Intravenous tranexamic acid reduces complications following surgical treatment of pathologic fractures of the lower extremity.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the postoperative complications associated with administering intravenous (IV) tranexamic acid (TXA) in patients undergoing surgical fixation for neoplastic pathologic fractures of the lower extremities. METHODS: Patients ≥18 years old who underwent surgical intervention for neoplastic pathologic lower extremity fractures from 2015 to 2021 were identified using the Premier Healthcare Database. This cohort was divided by TXA receipt on the index surgery day. Patient demographics, hospital factors, patient comorbidities, and 90-day complications were assessed and compared between the cohorts. RESULTS: From 2015 to 2021, 4497 patients met inclusion criteria (769 TXA[+] and 3728 TXA[-]). Following propensity score matching, patients who received TXA had a significantly shorter length of stay than those who did not (7.6 ± 7.3 days vs. 9.0 ± 15.2, p = 0.036). Between the two cohorts, there were no significant differences in comorbidities. Regarding differences in postoperative complications, TXA(+) patients had significantly decreased odds of deep vein thrombosis (DVT) (1.87% vs. 5.46%; odds ratio [OR]:0.33; 95% confidence interval: 0.17-0.62; p = 0.001). CONCLUSION: Administration of IV TXA may be associated with a decreased risk of postoperative DVT without an increased risk of other complications. Orthopedic surgeons should consider the utilization of IV TXA in patients treated surgically for neoplastic pathologic fractures of the lower extremity.

Total Hip Arthroplasty and the Spinopelvic Relationship: What's the Latest!

Although total hip arthroplasty (THA) has proved to be a successful surgical procedure, both prosthetic and bone impingement resulting in dislocation continue to occur. Studies have shown that spine pathology resulting in lumbar stiffness and hip arthritis often coexist. Spinopelvic mobility patterns during postural changes affect three-dimensional acetabular component position, which affects the incidence of prosthetic impingement and THA instability. Several spinopelvic risk factors that may affect THA stability have been identified. Numerous reports recommend performing a preoperative spinopelvic mobility analysis to identify risk factors and adjust acetabular component position accordingly to lessen the risk of impingement. In doing so, acetabular component position is individualized based on spinopelvic mobility patterns. Additionally, functional femoral anteversion, affected by individual femoral rotation patterns during dynamic activities, may contribute to the incidence of impingement. It is important to review the interrelationship between spine and pelvic mobility and how it relates to THA and may reduce the incidence of instability.

Total Hip and Total Knee Arthroplasty Outpatient Case Volume During the 2020 COVID-19 Pandemic in New York and California.

BACKGROUND: Inpatient total hip and total knee arthroplasty were substantially impacted by the SARS-CoV-2 (COVID-19) pandemic. We sought to characterize the transition of total joint arthroplasty (TJA) to the outpatient setting in 2 large state health systems during this pandemic. METHODS: Adult patients who underwent primary elective TJA between January 1, 2016 and December 31, 2020 were retrospectively reviewed using the New York Statewide Planning and Research Cooperative System and California Department of Health Care Access and Information datasets. Yearly inpatient and outpatient case volumes and patient demographics, including age, sex, race, and payer coverage, were recorded. Continuous and categorical variables were compared using descriptive statistics. Significance was set at P < .05. RESULTS: In New York during 2020, TJA volume decreased 16% because 22,742 fewer inpatient TJAs were performed. Much of this lost volume (46.6%) was offset by a 166% increase in outpatient TJA. In California during 2020, TJA volume decreased 20% because 34,114 fewer inpatient TJAs were performed. Much of this lost volume (37%) was offset by a 47% increase in outpatient TJA. CONCLUSIONS: This present study demonstrates a marked increase in the proportion of TJA being performed on an outpatient basis in both California and New York. In both states, despite a decrease in overall TJA volume in 2020, outpatient TJA volume increased markedly. LEVEL OF EVIDENCE: Therapeutic Level IV, Retrospective Cohort Study.

Limited Durability of Extensor Mechanism Reconstruction Following Total Knee Arthroplasty: Mesh and Allograft Show Equivalent Outcomes at Five-Year Follow-Up.

BACKGROUND: Extensor mechanism disruption is a challenging complication following total knee arthroplasty. The purpose of this study was to compare outcomes between patients who received mesh versus allograft extensor mechanism reconstruction. METHODS: All patients who underwent extensor mechanism reconstruction at a single institution were screened. Demographic and surgical variables were recorded, including technique (ie, synthetic mesh versus allograft reconstruction). Patients were assessed for preoperative and postoperative extensor lag, revision, and duration of follow-up. Analyses, including Kaplan-Meier survivorships, were performed to compare mesh to allograft reconstruction. In total, 50 extensor mechanism reconstructions (30 mesh and 20 allograft) were conducted between January 1st, 2001, and December 31st, 2022. RESULTS: There were no differences between the cohorts with respect to revision (26.7 [8 of 30] versus 35.0% [7 of 20], P = .680) or failure defined as above knee amputation or fusion (6.7 [2 of 30] versus 5.0% [1 of 20], P = .808). There were also no differences in time to reoperation (average 27 months [range, 6.7 to 58.8] versus 29 months [range, 1.2 to 84.9], P = .910) or in postoperative extensor lag among patients who did not undergo a reoperation (13 [0 to 50] versus 11° [0 to 30], P = .921). The estimated 5-year Kaplan-Meier survival with extensor mechanism revision as the endpoint was similar between the 2 groups (52.1, 95% confidence interval [CI] = 25.4 to 73.3 versus 55.0%, 95% CI = 23.0 to 78.4%, P = .990). CONCLUSIONS: The purpose of this study was to present the findings of a large cohort of patients who required extensor mechanism reconstruction. Regardless of the reconstruction type, the 5-year outcomes of patients requiring extensor mechanism reconstruction are suboptimal.

Risk Factors for Peripheral Nerve Injury Following Revision Total Knee Arthroplasty in 132,960 Patients.

BACKGROUND: Peripheral nerve injury (PNI) following revision total knee arthroplasty (rTKA) is a potentially devastating injury for patients. This study assessed the frequency of and risk factors for postoperative PNI following rTKA. METHODS: Patients who underwent rTKA from 2003 to 2015 were identified using the National Inpatient Sample. Demographics, medical histories, surgical details, and complications were compared between patients who sustained a PNI and those who did not to identify risk factors for the development of PNI after rTKA. RESULTS: Overall, 132,960 patients who underwent rTKA were identified, and 737 (0.56%) sustained a postoperative PNI. After adjusting for confounders, patients with a history of a spine condition (adjusted odds ratio [aOR]: 1.7, 95%-confidence interval 1.2 to 2.4, P = .003) and postoperative anemia (aOR: 1.3, 95%-CI: 1.1 to 1.5, P = .004) had higher risk of PNI following rTKA. Intraoperative periprosthetic fracture (aOR: 1.3, 0.78 to 2.2, P = .308), rheumatoid arthritis (aOR: 1.0, 95%-CI: 0.68 to 1.6, P = .865), and history of knee dislocation (aOR: 1.1, 95%-CI: 0.85 to 1.5, P = .412), were not significantly associated with higher risk for PNI. CONCLUSIONS: This study found a 0.56% incidence of PNI following rTKA, and patients who had preexisting spine conditions or postoperative anemia were at an increased risk for this complication. Orthopedic surgeons may use the results of this study to appropriately counsel patients on the potential for a PNI following rTKA.

Same-Day Total Joint Arthroplasty in the United States From 2016 to 2020: The Impact of the Medicare Inpatient Only List and the COVID-19 Pandemic.

BACKGROUND: Same-day total hip arthroplasty (THA) and total knee arthroplasty (TKA) continue to gain popularity in the United States. The present study sought to quantify recent same-day outpatient trends taking into consideration the COVID-19 pandemic as well as the removal of these procedures from the Medicare inpatient only (IPO) list. METHODS: Patients undergoing primary elective TKA and THA were identified using the Nationwide Ambulatory Surgery Sample and the National Inpatient Sample from January 1, 2016, to December 31, 2020. The same-day cohort included Nationwide Ambulatory Surgery Sample and National Inpatient Sample patients with a length of stay = 0 days. The inpatient cohort included patients with length of stay ≥1 day. National estimates were extrapolated using weight functions. RESULTS: From January 2016 to December 2020, the proportion of same-day TKA increased from 1.2 (719) to 62.4% (31,293) and the proportion of same-day THA increased from 2.0 (599) to 54.5% (18,252). Following removal from the Medicare IPO list, same-day TKAs increased from 3.2% (1,895) in December 2017 to 13.8% (9,269) in January 2018, and same-day THAs increased from 10.7% (4,295) in December 2019 to 22.5% (8,708) in January 2020. Between February and March 2020, same-day TKAs increased from 42.4 (26,148) to 44.4% (16,972) and same-day THAs increased from 28.5 (10,729) to 30.2% (7,409). CONCLUSIONS: The proportion of same-day TKA and THA dramatically increased following removal from the Medicare IPO list and in response to the COVID-19 pandemic. By December 2020, same-day TKA and THA accounted for >50% of all cases performed in the United States.

Dexamethasone-Associated Hyperglycemia is Not Associated With Infectious Complications After Total Joint Arthroplasty in Diabetic Patients.

BACKGROUND: Postoperative infection is a devastating complication of total joint arthroplasty (TJA). Perioperative use of dexamethasone in patients who have diabetes mellitus (DM) remains controversial due to concern for increased infection risk. This study aimed to evaluate the association between dexamethasone and infection risk among patients who have DM undergoing TJA. METHODS: This was a retrospective cohort study conducted on adult patients who underwent primary, elective total knee arthroplasty (TKA) or total hip arthroplasty (THA) between January 2016 and December 2021 using a large national database. We identified 110,568 TJA patients (TKA: 66.6%; THA: 33.4%), 31.0% (34,298) of which had DM. Patients who received perioperative dexamethasone were compared to those who did not. The primary end points were the 90-day risk of postoperative periprosthetic joint infection, surgical site infection (SSI), and other non-SSI (urinary tract infection, pneumonia, sepsis). RESULTS: When modeling the association between dexamethasone exposure and study outcomes while accounting for the interaction between dexamethasone and morning blood glucose levels, dexamethasone administration conferred no increased odds of postoperative periprosthetic joint infection nor SSI in diabetics. However, dexamethasone significantly lowered the adjusted odds of other postoperative infections in diabetic patients (TKA: adjusted odds ratio = 09, 95% confidence interval = 0.8 to 1.0, P = .030; THA: adjusted odds ratio = 0.7, 95% confidence interval = 0.6 to 0.9, P = .001); specifically in patients with morning blood glucose levels between 110 to 248 mg/dL in TKA and ≤ 172 mg/dL in THA. CONCLUSIONS: This study provides strong evidence against withholding dexamethasone in diabetic patients undergoing TJA based on concern for infection. Instead, short-course perioperative dexamethasone reduced infection risk in select patients. The narrative surrounding dexamethasone should shift away from questions about whether dexamethasone is appropriate for diabetic patients, and instead focus on how best to optimize its use.

Five-Year Incidence of Progression to Osteoarthritis and Total Joint Arthroplasty in Patients Prescribed Glucagon-Like Peptide 1 Receptor Agonists.

BACKGROUND: Research has suggested that glucagon-like peptide-1 receptor agonists (GLP-1-RAs) may have therapeutic effects on osteoarthritis of the hip and knee, in addition to managing diabetes and obesity. However, there is a lack of understanding regarding the association between GLP-1-RA use and the diagnosis of osteoarthritis (OA) of the hip and knee. METHODS: A collaborative network analytics platform was queried for obese diabetic (n = 1,094,198), obese nondiabetic (n = 916,235), and nonobese diabetic (n = 157,305) patients who had an index visit between 2015 and 2017. Patients who had pre-existing hip and/or knee OA were excluded. A 1:1 propensity score matching was used to balance GLP-1-RA use in stratified cohorts for age, sex, race, body mass index, and hemoglobin A1c. The primary outcomes were rates of progression to hip OA, knee OA, major joint injections, total hip arthroplasty, and total knee arthroplasty. Cox proportional hazards models determined hazard ratios (HRs) between cohorts prescribed and not prescribed GLP-1-RAs. RESULTS: All patients had a five-year follow-up. Rates of progression to hip and knee OA were higher among the GLP-1-RA users in both obese diabetic (hip HR: 1.63, 95% confidence interval [CI]: 1.46 to 1.82; knee HR: 1.52, CI: 1.41 to 1.64) and nonobese diabetic (hip HR: 1.78, CI: 1.50 to 2.10; knee HR: 1.58, CI: 1.39 to 1.80) cohorts. These diabetic cohorts received higher rates of major joint injections, though there was no difference in rates of total hip arthroplasty or total knee arthroplasty. No differences in five-year outcomes were seen when comparing obese, nondiabetic patients who were prescribed GLP-1-RAs with obese, nondiabetic patients not exposed to GLP-1-RAs. CONCLUSIONS: This five-year analysis found a greater risk of progression to hip and knee OA among obese and non-obese diabetic GLP-1-RA users. Further studies should explore GLP-1-RA effects upon glucose management, weight loss, and lower extremity arthritis development. LEVEL OF EVIDENCE: III, retrospective cohort study.

Perioperative Dexamethasone is Associated With a Decreased Risk of Pulmonary Embolism and Deep Vein Thrombosis Following Total Joint Arthroplasty: An Analysis of 70,000 High-Risk Patients.

BACKGROUND: Dexamethasone (DEX) has demonstrated promise with respect to decreasing postoperative thromboembolic complications following total joint arthroplasty (TJA). Therefore, the aim of this study was to investigate the effects of perioperative intravenous DEX on rates of pulmonary embolism (PE) and deep vein thrombosis (DVT) after primary TJA in patients who have a history of venous thromboembolism (VTE). METHODS: Patients who have a history of VTE who underwent primary elective TJA from 2015 to 2021 were identified using a commercial health care database. Patients were divided based on receipt of perioperative intravenous DEX [DEX(+) versus DEX(-)] on the day of index TJA. Patient demographics and hospital factors were collected. The 90-day risk of postoperative complications, readmission, and in-hospital mortality were compared. RESULTS: Overall, 70,147 patients who had a history of VTE underwent TJA, of which 40,607 (57.89%) received DEX and 29,540 (42.11%) did not. The DEX(+) patients were younger (67 ± 9.8 versus 68 ± 9.9 years, P < .001) and had a significantly shorter length of stay compared to the DEX(-) patients (1.8 ± 1.6 versus 2.2 ± 1.8 days, P < .001). The DEX(+) patients demonstrated lower rates of PE (1.37 versus 1.75%, P < .001) and DVT (2.37 versus 3.01%, P < .001) compared to DEX(-) patients. The DEX(+) patients experienced a lower risk of PE (adjusted odds ratio: 0.78, 95% confidence interval: 0.66 to 0.93, P = .006) and DVT (adjusted odds ratio: 0.84, 95% confidence interval: 0.74 to 0.95, P = .006) compared to DEX(-) patients. The DEX(+) patients demonstrated no differences in the odds of surgical site infection, periprosthetic joint infection, or sepsis compared to the DEX(-) patients (P > .05). CONCLUSIONS: The administration of DEX was associated with a decreased risk of PE and DVT in patients who have a history of VTE who underwent TJA. These data warrant further study investigating the postoperative benefits of perioperative DEX administration for high-risk patients undergoing TJA. LEVEL OF EVIDENCE: Level III.

How-To Create an Orthopaedic Systematic Review: A Step-by-Step Guide. Part III: Executing a Meta-Analysis.

At the top of the evidence-based pyramid, systematic reviews stand out as the most powerful, synthesizing findings from numerous primary studies. Specifically, a quantitative systematic review, known as a meta-analysis, combines results from various studies to address a specific research question. This review serves as a guide on how to: (1) design; (2) perform; and (3) publish an orthopedic arthroplasty systematic review. In Part III, we focus on how to design and perform a meta-analysis. We delineate the advantages and disadvantages of meta-analyses compared to systematic reviews, acknowledging their potential challenges due to time constraints and the complexities posed by study heterogeneity and data availability. Despite these obstacles, a well-executed meta-analysis contributes precision and heightened statistical power, standing at the apex of the evidence-based pyramid. The design of a meta-analysis closely mirrors that of a systematic review, but necessitates the inclusion of effect sizes, variability measures, sample sizes, outcome measures, and overall study characteristics. Effective data presentation involves the use of forest plots, along with analyses for heterogeneities and subgroups. Widely-used software tools are common in this domain, and there is a growing trend toward incorporating artificial intelligence software. Ultimately, the intention is for these papers to act as foundational resources for individuals interested in conducting systematic reviews and meta-analyses in the context of orthopaedic arthroplasty, where applicable.

How-To Create an Orthopaedic Systematic Review: A Step-by-Step Guide Part I: Study Design.

Systematic reviews are conducted through a consistent and reproducible method to search, appraise, and summarize information. Within the evidence-based pyramid, systematic reviews can be at the apex when incorporating high-quality studies, presenting the strongest form of evidence given their synthesis of results from multiple primary studies to level IV evidence, depending on the studies they incorporate. When combined and supplemented with a meta-analysis using statistical methods to pool the results of 3 or more studies, systematic reviews are powerful tools to help answer research questions. The aim of this review is to serve as a guide on how to: (1) design; (2) execute; and (3) publish an orthopaedic arthroplasty systematic review and meta-analysis. In Part I, we discuss how to develop an appropriate research question as well as source and screen databases. To date, commonly used databases to source studies include PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science. Although not all-encompassing, this paper serves as a starting point for those interested in performing and/or critically reviewing lower extremity arthroplasty systematic reviews and meta-analyses.

How-To Create an Orthopaedic Systematic Review: A Step-by-step Guide Part II: Study Execution.

Systematic reviews are the apex of the evidence-based pyramid, representing the strongest form of evidence synthesizing results from multiple primary studies. In particular, a quantitative systematic review, or meta-analysis, pools results from multiple studies to help answer a respective research question. The aim of this review is to serve as a guide on how to: (1) design, (2) execute, and (3) publish an orthopaedic arthroplasty systematic review. In Part II, we focus on methods to assess data quality through the Cochrane Risk of Bias, Methodological Index for Nonrandomized Studies criteria, or Newcastle-Ottawa scale; enumerate various methods for appropriate data interpretation and analysis; and summarize how to convert respective findings to a publishable manuscript (providing a previously published example). Use of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines is recommended and standard in all scientific literature, including that of orthopedic surgery. Pooled analyses with forest plots and associated odds ratios and 95% confidence intervals are common ways to present data. When converting to a manuscript, it is important to consider and discuss the inherent limitations of systematic reviews, including their inclusion and/or exclusion criteria and overall quality, which can be limited based on the quality of individual studies (eg, publication bias, heterogeneity, search/selection bias). We hope our papers will serve as starting points for those interested in performing an orthopaedic arthroplasty systematic review.

Strikingly High Rates of Periprosthetic Joint Infection Following Revision Surgery for Periprosthetic Fractures Regardless of Surgery Timing.

BACKGROUND: Periprosthetic fractures following total hip arthroplasty (THA) often occur in the early postoperative period. Recent data has indicated that early revisions are associated with higher complication rates, particularly periprosthetic joint infection (PJI). The purpose of this study was to assess the effect of timing of periprosthetic fracture surgery on complication rates. We hypothesized that complication rates would be significantly higher in revision surgeries performed within 3 months of the index THA. METHODS: The Medicare Part A claims database was queried from 2010 to 2017 to identify patients who underwent surgery for a periprosthetic fracture following primary THA. Patients were divided based on time between index and revision surgeries: <1, 1 to 2, 2 to 3, 3 to 6, 6 to 9, 9 to 12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics, comorbidities, and types of revision surgery. RESULTS: Of 492,340 THAs identified, 4,368 (0.9%) had a subsequent periprosthetic fracture requiring surgery: 1,725 (39.4%) at <1 month, 693 (15.9%) at 1 to 2 months, 202 (4.6%) at 2 to 3 months, 250 (5.7%) at 3 to 6 months, 134 (3.1%) at 6 to 9 months, 85 (19.4%) at 9 to12 months, and 1,279 (29.3%) at >12 months. The risk of PJI was 11.0% in the <1 month group, 11.1% at 1 to 2 months, 7.9% at 2 to 3 months, 6.8% at 3 to 6 months, 8.2% at 6 to 9 months, 9.4% at 9 to 12 months, and 8.5% at >12 months (P = .12). Adjusting for confounding factors, risk of PJI following periprosthetic fracture surgery was similar regardless of timing (P > .05). Rates of subsequent dislocation and aseptic loosening were also similar regardless of timing. CONCLUSIONS: The risk of PJI following repeat surgery for a periprosthetic fracture was strikingly high regardless of timing (6.8 to 11.1%), underscoring the high-risk of complications.

Super-Obesity is Associated With an Increased Risk of Complications Following Primary Total Knee Arthroplasty.

BACKGROUND: Obesity, defined as a body mass index (BMI) ≥ 30, is an ever-growing epidemic, with > 35% of adults in the United States currently classified as obese. Super-obese individuals, defined as those who have a BMI ≥ 50, are the fastest-growing portion of this group. This study sought to quantify the infection risk as well as the incidence of surgical, medical, and thromboembolic complications among super-obese patients undergoing total knee arthroplasty (TKA). METHODS: An all-payer claims database was used to identify patients who underwent elective, primary TKA between 2016 and 2021. Patients who had a BMI ≥ 50 were compared to those who had a normal BMI of 18 to 25. Demographics and the incidence of 90-days postoperative complications were compared between the 2 groups. Univariate analysis and multivariable regression were used to assess differences between groups. RESULTS: In total, 3,376 super-obese TKA patients were identified and compared to 17,659 patients who had a normal BMI. Multivariable analysis indicated that the super-obese cohort was at an increased postoperative risk of periprosthetic joint infection (adjusted odds ratio [aOR] 3.7, 95% confidence interval [CI]: 2.1 to 6.4, P < .001), pulmonary embolism (aOR 2.2, 95%-CI: 1.0 to 5.0, P = .047), acute respiratory failure (aOR 4.1, 95%-CI: 2.7 to 6.1, P < .001), myocardial infarction (aOR 2.5, 95%-CI: 1.1 to 5.8, P = .026), wound dehiscence (aOR 2.3, 95%-CI: 1.4 to 3.8, P = .001), and acute renal failure (aOR 3.2, 95%-CI: 2.4 to 4.2, P < .001) relative to patients who have normal BMI. CONCLUSIONS: Super-obese TKA patients are at an elevated risk of postoperative infectious, surgical, medical, and thromboembolic complications. As such, risk stratification, as well as appropriate medical management and optimization, is of utmost importance for this high-risk group.

Is the Rise of Medicare Advantage Impacting the Fidelity of Traditional Medicare Claims Data? Implications for Reporting of Long-Term Total Hip Arthroplasty Survivorship.

BACKGROUND: Arthroplasty registries often use traditional Medicare (TM) claims data to report long-term total hip arthroplasty (THA) survivorship. The purpose of this study was to determine whether the large number of patients leaving TM for Medicare Advantage (MA) has compromised the fidelity of TM data. METHODS: We identified 10,962 THAs in 9,333 Medicare-eligible patients who underwent primary THA from 2000 to 2020 at a single institution. Insurance type was analyzed, and 83% of patients had TM at the time of THA. Survivorship free from any revision or reoperation was calculated for patients who have TM. The same survivorship end points were recalculated with censoring performed when a patient transitioned to an MA plan after their primary THA to model the impact of losing patients from the TM dataset. Differences in survivorship were compared. The mean follow-up was 7 years. RESULTS: From 2000 to 2020, there was a decrease in TM insurance (93 to 73%) and a corresponding increase in MA insurance (0 to 19%) among THA patients. Following THA, 23% of TM patients switched to MA. For patients who had TM at the time of surgery, 15-year survivorship free from any reoperation or revision was 90% and 93%, respectively. When censoring patients upon transition from TM to MA, survivorship free from any reoperation became significantly higher (92 versus 90% at 15 years; hazard ratio = 1.16, P = .033), and there was a trend toward higher survivorship free from any revision (95 versus 93% at 15 years; hazard ratio = 1.16, P = .074). CONCLUSIONS: Approximately 1 in 4 patients left TM for MA after primary THA, effectively making them lost to follow-up within TM datasets. The mass exodus of patients out of TM appears to have led to a slight overestimation of survivorship free from any reoperation and trended toward overestimating survivorship free from any revision. If MA continues to grow, efforts to obtain MA data will become even more important.

Influence of donor age and comorbidities on transduced human adipose-derived stem cell in vitro osteogenic potential.

Human adipose-derived mesenchymal stem cells (ASCs) transduced with a lentiviral vector system to express bone morphogenetic protein 2 (LV-BMP-2) have been shown to reliably heal bone defects in animal models. However, the influence of donor characteristics such as age, sex, race, and medical co-morbidities on ASC yield, growth and bone regenerative capacity, while critical to the successful clinical translation of stem cell-based therapies, are not well understood. Human ASCs isolated from the infrapatellar fat pads in 122 ASC donors were evaluated for cell growth characteristics; 44 underwent additional analyses to evaluate in vitro osteogenic potential, with and without LV-BMP-2 transduction. We found that while female donors demonstrated significantly higher cell yield and ASC growth rates, age, race, and the presence of co-morbid conditions were not associated with differences in proliferation. Donor demographics or the presence of comorbidities were not associated with differences in in vitro osteogenic potential or stem cell differentiation, except that transduced ASCs from healthy donors produced more BMP-2 at day 2. Overall, donor age, sex, race, and the presence of co-morbid conditions had a limited influence on cell yield, proliferation, self-renewal capacity, and osteogenic potential for non-transduced and transduced (LV-BMP-2) ASCs. These results suggest that ASCs are a promising resource for both autologous and allogeneic cell-based gene therapy applications.

Spinal Versus General Anesthesia in Total Knee Arthroplasty: Are There Differences in Complication and Readmission Rates?

BACKGROUND: Spinal anesthesia (SP) utilization continues to expand in total knee arthroplasty (TKA). However, little is known regarding differences in complication rates between spinal and general anesthesia used for primary TKA. Therefore, the purpose of this study is to compare the length of stay (LOS), operative time, and readmission and revision rates between patients who received spinal and general anesthesia during TKA. METHODS: The American Joint Replacement Registry (AJRR) was used to identify primary elective TKA patients from 2017 to 2020. Patients were divided into 2 cohorts, general (GN) and SP, based on the mode of anesthesia administered during the index surgery. In total, 270,251 TKAs were identified, of which 126,970 (47.0%) received general anesthesia and 143,281 (53.0%) received spinal anesthesia. Length of stay, operative time, 90-day readmission, and 90-day revisions were compared between the 2 groups. Multivariable logistic regression analyses were used to adjust for potential confounders. RESULTS: After accounting for confounding factors, SP was associated with a lower risk of having a LOS greater than 3 days (odds ratio [OR] 0.470, 95% confidence interval [CI] 0.454-0.487, P < .0001), but a slightly higher likelihood of having a longer operative time (OR 1.075, 95% CI 1.056-1.094, P < .0001). SP was also linked to lower rates of 90-day readmission (OR 0.845, 95% CI 0.790-0.904, P < .0001) and lower risk of 90-day all-cause revision (OR 0.506, 95% CI 0.462-0.555, P < .0001). CONCLUSION: SP was associated with a lower 90-day readmission rate and a lower risk of 90-day revision. These findings support the best practice guidelines of The Joint Commission to use spinal anesthesia when possible as part of an enhanced recovery after surgery (ERAS) pathway.

The Utility of Routine Postoperative Radiographs in the Asymptomatic Total Hip Arthroplasty Patient.

BACKGROUND: Total hip arthroplasty (THA) patients often receive routine radiographs in the year following their index surgery. This study sought to investigate the clinical and economic value of obtaining routine postoperative hip radiographs for asymptomatic patients following primary elective THA. METHODS: A retrospective cohort study of consecutive patients who underwent primary elective THA from 2016 to 2019 was conducted. Patients undergoing nonelective or revision THA, radiographic follow-up <10 months, and patients aged <18 years were excluded. All radiographs were reviewed for abnormalities in the first postoperative year by an arthroplasty fellowship-trained orthopaedic surgeon, blinded to the symptoms of the patient. RESULTS: Of the 327 patients (351 hips) included, 57.2% were women and 68.2% were White, with an average age of 65 years (range, 22-97 years) and average body mass index of 29.1 kg/m2 (range, 16.2-49.8 kg/m2). Only four (0.4%) radiographic series revealed abnormalities with the potential to alter postoperative management. One patient experienced a change in management directly related to their abnormal finding (closed reduction for dislocation at 10.2 months postoperatively). The remaining three abnormal radiographic findings included femoral stem subsidence, progressive radiolucencies around an acetabular component, and cement mantle fracture. The average cost for each radiographic series was $155.27, resulting in total direct charges of $167,691.60. CONCLUSION: Routine postoperative radiographs may be of limited utility in the asymptomatic patient in the first year following elective primary THA. Consideration should be given to limit postoperative radiographs following standard elective THA, while reserving postoperative radiographic evaluation for patients who are symptomatic. LEVEL OF EVIDENCE: Level III.

Ceramic Femoral Heads Exhibit Lower Wear Rates Compared to Cobalt Chrome: A Meta-Analysis.

BACKGROUND: Wear between the femoral head and acetabular liners continues to limit the longevity of total hip arthroplasty implants despite advances in implant materials. The purpose of this meta-analysis was to compare linear wear rates of cobalt-chromium (CoCr) and fourth-generation ceramic femoral heads on highly cross-linked polyethylene (XLPE) liners. METHODS: A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted to identify all studies between 2003 and 2020 that examined in vivo wear rates of either fourth-generation ceramics or CoCr femoral heads on XLPE liners. Studies were analyzed in a weighted means analysis of wear rates and a random effects meta-analysis. RESULTS: A total of 36 studies met inclusion criteria (1,657 CoCr and 659 ceramic patients). The pooled, weighted mean wear rate was 0.063 mm/year (standard deviation [SD]: 0.061, confidence interval [CI]: 0.049-0.077) for CoCr and 0.047 mm/year (SD: 0.057, CI: 0.033-0.062; P < .01) for ceramic (P < .01). A meta-analysis of 4 studies directly comparing ceramic and CoCr found that CoCr heads demonstrated 0.029 mm/year more wear than ceramic heads (95% CI: 0.026-0.059, P = .306). Mean wear for 32-mm heads was significantly higher for ceramic (P < .01), while mean wear for 36-mm heads was significantly higher for CoCr (P < .01). CONCLUSION: Fourth-generation ceramic femoral heads were found to have significantly lower wear rates than CoCr heads. Unlike previous studies, this meta-analysis included only in vivo studies and those with the same generation of highly XLPE liners.

Does Prednisone Dose Affect Rates of Periprosthetic Joint Infection Following Primary Total Hip and Total Knee Arthroplasty?

BACKGROUND: Prednisone use is associated with higher rates of periprosthetic joint infection (PJI) following total joint arthroplasty (TJA). However, the relationship between prednisone dosage and infection risk is ill-defined. Therefore, this study aimed to assess the relationship between prednisone dosage and rates of PJI following TJA. METHODS: A national database was queried for all elective total hip (THA) and total knee arthroplasty (TKA) patients between 2015 and 2020. Patients who received oral prednisone following TJA were matched in a 1:2 ratio based on age and sex to patients who did not. Univariate and multivariate regression analyses were performed to assess the 90-day risk of infectious complications based on prednisone dosage as follows: 0 to 5, 6 to 10, 11 to 20, 21 to 30, and >30 milligrams. Overall, 1,322,043 patients underwent elective TJA (35.9% THA, 64.1% TKA). Of these, 14,585 (1.1%) received prednisone and were matched to 29,170 patients who did not. RESULTS: After controlling for confounders, TKA patients taking prednisone were at increased risk for sepsis (adjusted odds ratio [aOR] 2.76, P < .001), PJI (aOR 2.67, P < .001), and surgical site infection (aOR: 2.56, P = .035). THA patients taking prednisone were at increased risk for sepsis (aOR: 3.21, P < .001) and PJI (aOR: 1.73, P = .001). No dose-dependent relationship between prednisone and infectious complications was identified when TJA was assessed in aggregate. CONCLUSION: Patients receiving prednisone following TJA were at increased risk of PJI and sepsis. A dose-dependent relationship between prednisone and infectious complications was not identified. Arthroplasty surgeons should be aware of these risks and counsel TJA patients who receive prednisone therapy.