4+ PTCL had increased expression of GATA3, upregulation of its target genes, enrichment for PI3K/AKT/mTOR signaling, and downregulation of PTEN, features consistent with the more aggressive GATA3-PTCL subtype of human PTCL-NOS. In vitro assays validated the reliance of canine CD4+ PTCL cells on PI3K/AKT/mTOR signaling for survival and proliferation. Canine CD4+ PTCL was enriched for thymic precursor gene signatures, exhibited increased expression of markers of immaturity (CD34, KIT, DNTT, and CCR9), and downregulated genes associated with the T-cell receptor, MHC class II associated genes (DLA-DQA1, DLA-DRA, HLA-DQB1, and HLA-DQB2), and CD25. CONCLUSIONS: Canine CD4+ PTCL most closely resembled the GATA3-PTCL subtype of PTCL-NOS and may originate from an earlier stage of T-cell development than the more conventionally posited mature T-helper cell origin.

Early Prosthetic Hip Dislocation: Does the Timing of the Dislocation Matter?

BACKGROUND: Early dislocation following total hip arthroplasty (THA) is a common reason for revision. The purpose of this study was to determine if the acuity of the dislocation episode affects the risk of revision surgery. METHODS: A retrospective review of a national, all-payer administrative database comprised of claims from 2010 to 2020 was used to identify patients who had a prosthetic hip dislocation at various postoperative time intervals (0 to 7, 7 to 30, 30 to 60, and 60 to 90 days). Of the 45,352 primary unilateral THA patients who had sufficient follow-up, there were 2,878 dislocations within 90 days. Dislocators were matched 1:1 based on age, sex, and a comorbidity index with a control group (no dislocation). Demographics, surgical indications, comorbidities, ten-year revision rates, and complications were compared among cohorts. Multivariable logistic regression analysis was performed to identify risk factors for revision THA following early dislocation. RESULTS: Among matched cohorts, dislocation at any time interval was associated with significantly increased odds of subsequent 10-years revision (OR [odds ratio] = 25.60 to 33.4, P < .001). Acute dislocators within 7 days did not have an increased risk of all cause revisions at 10 years relative to other early dislocators. Revision for indication of instability decreased with time to first dislocation (<7 days: 85.7% versus 60 to 90 days: 53.9%). Primary diagnoses of posttraumatic arthritis (OR = 2.53 [1.84 to 3.49], P < .001), hip fracture (OR = 3.8 [2.53 to 5.72], P < .001), and osteonecrosis (OR = 1.75 [1.12 to 2.73], P = .010) were most commonly associated with revision surgery after an early dislocation. CONCLUSIONS: Dislocation within 90 days of THA is associated with increased odds of subsequent revision. Early dislocation within 7 days of surgery has similar all cause revision-free survivorship, but an increased risk of a subsequent revision for instability when compared to patients who dislocated within 7 to 90 days.

Revision Hip Arthroplasty Performed by Fellowship-Trained Versus Non-Fellowship-Trained Surgeons: A Comparison of Perioperative Management and Complications.

BACKGROUND: Successful revision hip arthroplasty (rTHA) requires major resource allocation and a surgical team adept at managing these complex cases. The purpose of this study was to compare the results of rTHA performed by fellowship-trained and non-fellowship-trained surgeons. METHODS: A national administrative database was utilized to identify 5,880 patients who underwent aseptic rTHA and 1,622 patients who underwent head-liner exchange for infection by fellowship-trained and non-fellowship-trained surgeons from 2010 to 2020 with a 5-year follow-up. Postoperative opioid and anticoagulant prescriptions were compared among surgeons. Patients treated by fellowship-trained and non-fellowship-trained surgeons had propensity scores matched based on age, sex, comorbidity index, and diagnosis. The 5-year surgical complications were compared using descriptive statistics. Multivariable analysis was performed to determine the odds of failure following head-liner exchange when performed by a fellowship-trained versus non-fellowship-trained surgeon. RESULTS: Aseptic rTHA patients treated by fellowship-trained surgeons received fewer opioids (132 versus 165 milligram morphine equivalents per patient) and nonaspirin anticoagulants (21.4 versus 32.0%, P < .001). Fellowship-training was associated with lower dislocation rates (9.9 versus 14.2%, P = .011), fewer postoperative infections, and fewer periprosthetic fractures and re-revisions (15.2 versus 21.3%, P < .001). Head-liner exchange for infection performed by fellowship-trained surgeons was associated with lower odds of failure (31.2 versus 45.7%, odds ratio 0.76, 95% confidence interval 0.62 to 0.91, P < .001). CONCLUSIONS: rTHA performed by adult reconstruction fellowship-trained surgeons results in fewer re-revisions in aseptic cases and head-liner exchanges. Variations in resources, volumes, and perioperative protocols may account for some of the differences.

Intra-articular corticosteroid injections are associated with a dose-dependent risk of total knee arthroplasty at 5 years.

PURPOSE: Intra-articular corticosteroid injections (CSI) are used commonly for the non-operative management of patients with knee pain. Recent literature has raised concern for chondrotoxicity of CSI. The purpose of the present study is to evaluate for any dose-dependent association between CSI in non-osteoarthritic knees and subsequent total knee arthroplasty (TKA). METHODS: The Pearl Diver database identified patients with a diagnosis of knee pain without concomitant osteoarthritis who were administered CSI over a 2-year period. Patients were compared to matched and unmatched cohorts. The primary endpoint was the incidence of TKA at 5 years. Multivariable regression analysis was used to assess CSI quantity as an independent risk factor. RESULTS: 49,443 of 986,162 (5.0%) Patients diagnosed with knee pain without concomitant knee osteoarthritis who received at least one CSI were identified. At 5 years, there was a higher incidence of TKA in the matched injection cohort relative to the non-injection matched cohort (0.26 vs 0.13%; p < 0.001) and unmatched cohort (0.26 vs. 0.10%, p < 0.001). The quantity of CSI corresponded with an increased probability of TKA at 5 years; one injection: 0.22% (OR 1.23, 95% CI [0.87-1.74], p = 0.236); two injections: 0.39% (OR 1.98 CI [1.06-3.67], p = 0.03, three or more injections: 0.49% (OR 3.22 CI [1.60-6.48], p = 0.001). The average time to TKA after one CSI was 3.03 ± 2.29 years. This time was nearly halved with three CSI (1.78 ± 0.80 years, p < 0.001). CONCLUSIONS: Intra-articular corticosteroid injections in patients without knee osteoarthritis at the time of injection are associated with a dose-dependent risk of TKA at 5 years. CSI may not be as benign of a treatment modality as previously thought.

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.

Contralateral Total Hip Arthroplasty Staged Within Six Weeks Increases the Risk of Adverse Events Compared to Unilateral Surgery.

BACKGROUND: The ideal timing for bilateral total hip arthroplasty (THA) remains controversial. This study compared 90-day outcomes after simultaneous bilateral THA and contralateral surgery in staged bilateral THA to a matched cohort of unilateral procedures. METHODS: Patients undergoing primary, elective THA during 2015 to 2020 were reviewed in a national database. Of the 273,281 patients identified, 39,905 (14.6%) were bilateral. Patients were divided into cohorts of unilateral THA, simultaneous bilateral THA, and staged bilateral THA at 1 to 14 days, 15 to 42 days, 43 to 90 days, and 91 to 365 days. Bilateral THA cohorts were matched with unilateral THA patients based on demographics and comorbidities. Ninety-day outcomes after the second THA were compared between matched groups. RESULTS: Simultaneous bilateral THA resulted in higher rates of transfusion (odds ratio [OR] 4.43, 95% confidence interval 2.31-2.63, P < .001), readmission (OR 2.60, 2.01-3.39, P < .001), and any complication (OR 1.86, 1.55-2.24, P < .001) compared to unilateral THA. Contralateral THA staged at 1 to 14 days increased the risk of readmission (OR 1.83, 1.49-2.24, P < .001) and any complication (OR 1.45, 1.26-1.66, P < .001) relative to unilateral THA. Contralateral THA staged at 15 to 42 days increased the risk of periprosthetic joint infection (OR 3.15, 1.98-5.19, P < .001), readmission (OR 1.92, 1.55-2.39, P < .001), and any complication (OR 1.70, 1.46-1.97, P < .001). Contralateral THA staged beyond 42 days resulted in similar or decreased rates of adverse events relative to unilateral THA. CONCLUSIONS: Bilateral THA should be staged a minimum of 6 weeks apart in appropriately selected patients to avoid an increased risk of adverse events after the second THA compared to unilateral THA.

Elective Joint Arthroplasty Should be Delayed by One Month After COVID-19 Infection to Prevent Postoperative Complications.

BACKGROUND: It remains unclear whether a history of recent COVID-19 infection affects the outcomes and risks of complications of total joint arthroplasty (TJA). The purpose of this study was to compare the outcomes of TJA in patients who have and have not had a recent COVID-19 infection. METHODS: A large national database was queried for patients undergoing total hip and total knee arthroplasty. Patients who had a diagnosis of COVID-19 within 90-days preoperatively were matched to patients who did not have a history of COVID-19 based on age, sex, Charlson Comorbidity Index, and procedure. A total of 31,453 patients undergoing TJA were identified, of which 616 (2.0%) had a preoperative diagnosis of COVID-19. Of these, 281 COVID-19 positive patients were matched with 281 patients who did not have COVID-19. The 90-day complications were compared between patients who did and did not have a diagnosis of COVID-19 at 1, 2, and 3 months preoperatively. Multivariate analyses were used to further control for potential confounders. RESULTS: Multivariate analysis of the matched cohorts showed that COVID-19 infection within 1 month prior to TJA was associated with an increased rate of postoperative deep vein thrombosis (odds ratio [OR]: 6.50, 95% confidence interval: 1.48-28.45, P = .010) and venous thromboembolic events (odds ratio: 8.32, confidence interval: 2.12-34.84, P = .002). COVID-19 infection within 2 and 3 months prior to TJA did not significantly affect outcomes. CONCLUSION: COVID-19 infection within 1 month prior to TJA significantly increases the risk of postoperative thromboembolic events; however, complication rates returned to baseline after that time point. Surgeons should consider delaying elective total hip arthroplasty and total knee arthroplasty until 1 month after a COVID-19 infection.

Ultrasound-Guided Iliopsoas Bursal Injections for Management of Iliopsoas Bursitis After Total Hip Arthroplasty.

BACKGROUND: Iliopsoas tendonitis can cause persistent pain after total hip arthroplasty (THA). Nonoperative management of iliopsoas tendonitis includes anti-inflammatory drugs and image-guided corticosteroid injections. This study evaluated the efficacy of ultrasound-guided corticosteroid injections (US-CSIs) for iliopsoas tendonitis following THA. METHODS: We retrospectively reviewed 42 patients who received an US-CSI for iliopsoas tendonitis after primary THA between 2009 and 2020 at a single institution. Outcomes including reoperation, groin pain at last follow-up, additional intrabursal injection, and Harris Hip Score (HHS) were evaluated at a minimum of 1 year. Cross-table lateral radiographs (36 patients) or computed tomography scans (6 patients) were reviewed to determine if anterior cup overhang was present, indicating a mechanical etiology of iliopsoas tendonitis. Descriptive statistics and univariate comparison of HHS preinjection and postinjection were performed, with alpha < 0.05. RESULTS: Among the 22 patients who did not have cup overhang, four (18.2%) had persistent groin pain at mean follow-up of 40 months (range, 14-94) after US-CSI. Three patients had a second injection; none had groin pain at most recent follow-up. No patients required acetabular revision. Mean HHS improved from 74 points (range, 52-94 points) to 91 points (range, 76-100 points; P < .001) at last follow-up. Among the 20 patients who had anterior cup overhang, five underwent acetabular revision after only temporary pain relief from injection. Groin pain was resolved in all revised patients at mean follow-up of 43 months (range, 12-60) after revision. Of the remaining 15 patients, five had persistent groin pain at mean follow-up of 35 months (range, 12-83). Mean HHS improved from 69 points (range, 50-96 points) preinjection to 81 (range, 56-98 points; P = .007) at last follow-up. CONCLUSION: Resolution of groin pain was demonstrated in 78.6% of patients in the cohort; however, those who did not have acetabular overhang had higher rates of success. The overall revision rate was 11.9%. US-CSI appears to be safe and effective in the diagnosis and treatment of iliopsoas tendonitis following primary THA. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List.

BACKGROUND: In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates. METHODS: Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions. RESULTS: In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001). CONCLUSION: Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

Outpatient Total Knee Arthroplasty Shows Decreasing Complication Burden From 2010 to 2020.

BACKGROUND: The number of total knee arthroplasties (TKAs) performed on an outpatient basis continues to increase. The purpose of this study was to compare complication rates over the last decade to evaluate trends in the safety of outpatient TKA. METHODS: Patients who underwent TKA from 2010 to 2020 from a large administrative claims database were retrospectively identified and stratified based on the year of surgery. Propensity-score matching was performed to match patients who were discharged within 24 hours of surgery to inpatients based on age, sex, comorbidity index, and year of surgery. Linear regression analyses were used to compare trends from 2010 to 2020. The 90-day adverse events in the early cohort (2010-2012) were compared to those in the late cohort (2018-2020) using multivariable regression analyses. Of the 547,137 patients in the sample, 28,951 outpatients (5.3%) were propensity matched to inpatients. RESULTS: The incidence of outpatient TKA increased from 2010 to 2018 (1.9 versus 13.8%, P < .001). Despite a similar complication rate early (24.1 versus 22.6%, P = .164), outpatient TKA had fewer complications at the end of the study period (13.7 versus 16.7%, P < .001). Multivariate analyses demonstrated that the risk of any complication after outpatient TKA was lower than inpatient from 2018 to 2020 (odds ratio, 0.78; 95% confidence interval, 0.71-0.84). CONCLUSIONS: Complications in both cohorts declined dramatically suggesting improvements in quality of care over time, with the greatest decline in patients undergoing outpatient surgery. These results suggest that outpatient TKA today is not higher risk for the patient than inpatient TKA. LEVEL OF EVIDENCE: Level III.

Extensor mechanism reconstruction with allograft following total knee arthroplasty: a systematic review and meta-analysis of achilles tendon versus extensor mechanism allografts for isolated chronic patellar tendon ruptures.

BACKGROUND: Extensor mechanism rupture is a severe complication with an incidence of 0.1-2.5% after total knee arthroplasty (TKA). Achilles tendon allograft (ATA) and extensor mechanism allograft (EMA) in TKA surgery have yielded mixed clinical results. Our systematic review aims to identify the proportion of failure in extensor mechanism reconstruction after TKA using allograft and evaluate clinical and functional outcomes and the most common complications. Furthermore, we performed a meta-analysis among studies dealing with isolated patellar tendon ruptures to assess the failure rate, surgical complications, and clinical findings (extensor lag and knee range of motion) of extensor mechanism reconstruction using either ATA or EMA grafts. METHODS: A systematic review of the literature was performed following the PRISMA guidelines, including the studies dealing with the use of EMA and ATA for extensor mechanism rupture following TKA. Coleman Methodology Score and the MINORS score were used to assess the quality of the studies. A meta-analysis was performed to evaluate the failure rate, complications, and clinical findings (extensor lag and knee range of motion) of the ATA and EMA treatments in isolated patellar tendon ruptures. RESULTS: A total of 238 patients (245 knees), with a mean age ranging from 54 to 74 years, who underwent extensor mechanism reconstruction with an allograft were identified in the 18 included studies. We analysed 166 patellar tendon ruptures, 29 quadriceps tendon ruptures, and 29 patellar fractures in the analysis. A chronic injury was described in the majority of included cases. ATA and whole EMA were used in 89 patients (92 knees) and 149 patients (153 knees), respectively. The overall failure percentage was 23%, while EMA and ATA were 23 and 24%. The most common complication was extensor lag (≥ 20°). The overall incidence of postoperative infection was 7%. Eleven of 14 included papers reported more than 100° of the mean postoperative knee flexion. The percentage of patients requiring walking aids is 55 and 34.5% in ATA and EMA, respectively. The failure outcome after extensor mechanism reconstruction in isolated patellar tendon ruptures was 27%, with no statistical difference between EMA and ATA in terms of failure rate and clinical outcomes. CONCLUSIONS: Extensor mechanism reconstruction with allograft represents a valid treatment option in patients with acute or chronic rupture following total knee arthroplasty. Persistent extensor lag represents the most common complication. EMA is associated with a lower frequency of patients requiring walking aids at last follow-up, although it has similar clinical and functional outcomes to ATA. In patellar tendon ruptures, ATA has a comparable success rate with EMA. LEVEL OF EVIDENCE: Level IV, therapeutic study. TRIAL REGISTRATION: PROSPERO 2019 CRD42019141574.

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.

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.

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.

Home Health Care in Medicare-Aged Patients is Associated With Increased Early Emergency Visits, Readmissions, and Costs Following Total Knee Arthroplasty.

BACKGROUND: Home health services are utilized in order to provide at-home care following total knee arthroplasty (TKA). The purpose of this study is to determine whether patients receiving home health services post-operatively had lower rates of complications, emergency room visits, and readmissions as well as to determine if home health provided value by reducing total episode-of-care costs. METHODS: The PearlDiver database was retrospectively reviewed to identify all primary TKA patients over 65 years old from 2010 to 2018. Patients who received home health services were matched using a propensity score algorithm to a set of similar patients who were discharged home under self-care. We compared complication rates, emergency room visits, readmissions, and 90-day episode-of-care claims costs between the groups. Multivariate regression analysis was performed to determine the independent effect of home health services on emergency department (ED) visits and hospital readmissions. RESULTS: Of the 185,444 TKA patients discharged home, 15,849 (8.5%) received home health services. Patients who received home health services had higher rates of ED visits at 2 weeks (3.3% vs 2.8%, P = .014) and 3 months (7.1% vs 6.5%, P = .038) as well as increased readmissions at 2 weeks (0.9% vs 0.7%, P = .028); complication rates were similar between groups (11.4% vs 10.9%, P = .159). Episode-of-care costs for home health patients were higher than those discharged under self-care ($24,266 vs $22,539, P < .001). CONCLUSION: Home health services do not appear to provide value as they are associated with significantly increased costs and do not lower the rates of complications, ED visits, or readmissions following TKA.

Preoperative Opioids and the Dose-Dependent Effect on Outcomes After Total Hip Arthroplasty.

BACKGROUND: The purpose of this study is to identify the preoperative daily opioid dose associated with increased complications after primary total hip arthroplasty (THA). METHODS: Primary THA patients in the Humana claims database (2007-2020) with an opioid prescription within 3 months prior to surgery were identified. Patients were stratified based on daily opioid dose: Tier 1, <5 milligram morphine equivalents (MME); Tier 2, 5-10 MME; Tier 3, 11-25 MME; Tier 4, 26-50 MME; Tier 5, >50 MME. Each tier was matched 1:1 to opioid-naïve patients. Emergency department (ED) visits, readmissions, and postoperative complications were compared. RESULTS: In total, 67,719 patients using preoperative opioids were identified and matched. 17.0% of patients using preoperative opioids visited the ED within 90 days, compared to 13.3% of opioid-naïve patients (P < .001). About 9.5% of patients using preoperative opioids were readmitted within 90 days, compared to 7.4% of opioid-naïve patients (P < .001). When stratified by tier, opioid users in all tiers had higher risk of ED visits and readmission. Rates of superficial infection, periprosthetic joint infection, and dislocation were increased in patients taking preoperative opioids in Tiers 2 through 5. Patients in Tiers 3 through 5 had an increased risk of revision surgery. CONCLUSION: Preoperative opioid use is associated with a dose-dependent increase in complications after THA. Just one 5 mg hydrocodone tablet daily leads to a significant increase in ED visits and readmission, while higher doses are associated with dislocation, superficial infection, periprosthetic joint infection, and revision surgery. Continued education regarding the harmful effects of opioids prescribed for the nonoperative treatment of osteoarthritis is still needed. LEVEL OF EVIDENCE: Level III.

COVID-19 Infection After Total Joint Arthroplasty Is Associated With Increased Complications.

BACKGROUND: The impact of a postoperative diagnosis of COVID-19 in patients undergoing total joint arthroplasty (TJA) remains unknown. The objective of this study is to characterize the effect of COVID-19 infection following TJA on perioperative complication rates. METHODS: The Mariner database was queried for patients undergoing total hip and total knee arthroplasty from January 2018 to April 2020. TJA patients who were diagnosed with COVID-19 within 90 days postoperatively were matched in a 1:3 fashion based on age, gender, iron deficiency anemia, payer status, and Charlson Comorbidity Index with patients who were not diagnosed with COVID-19. Preoperative comorbidity profiles and complications within 3 months of surgery were compared. Statistical analysis included chi-squared tests and multivariate logistic regression with outcomes considered significant at P < .05. RESULTS: Of the 239 COVID-19 positive patients, 132 (55.2%) underwent total hip arthroplasty. On multivariate analysis, COVID-19 diagnosis was associated with increased odds of deep vein thrombosis (odds ratio [OR] 4.86, 95% confidence interval [CI] 2.10-11.81, P < .001), pulmonary embolism (OR 6.27, 95% CI 2.57-16.71, P < .001), and all complications (OR 3.36, 95% CI 2.47-4.59, P < .001). Incidence of deep vein thrombosis/pulmonary embolism was greater the closer in time the COVID-19 diagnosis was to the surgical procedure (10.24 times at 1 month, 7.87 times at 2 months, and 1.42 times at 3 months; P < .001). A similar relationship was observed with all complications. CONCLUSION: Postoperative COVID-19 infection is associated with higher rates of cardiopulmonary complications, thromboembolic disease, renal injury, and urinary tract infections in patients undergoing hip and knee arthroplasty. COVID-19 infection earlier in the postoperative period is associated with a higher risk of complications.

The Cost-Effectiveness of Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty.

BACKGROUND: The purpose of this study is to evaluate the cost-effectiveness of tibial cones in revision total knee arthroplasty. METHODS: A Markov model was used for cost-effectiveness analysis. The average cone price was obtained from Orthopedic Network News. The average cone aseptic loosening rate was determined by literature review. Hospitalization costs and baseline re-revision rates were calculated using the PearlDiver Database. RESULTS: The maximum cost-effective cone price varied from $3514 at age 40 to $648 at age 90, compared to the current average selling price of $4201. Cones became cost-effective with baseline aseptic loosening rates of 0.89% annually at age 40 to 4.38% annually at age 90, compared to the current average baseline loosening rate of 0.76% annually. CONCLUSION: For the average patient, tibial cones are not cost-effective, but may become so at lower prices, in younger patients, or in patients at substantially increased risk of aseptic loosening.

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.