The Optimal Variation Range of Posterior Condylar Offset Associated with Positive Clinical Outcomes of Primary Total Knee Arthroplasty: A Retrospective Analysis.

OBJECTIVE: Posterior condylar offset (PCO) and anterior condylar offset (ACO) exert an influence on the sagittal alignment in total knee arthroplasty (TKA). However, there is no common consensus that the variation range of posterior condylar offset (PCO) is associated with patient-reported outcome measures (PROMs) and the optimum variation range of PCO. This study aims to investigate the correlation between PCO and the PROMs of primary TKA for osteoarthritis (OA) and find out the optimal variation range of the PCO. METHODS: In this study, we performed a radiographic analysis of 106 patients (112 knees) with primary TKA. Patients were divided into two cohorts (A and B) according to the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Correlations between the sagittal parameter and WOMAC were investigated using univariate and multivariate analysis. The receiver operating characteristic (ROC) curve was used to establish the cut-off value for the optimal variation range. We then further investigated how different variation range affects the WOMAC subscale score and forgotten-joint-score-12 (FJS-12). RESULTS: Univariate analysis revealed a correlation between the variation range of PCO (p < 0.01), ACO (p < 0.01) and PROMs. Multivariate analysis showed that only PCO was associated with PROMs. In the ROC graph, the cut-off value of the variation range of PCO is 2.85 mm (AUC = 0.66, Youden index = 0.26). The WOMAC functional ability score of the group outside the PCO variation range of 2.85 mm significantly increased compared to the group within the range. CONCLUSION: In this study, PCO variation was significantly associated with clinical outcomes in TKA and the optimal PCO variation range was within 2.85 mm. Maintaining the PCO variation within 2.85 mm could enhance functional recovery and patient satisfaction.

1,4-Disubstituted Piperazin-2-Ones as Selective Late Sodium Current Inhibitors with QT Interval Shortening Properties in Isolated Rabbit Hearts.

Late sodium current (INa) inhibitors are a new subclass of antiarrhythmic agents. To overcome the drawbacks, e.g., low efficacy and inhibition effect on K+ current, of the FDA-approved late INa inhibitor ranolazine, chain amide 6a-6q, 1,4-disubstituted piperazin-2-ones 7a-7s, and their derivatives 8a-8n were successively designed, synthesized, and evaluated in vitro on the NaV1.5-transfected HEK293T cells by the whole-cell patch clamp recording assay at the concentration of 40 µM. Among the new skeleton compounds, 7d showed the highest efficacy (IC50 = 2.7 µM) and good selectivity (peak/late ratio >30 folds), as well as excellent pharmacokinetics properties in mice (T1/2 of 3.5 h, F = 90%, 3 mg/kg, po). It exhibited low hERG inhibition and was able to reverse the ATX-II-induced augmentation of late INa phenotype of LQT3 model in isolated rabbit hearts. These results suggest the application potentials of 7d in the treatments of arrhythmias related to the enhancement of late INa.

CircIRAK3 exerts negative feedback regulation on inflammation by binding to HNRNP U and destabilizing proinflammatory cytokine mRNA in osteoarthritis and chondrogenesis.

Osteoarthritis (OA) is the most prevalent age-related and degenerative joint disease with limited treatment options. Previous studies have identified the therapeutic effects of mesenchymal stem cells (MSCs) therapy. Nevertheless, chronic inflammation impedes MSCs therapeutic effect. There have been reports suggesting that circular RNAs (circRNAs) are involved in OA and chondrogenesis. The combination of MSCs and circRNAs in therapies appears to be a promising option. In this study, we identified circIRAK3 as a significant regulator in cartilage degeneration and chondrogenesis through high-throughput sequencing analyses. We observed increased circIRAK3 in OA cartilage and during MSCs chondrogenesis. Knockdown of circIRAK3 resulted in excessive apoptosis, inhibited proliferation, and degradation of chondrocytes, along with the inhibition of MSCs chondrogenesis. Mechanistically, circIRAK3 bound to HNRNP U and competitively prevented its binding to IL-1ß, TNFα, and IL6 mRNA, thereby promoting mRNA degradation. Notably, circIRAK3 expression in plasma increased with higher OARSI scores. Intra-articular injection of adeno-associated virus-circIRAK3 delayed cartilage degeneration and reduced inflammation in DMM mouse model. Our study highlights a compensatory regulation network of circIRAK3 in chondrocytes in response to inflammation. CircIRAK3 has the potential to serve as a new therapeutic target for OA. Furthermore, therapies targeting circIRAK3 combined with MSCs hold promise.

FUNDC1/PFKP-mediated mitophagy induced by KD025 ameliorates cartilage degeneration in osteoarthritis.

Osteoarthritis (OA) is the most common joint disease, but no disease-modifying drugs have been approved for OA treatment. Mitophagy participates in mitochondrial homeostasis regulation by selectively clearing dysfunctional mitochondria, which might contribute to cartilage degeneration in OA. Here, we provide evidence of impaired mitophagy in OA chondrocytes, which exacerbates chondrocyte degeneration. Among the several classic mitophagy-regulating pathways and receptors, we found that FUNDC1 plays a key role in preserving chondrocyte homeostasis by inducing mitophagy. FUNDC1 knockdown in vitro and knockout in vivo decreased mitophagy and exacerbated mitochondrial dysfunction, exacerbating chondrocyte degeneration and OA progression. FUNDC1 overexpression via intra-articular injection of adeno-associated virus alleviated cartilage degeneration in OA. Mechanistically, our study demonstrated that PFKP interacts with and dephosphorylates FUNDC1 to induce mitophagy in chondrocytes. Further analysis identified KD025 as a candidate drug for restoring chondrocyte mitophagy by increasing the FUNDC1-PFKP interaction and thus alleviating cartilage degeneration in mice with DMM-induced OA. Our study highlights the role of the FUNDC1-PFKP interaction in chondrocyte homeostasis via mitophagy induction and identifies KD025 as a promising agent for treating OA by increasing chondrocyte mitophagy.

Pharmacokinetics of Antituberculosis Drugs in Plasma and Cerebrospinal Fluid in a Patient with Pre-Extensive Drug Resistant Tuberculosis Meningitis.

Drug-resistant tuberculous meningitis (TBM) is the most devastating and critical form of extrapulmonary tuberculosis. Here, we present a case of a 45-year-old male with pre-extensive drug-resistant tuberculosis meningitis (pre-XDR-TBM). He underwent emergency surgery for the long-tunneled external ventricular drainage (LTEVD). Molecular test and phenotypic drug sensitivity test (DST) of Mycobacterium tuberculosis in cerebrospinal fluid (CSF) showed that the isolate was resistant to both rifampin and fluoroquinolones. An anti-tuberculous regimen of isoniazid, pyrazinamide, cycloserine, moxifloxacin, clofazimine, and linezolid was tailored accordingly. We monitored the drug concentration in his plasma and CSF before (at 0-hour) and after anti-TB drugs administration (at 1-hour, 2-hour, 6-hour, and 12-hour) on 10th day after treatment initiation. We hope to provide reference values of drug exposures in plasma and CSF for patients with pre-XDR-TBM.

Higher Pelvic Incidence Was Associated with a Higher Risk of Sagittal Malposition of Femoral Component and Poor Outcomes of Primary Total Knee Arthroplasty: A Retrospective Cohort Analysis.

Spine-pelvis-lower extremity sagittal alignment is regarded as a global sagittal balance. Currently, there are few studies evaluating the pelvic and femoral sagittal alignment during total knee arthroplasty (TKA). This retrospective study aims to elucidate how pelvic and femoral sagittal alignment affect clinical outcomes of primary TKA for osteoarthritis (OA) and determine the proper range of femoral sagittal alignment. Patient-reported outcome measures (PROMs), including the Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC), and patient satisfaction scores, and clinician-reported outcomes (CROs), including range of motion (ROM) and pelvic and femoral sagittal parameters, of 67 cases were evaluated (89 knees) before and 1 year after TKA. The angle between the distal femur anterior cortex line and flange of the femoral component (FC) was defined as the α angle. Correlations between the α angle and PROM and CRO were investigated using multivariate and secondary regression analyses. Patients were further divided into four cohorts (A, B, C, and D) according to the α angle, and comparisons of their postoperative PROM and ROM scores were performed. Postoperative PROM and ROM scores improved significantly compared with the preoperative scores (p < 0.01). Only the α angle was significantly associated with postoperative knee extension among all PROM and CRO indexes (p = 0.001). Secondary regression demonstrated a convex upward function, and the scores were the highest at α angles of 0.57, 0.96, and -1.42 degrees for postoperative KSS, satisfaction, and range of knee extension, respectively (p < 0.01). However, the concave upward degree was the lowest at an α angle of 0.33 degrees for pelvic incidence (p < 0.001). Bonferroni's paired comparisons indicated that postoperative KSS and satisfaction of the cohort B (0 degrees ≤ α angle ≤ 3 degrees) were better than those of other cohorts (p < 0.0125). The results indicate that surgeons should pay more attention to the sagittal alignment of FC in patients with increased pelvic incidence, the distal femoral anterior cortex is recommended as an anatomic landmark, and 0 to 3 degrees might be "safe zones" of the sagittal flexion of FC in TKA. This study reflects the level of evidence III.

Circular RNA CREBBP modulates cartilage degradation by activating the Smad1/5 pathway through the TGFß2/ALK1 axis.

Osteoarthritis, characterized by articular cartilage degradation, is the leading cause of chronic disability in older adults. Studies have indicated that circular RNAs are crucial regulators of chondrocyte development and are involved in the progression of osteoarthritis. In this study, we investigated the function and mechanism of a circular RNA and its potential for osteoarthritis therapy. The expression levels of circCREBBP, screened by circular RNA sequencing during chondrogenic differentiation in adipose tissue-derived stem cells, and TGFß2 were significantly increased in the cartilage of patients with osteoarthritis and IL-1ß-induced chondrocytes. circCREBBP knockdown increased anabolism in the extracellular matrix and inhibited chondrocyte degeneration, whereas circCREBBP overexpression led to the opposite effects. Luciferase reporter assays, rescue experiments, RNA immunoprecipitation, and RNA pulldown assays confirmed that circCREBBP upregulated TGFß2 expression by sponging miR-1208, resulting in significantly enhanced phosphorylation of Smad1/5 in chondrocytes. Moreover, intra-articular injection of adeno-associated virus-sh-circCrebbp alleviated osteoarthritis in a mouse model of destabilization of the medial meniscus. Our findings reveal a critical role for circCREBBP in the progression of osteoarthritis and provide a potential target for osteoarthritis therapy.

Impaction Bone Grafting Combined with Titanium Mesh for Acetabular Bone Defects Reconstruction in Total Hip Arthroplasty Revision: A Retrospective and Mini-Review Study.

OBJECTIVE: To investigate the application of impaction bone grafting (IBG) combined with Ti-alloy mesh for acetabular bone defect reconstruction in total hip arthroplasty (THA) revision and follow up the clinical outcomes and imaging findings. METHODS: The clinical and imaging data of patients who were admitted to our hospital from January 2000 to December 2020 and underwent acetabular bone defects reconstruction using IBG combined with titanium mesh were retrospectively analyzed. Preoperative and post-revision Oxford and Harris scores, and post-revision complications were evaluated. Radiographs were used to determine center of rotation (COR) of the hip joint, transparency line, bone graft fusion, and bone mineral density (BMD) around the hip joint. RESULTS: Significant improvement was observed in both Oxford and Harris scores (P < 0.05). The radiographs taken at the last follow-up examination showed no significant differences in the acetabulum COR, offsets, inclination angle, mean ratio of vertical value, and BMD analysis between the post-revision side and contralateral side (P > 0.05). The follow-up data showed restoration of the mesh implant and graft bone fusion. CONCLUSIONS: The application of IBG combined with titanium-alloy mesh in revision THA patients with acetabular defects was found to provide satisfactory outcomes. However, large-scale studies are still needed to further elucidate the long-term outcomes.

Conjugated crosslinks boost the conductivity and stability of a single crystalline metal-organic framework.

A linker molecule with four pendant thiophene functions was crystallized with Zr(iv) ions to form a semiconductive porous coordination solid (1.1 × 10-5 S cm-1). Oxidative treatment with FeCl3 guests then coupled the thiophene units to form conjugated bridges as covalent crosslinks. The resulting hybrid of a metal-organic framework and conjugated polymer featured robust crystalline order that withstood long-term air exposure and broad pH (from 0 to 12) conditions. Moreover, the homocoupled thiophene units, conjugated through sulfide links (-S-) with the linker backbone, afforded higher electronic conductivity (e.g., >2.2 × 10-3 S cm-1), which is characteristic of conductive polymer prototypes of polythiophene and polyphenylene sulfide. The crosslinked solid also exhibited proton conductivity that could be increased broadly upon H2SO4 treatment (e.g., from 5.0 × 10-7 to 1.6 × 10-3 S cm-1).

[Comparison of hemostatic effect and safety in primary unilateral total hip arthroplasty receiving different anticoagulants after anti-fibrinolysis with tranexamic acid].

OBJECTIVE: To compare the hemostatic effect and safety in primary unilateral total hip arthroplasty (THA) receiving nadroparin calcium, enoxaparin sodium, rivaroxaban, or apixaban after anti-fibrinolysis with tranexamic acid (TXA) and explore the best anticoagulant. METHODS: A retrospective analysis was conducted on 184 patients who underwent the primary unilateral THA between January 2014 and December 2018, administrated 15 mg/kg TXA before surgery and received nadroparin calcium, enoxaparin sodium, rivaroxaban, or apixaban. The patients were divided into four groups based on the different anticoagulants: 46 patients received nadroparin calcium; 45 patients received enoxaparin sodium; 47 patients received rivaroxaban; the other 46 patients received apixaban. There was no significant difference in age, gender, body mass, body mass index, the types of hip joint diseases, complications, anesthesia mode, operation time, and preoperative laboratory indexes (hemoglobin, hematocrit, platelet, prothrombin time, activated partial prothrombin time, blood volume) ( P>0.05). Perioperative blood data (total blood loss, hidden blood loss, dominant blood loss, postoperative drainage volume, maximum loss of hemoglobin, and blood transfusion rate) and complications (incision, bleeding, and thrombosis) were recorded and compared between groups. RESULTS: There was no significant difference in total blood loss, hidden blood loss, dominant blood loss, postoperative drainage volume, maximum loss of hemoglobin, and blood transfusion rate between groups ( P>0.05). The comparison of postoperative complications showed that 1 case (2.1%) of redness and swelling of incision occurred in the rivaroxaban group, and 1 case (2.2%) of the other 3 groups each had poor incision healing. No incision infection, fat liquefaction, or other incision complications occurred in the 4 groups. There was no significant difference in incision complication between groups ( P>0.05). There were 2 cases (4.3%) bleeding events (1 case of right inguinal hematoma and 1 case of subcutaneous ecchymosis in front of left leg) in the nadroparin calcium group, while no bleeding event occurred in the other 3 groups, which had no significant difference in bleeding complication between groups ( χ 2=5.612, P=0.132). There was 1 case (2.2%) of intermuscular vein thrombosis of the lower extremity in the nadroparin calcium group and no case in the other 3 groups, which had no significant difference between groups ( χ 2=2.789, P=0.425). Neither deep venous thrombosis nor pulmonary embolism occurred in any group. CONCLUSION: No significant difference in the hemostatic effect and incidences of complications for patients underwent primary unilateral THA receiving nadroparin calcium, enoxaparin sodium, rivaroxaban, or apixaban after anti-fibrinolysis with TXA. One of the four anticoagulants can be selected to prevent thrombosis after anti-fibrinolysis with TXA, which has certain safety.

[Analysis of hemostatic effect and safety of tranexamic acid in primary simultaneous bilateral total hip arthroplasty].

OBJECTIVE: To explore the effect of tranexamic acid (TXA) on the transfusion rate, dominant blood loss, and postoperative complications in simultaneous bilateral total hip arthroplasty (SBTHA). METHODS: A clinical data of 72 patients who underwent the primary SBTHA between January 2010 and December 2018 was retrospectively analyzed. A single dose of 15 mg/kg TXA was administered intravenously before 5-10 minutes of operation in 48 patients of trial group and 24 patients were not treated with TXA in the control group. There was no significant difference between the two groups ( P>0.05) in the gender, age, body mass index, the type of disease, American Society of Anesthesiologists (ASA) grading, comorbidity, and preoperative hospital stay, hemoglobin, hematocrit, platelet count, coagulation function tests. The operation time, intraoperative blood loss, and postoperative transfusion rate, dominant blood loss, complication, and hospital stay were recorded and compared between the two groups. RESULTS: The median operation time of the trial group was 208.0 minutes, and that of the control group was 202.5 minutes, with no significant difference ( Z=-1.046, P=0.295). Postoperative transfusion was performed in 26 patients (54.2%) in the trial group and 21 patients (87.5%) in the control group, and the difference of transfusion rate between the two groups was significant ( χ 2 =7.843, P=0.005). However, there was no significant difference in the amount of transfused suspended red blood cells and plasma between the two groups ( P>0.05). The median intraoperative blood loss was 550 mL in the trial group and 600 mL in the control group, with no significant difference ( Z=-1.378, P=0.168). The postoperative drainage volume and median dominant blood loss in the trial group were (542±269) and 1 050 mL, respectively, which were significantly lower than those in the control group [(710±316) and 1 270 mL] ( P<0.05). There was 1 case of skin tension blisters around the incision, 1 case of lower limb numbness and muscle strength loss, and 1 case of lacunar cerebral infarction in the trial group, while in the control group, there was 1 case of skin ecchymosis around the incision and 1 case of bilateral lower limb numbness and muscle strength loss, which showed no significant difference in the incidences of complications ( P>0.05). No pulmonary embolism or deep venous thrombosis was found in the two groups. The median postoperative hospital stay and median total hospital stay were 9.0 and 13.0 days in the trial group, while 9.0 and 13.0 days in the control group, respectively, with no significant difference ( P>0.05). CONCLUSION: For patients who are treated with the primary SBTHA, TXA can reduce transfusion rate and perioperative dominant blood loss, and has a good hemostatic effect without increasing complications of incision, pulmonary embolism, deep venous thrombosis, and hospital stay. Therefore, TXA is relative safe.

Single-cell RNA-seq analysis identifies meniscus progenitors and reveals the progression of meniscus degeneration.

OBJECTIVES: The heterogeneity of meniscus cells and the mechanism of meniscus degeneration is not well understood. Here, single-cell RNA sequencing (scRNA-seq) was used to identify various meniscus cell subsets and investigate the mechanism of meniscus degeneration. METHODS: scRNA-seq was used to identify cell subsets and their gene signatures in healthy human and degenerated meniscus cells to determine their differentiation relationships and characterise the diversity within specific cell types. Colony-forming, multi-differentiation assays and a mice meniscus injury model were used to identify meniscus progenitor cells. We investigated the role of degenerated meniscus progenitor (DegP) cell clusters during meniscus degeneration using computational analysis and experimental verification. RESULTS: We identified seven clusters in healthy human meniscus, including five empirically defined populations and two novel populations. Pseudotime analysis showed endothelial cells and fibrochondrocyte progenitors (FCP) existed at the pseudospace trajectory start. Melanoma cell adhesion molecule ((MCAM)/CD146) was highly expressed in two clusters. CD146+ meniscus cells differentiated into osteoblasts and adipocytes and formed colonies. We identified changes in the proportions of degenerated meniscus cell clusters and found a cluster specific to degenerative meniscus with progenitor cell characteristics. The reconstruction of four progenitor cell clusters indicated that FCP differentiation into DegP was an aberrant process. Interleukin 1ß stimulation in healthy human meniscus cells increased CD318+ cells, while TGFß1 attenuated the increase in CD318+ cells in degenerated meniscus cells. CONCLUSIONS: The identification of meniscus progenitor cells provided new insights into cell-based meniscus tissue engineering, demonstrating a novel mechanism of meniscus degeneration, which contributes to the development of a novel therapeutic strategy.

Residual Mild Varus Alignment and Neutral Mechanical Alignment Have Similar Outcome after Total Knee Arthroplasty for Varus Osteoarthritis in Five-Year Follow-Up.

The effect of residual varus on survival rate and function in patients with varus knee osteoarthritis (OA) was considered an important issue for successful primary total knee arthroplasty (TKA). In this study, we compared the midterm clinical and functional outcomes in patients with different residual varus. A retrospective review of 175 patients (219 knees) with varus OA was > 3° for the hip-knee-ankle (HKA) who underwent primary TKA after exclusions and loss to follow-up from 237 patients (281 knees). The mean follow-up period was 5.2 ( ± 1.1) years. Patients were divided into four groups according to the first postoperative HKA angle from weight-bearing full-leg radiographs: "valgus" group (HKA angle > 0°, n = 44), "neutral" group (-3° ≤ HKA angle < 0°, n = 86), "mild varus" group (-6° ≤ HKA angle < -3°, n = 62), and "severe varus" group (HKA angle < -6°, n = 27). Survival analysis, Knee Society Score (KSS, including knee score and functional score), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were compared among the four groups. No knee required revision surgery during follow-up. For the KSS knee score and functional score at the last follow-up, the neutral and mild varus groups were better compared with the valgus and severe varus groups (p < 0.05), and there were no significant differences between the neutral and mild varus groups (p > 0.05). WOMAC scores of the neutral and mild varus groups were also better compared with the valgus and severe varus groups (p < 0.05), and there were no significant differences between the neutral and mild varus groups at the last follow-up. The postoperative HKA angle was significantly changed in valgus group between first and at the last follow-up when compared with the other three groups (p < 0.05). Leaving an HKA angle at < 6° varus had the same excellent functional outcome as neutral mechanical alignment after TKA for varus-type OA in the 5-year follow-up, using mechanically aligned technique. Caution is advised when leaving valgus or leaving severe varus after TKA.

Best bone of acetabulum for cup component placement in Crowe types I to III dysplastic hips: a computer simulation study.

BACKGROUND: During cup implantation, vertical height of the cup center (V-HCC) should be precisely controlled to achieve sufficient bone-cup coverage (BCC). Our study aimed to investigate the acetabular bone stock and the quantitative relationship between V-HCC and BCC in Crowe types I to III hips. METHODS: From November 2013 to March 2016, pelvic models of 51 patients (61 hips) with hip dysplasia were retrospectively reconstructed using a computer software. Acetabular height and doom thickness were measured on the mid-acetabular coronal cross section. V-HCC was defined as the vertical distance of cup rotational center to the interteardrop line (ITL). In the cup implantation simulation, the cup was placed at the initial preset position, with a V-HCC of 15 mm, and moved proximally by 3-mm increments. At each level, the BCC was automatically calculated by computer. Analysis of variance and Kruskal-Wallis test were used to compare the differences between groups. RESULTS: There were no significant between-group differences in maximum thickness of the acetabular doom; however, peak bone stock values were obtained at heights of 41.63 ±â€Š5.14 mm (Crowe type I), 47.58 ±â€Š4.10 mm (Crowe type II), and 55.78 ±â€Š3.64 mm (Crowe type III) above the ITL. At 15 mm of V-HCC, median BCC was 78% (75-83%) (Crowe type I), 74% (66-71%) (Crowe type II), and 61% (57-68%) (Crowe type III). To achieve 80% of the BCC, the median V-HCC was 16.27 (15.00-16.93) mm, 18.19 (15.01-21.53) mm, and 24.13 (21.02-28.70) mm for Crowe types I, II, and III hips, respectively. CONCLUSION: During acetabular reconstruction, slightly superior placement with V-HCC <25 mm retained sufficient bone coverage in Crowe I to III hips.

A Meta-Analysis Comparing Liposomal Bupivacaine and Traditional Periarticular Injection for Pain Control after Total Knee Arthroplasty.

Liposomal bupivacaine is a novel method for pain control after total knee arthroplasty (TKA), but recent studies showed no advantage for patients undergoing TKA compared with traditional periarticular injection (PAI). The purpose of this analysis was to compare the clinical outcomes between liposomal bupivacaine treatment and traditional PAI. We retrospectively reviewed data from 16 clinical trials in published databases from their inception to June 2017. The primary outcome was postoperative Visual Analogue Scale (VAS) score and secondary outcomes included opiate usage, narcotic consumption, range of motion, and length of stay. Nine randomized controlled trials and seven nonrandomized controlled trials involving 924 liposomal bupivacaine cases and 1,293 traditional PAI cases were eligible for inclusion in the meta-analysis. No differences were detected in most of the clinical outcomes, except for postoperative VAS within 12 hours and length of stay. This analysis showed that liposomal bupivacaine is not associated with significant improvement in postoperative pain control or other outcomes in TKA compared with PAI.

Value of Computed Tomography-Based Three-Dimensional Pre-operative Planning in Cup Placement in Total Hip Arthroplasty With Dysplastic Acetabulum.

Objects: To investigate the value of CT-based 3D templating software for pre-operative planning in patients with acetabular dysplasia undergoing total hip arthroplasty (THA) with a minimum follow-up of 2 years. Methods: We performed a retrospective review of a single surgeon's cohort of patients with Crowe I to III developmental dysplastic hip (49 hips in 41 patients) who underwent cementless primary THA and were available for follow-up at a mean of 2.7 years after THA. We analyzed the accuracy of cup size prediction, the reliability of pre- and post-operative cup orientation and position of reconstructed rotation center using CT-based 3D templating software. Post-operative Harris Hip Score and lower limb discrepancy was obtained at the last follow-up. Results: The sizes of 71% of the cup components (35/49) were estimated exactly, and 100% of the cup size estimates were accurate to within one-cup size. There was good reproducibility of pre- and post-operative position of reconstructed rotation center (correlation coefficient r = 0.396 for vertical position, p = 0.005; r = 0.326 for horizontal position, p = 0.024). There was no substantial agreement between the planned acetabular orientation and that measured post-operatively (correlation coefficient -0.174 for inclination and 0.045 for anteversion). There were 44 (90%) excellent or good results according to HHS. Seven patients (14%) reported lower limb discrepancy. Conclusions: Pre-operative CT-based 3D templating made it possible to predict accurate cup size and achieve reproducible cup position in patients with dysplastic acetabulum. The reproducibility of cup orientation could not be demonstrated in this study.

Expression of exosomal microRNAs during chondrogenic differentiation of human bone mesenchymal stem cells.

The aim of the current study was to compare the expression of microRNAs (miRNAs) in exosomes derived from human bone mesenchymal stem cells (hBMSCs) with and without chondrogenic induction. Exosomes derived from hBMSCs were isolated and identified. Microarray analysis was performed to compare miRNA expression between exosomes derived from hBMSCs with and without chondrogenic induction, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the differentially expressed miRNAs. hBMSCs were transfected with miRNA mimic to extract miRNA-overexpressed exosomes. The results showed that most exosomes exhibited a cup-shaped or round-shaped morphology with a diameter of approximately 50-200 nm and expressed CD9 and CD63. We detected 141 miRNAs that were differentially expressed with and without chondrogenic induction by over a twofold change, including 35 upregulated miRNAs, such as miR-1246, miR-1290, miR-193a-5p, miR-320c, and miR-92a, and 106 downregulated miRNAs, such as miR-377-3p and miR-6891-5p. qRT-PCR analysis validated these results. Exosomes derived from hBMSCs overexpressing miR-320c were more efficient than normal exosomes derived from control hBMSCs at promoting osteoarthritis chondrocyte proliferation, down-regulated matrix metallopeptidase 13 and up-regulated (sex determining region Y)-box 9 expression during hBMSC chondrogenic differentiation. In conclusion, we identified a group of upregulated miRNAs in exosomes derived from hBMSCs with chondrogenic induction that may play an important role in mesenchymal stem cell-derived exosomes in cartilage regeneration and, ultimately, the treatment of arthritis. We demonstrated the potential of these modified exosomes in the development of novel therapeutic strategies.

CDK6 and miR-320c Co-Regulate Chondrocyte Catabolism Through NF-κB Signaling Pathways.

BACKGROUND/AIMS: Cyclin-dependent kinase 6 (CDK6) regulates inflammatory response and cell differentiation. This study sought to determine whether CDK6 and miR-320c co-regulate chondrogenesis and inflammation. METHODS: Utilizing quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC), CDK6 and miR-320c expression were assessed in a micromass culture of human bone mesenchymal stem cells that underwent chondrogenesis in vitro as well as in chondrocytes from E16.5 mouse forelimbs. Normal chondrocytes were transfected with miR-320c mimic, miR-320c inhibitor, or CDK6-siRNA. Luciferase reporter assay results confirmed that miR-320c directly targets CDK6 by interacting with the 3'-untranslated region (3'-UTR) of its mRNA. qRT-PCR, Western blotting, and Cell Counting Kit-8 were subsequently used to evaluate the effects of miR-320c overexpression and CDK6 inhibition on inflammatory factor expression, as well as to investigate the effects of NF-kB and MAPK signaling pathway activation on IL-1ß-induced chondrocyte inflammation. RESULTS: Our results show that miR-320c expression increased during the middle stage and decreased during the late stage of hBMSC chondrogenic differentiation. In contrast, CDK6 expression decreased during the middle stage and increased during the late stage of hBMSC chondrogenic differentiation. Moreover, CDK6 expression increased in severe OA cartilage and in hypertrophic chondrocytes of mouse forelimbs at E16.5. Results of the luciferase reporter assay showed that miR-320c modulated CDK6 expression by binding to the 3'-UTR of its mRNA. miR-320c overexpression and CDK6 inhibition repressed IL-1ß-induced expression of inflammatory factors and regulated the NF-kB signaling pathway. CONCLUSION: CDK6 and miR-320c co-regulate hBMSC chondrogenesis and IL-1ß-induced chondrocyte inflammation through the NF-kB signaling pathway, suggesting that miR-320c and CDK6 inhibitors can be used to repress catabolism in human chondrocytes.

Exosomes derived from miR-92a-3p-overexpressing human mesenchymal stem cells enhance chondrogenesis and suppress cartilage degradation via targeting WNT5A.

BACKGROUND: WNT5A is known to be involved in the pathogenesis of osteoarthritis. This study investigated the molecular mechanism of exosomal miR-92a-3p and WNT5A in chondrogenesis and cartilage degeneration. METHODS: Exosomal miR-92a-3p expression was assessed in vitro in a human mesenchymal stem cell (MSC) model of chondrogenesis and in normal and OA primary human chondrocytes (PHCs). MSCs and PHCs were treated with exosomes derived from MSC-miR-92a-3p (MSC-miR-92a-3p-Exos) or its antisense inhibitor (MSC-anti-miR-92a-3p-Exos), respectively. Small interfering RNAs (siRNAs) and luciferase reporter assay were used to reveal the molecular role of exosomal miR-92a-3p and WNT5A in chondrogenesis. The protective effect of exosomes in vivo was measured using Safranin-O and Fast Green staining and immunohistochemical staining. RESULTS: Exosomal miR-92a-3p expression was elevated in the MSC chondrogenic exosome, while it was significantly reduced in the OA chondrocyte-secreted exosome compared with normal cartilage. Treatment with MSC-miR-92a-3p-Exos promoted cartilage proliferation and matrix genes expression in MSCs and PHCs, respectively. In contrast, treatment with MSC-anti-miR-92a-3p-Exos repressed chondrogenic differentiation and reduced cartilage matrix synthesis by enhancing the expression of WNT5A. Luciferase reporter assay demonstrated that miR-92a-3p suppressed the activity of a reporter construct containing the 3'-UTR and inhibited WNT5A expression in both MSCs and PHCs. MSC-miR-92a-3p-Exos inhibit cartilage degradation in the OA mice model. CONCLUSIONS: Our results suggest that exosomal miR-92a-3p regulates cartilage development and homeostasis by directly targeting WNT5A. This indicates that exosomal miR-92a-3p may act as a Wnt inhibitor and exhibits potential as a disease-modifying osteoarthritis drug.

Exosomal miR-95-5p regulates chondrogenesis and cartilage degradation via histone deacetylase 2/8.

MicroRNAs play critical roles in the pathogenesis of osteoarthritis, the most common chronic degenerative joint disease. Exosomes derived from miR-95-5p-overexpressing primary chondrocytes (AC-miR-95-5p) may be effective in treating osteoarthritis. Increased expression of HDAC2/8 occurs in the tissues and chondrocyte-secreted exosomes of patients with osteoarthritis and mediates cartilage-specific gene expression in chondrocytes. We have been suggested that exosomes derived from AC-miR-95-5p (AC-miR-95-5p-Exos) would enhance chondrogenesis and prevent the development of osteoarthritis by directly targeting HDAC2/8. Our in vitro experiments showed that miR-95-5p expression was significantly lower in osteoarthritic chondrocyte-secreted exosomes than in normal cartilage. Treatment with AC-miR-95-5p-Exos promoted cartilage development and cartilage matrix expression in mesenchymal stem cells induced to undergo chondrogenesis and chondrocytes, respectively. In contrast, co-culture with exosomes derived from chondrocytes transfected with an antisense inhibitor of miR-95-5p (AC-anti-miR-95-5p-Exos) prevented chondrogenic differentiation and reduced cartilage matrix synthesis by enhancing the expression of HDAC2/8. MiR-95-5p suppressed the activity of reporter constructs containing the 3'-untranslated region of HDAC2/8, inhibited HDAC2/8 expression and promoted cartilage matrix expression. Our results suggest that AC-miR-95-5p-Exos regulate cartilage development and homoeostasis by directly targeting HDAC2/8. Thus, AC-miR-95-5p-Exos may act as an HDAC2/8 inhibitor and exhibit potential as a disease-modifying osteoarthritis drug.