Safety and Efficacy of Rivaroxaban in Primary Total Hip and Knee Arthroplasty.

BACKGROUND: An optimal venous thromboembolism prophylaxis agent should balance efficacy and safety. While rivaroxaban provides effective venous thromboembolism prophylaxis after total joint arthroplasty, it may be associated with higher rates of bleeding. This study aimed to compare the safety and efficacy of rivaroxaban to aspirin and enoxaparin. METHODS: A large national database was queried for patients who underwent elective primary total hip (THA) or total knee arthroplasty (TKA) from January 2015 through December 2020 who received rivaroxaban, aspirin, or enoxaparin. Multivariate analyses were performed to assess the 90-day risk of bleeding and thromboembolic complications. Among TKA patients identified, 86,721 (10.8%) received rivaroxaban, 408,038 (50.8%) received aspirin, and 108,377 (13.5%) received enoxaparin. Among THA patients, 42,469 (9.5%) received rivaroxaban, 242,876 (54.5%) received aspirin, and 59,727 (13.4%) received enoxaparin. RESULTS: After accounting for confounding factors, rivaroxaban was associated with increased risk of transfusion (TKA: adjusted odds ratio [aOR] = 2.58, P < .001; THA: aOR 1.64, P < .001), pulmonary embolism (TKA: aOR = 1.25, P = .007), and deep vein thrombosis (TKA: aOR = 1.13, P = .022) compared to aspirin. Compared to enoxaparin, rivaroxaban was associated with an increased risk of combined bleeding events (TKA: aOR = 1.07, P < .001, THA: aOR = 1.11, P < .001), but decreased risk of combined prothrombotic events (THA: aOR = 0.85, P = .036). CONCLUSION: Rivaroxaban chemoprophylaxis following TKA and THA was associated with an increased risk of bleeding and prothrombotic complications compared to aspirin and enoxaparin.

Timing of treatment in osteosarcoma: challenges and perspectives - a scoping review.

BACKGROUND: The timing of events in the management of osteosarcoma may be critical for patient survivorship; however, the prognostic value of factors such as onset of symptoms or initiation of therapy in these patients has not been studied. This study sought to review the literature reporting treatment of osteosarcoma to determine the utility of event timing as a prognostic indicator. Due to significant heterogeneity in the literature, this study was conducted as a scoping review to assess the current state of the literature, identify strengths and weaknesses in current reporting practices, and to propose avenues for future improvement. MAIN BODY: This review screened 312 peer-reviewed studies of osteosarcoma in any anatomic location published in an English journal for reporting of an event timing metric of any kind in a population of 6 or more. Thirty-seven studies met inclusion/exclusion criteria and were assessed for level of evidence, quality, and event timing metric. Reviewers also collated: publication year, population size, population age, tumor site, tumor type, surgical treatment, and adjuvant medical treatment. Extracted event timing data were further characterized using nine standardized categories to enable systematic analysis. The reporting of event timing in the treatment of osteosarcoma was incomplete and heterogenous. Only 37 of 312 (11.9%) screened studies reported event timing in any capacity. The period between patient-reported symptom initiation and definitive diagnosis was the most reported (17/37, 45.9%). Symptom duration was the second most reported period (10/37, 27.0%). Event timing was typically reported incidentally and was never rigorously incorporated into data analysis or discussion. No studies considered the impact of event timing on a primary outcome. The six largest studies were assessed in detail to identify pearls for future researchers. Notable shortcomings included the inadequate reporting of the definition of an event timing period and the pooling of patients into poorly defined timing groups. CONCLUSIONS: Inconsistent reporting of event timing in osteosarcoma treatment prevents the development of clinically useful conclusions despite evidence to suggest event timing is a useful prognostic indicator. Consensus guidelines are necessary to improve uniformity and utility in the reporting of event timing.

Midterm Survivorship of Robotic-Assisted Lateral Unicompartmental Knee Arthroplasty.

BACKGROUND: Lateral unicompartmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) for patients with isolated lateral compartment osteoarthritis. Few studies have investigated outcomes following robotic-assisted lateral UKA. The purpose of this study is to evaluate mid-term survivorship and patient-reported outcomes of robotic-assisted lateral UKA. METHODS: A retrospective case series was conducted on all robotic-assisted lateral UKAs performed by a single surgeon between 2013 and 2019. Patient demographics, surgical variables, and Kozinn and Scott criteria were collected. Implant survivorship was estimated using the Kaplan-Meier method with all-cause reoperation and conversion to TKA as endpoints. Participating patients were assessed for patient satisfaction and the Forgotten Joint Score-12. Correlations between patient demographics and patient outcome scores were investigated. RESULTS: In total, 120 lateral UKAs were identified, 84 of which met inclusion criteria, with a mean follow-up of 4.0 years (range 2.0-7.0). Five-year survivorship was 92.9% (95% confidence interval [CI] 84.5-96.7) with all-cause reoperation as the endpoint, and 100% (95% CI 95.0-100) with conversion to TKA as the endpoint. One patient was converted to TKA after the 5-year mark, resulting in a 6-year survival for conversion to TKA of 88.9% (95% CI 44.9-98.5). Average Forgotten Joint Score-12 score was 82.7/100, and patient satisfaction 4.7/5. Mean coronal plane correction was 2.5° ± 1.9° toward the mechanical axis. Neither final postoperative alignment nor failure to meet classic Kozinn and Scott criteria for UKA resulted in differences in patient-reported outcomes. CONCLUSION: The current study demonstrates high mid-term survivorship and excellent patient-reported outcomes with robotic-assisted lateral UKA. Robotic-assisted lateral UKA is a viable treatment option for isolated lateral compartment arthritis even in patients who do not meet classic indications.

Conversion rates and timing to total knee arthroplasty following anterior cruciate ligament reconstruction: a US population-based study.

PURPOSE: To define the rate of subsequent TKA following ACLR in a large US cohort and to identify factors that influence the risk of later undergoing TKA after ACLR. METHODS: The California's Office of Statewide Health Planning and Development (OSHPD) database was queried from 2000 to 2014 to identify patients who underwent primary ACLR (ACL group). An age-and gender-matched cohort that underwent appendectomy was selected as the control group. The cumulative incidence of TKA was calculated and ten-year survival was investigated using Kaplan-Meier analysis with failure defined as conversion to arthroplasty. Univariate and multivariate analyses were performed to explore the risk factors for conversion to TKA following ACLR. RESULTS: A total of 100,580 ACLR patients (mean age 34.48 years, 66.1%male) were matched to 100,545 patients from the general population. The ACL cohort had 1374 knee arthroplasty events; conversion rate was 0.71% at 2-year follow-up, 2.04% at 5-year follow-up, and 4.86% at 10-year follow-up. This conversion rate was higher than that of the control group at all time points, with an odds ratio of 3.44 (p<0.001) at 10-year follow-up. Decreasing survivorship following ACLR was observed with increasing age, female gender, and worker's compensation insurance, while increased survivorship was found in patients of Hispanic and Asian Pacific Islander racial heritage and those who underwent concomitant meniscal repair. CONCLUSIONS: In this US statewide study, the rate of TKA after ACLR is higher than reported elsewhere, with significantly increased odds when compared to a control group. Age, gender, concomitant knee procedures and other socioeconomic factors influence the rate of conversion to TKA following ACLR.

Apolipoprotein E-mediated regulation of selenoprotein P transportation via exosomes.

Selenoprotein P (SELENOP), secreted from the liver, functions as a selenium (Se) supplier to other tissues. In the brain, Se homeostasis is critical for physiological function. Previous studies have reported that SELENOP co-localizes with the apolipoprotein E receptor 2 (ApoER2) along the blood-brain barrier (BBB). However, the mechanism underlying SELENOP transportation from hepatocytes to neuronal cells remains unclear. Here, we found that SELENOP was secreted from hepatocytes as an exosomal component protected from plasma kallikrein-mediated cleavage. SELENOP was interacted with apolipoprotein E (ApoE) through heparin-binding sites of SELENOP, and the interaction regulated the secretion of exosomal SELENOP. Using in vitro BBB model of transwell cell culture, exosomal SELENOP was found to supply Se to brain endothelial cells and neuronal cells, which synthesized selenoproteins by a process regulated by ApoE and ApoER2. The regulatory role of ApoE in SELENOP transport was also observed in vivo using ApoE-/- mice. Exosomal SELENOP transport protected neuronal cells from amyloid ß (Aß)-induced cell death. Taken together, our results suggest a new delivery mechanism for Se to neuronal cells by exosomal SELENOP.

Compensatory Protection of Thioredoxin-Deficient Cells from Etoposide-Induced Cell Death by Selenoprotein W via Interaction with 14-3-3.

Selenoprotein W (SELENOW) is a 9.6 kDa protein containing selenocysteine (Sec, U) in a conserved Cys-X-X-Sec (CXXU) motif. Previously, we reported that SELENOW regulates various cellular processes by interacting with 14-3-3ß at the U of the CXXU motif. Thioredoxin (Trx) is a small protein that plays a key role in the cellular redox regulatory system. The CXXC motif of Trx is critical for redox regulation. Recently, an interaction between Trx1 and 14-3-3 has been predicted. However, the binding mechanism and its biological effects remain unknown. In this study, we found that Trx1 interacted with 14-3-3ß at the Cys32 residue in the CXXC motif, and SELENOW and Trx1 were bound at Cys191 residue of 14-3-3ß. In vitro binding assays showed that SELENOW and Trx1 competed for interaction with 14-3-3ß. Compared to control cells, Trx1-deficient cells and SELENOW-deficient cells showed increased levels of both the subG1 population and poly (ADP-ribose) polymerase (PARP) cleavage by etoposide treatment. Moreover, Akt phosphorylation of Ser473 was reduced in Trx1-deficient cells and was recovered by overexpression of SELENOW. These results indicate that SELENOW can protect Trx1-deficient cells from etoposide-induced cell death through its interaction with 14-3-3ß.

Cross-cultural adaptation and validation of the Musculoskeletal Tumor Society (MSTS) scoring system and Toronto Extremity Salvage Score (TESS) for musculoskeletal sarcoma patients in Greece.

PURPOSE: To perform translation, cross-cultural adaptation, and validation of the Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scoring system in Greek patients with lower extremity sarcoma. METHODS: The Greek version of the MSTS for the lower extremity and TESS questionnaires was developed using previously reported methods. Included were 100 patients with musculoskeletal sarcoma who underwent limb salvage surgery. The test-retest reliability [interclass correlation coefficient (ICC) between 2 different time points], internal consistency (Cronbach's alpha), construct validity (Kaiser's criteria, Eigenvalue > 1 rule), and external validity (Short form-36, Spearman's Rho) were assessed. RESULTS: The test-retest reliability (ICC was 0.99 for MSTS-LE and 1 for TESS) and internal consistency were high (Cronbach's alpha was 0.763 for MSTS-LE and 0.924 for TESS) for both questionnaires. Based on the Scree plot, the number of factors retained was 1 for MSTS-LE and 2 for TESS. The TESS showed a strong correlation with SF-36 (Spearman's rho = 0.714, p < 0.001), but the correlation between MSTS for lower extremity and SF-36 was weak (Spearman's Rho = 0.313, p = 0.002). CONCLUSIONS: The Greek version of both the MSTS for lower extremity and TESS questionnaire showed sufficient reliability, internal consistency and good performance using the loading factor analysis when used postoperatively in Greek patients who underwent surgical resection of lower extremity sarcoma. However, only the TESS showed strong correlation with the SF-36, indicating that MSTS for lower extremity was not as powerful for the evaluation of the global health status of these patients.

Proximal Row Carpectomy Versus 4-Corner Fusion: Incidence, Conversion to Fusion, and Cost.

PURPOSE: The primary objective of this study was to compare incidence, demographic trends, and rates of subsequent fusion between proximal row carpectomy (PRC) and 4-corner fusion (4CF) among patients in the United States. METHODS: A total of 3,636 patients who underwent PRC and 5,047 who underwent 4CF were identified from the years 2005 through 2014 among enrollees in the PearlDiver database. Regional distribution, demographic characteristics, annual incidence, comorbidities, and subsequent wrist fusion were compared between the 2 groups. Of the patients identified, 3,512 from each group were age- and sex-matched and subsequently compared for rates of converted fusion, 30- and 90-day readmission rates, and average direct cost. RESULTS: Patients undergoing 4CF and PRC did not have statistically significant differences in comorbidities. The incidence of the procedures among all subscribers increased for both PRC (1.8 per 10,000 to 2.6 per 10,000) and 4CF (1.2 per 10,000 to 2.0 per 10,000) from 2005 to 2014. Comparing the matched cohorts, patients who underwent 4CF had a higher rate of subsequent fusion than those who underwent PRC (2.67% vs 1.79%). Readmission rates were not significantly different at 30 or 90 days. Average direct cost was significantly greater for 4CF than for PRC. CONCLUSIONS: Both PRC and 4CF have been utilized at increasing rates in the past decade. Wrist fusion rates and average costs are higher in the 4CF group without a significant difference in readmission rates. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Knee Arthroscopy After Total Knee Arthroplasty: Not a Benign Procedure.

BACKGROUND: Outcomes of knee arthroscopy (KA) after total knee arthroplasty (TKA) have been limited to small case series with short-term follow-up. The purpose of this study is to report the outcomes of patients who undergo a KA after a TKA using a large longitudinal database. METHODS: The PearlDiver Medicare database was queried for patients who underwent a KA procedure after a TKA on the ipsilateral extremity. A randomly selected control group was created by matching controls to cases in a 3:1 ratio based on age, gender, year of procedure, and Elixhauser Comorbidity Index. Revision for infection and all-cause revision were used as end points. RESULTS: A total of192 TKA patients who underwent a subsequent KA (TKA + KA group) were compared to 571 TKA patients who did not have a subsequent KA (TKA - KA group). The incidence of revision for infection was 6.3% in the TKA + KA group compared to 2.2% in the TKA - KA group (odds ratio, 2.87; P = .009). The incidence of all-cause revision was 18.8% in the TKA + KA group compared to 5.1% in the TKA - KA group (odds ratio, 4.34; P < .001). CONCLUSION: KA after TKA was associated with increased infection-related and all-cause revision. The association between KA and subsequent infection requires further investigation.

Are Orthopaedic Surgeons Performing Fewer Arthroscopic Partial Meniscectomies in Patients Greater Than 50 Years Old? A National Database Study.

PURPOSE: To report the trends in arthroscopic partial meniscectomy (APM) for degenerative meniscal tears in a large private insurance database among patients older than 50 years. METHODS: The Humana database between 2007 and 2015 was queried for this study. Patients meeting the inclusion criteria with degenerative meniscal tears who underwent APMs were identified by International Classification of Diseases, Ninth Revision codes, followed by Current Procedural Terminology codes. A linear regression analysis was performed with a significance level set at F < 0.05. RESULTS: A total of 21,759 APMs were performed between 2007 and 2015 in patients older than 50 years. Normalized data for total yearly enrollment showed a significant increase in APMs performed from 2007 to 2010 (R2 = 0.986, P = .007). The average percentage increase per year from 2007 to 2010 was 18.59%. However, there was a significant decrease in APMs performed from 2010 to 2015 (R2 = 0.748, P = .026). The average percentage decrease per year from 2010 to 2015 was 7.74%. The percentage decrease overall from 2010 to 2015 was 71.68%. No difference in statistical significance was found when age was broken into 5-year age intervals. We found a significant difference in APM based on region (P < .001). CONCLUSIONS: The rate of APMs in patients older than 50 years increased from 2007 until 2010. Since 2010, the rate of APMs in patients older than 50 years has significantly decreased. These trends are likely multifactorial. Regardless of cause, it appears that the orthopaedic surgery community is performing fewer APMs in this patient population. LEVEL OF EVIDENCE: Level III, retrospective database epidemiological study.

Injections Prior to Rotator Cuff Repair Are Associated With Increased Rotator Cuff Revision Rates.

PURPOSE: To determine whether shoulder injections prior to rotator cuff repair (RCR) are associated with deleterious surgical outcomes. METHODS: Two large national insurance databases were used to identify a total of 22,156 patients who received ipsilateral shoulder injections prior to RCR. They were age, sex, obesity, smoking status, and comorbidity matched to a control group of patients who underwent RCR without prior injections. The 2 groups were compared regarding RCR revision rates. RESULTS: Patients who received injections prior to RCR were more likely to undergo RCR revision than matched controls (odds ratio [OR], 1.52; 95% confidence interval [CI], 1.38-1.68; P < .0001). Patients who received injections closer to the time of index RCR were more likely to undergo revision (P < .0001). Patients who received a single injection prior to RCR had a higher likelihood of revision (OR, 1.25; 95% CI, 1.10-1.43; P = .001). Patients who received 2 or more injections prior to RCR had a greater than 2-fold odds of revision (combined OR, 2.12; 95% CI, 1.82-2.47; P < .0001) versus the control group. CONCLUSIONS: This study strongly suggests a correlation between preoperative shoulder injections and revision RCR. There is also a frequency dependence and time dependence to this finding, with more frequent injections and with administration of injections closer to the time of surgery both independently associated with higher revision RCR rates. Presently, on the basis of this retrospective database study, orthopaedic surgeons should exercise due caution regarding shoulder injections in patients whom they are considering to be surgical candidates for RCR. LEVEL OF EVIDENCE: Level III, therapeutic study.

Multi-Modal Compositional Analysis of Layered Paint Chips of Automobiles by the Combined Application of ATR-FTIR Imaging, Raman Microspectrometry, and SEM/EDX.

For the forensic analysis of multi-layered paint chips of hit-and-run cars, detailed compositional analysis, including minor/trace chemical components in the multi-layered paint chips, is crucial for the potential credentials of the run-away car as the number of layers, painting process, and used paints are quite specific to the types of cars, color of cars, and their surface protection depending on the car manufacturer and the year of manufacture, and yet overall characteristics of some paints used by car manufacturers might be quite similar. In the present study, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) imaging, Raman microspectrometry (RMS), and scanning electron microscopy/energy-dispersive X-ray spectrometric (SEM/EDX) techniques were performed in combination for the detailed characterization of three car paint chip samples, which provided complementary and comprehensive information on the multi-layered paint chips. That is, optical microscopy, SEM, and ATR-FTIR imaging techniques provided information on the number of layers, physical heterogeneity of the layers, and layer thicknesses; EDX on the elemental chemical profiles and compositions; ATR-FTIR imaging on the molecular species of polymer resins, such as alkyd, alkyd-melamine, acrylic, epoxy, and butadiene resins, and some inorganics; and RMS on the molecular species of inorganic pigments (TiO2, ZnO, Fe3O4), mineral fillers (kaolinite, talc, pyrophyllite), and inorganic fillers (BaSO4, Al2(SO4)3, Zn3(PO4)2, CaCO3). This study demonstrates that the new multi-modal approach has powerful potential to elucidate chemical and physical characteristics of multi-layered car paint chips, which could be useful for determining the potential credentials of run-away cars.

Total Hip Arthroplasty Bearing Surface Trends in the United States From 2007 to 2014: The Rise of Ceramic on Polyethylene.

BACKGROUND: Wear of the bearing surface is a critical element in determining the longevity of a total hip arthroplasty (THA). Over the past decade, concerns related to modern metal-on-metal (MoM) bearings and corrosion at the femoral head-neck interface have influenced surgeon selection of bearing surfaces. The purpose of this study is to analyze trends in THA bearing surface selection from 2007 through 2014 using a large national database. METHODS: The Nationwide Inpatient Sample database was used to extract bearing surface data from patients who underwent a primary THA between 2007 and 2014. Patients were grouped by bearing surface type: metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), MoM, and ceramic-on-ceramic (CoC) bearings. Descriptive statistics were employed to describe trends. Univariate and multivariate analyses were performed to identify differences between bearing surface groups. RESULTS: During the study period, 2,460,640 THA discharges were identified, of which 1,059,825 (43.1%) had bearing surface data. A total of 496,713 (46.9%) MoP, 307,907 (29.1%) CoP, 210,381 (19.9%) MoM, and 44,823 (4.2%) CoC cases were identified. MoM utilization peaked in 2008 representing 40.1% of THAs implanted that year and steadily declined to 4.0% in 2014. From 2007 to 2014, the use of CoP bearing surfaces increased from 11.1% of cases in 2007 to 50.8% of cases in 2014. In 2014, CoP utilization surpassed MoP which represented 42.1% of bearing surfaces that year. CONCLUSION: During the study period, MoM bearing surfaces decreased precipitously, while CoP surpassed MoP as the most popular bearing surface used in a THA.

Effect of double blocking layers at TiO2/Sb2S3 and Sb2S3/spiro-MeOTAD interfaces on photovoltaic performance.

The effect of double blocking layers on the Sb(2)S(3)-sensitized all solid state solar cell are investigated. Thin layers of ZrO(2) (blocking layer 1, BL1) and ZnS (blocking layer 2, BL2) are introduced at the TiO(2)/Sb(2)S(3) and Sb(2)S(3)/hole transporting material (HTM) interfaces. The presence of BL1 is found to improve the open-circuit voltage (V(oc)) from 457 mV to 618 mV, whereas BL2 improves mainly short-circuit current density (J(sc)) from 11.1 mA cm(-2) to 14.0 mA cm(-2). Transient photovoltage confirms that the BL1 efficiently blocks charge recombination, responsible for the V(oc) enhancement, whereas the BL2 has little effect on suppression of charge recombination. Surface modification of Sb(2)S(3) by BL2, on the other hand, leads to recovery of Sb(2)S(3) from the surface oxidized Sb(2)O(5), which affects the J(sc) increment. The present results suggest that the TiO(2)/Sb(2)S(3) interface is the main pathway for charge recombination rather than the Sb(2)S(3)/HTM interface. Double blocking layers enhanced the power conversion efficiency by 30%.

Combined use of quantitative ED-EPMA, Raman microspectrometry, and ATR-FTIR imaging techniques for the analysis of individual particles.

In this work, quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA) (called low-Z particle EPMA), Raman microspectrometry (RMS), and attenuated total reflectance Fourier transform infrared spectroscopic (ATR-FTIR) imaging were applied in combination for the analysis of the same individual airborne particles for the first time. After examining individual particles of micrometer size by low-Z particle EPMA, consecutive examinations by RMS and ATR-FTIR imaging of the same individual particles were then performed. The relocation of the same particles on Al or Ag foils was successfully carried out among the three standalone instruments for several standard samples and an indoor airborne particle sample, resulting in the successful acquisition of quality spectral data from the three single-particle analytical techniques. The combined application of the three techniques to several different standard particles confirmed that those techniques provided consistent and complementary chemical composition information on the same individual particles. Further, it was clearly demonstrated that the three different types of spectral and imaging data from the same individual particles in an indoor aerosol sample provided richer information on physicochemical characteristics of the particle ensemble than that obtainable by the combined use of two single-particle analytical techniques.

Risk of Subsequent Hip Fractures across Varying Treatment Patterns for Index Vertebral Compression Fractures.

Introduction: Vertebral compression fractures (VCFs) pose a considerable healthcare burden and are linked to elevated morbidity and mortality. Despite available anti-osteoporotic treatments (AOTs), guideline adherence is lacking. This study aims to evaluate subsequent hip fracture incidence after index VCF and to elucidate AOT prescribing patterns in VCF patients, further assessing the impact of surgical interventions on these patterns. Materials and Methods: Patients with index VCFs between 2010 and 2021 were identified using the PearlDiver database. Diagnostic and procedural data were recorded using International Classification of Diseases (ICD-9, ICD-10) and Current Procedural Terminology (CPT) codes. Patients under age 50 and follow-up

Preoperative Epidural Steroid Injection Does Not Increase Infection Risk Following Posterior Cervical Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study was to characterize the infection risk of preoperative epidural steroid injection (ESI) in patients undergoing posterior cervical surgery. SUMMARY OF BACKGROUND DATA: ESI is a helpful tool for alleviating pain and is often used as a diagnostic tool before cervical surgery. However, a recent small-scale study found that ESI before cervical fusion was associated with an increased risk of postoperative infection. MATERIALS AND METHODS: Patients from 2010 to 2020 with cervical myelopathy, spondylosis, and radiculopathy who underwent posterior cervical procedure including laminectomy, laminoforaminotomy, fusion, or laminoplasty were queried from the PearlDiver database. Patients who underwent revision or fusion above C2 or who had a diagnosis of neoplasm, trauma, or preexisting infection were excluded. Patients were divided on whether they received an ESI within 30 days before the procedure and subsequently matched by age, sex, and preoperative comorbidities. The χ 2 analysis was used to calculate the risk of postoperative infection within 90 days. Logistic regression controlling for age, sex, Elixhauser Comorbidity Index, and operated levels was conducted within the unmatched population to assess infection risk for injected patients across procedure subgroups. RESULTS: Overall, 299,417 patients were identified with 3897 having received a preoperative ESI and 295,520 who did not. Matching resulted in 975 in the injected group and 1929 in the control group. There was no significant difference in postoperative infection rate in those who received an ESI within 30 days preoperatively and those who did not (3.28% vs. 3.78%, odds ratio=0.86, 95% CI: 0.57-1.32, P =0.494). Logistic regression accounting for age, sex, Elixhauser Comorbidity Index, and levels operated demonstrated that injection did not significantly increase infection risk in any of the procedure subgroups. CONCLUSIONS: The present study found no association between preoperative ESI within 30 days before surgery and postoperative infection in patients undergoing posterior cervical surgery.

Stability analysis of tranexamic acid in the presence of various antiseptic solutions.

Tranexamic acid (TXA) effectively reduces blood loss and transfusion risk during total joint arthroplasty. Additionally, intraoperative irrigation with various antiseptic solutions is often utilized for the management and prevention of surgical site infection. However, interactions between various antiseptic solutions and TXA have not been investigated. The purpose of this in vitro study is to evaluate the stability of TXA in the presence of common orthopedic antiseptic solutions. Five antiseptic solutions-0.1% chlorhexidine (CHX) gluconate, 10% povidone-iodine (BTD), 0.5% sodium hypochlorite (Dakin's), 3% hydrogen peroxide (H2 O2 ), and 1.5% H2 O2 -and a 0.9% normal saline (NS) control were obtained. A stock 100 mg/ml TXA solution was diluted in each antiseptic solution to a concentration of 10.0 mg/ml to generate reference standard and stability samples. TXA stability in each solution was measured using high performance liquid chromatography at t = 0 and t = 120 min and reported as mean percent of theoretical concentration (MPT) with associated relative standard deviation (RSD). All experiments were performed in triplicate at room temperature. At t = 0 min, TXA remained stable when mixed with 0.9% NS, 0.1% CHX, 10% BTD, 3% H2 O2 , and 1.5% H2 O2 (MPT range: 102.0%-105.0%, RSD range: 0.80%-2.92%). Only 0.5% Dakin's led to significant degradation of TXA at t = 0 min (MPT: 14.3%, RSD:1.28%). At t = 120 min, TXA stability persisted for all compounds except Dakin's 0.5% (MPT: 18.4%, RSD: 28.7%). TXA efficacy may be significantly diminished when 0.5% Dakin's is used as an intraoperative irrigation solution. CHX, BTD, and H2 O2 do not degrade TXA.

Increased dislocation rates following total hip arthroplasty in patients with ankylosing spondylitis.

BACKGROUND: Patients with ankylosing spondylitis (AS) experience abnormal spinopelvic motion due to chronic inflammation of the axial skeleton, predisposing them to impingement and dislocation. The purpose of this study was to evaluate total hip arthroplasty (THA) dislocation rates in AS patients and evaluate the effects of age and gender on dislocation risk. METHODS: Patients who underwent primary THA from 2005 to 2014 were identified using the PearlDiver database. AS patients were compared to age- and gender-matched controls without AS. Patients with a history of spine pathology or spine surgery were excluded. Univariate analyses were performed based on age and sex to evaluate dislocation rates at 90 days, 6 months, 1 year, and 5 years postoperatively. RESULTS: A total of 2792 THA patients (59.6% male) with AS were identified and compared to an age- and gender-matched control group of 5582 THA patients (59.5% male) without AS or known spine pathology. At final follow-up, there were 96 dislocations (3.4%) in the AS group and 138 (2.5%) dislocations in the control group (OR 1.40; 95% CI, 1.08-1.83; p = 0.0118). AS patients ⩾70 years old had higher dislocation rates at all time points (OR range, 1.75-2.09; p < 0.05) compared to controls. At 5-year follow-up, dislocation-free survivorship was 95.7% (95% CI, 94.5-96.9%) for AS patients ⩾70 years old compared to 97.3% (95% CI, 96.6-98.0%) for patients ⩾70 years old without AS. CONCLUSIONS: Older AS patients have higher dislocation rates following THA. This effect is likely related to decreased spinopelvic motion in the sagittal plane, predisposing patients to impinge and dislocate.

Influence of Intramuscular Injection Sites on Pharmacokinetics of Amoxicillin in Olive Flounder (Paralichthys olivaceus) and Its Implication for Antibacterial Efficacy.

This study aimed to investigate the effects of different injection sites, including dorsal, cheek, and pectoral fin muscles, on the pharmacological properties of amoxicillin (AMOX) in olive flounder (Paralichthys olivaceus) after a single intramuscular (IM) injection of 40 mg/kg. The AMOX concentration was measured using high-performance liquid chromatography-tandem mass spectrometry, followed by a non-compartmental model analysis. The peak serum concentrations (Cmax) achieved 3 h after dorsal, cheek, and pectoral fin IM injections were 202.79, 203.96, and 229.59 µg/mL, respectively. The area under the concentration-time curve (AUC) was 1697.23, 2006.71, and 1846.61 µg/mL·h, respectively. The terminal half-life (t1/2λZ) was prolonged for cheek and pectoral fin IM injections (10.12 and 10.33 h, respectively) compared to dorsal IM injection (8.89 h). In the pharmacokinetic-pharmacodynamic analysis, a higher T > minimum inhibitory concentration (MIC) and AUC/MIC values were observed after AMOX was injected into the cheek and pectoral fin muscles compared to the dorsal muscle. Muscle residue depletion was below the maximum residue level from day 7 after IM injection at all three sites. These findings suggest that the cheek and pectoral fin sites provide advantages regarding systemic drug exposure and prolonged action compared with the dorsal site.