Advanced glycation end products promote meniscal calcification by activating the mTOR-ATF4 positive feedback loop.

The meniscus is vital for maintaining knee homeostasis and function. Meniscal calcification is one of the earliest radiological indicators of knee osteoarthritis (KOA), and meniscal calcification is associated with alterations in biomechanical properties. Meniscal calcification originates from a biochemical process similar to vascular calcification. Advanced glycation end products (AGEs) and their receptors (RAGEs) reportedly play critical roles in vascular calcification. Herein, we investigated whether targeting AGE-RAGE is a potential treatment for meniscal calcification. In our study, we demonstrated that AGE-RAGE promotes the osteogenesis of meniscal cells and exacerbates meniscal calcification. Mechanistically, AGE-RAGE activates mTOR and simultaneously promotes ATF4 accumulation, thereby facilitating the ATF4-mTOR positive feedback loop that enhances the osteogenic capacity of meniscal cells. In this regard, mTOR inhibits ATF4 degradation by reducing its ubiquitination, while ATF4 activates mTOR by increasing arginine uptake. Our findings substantiate the unique role of AGE-RAGE in the meniscus and reveal the role of the ATF4-mTOR positive feedback loop during the osteogenesis of meniscal cells; these results provide potential therapeutic targets for KOA.

After-hour elective total knee arthroplasty does not affect clinical outcomes but negatively affects alignment.

INTRODUCTION: In cases of limited medical resources, elective total knee arthroplasty (TKA) sometimes needs to be performed after typical work hours. However, surgeon fatigue and logistical factors may potentially affect outcomes. This study aimed to detect whether after-hour procedures impair outcomes after TKA. MATERIALS AND METHODS: Elective unilateral TKA from Jan 1, 2016 to Nov 31, 2018 was retrospectively selected and separated into two groups. Procedures started from 8:00 A.M. to 5:29 P.M. were identified as day-time surgeries, whereas those started from 5:30 P.M. to 11:59 P.M. were considered after-hour surgeries. Operative period, Knee Society Score (KSS), range of motion (ROM), total blood loss, length of hospital stay (LOS), and postoperative adverse events and complications were compared. Additionally, the components were evaluated radiologically. RESULTS: A total of 321 patients were selected, including 258 (80.37%) patients in the day-time group and 63 (19.63%) patients in the after-hour group. Operative period, LOS, total blood loss were similar between groups. The overall and each specific incidence of postoperative complications were comparable between the two groups, but the incidence of postoperative vomiting (POV) was higher in the after-hour group. There was no significant difference in knee joint function as shown by the KSS and ROM, both on the 3rd day and at 2 years after surgeries. Radiologically, there were no significant differences between the two groups in the femoral notches (P = 0.592). However, better coronal alignment was detected in the day-time group (P = 0.002), consistent with which there were less outliers (P = 0.033). CONCLUSION: After-hour TKA procedure does not exert an impact on clinical outcomes, but negatively affects lower limb alignment. Besides, after-hour TKA surgery impairs patients' comfort by increasing POV.

Complications of primary total hip arthroplasty among patients with rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and primary osteoarthritis.

BACKGROUND: Limited information exists comparing the perioperative complications of the different inflammatory arthropathies (IAs) after total hip arthroplasty (THA). Our study was aimed to (1) compare perioperative complications and (2) determine the most common complications between the different IA subtypes compared with patients with primary osteoarthritis (OA) undergoing primary THA and (3) find whether the difference in postoperative complications also exists between different IA after THA. METHODS: The Nationwide Inpatient Sample (NIS) was used to identify patients with Rheumatoid arthritis (RA), psoriatic arthritis, ankylosing spondylitis (AS), and primary OA undergoing unilateral THA between 2005 and 2014. Preoperative diagnosis, comorbidities, and postoperative complications were determined using the International Classification of Disease Clinical Modification version 9 codes. The prevalence of perioperative complications was compared between patients with IA and primary OA and between patients with different IA. RESULTS: When compared with patients with primary OA, patients with RA had significantly more postoperative surgical and medical complications. Yet there are just several medical complications differences exist between PA and primary OA or AS and primary OA, including stroke and acute renal failure for psoriatic arthritis and urinary tract infection and pneumonia for AS. What is more, there were also several differences in perioperative medical complications seen in patients with different IA. CONCLUSION: Except for patients with RA, the differences in perioperative complications was small between patients with IA and primary OA and between patients with different types of IA.

Using a degradable three-layer sandwich-type coating to prevent titanium implant infection with the combined efficient bactericidal ability and fast immune remodeling property.

Titanium (Ti) implant-associated infections are a challenge in orthopedic surgery, for which a series of antibacterial coatings have been designed and fabricated to reduce the risk of bacterial contamination. Herein, we created a degradable three-layer sandwich-type coating to achieve long-term antibacterial effects while simultaneously reconstructing the local immune microenvironment. The vancomycin (Van)-loaded vaterite coating constitutes the outer and inner layers, whereas Interleukin-12 (IL-12)-containing liposomes embedded in sodium alginate constitutes the middle layer. Van, released from the vaterite, demonstrated a favorable and rapid bactericidal ability against the representative methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. The released IL-12 exhibited the desired immune reconstitution abilities, actively facilitating defenses against subsequent bacterial invasions. Furthermore, the biocompatibility and cell-binding feature of the multifunctional coating was beneficial for achieving solid interface intergradation. Overall, the benefits of the three-layer sandwich-type coating, including the convenient fabrication process, efficient antimicrobial activity, fast immune remodeling property, fine cell-binding feature, and biodegradability, highlight its promising translational potential in preventing implant infection. STATEMENT OF SIGNIFICANCE: To prevent titanium implant infections, researchers have designed various antibacterial coatings. However, most of these coatings focused only on killing the invading bacteria over a limited postoperative period. However, the local immune microenvironment is compromised during surgery. Local immune deflection impedes the ability of the local immune defenses to clear bacteria and limits immune memory building from active defense against long-term subsequent bacterial invasions. Furthermore, these coatings are usually nondegradable and differ substantially from bone components, thereby impairing the integration of the coating and bone interface and generating concerns about implant stability and bacterial contamination. In this work, we synthesized a degradable coating that provides sustained antibacterial activity, promotes immune reconstitution, and simultaneously achieves solid bone integration.

Influence of frailty and its interaction with comorbidity on outcomes among total joint replacement.

BACKGROUND: Patients with frailty get more and more attention in clinical practice. Yet, no large-scale studies have explored the impact of frailty on the perioperative acute medical and surgical complications following TJA. what is more, comorbid diseases may lead, at least additively, to the development of frailty. There also no studies to find the possible interaction between comorbidity and frailty on the postoperative complications after TJA. METHODS: Discharge data of 2,029,843 patients who underwent TJA from 2005 to 2014 from the National Inpatient Sample (NIS) database, which was analyzed using cross-tabulations and multivariate regression modeling. Frailty was defined based on frailty-defining diagnosis clusters from frailty-defining diagnosis indicator of Johns Hopkins Adjusted Clinical Groups. RESULTS: Among patients who underwent total joint replacement surgeries, 50,385 (2.5%) were identified as frail. Frailty is highly associated with old age, especially for those over the age of 80, meanwhile females and black races have a high Charlson comorbidity index (CCI) of ≥ 3, together with emergency/urgent admission and teaching hospital. While comorbidity is associated with greater odds of acute medical complications, and frailty has a better predictive effect on in-hospital deaths, acute surgical complications. Furthermore, frailty did not show an enhancement in the predictive power of the Charlson comorbidity score for postoperative complications or in-hospital deaths but postoperative LOS and hospitalization costs. CONCLUSION: Frailty can be used to independently predicted postoperative surgical and medical complications, which also has a synergistic interaction with comorbidity for patients who are preparing to undergo TJA.

Assessment of hepatoprotective potential of Radix Fici Hirtae on alcohol-induced liver injury in Kunming mice.

OBJECTIVE: The objective of the present study was to investigate the hepatoprotective role of Radix Fici Hirtae on acute alcohol-induced liver injury in mice. METHODS: The component of Radix Fici Hirtae was extracted using petroleum ether, chloroform, ethyl acetate and n-butanol and divided into three dose groups of high, medium and low according to the clinical man's normal dose of the 50 g crude drug/d (0.83 g/kg body weight). Saline in concentration of 10 mg/mL, 5 mg/mL and 2.5 mg/mL and a dose of mouse lavage (0.2 mL/10 g mouse body weight) were added to the solution. Histopathlogical analysis of liver was performed. Finally, liver protection was validated by examining the effect of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AKP), and lactate dehydrogenase (LDH) on the hepatic function of mice in alcohol-induced liver injury model. RESULTS: Except for group with saturated n-butyl alcohol, for the rest of the groups, pathological changes of hepatic lipid and inflammatory cells infiltration were alleviated and liver sinus was normal. As compared to model group, the concentrations of AST, ALT, AKP and LDH in chloroform groups and ethyl acetate groups were significantly decreased. CONCLUSIONS: Extracts of Radix Fici Hirtae are effective for the prevention of alcohol-induced hepatic damage in mice. The results revealed that extracts of Radix Fici Hirtae could be used as hepatoprotective agent.