The Long-term Efficacy of Total Knee Arthroplasty on End-stage Kashin-Beck Disease of the Knee in Highland Tibetan Areas Patients: A Retrospective Study with 10-Year Follow-up.

OBJECTIVE: Despite the established success of total knee arthroplasty (TKA) with end-stage osteoarthritis, there is a notable scarcity of research on its long-term outcomes in individuals suffering from end-stage Kashin-Beck disease (KBD). This retrospective study aimed to assess the long-term outcomes and effectiveness of clinical function, quality of life, and complications of TKA and end-stage KBD patients in Tibetan highland areas. METHODS: The retrospective cohort included 43 KBD patients, comprising a total of 59 knees, who had undergone TKA at West China Hospital, Sichuan University between 2008 and 2021. Patients were subsequently followed up for a minimum of 3 years, and received rigorous radiological and clinical assessments at 3, 6, and 12 months post surgery, followed by annual examinations thereafter. The evaluation included various efficacy indices, including visual analogue scale (VAS) scores, hospital for special surgery (HSS) scores, functional score for adult Tibetans with Kashin-Beck disease (FSAT-KBD), and radiographic findings. Comparison of indicators within the same group was conducted using one-way repeated-measures analysis of variance or paired sample t-tests, whereas between-group differences were compared using an independent t-test. RESULTS: Throughout the average follow-up duration of 10.8 years, patients experienced a substantial reduction in knee pain and noteworthy functional improvement. The VAS scores decreased significantly from 77.47 ± 4.12 mm before surgery to 10.91 ± 1.97 mm after surgery, indicating considerable alleviation of knee pain. The HSS scores improved markedly, increasing from 44.26 ± 4.95 preoperatively to 91.26 ± 4.37, indicating enhanced joint function. Similarly, the FSAT-KBD exhibited positive progression, increasing from 25.90 ± 3.12 to 36.95 ± 3.54. Importantly, at the last follow-up, none of the patients presented with periprosthetic infection, prosthesis loosening, or periprosthetic fracture. CONCLUSION: At long-term follow-up, compared with patients in the preoperative period, patients in Tibetan highland areas with KBD of the knee who underwent TKA benefited from a significant reduction in pain, improvement in joint function, and satisfactory improvement in quality of life.

Effects of Dexamethasone on Postoperative Glycemic Control in Patients After Primary Total Joint Arthroplasty: A Randomized Double-Blind Controlled Trial.

BACKGROUND: In patients undergoing total joint arthroplasty (TJA), the use of dexamethasone (DEX) may cause perioperative blood glucose (BG) disorders, leading to complications even in patients who do not have diabetes. We aimed to evaluate the effects of different DEX doses on perioperative BG levels. METHODS: A total of 135 patients who do not have diabetes were randomized into three groups: preoperative intravenous injection of normal saline (Group A, the placebo group), preoperative intravenous injection of 10 mg DEX (Group B), and preoperative intravenous injection of 20 mg DEX (Group C). Postoperative fasting blood glucose (FBG) levels were designated as the primary outcome, while postoperative postprandial blood glucose (PBG) levels were assigned as the secondary outcome. The incidence of complications was recorded. We also investigated the risk factors for FBG ≥ 140 mg/dl and PBG ≥ 180 mg/dl. RESULTS: The FBG levels were higher in Groups B and C than in Group A on postoperative days (POD) 0 and 1. The PBG levels were lower for Groups A and B compared to Group C on POD 1. No differences in FBG or PBG were detected beyond POD 1. Elevated preoperative glycosylated hemoglobin A1c (HbA1c) levels increased the risk of FBG ≥ 140 mg/dl and PBG ≥ 180 mg/dl, respectively. However, preoperative intravenous injection of DEX was not associated with FBG ≥ 140 mg/dl or PBG ≥ 180 mg/dl. No differences were found in postoperative complications among the three groups. CONCLUSION: The preoperative intravenous administration of 10 or 20 mg DEX in patients who do not have diabetes showed transient effects on postoperative BG after TJA. The preoperative HbA1c level threshold (regardless of the administration or dosage of DEX) that increased the risk for the occurrence of FBG ≥ 140 mg/dl and PBG ≥ 180 mg/dl was 5.75% and 5.85%, respectively.

Cocktail of Ropivacaine, Morphine, and Diprospan Reduces Pain and Prolongs Analgesic Effects after Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

Background: Local infiltration analgesia (LIA) provides postoperative analgesia for total knee arthroplasty (TKA). The purpose of this study was to evaluate the analgesic effect of a cocktail of ropivacaine, morphine, and Diprospan for TKA. Methods: A total of 100 patients from September 2018 to February 2019 were randomized into 2 groups. Group A (control group, 50 patients) received LIA of ropivacaine alone (80 ml, 0.25% ropivacaine). Group B (LIA group, 50 patients) received an LIA cocktail of ropivacaine, morphine, and Diprospan (80 ml, 0.25% ropivacaine, 0.125 mg/ml morphine, and 62.5 µg/ml compound betamethasone). The primary outcomes were the levels of inflammatory markers C-reactive protein (CRP) and interleukin-6 (IL-6), pain visual analog scale (VAS) scores, opioid consumption, range of motion (ROM), functional tests, and sleeping quality. The secondary outcomes were adverse events, satisfaction rates, HSS scores, and SF-12 scores. The longest follow-up was 2 years. Results: The two groups showed no differences in terms of characteristics (P > 0.05). Group B had lower resting VAS pain scores (1.54 ± 0.60, 95% CI = 1.37 to 1.70 vs. 2.00 ± 0.63, 95% CI = 2.05 to 2.34) and active VAS pain scores (2.64 ± 0.62, 95% CI = 2.46 to 2.81 vs. 3.16 ± 0.75, 95% CI = 2.95 to 3.36) within 48 h postoperatively than Group A (P < 0.001), while none of the pain differences exceeded the minimal clinically important difference (MCID). Group B had significantly lower CRP levels (59.49 ± 13.01, 95% CI = 55.88 to 63.09 vs. 65.95 ± 14.41, 95% CI = 61.95 to 69.94) and IL-6 levels (44.11 ± 13.67, 95% CI = 40.32 to 47.89 vs. 60.72 ± 15.49, 95% CI = 56.42 to 65.01), lower opioid consumption (7.60 ± 11.10, 95% CI = 4.52 to 10.67 vs. 13.80 ± 14.68, 95% CI = 9.73 to 17.86), better ROM (110.20 ± 10.46, 95% CI = 107.30 to 113.09 vs. 105.30 ± 10.02, 95% CI = 102.52 to 108.07), better sleep quality (3.40 ± 1.03, 95% CI = 3.11 to 3.68 vs. 4.20 ± 1.06, 95% CI = 3.90 to 4.49), and higher satisfaction rates than Group A within 48 h postoperatively (P < 0.05). Adverse events, HSS scores, and SF-12 scores were not significantly different within 2 years postoperatively. Conclusions: A cocktail of ropivacaine, morphine, and Diprospan prolongs the analgesic effect up to 48 h postoperatively. Although the small statistical benefit may not result in MCID, the LIA cocktail still reduces opioid consumption, results in better sleeping quality and faster rehabilitation, and does not increase adverse events. Therefore, cocktails of ropivacaine, morphine, and Diprospan have good application value for pain control in TKA. This trial is registered with ChiCTR1800018372.

Comparison of Outcomes in Obese Patients after Total Knee Arthroplasty with Neutral or Mild Varus: A Retrospective Study with 8-Year Follow-Up.

OBJECTIVES: Residual varus after total knee arthroplasty (TKA) can affect functional outcomes, which may worsen in the presence of obesity. However, no studies were found to compare the outcomes of obese patients involving postoperative residual mild varus or neutral. The aim of this study was to compare postoperative complications and prosthesis survival, and functional outcomes for knees of obese patients with neutral or mild varus after TKA. METHODS: We retrospectively reviewed 188 consecutive obese patients (body mass index ≥30 kg/m2) at our hospital who underwent TKA due to varus knee osteoarthritis from January 2010 to December 2015. The mechanical hip-knee-ankle axis angle was measured in all patients at admission and discharge. Knee functions were retrospectively assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society Knee Score (KS-KS), Knee Society Function Score (KS-FS), Forgotten Joint Score (FJS), and range of motion (ROM). Continuous data were compared between knees with neutral or mild varus alignment using analysis of Student's t test or variance or the Kruskal-Wallis test as appropriate. For multiple comparisons of outcomes, we used Bonferroni-Dunn method to adjust p-values. Categorical data were compared using the chi-squared test. RESULTS: Of the 156 knees in 137 obese patients who completed follow-up for a mean of 8.32 ± 1.47 years, 97 knees were corrected from varus to neutral and 54 knees were kept in mild residual varus. Patients with mild varus knees had significantly WOMAC (8.25 ± 8.637 vs. 14.97 ± 14.193, p = 0.009) and better FJS (86.03 ± 15.607 vs. 70.22 ± 30.031, p = 0.002). The two types of knees did not differ significantly in KS-KS, KS-FS, or ROM. Although one patient with a neutral knee had to undergo revision surgery, there was no significant difference between two groups. CONCLUSIONS: For obese patients with osteoarthritis, preservation of residual varus alignment after TKA can improve functional outcomes without compromising prosthesis survival.

DLP Fabrication of Multiple Hierarchical Biomimetic GelMA/SilMA/HAp Scaffolds for Enhancing Bone Regeneration.

Severe bone defects resulting from trauma and diseases remain a persistent clinical challenge. In this study, a hierarchical biomimetic microporous hydrogel composite scaffold was constructed by mimicking the hierarchical structure of bone. Initially, gelatin methacrylamide (GelMA) and methacrylic anhydride silk fibroin (SilMA) were synthesized, and GelMA/SilMA inks with suitable rheological and mechanical properties were prepared. Biomimetic micropores were then generated by using an aqueous two-phase emulsification method. Subsequently, biomimetic microporous GelMA/SilMA was mixed with hydroxyapatite (HAp) to prepare biomimetic microporous GelMA/SilMA/HAp ink. Hierarchical biomimetic microporous GelMA/SilMA/HAp (M-GSH) scaffolds were then fabricated through digital light processing (DLP) 3D printing. Finally, in vitro experiments were conducted to investigate cell adhesion, proliferation, and inward migration as well as osteogenic differentiation and vascular regeneration effects. In vivo experiments indicated that the biomimetic microporous scaffold significantly promoted tissue integration and bone regeneration after 12 weeks of implantation, achieving 42.39% bone volume fraction regeneration. In summary, this hierarchical biomimetic microporous scaffold provides a promising strategy for the repair and treatment of bone defects.

Safety and Effectiveness of Robotic-Arm Assisted Total Knee Arthroplasty.

OBJECTIVE: We investigated the advantages of robotic arm-assisted total knee arthroplasty (raTKA) over conventional manual TKA (cmTKA) by comprehensively comparing patients who received raTKA and cmTKA in terms of postoperative pain, function, imaging assessment, and trauma to the body. This study investigated the efficacy and safety of raTKA in patients using the YUANHUA-TKA system. METHODS: In a prospective, randomized single-blind trial, 60 patients undergoing primary unilateral TKA from October 2020 to December 2020 were randomly assigned to either raTKA or cmTKA. Clinical evaluation, including the time of osteotomy and prosthesis model testing, the total operation time, the visual analogue scale at rest, VAS in motion, opioid consumption, white blood cell count, neutrophil ratio, erythrocyte sedimentation rate, C-reactive protein (CRP), passive and active range of motion (pROM, aROM), Western Ontario and McMaster Universities Arthritis Index (WOMAC [stiffness, pain, and function]) score, gait analysis, keen society score (KSS), adverse events, and blood loss were collected by the project nurse, as well as the imaging evaluation, including the lateral tibia component angle (LTC), frontal femoral component angle, frontal tibia component angle (FTC), lateral femoral component angl, and hip-knee-ankle angle (HKA). The student t-test (or the Wilcoxon signed-rank test) and the χ2-test (or the Fisher exact test) were used to determine differences in categorical variables. RESULTS: No significant difference was found between the two groups in pain throughout the whole follow-up period. On the third day postoperatively, the erythrocyte sedimentation rate in the cmTKA group was significantly higher (p = 0.02), as well as the CRP (p = 0.04). No significant difference was found in the WOMAC stiffnes score or pROM. However, the aROM and the flexion range when walking (FRW) were significantly better in the raTKA group throughout the trial (p < 0.05). The KSS at the 1-month follow-up and the WOMAC function score at the 1-year follow-up were both significantly better in the raTKA group (p < 0.05). The HKA and the LTC in the raTKA group closer to the ideal angle, and the difference between the groups was significant (p < 0.05). The total operation time of the raTKA group was significantly longer (p = 0.001). The intraoperative blood loss had no significant difference in the two groups. CONCLUSION: Compared with cmTKA, raTKA with the YUANHUA robot not only avoids extra pain and trauma in patients but promises better functional recovery and improves the accuracy of the prosthesis position and axial alignment reconstruction.

M2 macrophage-derived exosome-functionalized topological scaffolds regulate the foreign body response and the coupling of angio/osteoclasto/osteogenesis.

Designing scaffolds that can regulate the innate immune response and promote vascularized bone regeneration holds promise for bone tissue engineering. Herein, electrospun scaffolds that combined physical and biological cues were fabricated by anchoring reparative M2 macrophage-derived exosomes onto topological pore structured nanofibrous scaffolds. The topological pore structure of the fiber and the immobilization of exosomes increased the nanoscale roughness and hydrophilicity of the fibrous scaffold. In vitro cell experiments showed that exosomes could be internalized by target cells to promote cell migration, tube formation, osteogenic differentiation, and anti-inflammatory macrophage polarization. The activation of fibrosis, angiogenesis, and macrophage was elucidated during the exosome-functionalized fibrous scaffold-mediated foreign body response (FBR) in subcutaneous implantation in mice. The exosome-functionalized nanofibrous scaffolds also enhanced vascularized bone formation in a critical-sized rat cranial bone defect model. Importantly, histological analysis revealed that the biofunctional scaffolds regulated the coupling effect of angiogenesis, osteoclastogenesis, and osteogenesis by stimulating type H vessel formation. This study elaborated on the complex processes within the cell microenvironment niche during fibrous scaffold-mediated FBR and vascularized bone regeneration to guide the design of implants or devices used in orthopedics and maxillofacial surgery. STATEMENT OF SIGNIFICANCE: How to design scaffold materials that can regulate the local immune niche and truly achieve functional vascularized bone regeneration still remain an open question. Here, combining physical and biological cues, we proposed new insight to cell-free and growth factor-free therapy, anchoring reparative M2 macrophage-derived exosomes onto topological pore structured nanofibrous scaffolds. The exosomes functionalized-scaffold system mitigated foreign body response, including excessive fibrosis, tumor-like vascularization, and macrophage activation. Importantly, the biofunctional scaffolds regulated the coupling effect of angiogenesis, osteoclastogenesis, and osteogenesis by stimulating type H vessel formation.

Engineered Microchannel Scaffolds with Instructive Niches Reinforce Endogenous Bone Regeneration by Regulating CSF-1/CSF-1R Pathway.

Structural and physiological cues provide guidance for the directional migration and spatial organization of endogenous cells. Here, a microchannel scaffold with instructive niches is developed using a circumferential freeze-casting technique with an alkaline salting-out strategy. Thereinto, polydopamine-coated nano-hydroxyapatite is employed as a functional inorganic linker to participate in the entanglement and crystallization of chitosan molecules. This scaffold orchestrates the advantage of an oriented porous structure for rapid cell infiltration and satisfactory immunomodulatory capacity to promote stem cell recruitment, retention, and subsequent osteogenic differentiation. Transcriptomic analysis as well as its in vitro and in vivo verification demonstrates that essential colony-stimulating factor-1 (CSF-1) factor is induced by this scaffold, and effectively bound to the target colony-stimulating factor-1 receptor (CSF-1R) on the macrophage surface to activate the M2 phenotype, achieving substantial endogenous bone regeneration. This strategy provides a simple and efficient approach for engineering inducible bone regenerative biomaterials.

Ultrasound-activated piezo-hot carriers trigger tandem catalysis coordinating cuproptosis-like bacterial death against implant infections.

Implant-associated infections due to the formation of bacterial biofilms pose a serious threat in medical healthcare, which needs effective therapeutic methods. Here, we propose a multifunctional nanoreactor by spatiotemporal ultrasound-driven tandem catalysis to amplify the efficacy of sonodynamic and chemodynamic therapy. By combining piezoelectric barium titanate with polydopamine and copper, the ultrasound-activated piezo-hot carriers transfer easily to copper by polydopamine. It boosts reactive oxygen species production by piezoelectrics, and facilitates the interconversion between Cu2+ and Cu+ to promote hydroxyl radical generation via Cu+ -catalyzed chemodynamic reactions. Finally, the elevated reactive oxygen species cause bacterial membrane structure loosening and DNA damage. Transcriptomics and metabolomics analysis reveal that intracellular copper overload restricts the tricarboxylic acid cycle, promoting bacterial cuproptosis-like death. Therefore, the polyetherketoneketone scaffold engineered with the designed nanoreactor shows excellent antibacterial performance with ultrasound stimulation and promotes angiogenesis and osteogenesis on-demand in vivo.

Predicting the Probability of Tumor-Specific Survival in Patients Diagnosed With Primary Tumors in the Spinal Cord Using Nomogram Models.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The goal of this study was to develop a useful clinical prediction nomogram to accurately predict the cancer-specific survival (CSS) of patients with primary spinal cord tumor (SCT), thereby formulating scientific prevention and aiding clinical decision-making. METHODS: In this study, patients with SCT diagnoses from the surveillance, epidemiology, and end results (SEER) database (2000-2018) were taken into account. Initially, a nomogram was created using the CSS-associated independent factors that were determined from both univariate and multivariable Cox regression analyses. Furthermore, the nomogram's capacity for calibration, ability to discriminate, and actual clinical effectiveness were assessed through calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA), respectively. Finally, a strategy for categorizing SCT patients' risk was developed. RESULTS: This study included 909 SCT individuals. A novel nomogram was developed to forecast SCT patients' CSS, taking into account age, histological type, tumor grade, tumor stage, and radiotherapy. These factors were identified as independent prognostic indicators for CSS in SCT patients. Elderly SCT patients with distant metastasis, advanced tumor grade, received radiotherapy, and confirmed lymphoma have a poor prognosis. Meanwhile, the risk classification system could differentiate SCT patients and realize targeted management. CONCLUSIONS: The developed nomogram has the ability to accurately forecast the CSS in SCT individuals, aiding in precise decision-making during clinical practice, enhancing health planning, maximizing treatment advantages, and ultimately improving patient prognosis.

Molecular co-assembled strategy tuning protein conformation for cartilage regeneration.

The assembly of oligopeptide and polypeptide molecules can reconstruct various ordered advanced structures through intermolecular interactions to achieve protein-like biofunction. Here, we develop a "molecular velcro"-inspired peptide and gelatin co-assembly strategy, in which amphiphilic supramolecular tripeptides are attached to the molecular chain of gelatin methacryloyl via intra-/intermolecular interactions. We perform molecular docking and dynamics simulations to demonstrate the feasibility of this strategy and reveal the advanced structural transition of the co-assembled hydrogel, which brings more ordered ß-sheet content and 10-fold or more compressive strength improvement. We conduct transcriptome analysis to reveal the role of co-assembled hydrogel in promoting cell proliferation and chondrogenic differentiation. Subcutaneous implantation evaluation confirms considerably reduced inflammatory responses and immunogenicity in comparison with type I collagen. We demonstrate that bone mesenchymal stem cells-laden co-assembled hydrogel can be stably fixed in rabbit knee joint defects by photocuring, which significantly facilitates hyaline cartilage regeneration after three months. This co-assembly strategy provides an approach for developing cartilage regenerative biomaterials.

Efficacy and safety of two-stage revision for patients with culture-negative versus culture-positive periprosthetic joint infection: a single-center retrospective study.

BACKGROUND: The safety and efficacy of two-stage revision for culture-negative PJI remain controversial. This study analyzed outcomes after two-stage revision in patients with culture-negative and culture-positive periprosthetic joint infection (PJI) during follow-up lasting at least two years. METHODS: Data were retrospectively analysed patients who underwent hip or knee revision arthroplasty from January 2008 to October 2020 at our medical center. The primary outcome was the re-revision rate, while secondary outcomes were the rates of reinfection, readmission, and mortality. Patients with culture-negative or culture-positive PJI were compared in terms of these outcomes, as well as survival time without reinfection or revision surgery, based on Kaplan‒Meier analysis. RESULTS: The final analysis included 87 patients who were followed up for a mean of 72.3 months (range, 24-123 months). The mean age was 58.1 years in the culture-negative group (n = 24) and 59.1 years in the culture-positive group (n = 63). The two groups (culture-negative versus culture-positive) did not differ significantly in rates of re-revision (0.0% vs. 3.2%, p > 0.05), reinfection (4.2% vs. 3.2%, p > 0.05), readmission (8.4% vs. 8.0%, p > 0.05), or mortality (8.3% vs. 7.9%, p > 0.05). They were also similar in survival rates without infection-related complications or revision surgery at 100 months (91.5% in the culture-negative group vs. 87.9% in the culture-positive group; Mantel‒Cox log-rank χ2 = 0.251, p = 0.616). CONCLUSION: The two-stage revision proves to be a well-tolerated and effective procedure in both culture-negative and culture-positive PJI during mid to long-term follow-up.

Decoding the "Fingerprint" of Implant Materials: Insights into the Foreign Body Reaction.

Foreign body reaction (FBR) is a prevalent yet often overlooked pathological phenomenon, particularly within the field of biomedical implantation. The presence of FBR poses a heavy burden on both the medical and socioeconomic systems. This review seeks to elucidate the protein "fingerprint" of implant materials, which is generated by the physiochemical properties of the implant materials themselves. In this review, the activity of macrophages, the formation of foreign body giant cells (FBGCs), and the development of fibrosis capsules in the context of FBR are introduced. Additionally, the relationship between various implant materials and FBR is elucidated in detail, as is an overview of the existing approaches and technologies employed to alleviate FBR. Finally, the significance of implant components (metallic materials and non-metallic materials), surface CHEMISTRY (charge and wettability), and physical characteristics (topography, roughness, and stiffness) in establishing the protein "fingerprint" of implant materials is also well documented. In conclusion, this review aims to emphasize the importance of FBR on implant materials and provides the current perspectives and approaches in developing implant materials with anti-FBR properties.

Unreliability of Serum- or Plasma-based Assays of D-dimer or Fibrin (Fibrinogen) Degradation Product for Diagnosing Periprosthetic Joint Infection: A Prospective Parallel Study.

OBJECTIVE: The ability of D-dimer to diagnose periprosthetic joint infection (PJI) before revision hip or knee arthroplasty is still controversial, and the differences in diagnostic ability between serum- or plasma-based assays of D-dimer and fibrin (fibrinogen) degradation product (FDP) are uncertain. The prospective parallel study was performed to determine the ability of D-dimer to diagnose PJI before revision hip or knee arthroplasty, and the differences in diagnostic ability between serum- or plasma-based assays of D-dimer and FDP. METHODS: Patients undergoing knee or hip arthroplasty at our institution were prospectively enrolled into the following groups: those without inflammatory diseases who were undergoing primary arthroplasty ("Prim" group), those with inflammatory arthritis who were undergoing primary arthroplasty ("Prim/Inflam"), those undergoing revision arthroplasty because of aseptic failure ("Rev/Asept"), or those undergoing revision arthroplasty because of PJI ("Rev/PJI"). The ability of preoperative levels of D-dimer or FDP in serum or plasma to diagnose PJI in each group was assessed using areas under receiver operating characteristic curves (AUCs) and other diagnostic performance indicators. The diagnostic performance of these assays was compared with that of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). RESULTS: In the final analysis, Prim included 42 patients; Prim/Inflam, 40; Rev./Asept, 62; and Rev./PJI, 47. D-dimer assays led to AUCs of 0.635 in serum and 0.573 in plasma, compared to 0.593 and 0.607 for FDP. Even in combination with CRP or ESR, these assays failed to perform as well as the combination of CRP and ESR for diagnosing PJI. CONCLUSION: Levels of D-dimer or FDP in serum or plasma, whether used alone or together with CRP or ESR, are unreliable for diagnosing PJI before revision arthroplasty.

Outcomes of culture-negative or -positive periprosthetic joint infections: A systematic review and meta-analysis.

OBJECTIVES: This study overviewed the current database of studies on periprosthetic joint infections (PJIs) to compare outcomes and antibiotic side effects in culture-negative or culture-positive PJIs and assess treatment options for culture-negative PJIs. PATIENTS AND METHODS: A systematic review and meta-analysis was undertaken using studies published before July 2022 in MEDLINE, EMBASE, and Cochrane Library. All studies comparing treatment of culture-negative or -positive PJIs were included. Afterward, the infection control rate, periprosthetic or spacer fracture, hip joint or spacer dislocation, and antibiotic side effects in different treatment methods of PJI were analyzed. RESULTS: Eleven studies involving 1,747 patients were included. Most studies clearly defined the infection control criteria: no pain or swelling, no wound drainage, normal serology, and normal radiographic findings. Patients were followed until treatment failure, death, or until the last clinical visit without evidence of treatment failure. The two types of PJIs did not differ significantly in infection control rates (culture-negative PJI 79.2% vs. culture-positive PJI 76.6%; odds ratio [OR]=1.20, 95% confidence interval [CI]: 0.84 to 1.70), either after all types of surgical treatment or after two-stage revision arthroplasty (OR=1.12, 95% CI: 0.72 to 1.75), single-stage revision arthroplasty (OR=0.51, 95% CI: 0.19 to 1.37), or debridement, antibiotics, and implant retention (OR=0.88, 95% CI: 0.50 to 1.54). Similarly, we did not find differences in periprosthetic or spacer fracture and hip joint or spacer dislocation. For culture-negative PJIs, the infection control rate was 85.2% after two-stage revision arthroplasty, 90.6% after single-stage revision arthroplasty, and 69.7% after debridement, antibiotics, and implant retention. Data pooled from three studies showed higher incidence of antibiotic side effects for culture-negative PJIs. CONCLUSION: The clinical outcomes of one-stage revision and two-stage revision are comparable. Therefore, both of them can be considered in surgical treatment for culture-negative PJIs. In addition, limited data showed a higher incidence of antibiotic side effects in culture-negative PJIs.

Direct Reprogramming of Mouse Fibroblasts to Osteoblast-like Cells Using Runx2/Dlx5 Factors on Engineered Stiff Hydrogels.

Direct reprogramming of somatic cells into functional cells still faces major limitations in terms of efficiency and achieving functional maturity of the reprogramed cells. While different approaches have been developed commonly based on exploiting biochemical signals, introducing appropriate mechanical cues that stimulate the reprogramming process is rarely reported. In this study, collagen-coated polyacrylamide (PAM) hydrogels with stiffness close to that of collagenous bone (40 kPa) were adopted to augment the direct reprogramming process of mouse fibroblasts to osteoblastic-like cells. The results suggested that culturing cells on a hydrogel substrate enhanced the overexpression of osteogenic transcription factors using nonviral vectors and improved the yield of osteoblast-like cells. Particularly, a synergistic effect on achieving osteogenic functionality has been observed for the mechanical cues and overexpression of transcriptional factors, leading to enhanced osteogenic transformation and production of bone mineral matrix. Animal experiments suggested that reprogramed cells generated on matrix hydrogels accelerated bone regeneration and stimulated ectopic osteogenesis. Mechanism analysis suggested the critical involvement of actomyosin contraction and mechanical signal-mediated pathways like the RhoA-ROCK pathway, leading to a synergistic effect on the key transcriptional processes, including chromatin remodeling, nuclear translocation, and epigenetic transition. This study provides insights into the mechanical cue-enhanced direct reprogramming and cell therapy.

Ingenious Synergy of a Pathology-Specific Biomimetic Multifunctional Nanoplatform for Targeted Therapy in Rheumatoid Arthritis.

Based on the pathological characteristics of rheumatoid arthritis, including the overproduction of reactive oxygen species (ROS), inflammatory responses, and osteoclast differentiation, a biomimetic multifunctional nanomedicine (M-M@I) is designed. Iguratimod (IGU) is loaded, which inhibits inflammatory responses and osteoclast differentiation, into mesoporous polydopamine (MPDA), which scavenges ROS. Subsequently, the nanoparticles are coated with a cell membrane of macrophages to achieve actively targeted delivery of the nanoparticles to inflamed joints. It is shown that the M-M@I nanoparticles are taken up well by lipopolysaccharide-induced RAW 264.7 macrophages or bone marrow-derived macrophages (BMDMs). In vitro, the M-M@I nanoparticles effectively scavenge ROS, downregulate genes related to inflammation promotion and osteoclast differentiation, and reduce the proinflammatory cytokines and osteoclast-related enzymes. They also reduce the polarization of macrophages to a pro-inflammatory M1 phenotype and inhibit differentiation into osteoclasts. In mice with collagen-induced arthritis, the M-M@I nanoparticles accumulate at arthritic sites and circulate longer, significantly mitigating arthritis symptoms and bone destruction. These results suggest that the pathology-specific biomimetic multifunctional nanoparticles are effective against rheumatoid arthritis, and they validate the approach of developing multifunctional therapies that target various pathological processes simultaneously.

The role of toll-like receptors in orchestrating osteogenic differentiation of mesenchymal stromal cells and osteoimmunology.

Osteoimmunology is a concept involving molecular and cellular crosstalk between the skeletal and immune systems. Toll-like receptors (TLRs) are widely expressed both on mesenchymal stromal cells (MSCs), the hematopoietic cells, and immune cells in the osteogenic microenvironment for bone development or repair. TLRs can sense both exogenous pathogen-associated molecular patterns (PAMPs) derived from microorganisms, and damage-associated molecular patterns (DAMPs) derived from normal cells subjected to injury, inflammation, or cell apoptosis under physiological or pathological conditions. Emerging studies reported that TLR signaling plays an important role in bone remodeling by directly impacting MSC osteogenic differentiation or osteoimmunology. However, how to regulate TLR signaling is critical and remains to be elucidated to promote the osteogenic differentiation of MSCs and new bone formation for bone tissue repair. This review outlines distinct TLR variants on MSCs from various tissues, detailing the impact of TLR pathway activation or inhibition on MSC osteogenic differentiation. It also elucidates TLR pathways' interplay with osteoclasts, immune cells, and extracellular vesicles (EVs) derived from MSCs. Furthermore, we explore biomaterial-based activation to guide MSCs' osteogenic differentiation. Therefore, understanding TLRs' role in this context has significant implications for advancing bone regeneration and repair strategies.

Tetrahedral Framework Nuclear Acids Can Regulate Interleukin-17 Pathway to Alleviate Inflammation and Inhibit Heterotopic Ossification in Ankylosing Spondylitis.

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease that leads to serious spinal deformity and ankylosis. Persistent inflammation and progressive ankylosis lead to loss of spinal flexibility in patients with AS. Tetrahedral framework nucleic acids (tFNAs) have emerged as a one kind of nanomaterial composed of four specially designed complementary DNA single strands with outstanding biological properties. Results from in vivo experiments demonstrated that tFNAs treatment could inhibit inflammatory responses and heterotopic ossification to halt disease progression. In vitro, tFNAs were proved to influence the biological behavior of AS primary chondrocytes and inhibit the secretion of pro-inflammatory cytokines through interleukin-17 pathway. The osteogenic process of chondrocytes was as well inhibited at the transcriptional level to regulate the expression of related proteins. Therefore, we believe tFNAs had a strong therapeutic effect and could serve as a nonsurgical remedy in the future to help patients suffering from AS.