A Nationwide Analysis of the Impact of Socioeconomic Status on Complications and Health Care Utilizations After Total Knee Arthroplasty Using the Area Deprivation Index: Consideration of the Disadvantaged Patient.

BACKGROUND: Socioeconomic status has been demonstrated to be an important prognostic risk factor among patients undergoing total joint arthroplasty. We evaluated patients living near neighborhoods with higher socioeconomic risk undergoing total knee arthroplasty (TKA) and if they were associated with differences in the following: (1) medical complications; (2) emergency department (ED) utilizations; (3) readmissions; and (4) costs of care. METHODS: A query of a national database from 2010 to 2020 was performed for primary TKAs. The Area Deprivation Index (ADI) is a weighted index comprised of 17 census-based markers of material deprivation and poverty. Higher numbers indicate a greater disadvantage. Patients undergoing TKA in zip codes associated with high ADI (90%+) were 1:1 propensity-matched to a comparison group by age, sex, and Elixhauser Comorbidity Index. This yielded 225,038 total patients, evenly matched between cohorts. Outcomes studied included complications, ED utilizations, readmission rates, and 90-day costs. Logistic regression models computed the odds ratios (OR) of ADI on the dependent variables. P values less than .003 were significant. RESULTS: High ADI led to higher rates and odds of any medical complications (11.7 versus 11.0%; OR: 1.05, P = .0006), respiratory failures (0.4 versus 0.3%; OR: 1.28, P = .001), and acute kidney injuries (1.7 versus 1.5%; OR: 1.15, P < .0001). Despite lower readmission rates (2.9 versus 3.5%), high ADI patients had greater 90-day ED visits (4.2 versus 4.0%; OR: 1.07, P = .0008). The 90-day expenditures ($15,066 versus $12,459; P < .0001) were higher in patients who have a high ADI. CONCLUSIONS: Socioeconomically disadvantaged patients have increased complications and ED utilizations. Neighborhood disadvantage may inform health care policy and improve postdischarge care. The socioeconomic status metrics, including ADI (which captures community effects), should be used to adequately risk-adjust or risk-stratify patients so that access to care for deprived regions and patients is not lost. LEVEL OF EVIDENCE: III.

Preoperative Depression Screening for Primary Total Knee Arthroplasty: An Evaluation of Its Modifiability on Outcomes in Patients Who Have Depression.

INTRODUCTION: Few studies have evaluated preoperative depression screenings in patients who have depression. We studied whether depression screenings before total knee arthroplasty (TKA) were associated with lower: 1) medical complications; 2) emergency department (ED) utilizations and readmissions; 3) implant complications; and 4) costs. METHODS: A nationwide sample from January 1, 2010 to April 30, 2021 was collected using an insurance database. Depression patients were 1:1 propensity-score matched based on those who had (n=29,009) and did not have (n=29,009) pre-operative depression screenings or psychotherapy visits within 3 months of TKA. A case-matched population who did not have depression was compared (n=144,994). A 90-day period was used to compare complications and healthcare utilization and 2-year follow-up for periprosthetic joint infections (PJIs) and implant survivorship. Costs were 90-day reimbursements. Logistic regression models computed odds ratios (OR) of depression screening on dependent variables. P-values less than 0.001 were significant. RESULTS: Patients who did not receive preoperative screening were associated with higher medical complications (18.7 versus 5.2%, OR:4.15, P < 0.0001) and ED utilizations (11.5 versus 3.2%, OR: 3.93, P < 0.0001) than depressed patients who received screening. Patients who had screening had lower medical complications (5.2 versus 5.9%, OR: 0.88, P < 0.0001) and ED utilizations compared to patients who did not have depression (3.2 versus 3.8%, OR: 0.87, P = 0.0001). Two-year PJI incidences (3.0 versus 1.3%, OR: 2.63, P < 0.0001) and TKA revisions (4.3 versus 2.1%, OR: 2.46, P < 0.0001) were greater in depression patients who were not screened preoperatively versus screened patients. Depression patients who had screening had lower PJIs (1.3 versus 1.8%, OR: 0.74, P < 0.0001) compared to non-depressed patients. Reimbursements ($13,949 versus $11,982; P < 0.0001) were higher in depression patients who did not have screening. CONCLUSIONS: Pre-operative screening was associated with improved outcomes in depression patients.

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.

The Association of Dental Caries or Dental Implant Placement Within One Year of Primary Total Hip Arthroplasty on Medical and Implant Complications.

BACKGROUND: Total hip arthroplasty (THA) adverse events among patients who have dental diagnoses remain unclear. We sought to determine if dental caries or dental implant placements increased (1) 90-day medical complications, (2) 90-day readmissions, and (3) 2-year implant-related complications, including periprosthetic joint infections (PJIs) after THA. METHODS: A nationwide database for primary THAs from 2010 to 2021 was queried to compare 3 patient cohorts. Patients who had a history of dental implants or caries within 12 months prior to THA (n = 1,179) or 12 months after THA (n = 1,218) were case-matched to patients who did not have dental history (n = 6,090) by age and comorbidities. Outcomes included 90-day complications, 90-day readmissions, and 2-year implant-related complications. Logistic regression models computed the odds ratios (ORs) of complications and readmissions. P values less than .006 were significant. RESULTS: Patients who had dental caries or implant placement 12 months before or after THA experienced 1.6-fold greater odds of 90-day medical complications compared to case-matched patients. Readmissions within 90 days increased for patients who had a dental history before (11.7% versus 8.3%; OR: 1.49, P < .0001) and after (14.2% versus 8.3%; OR: 1.84, P < .0001) THA compared to case-matched patients. A dental caries diagnosis or dental implant placement within 12 months following THA increased 2-year implant complications compared to case-matched patients (15.2% versus 9.3%; OR: 1.69, P < .0001), including PJIs (5.3% versus 2.8%; OR: 1.98, P < .0001), dislocations (4.4% versus 2.7%; OR: 1.63, P = .002), and THA revisions (3.9% versus 2.5%; OR: 1.61, P = .005). CONCLUSIONS: Dental diagnoses within 12 months of THA are associated with increased medical complications. Dental diagnoses occurring 12 months after THA are associated with greater implant-related complications, including PJIs. Delaying invasive dental procedures for 12 months after THA may be advisable.

Improved Pain and Function with Triamcinolone Acetonide Extended-Release and Cryoneurolysis for Knee Osteoarthritis: Use of a New Real-World Registry.

INTRODUCTION: Knee osteoarthritis (OA) affects 19% of American adults over 45 years old and costs $27+ billion annually. A wide range of non-operative treatment options are available. This study compared six treatments: cryoneurolysis with deep genicular nerve block (Cryo-Deep/Both), cryoneurolysis with superficial nerve block (Cryo-Superficial), intra-articular hyaluronic acid (IA-HA) injections, non-steroidal anti-inflammatory drug injections (IA-NSAIDs), IA-corticosteroids (IA-CS) injections, or IA-triamcinolone extended release (IA-TA-ER) injections over 4 months for: 1) pain severity and analgesic use; and 2) physical function (from Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR)). METHODS: Patients who had unilateral knee OA and received non-operative intervention were enrolled in the Innovations in Genicular Outcomes (iGOR) registry, a novel, multi-center real-world registry, between September 2021 and February 2024. A total of 480 patients were enrolled. Both pain and functional outcomes were assessed at baseline, weekly, and monthly, which were analyzed by: overall trend, magnitude changes pre- to post-treatment, and distribution-based minimal clinically important difference score (MCID). Multivariate linear regressions with adjustments for seven confounding factors were used to compare follow-up outcomes among six treatment groups. RESULTS: Use of IA-TA-ER injections was associated with the lowest pain, greatest pain reduction, and highest prevalence of patients achieving MCID relative to other treatments (P < 0.001). Deep/Both-Cryo and IA-CS were associated with a higher prevalence of achieving MCID than IA-HA, IA-NSAIDs, and Cryo-Superficial (P ≤ 0.001). Use of IA-TA-ER was also associated with the greatest functional score, improvement from baseline, and highest prevalence of patients achieving MCID than other treatments (P ≤ 0.003). CONCLUSIONS: The IA-TA-ER appears to outperform other treatments in terms of pain relief and functional improvement for up to 4 months following treatment. In addition, outcomes in the novel cryoneurolysis and conventional IA-CS were similar to one another and better than those in IA-HA and IA-NSAIDs.

Cryoneurolysis Associated with Improved Pain, Function, and Sleep in Patients Following Total Knee Arthroplasty: Use of a New Real-World Registry.

INTRODUCTION: Total knee arthroplasty (TKA) is performed on approximately 790,000 patients annually in the United States and is projected to increase to 1.5 million by 2050. This study aimed at assessing the use of preoperative cryoneurolysis on patients undergoing TKA by analyzing: 1) pain severity; 2) opioid use; 3) functional status; and 4) sleep disturbance over 6 months following discharge. METHODS: Patients enrolled in the Innovations in Genicular Outcomes Registry (iGOR) between September 2021 and February 2024 were followed for 6 months. Our analyses included patients undergoing unilateral primary TKA with no pre-operative opioid prescription who either received, or did not receive, cryoneurolysis. Baseline patient demographics were collected before TKA and tabulated. Pain management was assessed via the Brief Pain Inventory-Short Form (BPI-SF) instrument for pain severity. Sleep disturbance was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire. Each outcome measure was assessed prior to TKA, weekly, and at monthly follow-up. Data was analyzed by a generalized linear mixed-effect regression model to compare cryoneurolysis versus control patients, with a P < 0.05 as significant. RESULTS: There were 80 patients who were treated with preoperative cryoneurolysis, while 60 control patients did not have treatment. Patients receiving cryoneurolysis experienced significantly lower pain severity and sleep disturbance over the 6-month follow-up than control patients (P = 0.046). Cryoneurolysis was also associated with a trend toward greater functional improvement that did not reach statistical significance (P = 0.061). Further, patients who underwent cryoneurolysis were 72% less likely than controls to take opioids over six months following discharge (P <0.001). CONCLUSIONS: Pre-operative cryoneurolysis therapy in opioid-naïve patients undergoing TKA is associated with improved pain, decreased opioid use, and improved sleep disturbance for 6 months postoperatively. Cryoneurolysis, a non-opioid pain relief modality administered pre-operatively, demonstrated substantial benefits in patients who underwent TKA.

Market resilience of orthopaedic hip/knee arthroplasty sales during COVID-19.

INTRODUCTION: The coronavirus 2019 (COVID-19) pandemic led to a marked decrease in elective surgical volume and orthopaedic device sales. The aim of this paper was to quantify this decrease and the related financial impact on the largest hip/knee arthroplasty companies by: (1) tracking individual hip/knee company valuations; (2) calculating aggregate changes in overall hip/knee arthroplasty market valuations; and (3) quantifying quarterly hip/knee revenues relative to prior years. MATERIALS AND METHODS: Financial data on the top five hip/knee arthroplasty companies by size between January 1, 2019, and October 1, 2020, was collected from a Wall Street financial database, S&P Capital IQ. Changes in valuation of these companies were compared against benchmark market indices, the S&P500 and Vanguard Healthcare ETF. U.S. hip/knee arthroplasty-specific revenue for Q1 and Q2 of 2019 and 2020 was collected from Securities Exchange Commission 10-Q forms. Quarterly revenue changes were calculated using 1-2Q19 revenues as baselines and aggregate to approximate the overall hip/knee arthroplasty market. RESULTS: The top five hip/knee companies lost $179.2 billion (32.7% loss) in market value from pre COVID-19 market highs to COVID-19 market lows (March 2020), while S&P500 and Vanguard Healthcare ETF decreased 36.1 and 33.2%, respectively. From market lows to October 2020, arthroplasty companies rallied 38.6% while the S&P500 and Vanguard Healthcare ETF regained 43.5 and 56.4% respectively. Notably, this occurred while aggregate 1Q/2Q20 revenue lagged 7.1/41.8% relative to 2019, with an overall decrease of $1.58B (24.8%). CONCLUSIONS: Similar to the overall market and healthcare sector, the top five hip/knee arthroplasty companies have recovered from their COVID market lows. Our results reveal that the valuations of hip/knee companies remained robust during COVID, even as revenues fell, likely due to strong investor confidence in the industry outlook and the greater overall healthcare system utilization.

Comparison of Patient Demographics and Risk of Surgical Site Infections Following Open Reduction and Internal Fixation of Trimalleolar Ankle Fractures: A Nationwide Analysis of a Private Payor.

Surgical site infections (SSIs) are a notable complication following open reduction and internal fixation (ORIF) for ankle fractures. The purpose of this study was to (1) compare baseline demographics of patients who did and did not develop SSIs within 90 days following ORIF for trimalleolar ankle fractures and (2) identify risk factors associated with SSIs in this setting. A retrospective analysis from 2010 to 2020 was completed using a national administrative database. The study group consisted of patients who underwent ORIF for trimalleolar ankle fractures and developed SSIs within 90 days postoperatively. Patients without SSIs served as the comparison cohort. Baseline demographics of the two cohorts were compared utilizing Pearson's Chi-Square Analyses. A multivariate binomial logistic regression model determined the association of various comorbidities on developing SSIs in this setting. Out of a total sample of 22,118 patients, 1000 individuals (4.52%) developed SSIs. The study revealed that the SSI cohort exhibited a greater burden of comorbidities, as evidenced by significant differences in various individual comorbidities and average Elixhauser-Comorbidity Indices scores. The most strongly associated risk factors for the development of SSIs following ORIF for trimalleolar ankle fractures were peripheral vascular disease (OR: 1.53, p < .0001), diabetes mellitus (OR: 1.26, p = .0010), iron deficiency anemia (OR: 1.24, p = .0010), male sex (OR: 1.22, p = .0010), and tobacco use (OR: 1.15, p = .0010). This study identified several patient risk factors that were associated with developing SSIs after ORIF for trimalleolar ankle fractures, recognizing potential patient-directed interventions that may reduce the rate of SSIs in this setting.

Anterolateral knee complex considerations in contemporary anterior cruciate ligament reconstruction and total knee arthroplasty: a systematic review.

The anterolateral ligament (ALL) was first described in 1879 in the context of Segond fractures, which correlate with a 75-100% chance of an anterior cruciate ligament (ACL) tear or a 66-75% chance of a meniscal tear. The purpose of this paper is to provide an updated comprehensive review on the anterolateral ligament complex of the knee focusing on the: (1) anatomy of the ALL/ALC; (2) associated biomechanics/function; and (3) important surgical considerations in contemporary anterior cruciate ligament (ACL) reconstruction and total knee arthroplasty (TKA). A systematic review of studies on ALL was conducted on Pubmed/MEDLINE and Cochrane databases (May 7th, 2020 to February 1st, 2022), with 20 studies meeting inclusion/exclusion criteria. Studies meeting inclusion criteria were anatomical/biomechanical studies assessing ALL function, cadaveric and computer simulations, and comparative studies on surgical outcomes of ALLR (concomitant with ACL reconstruction). Eight studies were included and graded by MINOR and Newcastle-Ottawa scale to identify potential biases. The anatomy of the ALL is part of the anterolateral ligament complex (ALC), which includes the superficial/deep iliotibial band (including the Kaplan fiber system), iliopatellar band, ALL, and anterolateral capsule. Multiple biomechanical studies have characterized the ALC as a secondary passive stabilizer in resisting tibial internal rotation. Given the role of the ALC in resisting internal tibial rotation, lateral extra-articular procedures including ALL augmentation may be considered for chronic ACL tears, ACL revisions, and a high-grade pivot shift test. In the context of TKA, in the event of injury to the ALC, a more constrained implant or soft-tissue reconstruction may be necessary to restore appropriate knee stability.

Inflammatory panel cytokines are elevated in the neocortex of late-stage Alzheimer's disease but not Lewy body dementias.

BACKGROUND: Chronically dysregulated neuroinflammation has been implicated in neurodegenerative dementias, with separate studies reporting increased brain levels of inflammatory mediators and gliosis in Alzheimer's disease (AD) as well as in Lewy body dementias (LBD). However, it is unclear whether the nature and extent of neuroinflammatory responses in LBD are comparable to those in AD. In this study, we performed head-to-head measurements of a panel of cytokines in the post-mortem neocortex of AD versus the two major clinical subtypes of LBD, namely, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). METHODS: Post-mortem tissues from the mid-temporal cortex (Brodmann area 21) of a cohort of neuropathologically well-defined AD, PDD and DLB patients were processed and measured for a comprehensive range of cytokines (IL-1α, IL-1Ra, IL-8, IL-10, IL-12p70, IL-13, IFN-γ, GM-CSF and FGF-2) using a multiplex immunoassay platform. Associations between inflammation markers and neuropathological measures of neuritic plaques, neurofibrillary tangles as well as Lewy bodies were also performed. RESULTS: We found IL-1α, IFN-γ, GM-CSF and IL-13 to be elevated in the mid-temporal cortex of AD patients. In contrast, none of the measured cytokines were significantly altered in either DLB or PDD. Similar cytokine changes were observed in two other neocortical areas of AD patients. Furthermore, increases of IL-1α, IFN-γ, GM-CSF, IL-10 and IL-13 associated with moderate-to-severe neurofibrillary tangle burden, but not with neuritic plaques or Lewy bodies. Our findings of elevated neocortical pro- and anti-inflammatory cytokines in AD, but not in DLB or PDD, suggest that neuroinflammatory responses are strongly linked to neurofibrillary tangle burden, which is higher in AD compared to LBD. In conclusion, neuroinflammation may not play a prominent role in the pathophysiology of late-stage LBD.

Invited review: Rumen modifiers in today's dairy rations.

Our aim was to review feed additives that have a potential ruminal mechanism of action when fed to dairy cattle. We discuss how additives can influence ruminal fermentation stoichiometry through electron transfer mechanisms, particularly the production and usage of dihydrogen. Lactate accumulation should be avoided, especially when acidogenic conditions suppress ruminal neutral detergent fiber digestibility or lead to subclinical acidosis. Yeast products and other probiotics are purported to influence lactate uptake, but growing evidence also supports that yeast products influence expression of gut epithelial genes promoting barrier function and resulting inflammatory responses by the host to various stresses. We also have summarized methane-suppressing additives for potential usage in dairy rations. We focused on those with potential to decrease methane production without decreasing fiber digestibility or milk production. We identified some mitigating factors that need to be addressed more fully in future research. Growth factors such as branched-chain volatile fatty acids also are part of crucial cross-feeding among groups of microbes, particularly to optimize fiber digestibility in the rumen. Our developments of mechanisms of action for various rumen-active modifiers should help nutrition advisors anticipate when a benefit in field conditions is more likely.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. II: Biohydrogenation and incorporation into bacterial lipids.

To maintain membrane homeostasis, ruminal bacteria synthesize branched-chain fatty acids (BCFA) or their derivatives (vinyl ethers) that are recovered during methylation procedures as branched-chain aldehydes (BCALD). Many strains of cellulolytic bacteria require 1 or more branched-chain volatile fatty acid (BCVFA). Therefore, the objective of this study was to investigate BCVFA incorporation into bacterial lipids under different dietary conditions. The study was an incomplete block design with 8 continuous culture fermenters used in 4 periods with treatments (n = 4) arranged as a 2 × 2 × 2 factorial. The factors were high (HF) or low forage (LF, 67 or 33% forage, 33:67 alfalfa:orchardgrass), without or with supplemental corn oil (CO; 3% dry matter, 1.5% linoleic fatty acid), and without or with 2.15 mmol/d (5 mg/d 13C each of isovalerate, isobutyrate, and 2-methylbutyrate). After methylation of bacterial pellets collected from each fermenter's effluent, fatty acids and fatty aldehydes were separated before analysis by gas chromatography and isotope ratio mass spectrometry. Supplementation of BCVFA did not influence biohydrogenation extent. Label was only recovered in branched-chain lipids. Lower forage inclusion decreased BCFA in bacterial fatty acid profile from 9.45% with HF to 7.06% with LF and decreased BCALD in bacterial aldehyde profile from 55.4% with HF to 51.4% with LF. Supplemental CO tended to decrease iso even-chain BCFA and decreased iso even-chain BCALD in their bacterial lipid profiles. The main 18:1 isomer was cis-9 18:1, which increased (P < 0.01) by 25% from CO (data not shown). Dose recovery in bacterial lipids was 43.3% lower with LF than HF. Supplemental CO decreased recovery in the HF diet but increased recovery with LF (diet × CO interaction). Recovery from anteiso odd-chain BCFA and BCALD was the greatest; therefore, 2-methylbutyrate was the BCVFA primer most used for branched-chain lipid synthesis. Recovery in iso odd-chain fatty acids (isovalerate as primer) was greater than label recovery in iso even-chain fatty acids (isobutyrate as primer). Fatty aldehydes were less than 6% of total bacterial lipids, but 26.0% of 13C recovered in lipids were recovered in BCALD because greater than 50% of aldehydes were branched-chain. Because BCFA and BCALD are important in the function and growth of bacteria, especially cellulolytics, BCVFA supplementation can support the rumen microbial consortium, increasing fiber degradation and efficiency of microbial protein synthesis.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. III: Protein metabolism and incorporation into bacterial protein.

Some cellulolytic bacteria cannot transport branched-chain AA (BCAA) and do not express complete synthesis pathways, thus depending on cross-feeding for branched-chain volatile fatty acid (BCVFA) precursors for membrane lipids or for reductive carboxylation to BCAA. Our objective was to assess BCVFA uptake for BCAA synthesis in continuous cultures administered high forage (HF) and low forage (LF) diets without or with corn oil (CO). We hypothesized that BCVFA would be used for BCAA synthesis more in the HF than in LF diets. To help overcome bacterial inhibition by polyunsaturated fatty acids in CO, BCVFA usage for bacterial BCAA synthesis was hypothesized to decrease when CO was added to HF diets. The study was an incomplete block design with 8 dual-flow fermenters used in 4 periods with 8 treatments (n = 4) arranged as a 2 × 2 × 2 factorial. The factors were: HF or LF (67 or 33% forage, 33:67 alfalfa:orchardgrass pellets), without or with supplemental CO (3% of dry matter), and without or with 2.15 mmol/d (5 mg/d 13C) each of isovalerate, isobutyrate, and 2-methylbutyrate for one combined BCVFA treatment. The flow of bacterial BCAA increased by 10.7% by supplementing BCVFA and 9.14% with LF versus HF; similarly, dosing BCVFA versus without BCVFA increased BCAA by 1.98% in total bacterial AA, whereas LF increased BCAA by 1.92% versus HF. Additionally, BCVFA supplementation increased bacterial AA flow by 16.6% when supplemented in HF - CO and 12.4% in LF + CO diets, but not in the HF + CO (-1.5%) or LF - CO (+6.7%) diets (Diet × CO × BCVFA interaction). The recovery of 13C in bacterial AA flow was 31% lower with LF than with HF. Of the total 13C recovered in bacteria, 13.8, 17.3, and 30.2% were recovered in Val, Ile, and Leu, respectively; negligible 13C was recovered in other AA. When fermenters were dosed with BCVFA, nonbacterial and total effluent flows of AA, particularly of alanine and proline, suggest decreased peptidolysis. Increased ruminal outflow of bacterial AA, especially BCAA, but also nonbacterial AA could potentially support postabsorptive responses from BCVFA supplementation to dairy cattle.

Supplementing branched-chain volatile fatty acids in dual-flow cultures varying in dietary forage and corn oil concentrations. I: Digestibility, microbial protein, and prokaryotic community structure.

Branched-chain amino acids are deaminated by amylolytic bacteria to branched-chain volatile fatty acids (BCVFA), which are growth factors for cellulolytic bacteria. Our objective was to determine the dietary conditions that would increase the uptake of BCVFA by rumen bacteria. We hypothesized that increased forage would increase cellulolytic bacterial abundance and incorporation of BCVFA into their structure. Supplemental polyunsaturated fatty acids, supplied via corn oil (CO), should inhibit cellulolytic bacteria growth, but we hypothesized that additional BCVFA would alleviate that inhibition. Further, supplemental BCVFA should increase neutral detergent fiber degradation and efficiency of bacterial protein synthesis more with the high forage and low polyunsaturated fatty acid dietary combination. The study was an incomplete block design with 8 dual-flow continuous cultures used in 4 periods with 8 treatments (n = 4 per treatment) arranged as a 2 × 2 × 2 factorial. The factors were: high forage (HF) or low forage (LF; 67 or 33%), without or with supplemental CO (3% dry matter), and without or with 2.15 mmol/d (which included 5 mg/d of 13C each of BCVFA isovalerate, isobutyrate, and 2-methylbutyrate). The isonitrogenous diets consisted of 33:67 alfalfa:orchardgrass pellet, and was replaced with a concentrate pellet that mainly consisted of ground corn, soybean meal, and soybean hulls for the LF diet. The main effect of supplementing BCVFA increased neutral detergent fiber (NDF) degradability by 7.6%, and CO increased NDF degradability only in LF diets. Supplemental BCVFA increased bacterial N by 1.5 g/kg organic matter truly degraded (6.6%) and 0.05 g/g truly degraded N (6.5%). The relative sequence abundance decreased with LF for Fibrobacter succinogenes, Ruminococcus flavefaciens, and genus Butyrivibrio compared with HF. Recovery of the total 13C dose in bacterial pellets decreased from 144 µg/ mg with HF to 98.9 µg/ mg with LF. Although isotope recovery in bacteria was greater with HF, BCVFA supplementation increased NDF degradability and efficiency of microbial protein synthesis under all dietary conditions. Therefore, supplemental BCVFA has potential to improve feed efficiency in dairy cows even with dietary conditions that might otherwise inhibit cellulolytic bacteria.

Assessing milk response to different combinations of branched-chain volatile fatty acids and valerate in Jersey cows.

Some cellulolytic bacteria require 1 or more branched-chain volatile fatty acids (BCVFA) for the synthesis of branched-chain AA and branched-chain long-chain fatty acids because they are not able to uptake branched-chain AA or lack 1 or more enzymes to synthesize branched-chain AA de novo. Supplemental BCVFA and valerate were included previously as a feed additive that was later removed from the market; these older studies and more current studies have noted improvements in neutral detergent fiber digestibility and milk efficiency. However, most studies provided a single BCVFA or else isobutyrate (IB), 2-methylbutyrate (MB), isovalerate, and valerate altogether without exploring optimal combinations. Our objective was to determine a combination of isoacids that is optimal for milk production. Sixty (28 primiparous and 32 multiparous) lactating Jersey cows (106 ± 54 days in milk) were blocked and assigned randomly to either a control (CON) treatment without any isoacids, MB [12.3 mmol/kg dry matter (DM)], MB + IB (7.7 and 12.6 mmol/kg DM of MB and IB, respectively), or all 4 isoacids (6.2, 7.3, 4.2, and 5.1 mmol/kg DM of MB, IB, isovalerate, and valerate, respectively). Cattle were fed the CON treatment for a 2-wk period, then were assigned randomly within a block to treatments for 8 wk (n = 15). There was a trend for an interaction of supplement and parity for milk components. There were no differences in components for primiparous cows, whereas MB + IB tended to increase protein concentration by 0.04 and 0.08 percentage units in multiparous cows compared with the CON and MB treatments, respectively. Feeding MB + IB increased fat concentration by 0.23 to 0.31 percentage units compared with all other treatments in multiparous cows. Milk yield and dry matter intake (DMI) did not change with treatment. Treatment interacted with week for milk net energy for lactation/DMI; MB + IB tended to increase milk net energy of lactation/DMI by 0.10 Mcal/kg compared with MB and approached a trend for CON, mainly during the early weeks of the treatment period, whereas differences decreased during the last 2 wk of the treatment period. Cows fed MB had the highest 15:0 anteiso fatty acids in the total milk fatty acid profile, which was greater than that for CON or MB + IB cows, but not cows supplemented with isoacids. Cows fed MB alone had the numerically lowest milk net energy for lactation/DMI. The combination of MB + IB appeared optimal for increasing feed efficiency in our study and was not at the expense of average daily gain. Further research is needed for evaluating how potential changes in supplemental isoacid dosage should vary under differing dietary conditions.

Surgical Trends for Managing Knee Osteonecrosis: A 2010 to 2020 United States Nationwide Study.

BACKGROUND: Knee osteonecrosis (ON) is rare, with an estimated incidence of 0.01-0.17 per 1,000 person years. Our study aimed to do the following: 1) quantify total operative procedures with rates normalized to the United States population; 2) compare arthroplasty versus joint-preserving procedural trends; and 3) determine rates of specific operative techniques/demographics in patients aged <50 versus >50 years. METHODS: Using a nationwide database, 8,269 patients diagnosed with knee ON underwent surgical treatment from 2010 to 2020. Documented surgical procedures included total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and core decompression. Primary outcomes included procedural utilization with subanalyses comparing arthroplasty versus joint-preserving procedures, and age-stratified by under/over 50 years. Linear regressions were evaluated for trends in procedural volumes over time. RESULTS: From 2010 to 2014, 0.54% of all knee procedures were to treat ON compared to 0.71% from 2015 to 2020 (P < .001). Overall rates of TKA (85.4%) and UKA (10.3%) far exceeded rates of joint preserving procedures (4.3%). Comparing 2010-2014 with 2015-2019, joint-preserving procedures proportionally increased (0.7 to 5.0%, P < .001). Patients <50 years had significantly more joint-preserving procedures (19.5 versus 2.7%). Overall, TKA was the most common procedure (7,062; 85.40%), following by UKA 853; 10.32%) and core decompression (354; 4.28%). CONCLUSION: To our knowledge, this is the first study to characterize surgical trends in management of knee ON. Overall surgical volume for knee ON has continued to increase, outpacing population growth. Patients who have knee ON are most commonly managed with arthroplasty procedures, specifically TKA. Younger aged patients (<50 years) are more likely to undergo joint-preserving procedures, namely core decompression.

The Importance of Oral History: Does Dental Implant Placement or Caries One Year Before or After Primary Total Knee Arthroplasty Increase Medical Complications and Periprosthetic Joint Infections?

BACKGROUND: Consensus regarding prior dental problems on the outcomes of total knee arthroplasty (TKA) patients is lacking. Therefore, our objectives were to determine the association of dental caries or dental implant placement in TKA patients on the following: (1) medical complications; (2) health care utilization (lengths of stay and readmissions); (3) implant-related complications; and (4) expenditures. METHODS: A retrospective query was performed using an administrative claims database for 3 patient cohorts undergoing primary TKA from 2010 to 2020. Patients who had a history of dental caries or implant placement 1 year prior to TKA (n = 1,466) and 1 year after TKA (n = 1,127) were case-matched to patients who did not have a dental history by age and comorbidities. Outcomes included 90-day complications, health care utilization parameters, 2-year implant complications, and expenditures. Logistic regression models computed odds ratios (OR) of complications and readmissions. P values less than 0.005 were significant. RESULTS: Patients who had a dental implant placement prior to TKA had higher frequency of complications (20.05 versus 14.01%; OR: 1.53, P < .0001), including myocardial infarctions (2.52 versus 1.23%; OR: 2.08, P = .0002) and pneumonia (2.52 versus 1.24%; OR: 2.06, P = .0002). Lengths of stay (3.28 versus 2.98 days; P = .255), readmission rates (4.71 versus 4.28%; P = .470), and implant-related complications including periprosthetic joint infections (3.14 versus 2.63%; OR: 1.20, P = .279) were similar between patients lacking dental history. Expenditures were higher in patients who had a postoperative and preoperative dental history ($19,252 versus $19,363 versus 17,980; P < .001). CONCLUSION: Dental caries or implant placement may reflect overall worse medical condition resulting in more complications and higher costs after TKA. Dental history screening preoperatively may assist arthroplasty surgeons in minimizing complications.

Does Semaglutide Use Decrease Complications and Costs Following Total Knee Arthroplasty?

BACKGROUND: Diabetes mellitus (DM) and obesity are associated with total knee arthroplasty (TKA) complications. Semaglutide, a medication for DM and weight loss, can potentially affect TKA outcomes. This study investigated whether semaglutide use during TKA demonstrates fewer: (1) medical complications; (2) implant-related complications; (3) readmissions; and (4) costs. METHODS: A retrospective query was performed using a National database to 2021. Patients undergoing TKA for osteoarthritis with DM and semaglutide use were successfully propensity score-matched to controls semaglutide = 7,051; control = 34,524. Outcomes included 90-day postoperative medical complications, 2-year implant-related complications, 90-day readmissions, in-hospital lengths of stay, and costs. Multivariate logistical regressions calculated odds ratios (ORs), 95% confidence intervals, and P values (P < .003 as significance threshold after Bonferroni correction). RESULTS: Semaglutide cohorts had higher incidence and odds of myocardial infarction (1.0 versus 0.7%; OR 1.49; P = .003), acute kidney injury (4.9 versus 3.9%; OR 1.28; P < .001), pneumonia (2.8 versus 1.7%; OR 1.67; P < .001), and hypoglycemic events (1.9 versus 1.2%; OR 1.55; P < .001), but lower odds of sepsis (0 versus 0.4%; OR 0.23; P < .001). Semaglutide cohorts also had lower odds of prosthetic joint infections (2.1 versus 3.0%; OR 0.70; P < .001) and readmission (7.0 versus 9.4%; OR 0.71; P < .001), and trended toward lower odds of revisions (4.0 versus 4.5%; OR 0.86; P = .02) and 90-day costs ($15,291.66 versus $16,798.46; P = .012). CONCLUSION: Semaglutide use during TKA decreased risk for sepsis, prosthetic joint infections, and readmissions, but also increased risk for myocardial infarction, acute kidney injury, pneumonia, and hypoglycemic events.