Aims

The metabolic variations between the cartilage of osteoarthritis (OA) and Kashin-Beck disease (KBD) remain largely unknown. Our study aimed to address this by conducting a comparative analysis of the metabolic profiles present in the cartilage of KBD and OA.

Aims

To assess the alterations in cell-specific DNA methylation associated with chondroitin sulphate response using peripheral blood collected from Kashin-Beck disease (KBD) patients before initiation of chondroitin sulphate treatment.

Osteoarthritis, the most common degenerative joint disease, significantly impairs life quality and labor capability of patients. Synovial inflammation, initiated by HMGB1 (High mobility group box 1)-induced activation of macrophage, precedes other pathological changes. As an upstream regulator of NF-κB (nuclear factor-kappa B) and MAPK (mitogen-activated protein kinase) signaling pathway, TAK1 (TGF-β activated kinase 1) participates in macrophage activation, while its function in osteoarthritis remains unveiled. This study aims to investigate the role of TAK1 in the pathogenesis of osteoarthritis via both in vitro and in vivo approaches.

We performed immunohistochemical staining for TAK1 in synovial tissue, both in osteoarthritis patients and healthy control. Besides, immunofluorescence staining for F4/80 as macrophage marker and TAK1 were conducted as well. TAK1 expression was examined in RAW264.7 macrophages stimulated by HMGB1 via qPCR (Quantitative polymerase chain reaction) and Western blotting, and the effect of TAK1 inhibitor (5z-7 oxozeaenol) on TNF-α production was evaluated by immunofluorescence staining. Further, we explored the influence of intra-articular shRNA (short hairpin RNA) targeting TAK1 on collagenase-induced osteoarthritis in mice.

Immunohistochemical staining confirmed significant elevation of TAK1 in osteoarthritic synovium, and immunofluorescence staining suggested macrophages as predominant residence of TAK1. In HMGB1-stimulated RAW264.7 macrophages, TAK1 expression was up-regulated both in mRNA and protein level. Besides, TAK1 inhibitor significantly impairs the production of TNF-α by macrophages upon HMGB1 stimulation. Moreover, intra-articular injection of lentivirus loaded with shRNA targeting TAK1 (sh-TAK1) reduced peri-articular osteophyte formation in collagenase-induced osteoarthritis in mice.

TAK1 exerts a potent role in the pathogenesis of osteoarthritis by mediating the activation of macrophages.

Intervertebral disc degeneration can lead to physical disability and significant pain, while the present therapeutics still fail to biochemically and biomechanically restore the tissue. Stem cell-based therapy in treating intervertebral disc (IVD) degeneration is promising while transplanting cells alone might not be adequate for effective regeneration. Recently, gene modification and 3D-printing strategies represent promising strategies to enhanced therapeutic efficacy of MSC therapy. In this regard, we hypothesized that the combination of thermosensitive chitosan hydrogel and adipose derived stem cells (ADSCs) engineered with modRNA encoding Interleukin − 4 (IL-4) can inhibit inflammation and promote the regeneration of the degenerative IVD.

Rat ADSCs were acquired from adipose tissue and transfected with modRNAs. First, the kinetics and efficacy of modRNA-mediated gene transfer in mouse ADSCs were analyzed in vitro. Next, we applied an indirect co-culture system to analyze the pro-anabolic potential of IL-4 modRNA engineered ADSCs (named as IL-4-ADSCs) on nucleus pulposus cells.

ModRNA transfected mouse ADSCs with high efficiency and the IL-4 modRNA-transfected ADSCs facilitated burst-like production of bio-functional IL-4 protein. In vitro, IL-4-ADSCs induced increased anabolic markers expression of nucleus pulposus cells in inflammation environment compared to untreated ADSCs.

These findings collectively supported the therapeutic potential of the combination of thermosensitive chitosan hydrogel and IL-4-ADSCs for intervertebral disc degeneration management. Histological and in vivo validation are now being conducted.

Quantitative ultrasound (QUS) is a promising tool to estimate bone structure characteristics and predict fragile fracture. The aim of this pilot cross-sectional study was to evaluate the performance of a multi-channel residual network (MResNet) based on ultrasonic radiofrequency (RF) signal to discriminate fragile fractures retrospectively in postmenopausal women.

Total joint replacement (TJR) was one of the most revolutionary breakthroughs in joint surgery. The majority studies had shown that most implants could last about 25 years, anyway, there is still variation in the longevity of implants. In US, for all the hip revisions from 2012 to 2017 in the United States, 12.0% of the patients were diagnosed as aseptic loosening. Variable studies have showed that any factor that could cause a systemic or partial bone loss, might be the risk of periprosthetic osteolysis and aseptic loosening.

Breast cancer is the most frequent malignancy in women, more than 2.1 million women were newly diagnosed with breast cancer, 626,679 women with breast cancer died in 2018. It's been reported that the mean incidence of THA was 0.29% for medicare population with breast cancer in USA, of which the incidence was 3.46% in Norwegian. However, the effects of breast cancer chemotherapy and hormonotherapy, such as aromatase inhibitors (AI), significantly increased the risk of osteoporosis, and had been proved to become a great threat to hip implants survival.

In this case, a 46-year-old female undertook chemotherapy and hormonotherapy of breast cancer 3 years after her primary THA, was diagnosed with aseptic loosening of the hip prosthesis. Her treatment was summarized and analyzed.

Breast cancer chemotherapy and hormonotherapy might be a threat to the stability of THA prosthesis. More attention should be paid when a THA paitent occurred with breast cancer. More studies about the effect of breast cancer treatments on skeleton are required.

As peri-prosthetic aseptic loosening is one of the main causes of implant failure, inhibiting wear particles induced macrophages inflammation is considered as a promising therapy for AL to expand the lifespan of implant. Here, we aim at exploring the role of p110δ, a member of class IA PI3K family, and Krüppel-like factor 4 (KLF4) in titanium particles (TiPs) induced macrophages-inflammation and osteolysis.

Firstly, IC87114, the inhibitor of p110δ and siRNA targeting p110δ were applied and experiments including ELISA and immunofluorescence assay were conducted to explore the role of p110δ. Sequentially, KLF4 was predicted as the transcription factor of p110δ and the relation was confirmed by dual luciferase reporter assay. Next, assays including RT-PCR, western blotting and flow cytometry were performed to ensure the specific role of KLF4. Finally, TiPs-induced mice cranial osteolysis model was established, and micro-CT scanning and immunohistochemistry assay were performed to reveal the role of p110δ and KLF4 in vivo.

Here, we found that p110δ was upregulated in TiPs-stimulated macrophages. The inhibition of p110δ or knockdown of p110δ could significantly dampen the TiPs-induced secretion of TNFα and IL-6. Further mechanistic studies confirmed that p110δ was responsible for TNFα and IL-6 trafficking out of Golgi complex without affecting their expression in TiPs-treated macrophages. Additionally, we explored the upstream regulators and confirmed that Krüppel-like factor 4 (KLF4) was the transcription repressor of p110δ. Apart from that, KLF4, targeted by miR-92a, could also attenuate TiPs-induced inflammation by mediating NF-κB pathway and M1/M2 polarization. By the establishment of TiPs-induced mice cranial osteolysis model, we found that KLF4 knockdown exacerbated TiPs-induced osteolysis which was strikingly ameliorated by knockdown of p110δ.

In summary, our study suggests the key role of miR-92a/KLF4/p110δ signal in TiPs-induced macrophages inflammation and osteolysis.

Aims

Circular RNA (circRNA) is involved in the regulation of articular cartilage degeneration induced by inflammatory factors or oxidative stress. In a previous study, we found that the expression of circStrn3 was significantly reduced in chondrocytes of osteoarthritis (OA) patients and OA mice. Therefore, the aim of this paper was to explore the role and mechanism of circStrn3 in osteoarthritis.

Aims

Developmental dysplasia of the hip (DDH) is a complex musculoskeletal disease that occurs mostly in children. This study aimed to investigate the molecular changes in the hip joint capsule of patients with DDH.

To explore a novel machine learning model to evaluate the vertebral fracture risk using Decision Tree model and train the model by Bone Mineral Density (BMD) of different compartments of vertebral body.

We collected a Computed Tomography image dataset, including 10 patients with osteoporotic fracture and 10 patients without osteoporotic fracture. 40 non-fracture Vertebral bodies from T11 to L5 were segmented from 10 patients with osteoporotic fracture in the CT database and 53 non-fracture Vertebral bodies from T11 to L5 were segmented from 10 patients without osteoporotic fracture in the CT database. Based on the biomechanical properties, 93 vertebral bodies were further segmented into 11 compartments: eight trabecular bone, cortical shell, top and bottom endplate. BMD of these 11 compartments was calculated based on the HU value in CT images.

Decision tree model was used to build fracture prediction model, and Support Vector Machine was built as a compared model. All BMD data was shuffled to a random order. 70% of data was used as training data, and 30% left was used as test data. Then, training prediction accuracy and testing prediction accuracy were calculated separately in the two models.

The training accuracy of Decision Tree model is 100% and testing accuracy is 92.14% after trained by BMD data of 11 compartments of the vertebral body. The type I error is 7.14% and type II error is 0%. The training accuracy of Support Vector Machine model is 100% and the testing accuracy is 78.57%. The type I error is 17.86% and type II error is 3.57%.

The performance of vertebral body fracture prediction using Decision Tree is significantly higher than using Support Vector Machine. The Decision Tree model is a potential risk assessment method for clinical application. The pilot evidence showed that Decision Tree prediction model overcomes the overfitting drawback of Support Vector Machine Model. However, larger dataset and cohort study should be conducted for further evidence.

Objectives

The objective of this study was to investigate the association of four single-nucleotide polymorphisms (SNPs) of the cannabinoid receptor 2 (CNR2) gene, gene-obesity interaction, and haplotype combination with osteoporosis (OP) susceptibility.

Objectives

Irrigation is the cornerstone of treating skeletal infection by eliminating pathogens in wounds. A previous study shows that irrigation with normal saline (0.9%) and ethylenediaminetetraacetic acid (EDTA) could improve the removal of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) compared with normal saline (NS) alone. However, it is still unclear whether EDTA solution is effective against infection with drug-resistant bacteria.

Aim

Radiologic signs such as radiolucent lines around the implant, hardware fracture or displacement and periosteal reaction have been considered suggestive of implant-associated infection. The goal of this study is to assess the correlation of these signs with confirmed internal fixation-associated infection evaluated in a prospective cohort.

Aim

Unexpected positive infections are distinct entity in prosthetic revision surgery. The prevalence and characteristics of unexpected positive cultures in internal fixation are however less established. The aim of this study was to describe the prevalence and characteristics of unexpected diagnosis of infection in a prospective cohort of revision surgeries following internal fixation.

Although single-stage revision has attracted a lot of attention due to less socioeconomic cost, this technique is not widely used throughout the world due to strict indications. In this situation, we report our outcome on single-stage revision combined with selective direct intra-articular antibiotic infusion for chronic infected THA, especially for patients with culture-negative hip, fungal infections and multidrug-resistant organism.

We retrospectively reviewed 131 patients with chronic infected THA between January 2010 and February 2017 who underwent single-stage revision, including soakage of surgical area with 0.5% aqueous betadine, pouring powdered vancomycin or imipenem into the medullary cavity. For patients with culture-negative hip, fungal infections and multidrug-resistant organism, a direct intra-articular infusion of pathogens-sensitive antibiotics via three-branch catheter were performed postoperatively. Recurrence of infection and clinical outcomes were evaluated.

One hundred and fifteen patients were followed-up for an average of 4.5 years (range, 1.2–8 years). Of the 115 patients, 103 patients (89.6%) required no additional surgical or medical treatment for recurrence of infection. A recurrent infection was observed in 4 of the 23 patients (17.4%) with culture-negative infected hip. One of 4 fungal infections was relapse and the success rate in patients with multidrug-resistant organism was 84.2% (16/19). The mean postoperative Harris hip score was 81 points (63 to 92; p < 0.05) at the most recent assessment.

Treatment of chronic infected THA by single-stage revision combined with selective direct intra-articular antibiotic infusion can be fairly effective, even for patients with relative “contraindication” of this approach.

Infection is a potentially disastrous complication of total knee arthroplasty (TKA). Although advances in surgical technique and antibiotic prophylaxis have reduced the incidence of infection to approximately 1% in primary TKA, there is still a substantial number of patients. Treatment options include antibiotic suppression, irrigation and debridement with component retention (with or without polyethylene exchange), one-stage or two-stage revision, resection arthroplasty and rarely arthrodesis or amputation. Salvage of prostheses has always been associated with low rates of success. It was reported a success rate of 27% for open debridement. It is suitable for selective cases where infection occurs within the first 4–6 weeks of primary TKA or in the setting of acute hematogenous gram positive infection with stable implants. With the advances in arthroscopic technique, arthroscopy after TKA has become an accepted method to assess and manage the complications of TKA. Arthroscopic treatment for infected TKA was reported and the successful rate was similar or better than open debridement in selected situations. We used arthroscopic debridement combined with continuous antibiotic irrigation and suction to treat acute presentation of infected TKA with acceptable result. From 2010∼2013, we has performed arthroscopic debridement and continuous antibiotic irrigation system for seven patients with infected TKA. All of the seven patients had no open wounds nor sinuses and no radiological evidence of prosthetic instability or evidence of osteomyelitis. Most of the surgical intervention was performed within two weeks from the onset of symptoms. Arthroscopic debridement was performed with a shaver using a multiportal technique (anterolateral, anteromedial, superolateral, superomedial, posterolateral, posteromedial) and a continuous antibiotic irrigation system was used to dilutes concentration of the causative microorganism and keep high local bactericidal concentration of antibiotics. We evaluated the efficacy by using follow up of the C-reactve protein (CRP) test, erythrocyte sedimentation rate (ESR) test and physical examination. Successful treatment was defined as prosthesis retention without recurrent infection by the final follow-up. Six of seven infected TKA were cured without recurrence at a mean follow-up of 23 months (range, 6–41 months). One case with rheumatoid arthritis under long-term steroid therapy had recurred after episode of upper respiratory tract infection for 3 times. However, the infection was controlled by arthroscopic debridement and retention of the prosthesis was achieved. We emphasize the importance of posterior portal to ensure adequate arthroscopic debridement. It is imperative to make early diagnosis and treatment for infected TKA. We should make more effort to preserve the prosthesis in acute infection(within 2 weeks). With the advantage of minimal morbidity, arthroscopic treatement shoulder be an alternative to open debridement.

Implant-related infection (IRI) is closely related to the local immunity of peri-implant tissues. The generation of reactive oxygen species (ROS) in activated macrophages plays a prominent role in the innate immune response. In previous studies, we indicated that implant wear particles promote endotoxin tolerance by decreasing the release of proinflammatory cytokines. However, it is unclear whether ROS are involved in the damage of the local immunity of peri-implant tissues. In the present study, we assessed the mechanism of local immunosuppression using titanium (Ti) particles and/or lipopolysaccharide (LPS) to stimulate RAW 264.7 cells. The results indicate that the Ti particles induced the generation of a moderate amount of ROS through nicotinamide adenine dinucleotide phosphate oxidase-1 (NOX-1), but not through catalase. Pre-exposure to Ti particles inhibited ROS generation and extracellular regulated protein kinase (ERK) activation in LPS-stimulated macrophages. These findings indicate that chronic stimulation by Ti particles may lead to a state of oxidative stress and persistent inflammation, which may result in the attenuation of the immune response of macrophages to bacterial components such as LPS. Eventually, immunosuppression develops in peri-implant tissues, which may be a risk factor for IRI.

Summary Statement

This study demonstrated that Sclerostin monoclonal antibody (Scl-Ab) enhanced bone healing in the rat osteotomy model. Scl-Ab increased callus size, callus bone volume fraction, rate of callus bone formation and fracture callus strength.

INTRODUCTION:

The use of tapered junctions in primary hip arthroplasty has excellent results. Large heads are being used to mitigate dislocation and optimize range of motion. The prevalence of larger heads, coupled with recent findings regarding corrosion artifacts at tapered surfaces, has spurred growing interest when considering revision rates. The purpose of this study was to determine if correlations exist between severity of corrosion artifacts and head size, head offset, time in vivo, orhead material in a 15 year retrieval database.

INTRODUCTION

One of the recent advances in the hard-on-hard hip arthroplasty is the development of a new material of diffusion hardened oxidised zirconium (DHOxZr). The DHOxZr material consists of a ceramic layer on the top surface which is supported by a thick oxygen diffusion hardened (DH) zone underneath. With the desired properties of metal substrate, ceramic surface and a gradient structure of the oxygen diffusion zone, the DHOxZr-on-DHOxZr bearing combination is expected to produce low wear and minimal metal ions. This can possibly address the concerns associated with metal hypersensitivity associated with metal on metal bearings and fracture risk associated with ceramics. The aim of this study was to evaluate the wear of DHOxZr-on-DHOxZr as a possible hard on hard bearing combination in hips.