Screening of diagnostic biomarkers for ferroptosis-related osteoarthritis and construction of a risk-prognosis model.

Background: Osteoarthritis (OA) is the most prevalent and commonly chronic joint disease that frequently develops among the elderly population. It is not just a single tissue that is affected, but rather a pathology involving the entire joint. Among them, synovitis is a key pathological change in OA. Ferroptosis is a newly discovered form of cell death that results from the buildup of lipid peroxidation. However, the role and impact of it in OA are yet to be explored. Objective: The key to this work is to uncover the mechanisms of ferroptosis-related OA pathogenesis and develop more novel diagnostic biomarkers to facilitate the diagnostic and therapeutic of OA. Materials and methods: Download ferroptosis-related genes and OA synovial chip datasets separately from the FerrDB and Gene Expression Omnibus databases. Identify ferroptosis differentially expressed genes using R software, obtain the intersection genes through two machine learning algorithms, and obtain diagnostic biomarkers after logistic regression analysis. Verify the diagnostic and therapeutic efficacy of specific genes for OA through the construction of clinical risk prognostic models using ROC curves and nomogram. Simultaneously, correlations between specific genes and OA immune cell infiltration co-expression were constructed. Finally, verify the differential presentation of specific genes in OA and health control synovium. Results: Obtain 38 ferroptosis differentially expressed genes through screening. Based on machine learning algorithms and logistic regression analysis, select AGPS, BRD4, RBMS1, and EGR1 as diagnostic biomarker genes. The diagnostic and therapeutic efficacy of the four specific genes for OA has been validated by ROC curves and nomogram of clinical risk prognostic models. The analysis of immune cell infiltration and correlation suggests a close association between specific genes and OA immune cell infiltration. Further revealing the diagnostic value of specific genes for OA by the differential presentation analysis of their differential presentation in synovial tissue from OA and health control. Conclusion: This study identified four diagnostic biomarkers for OA that are associated with iron death. The establishment of a risk-prognostic model is conducive to the premature diagnosis of OA, evaluating functional recovery during rehabilitation, and guidance for subsequent treatment.

CEP55, serving as a diagnostic marker gene for osteosarcoma, triggers the JAK2-STAT3-MMPs axis.

Background: Osteosarcoma (OS) stands as the prevailing form of primary bone cancer in clinical practice. Lack of effective treatment options and an overall poor prognosis are caused by the disease's exceptionally rare occurrence and unclear rationale. Objective: This study's goal is to determine diagnostic marker genes involved in the progression of OS and investigate related pathways and mechanisms with the purpose of offering effective methods for OS diagnostics and therapy. Methods: The Gene Expression Omnibus database provided the gene microarray data. Core genes were identified through differential expression analysis and WGCNA. Three techniques for machine learning, random forest, least absolute shrinkage and selection operator regression, and support vector machine recursive feature elimination, were used to further screen the core genes and obtain diagnostic marker genes for OS. The specificity and sensitivity of the diagnostic marker genes for OS diagnosis were evaluated using receiver operating characteristic curves. Western blotting analysis was used for preliminary validation of the diagnostic marker genes and their related pathways. Results: Two diagnostic marker genes were identified through screening, including CEP55 and VWF. Receiver operating characteristic curves have been utilized to assess the diagnostic and therapeutic effects of CEP55 and VWF on OS. Western blotting analysis preliminarily validated the overexpression of CEP55 in OS and its capacity to control MMP2 and MMP9 levels by activating the JAK2/STAT3 signaling pathway. Conclusion: At the first time, this research shows that CEP55 and VWF are more powerful diagnostic and predictive indicators for OS. CEP55 holds the capacity to activate the JAK2/STAT3 signaling pathway and modulate MMP2 and MMP9 levels, thereby positioning it as a promising target in OS treatment.

In vitro evaluation of BMSCs early proliferation on minocycline-loaded electrospun nanofibers membrane.

BACKGROUND: Electrospun nanofibers could simulate the natural extracellular matrix (ECM) of the host bone, while minocycline (MINO) is a broad-spectrum tetracycline antibiotic which has been found to have multiple non-antibiotics biological effects that promotes osteogenesis in vitro and in vivo. OBJECTIVE: The present study aims at constructing a polylactic acid (PLA) electrospun nanofiber membrane loaded with MINO to enhance Bone marrow mesenchymal stem cells (BMSCs) adhesion and proliferation for early clinical treatment. METHODS: The MINO-PLA membrane were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and in vitro drug release study. The antibacterial ability was also investigated. In addition, in vitro cellular proliferation experiment was performed to verify whether the PLA electrospun nanofibers membrane loaded with MINO enhance BMSCs adhesion and proliferation. RESULTS: Analyzing the drug release and cell growth results, it was found that only the effective concentration of MINO-PLA could help the growth of BMSCs in the short term. This is related to the drug release rate of MINO-PLA and the initial concentration of MINO. CONCLUSION: This study shows that by controlling the concentration and release rate of MINO with electrospinning PLA, BMSCs could proliferate on it, and a new bone repair material had been made in this study.

Diagnostic value and immune infiltration characterization of YTHDF2 as a critical m6A regulator in osteoarthritic synovitis.

BACKGROUND: N6-methyladenosine (m6A) is a universal RNA modification pattern regulated by multiple m6A regulators. In osteoarthritis (OA), m6A regulators influence disease progression by regulating cartilage degradation. However, the function of m6A regulators in synovial tissue remains unclear. In this work, we investigated the biological significance of m6A regulators in osteoarthritic synovitis. METHODS: Datasets were acquired from Gene Expression Omnibus. Differential analysis of merged data identified the differentially expressed m6A regulators. Machine learning models were used to evaluate genetic importance. To predict disease risk, a nomogram was constructed based on above m6A regulators. Cluster analysis divided the OA sample into different subgroups. Immune infiltration revealed the immune m6A regulators, which were validated using clinical samples. Eventually, a competing endogenous RNA (ceRNA) network was constructed. RESULTS: We acquired five differentially expressed m6A regulators and a random forest model. The nomogram accurately predicted disease risk. We identified 122 differentially expressed genes between two m6A subgroups. The analysis of immune infiltration showed that YTHDF2 was an immune-related m6A regulator closely related with macrophages. In clinical samples, the protein and mRNA contents of YTHDF2 were consistent with the results of bioinformatic analysis. The ceRNA network based on YTHDF2 revealed 75 lncRNA nodes and 19 miRNA nodes. CONCLUSION: YTHDF2 has a high diagnostic value in the synovitis of OA and significantly influences the immune status of patients. Hence, YTHDF2, a critical m6A regulator, may provide a biomarker for diagnosis and immune therapy of osteoarthritic synovitis.

A Meaningful Attempt: Applying Dielectric Barrier Discharge Plasma to Induce Polarization of Macrophages.

Macrophage polarization plays an important role in many macrophage-related diseases. This study was designed to preliminarily explore the effects of dielectric barrier discharge (DBD) plasma on the polarization direction and cell activity of macrophages with different phenotypes (ie, M0, M1, and M2). The M1 macrophage marker inducible nitric oxide synthase (iNOS) and M2 macrophage marker cluster of differentiation 206 (CD206) were detected by western blot (WB). The effects of DBD plasma on macrophage viability were analyzed by using a cell counting kit-8 detection kit. M0, M1, and M2 macrophages exhibited a decrease in iNOS expression and an increase in CD206 expression after the DBD plasma intervention. Additionally, the decrease in macrophage viability remained non-significant after initiating the intervention. DBD plasma can promote the transformation of M0 and M1 macrophages to M2 macrophages, and can further enhance the expression of the M2 macrophage phenotype marker CD206. Our study not only demonstrates the potential therapeutic value of DBD plasma for macrophage-related diseases, but it also provides a new direction for research to improve the treatment of macrophage-related diseases. © 2023 Bioelectromagnetics Society.

Corrigendum: Treatment of avulsion fracture of posterior cruciate ligament tibial insertion by a minimally invasive approach in the posterior medial knee.

[This corrects the article DOI: 10.3389/fsurg.2022.885669.].

Corrigendum: Treatment of avulsion fracture of posterior cruciate ligament tibial insertion by minimally invasive approach in posterior medial knee.

[This corrects the article DOI: 10.3389/fsurg.2022.885669.].

Analysis of Madelung disease based on sc-RNA sequencing: A case report and literature review.

Madelung disease (MD) was first described by Brodie in 1846 as a rare multiple lipoma. It is a benign tumor characterized by symmetrical diffuse adipose tissue deposition in the proximal extremities and neck. Until now, the etiology and pathogenesis of the disease have not been fully explained, resulting in difficulties in diagnosis and treatment; moreover, palliative treatment, such as surgical resection of adipose tissue or liposuction, is still the mainstream treatment for MD. However, the effectiveness of palliative surgery is limited, and most patients still relapse or metastasize after treatment. Therefore, we analyzed the relationship between tumor cells and immune cells in MD using single-cell RNA sequencing for the first time and combined an analysis of our results with a review of previous literature reports. Our study provides a new perspective on the pathogenesis of MD and provides a vital clinical basis for targeted therapy. DATA AVAILABILITY: The authors declare that all the data supporting the findings of this study are available within the article and its Supplemental information files.

Titanium dioxide nanotubes increase purinergic receptor P2Y6 expression and activate its downstream PKCα-ERK1/2 pathway in bone marrow mesenchymal stem cells under osteogenic induction.

Titanium dioxide (TiO2) nanotubes can improve the osseointegration of pure titanium implants, but this exact mechanism has not been fully elucidated. The purinergic receptor P2Y6 is expressed in bone marrow mesenchymal stem cells (BMSCs) and participates in the regulation of bone metabolism. However, it is unclear as to whether P2Y6 is involved in the osteogenic differentiation of BMSCs induced by TiO2 nanotubes. TiO2 nanotubes were prepared on the surface of titanium specimens using the anodizing method and characterized their features. Quantitative reverse transcriptase polymerase chain reaction and western blotting were used to detect the expression of P2Y6, markers of osteogenic differentiation, and PKCα-ERK1/2. A rat femoral defect model was established to evaluate the osseointegration effect of TiO2 nanotubes combined with P2Y6 agonists. The results showed that the average inner diameter of the TiO2 nanotubes increased with an increase in voltage (voltage range of 30-90V), and the expression of P2Y6 in BMSCs could be upregulated by TiO2 nanotubes in osteogenic culture. Inhibition of P2Y6 expression partially inhibited the osteogenic effect of TiO2 nanotubes and downregulated the activity of the PKCα-ERK1/2 pathway. When using in vitro and in vivo experiments, the osteogenic effect of TiO2 nanotubes when combined with P2Y6 agonists was more pronounced. TiO2 nanotubes promoted the P2Y6 expression of BMSCs during osteogenic differentiation and promoted osteogenesis by activating the PKCα-ERK1/2 pathway. The combined application of TiO2 nanotubes and P2Y6 agonists may be an effective new strategy to improve the osseointegration of titanium implants. STATEMENT OF SIGNIFICANCE: Titanium dioxide (TiO2) nanotubes can improve the osseointegration of pure titanium implants, but this exact mechanism has not been fully elucidated. The purinergic receptor P2Y6 is expressed in bone marrow mesenchymal stem cells (BMSCs) and participates in the regulation of bone metabolism. However, it is unclear as to whether P2Y6 is involved in the osteogenic differentiation of BMSCs induced by TiO2 nanotubes. For the first time, this study revealed the relationship between TiO2 nanotubes and purine receptor P2Y6, and further explored its mode of action, which may provide clues as to the regulatory role of TiO2 nanotubes on osteogenic differentiation of BMSCs. These findings will help to develop novel methods for guiding material design and biosafety evaluation of nano implants.

Minimally invasive versus traditional inverted "L" approach for posterior cruciate ligament avulsion fractures: a retrospective study.

Purpose: To evaluate the clinical efficacy of a minimally invasive arthroscopic approach and to compare it with the traditional inverted "L" approach for the treatment of posterior cruciate ligament (PCL) avulsion fractures. Methods: From January 2016 to January 2020, the clinical data from patients with PCL avulsion fracture of the tibial insertion were analyzed retrospectively. They were divided into two groups based on surgical approaches: minimally invasive approach group (n = 15) and traditional inverted "L" group (n = 15 cases). The operation time, incision length, intraoperative blood loss, hospitalization time and complications were all recorded and compared between the two groups. The fracture healing time, knee range of motion (ROM), and residual relaxation degree were compared between the two groups after regular follow-up. The International Knee Documentation Committee (IKDC) and Lysholm scores were used to assess knee joint function. Results: There were no significant differences between the two groups in terms of gender, age, side, body mass index, cause of injury, Meyers McKeever classification and time from injury to operation (P > 0.05). The incision length and intraoperative bleeding in the minimally invasive group were significantly lower (P < 0.05) than those in the traditional group. There were no significant differences between the two groups in terms of operative time, fracture healing time, or residual relaxation (P > 0.05). The Lachman test and posterior drawer test were both negative, and there were no postoperative complications. The VAS pain score within 2 weeks and ROM within 4 weeks in the minimally invasive group were significantly better (P < 0.05) than those in the traditional inverted "L" approach group. The knee joint stability of both groups was good 12 months after surgery, and there were no significant differences in IKDC score, Lysholm score and ROM (P > 0.05) between the two groups. Conclusion: The minimally invasive approaches for the treatment of PCL avulsion fractures provide adequate exposure without the surgical complications associated with traditional open surgical approaches. The procedure is safe, fast and minimally invasive, and does not need a long learning curve.

Prognostic value of p16, p53, and pcna in sarcoma and an evaluation of immune infiltration.

BACKGROUND: p16, p53, and proliferating cell nuclear antigen (pcna) genes play significant roles in many chromatin modifications and have been found to be highly expressed in a variety of tumor tissues. Therefore, they have been used as target genes for some tumor therapies. However, the differential expressions of the p16, p53, and pcna genes in human sarcomas and their effects on prognosis have not been widely reported. METHODS: The Oncomine dataset was used to analyze the transcription levels of p16, p53, and pcna genes, and the gene expression profile interactive analysis (GEPIA) dataset was used to analyze the differential expressions of p16, p53, and pcna. The expression levels of p16, p53, and pcna were further analyzed by Western Blotting. GEPIA and Kaplan-Meier analyses were used to analyze the prognostic value of p16, p53, and pcna. Furthermore, p16, p53, and pcna gene mutations and their association with overall survival (OS) and disease-free survival (DFS) were analyzed using cBioPortal datasets. In addition, genes co-expressed with p16, p53, and pcna were analyzed using Oncomine. The DAVID dataset was used to analyze the functional enrichment of p16, p53, pcna, and their co-expressed genes by Gene Ontology (GO) and Metascape were used to construct a network map. Finally, the immune cell infiltration of p16, p53, and pcna in patients with sarcoma was reported by Tumor Immune Estimation Resource (TIMER). RESULTS: p16, p53, and pcna were up-regulated in human sarcoma tissues and almost all sarcoma cell lines. Western Blotting showed that the expression of p16, p53, and pcna was elevated in osteosarcoma cell lines. The expression of pcna was correlated with OS, the expression of p16, p53, and pcna was correlated with relapse-free survival, and the genetic mutation of p16 was negatively correlated with OS and DFS. We also found that p16, p53, and pcna genes were positively/negatively correlated with immune cell infiltration in sarcoma. CONCLUSIONS: The results of this study showed that p16, p53, and pcna can significantly affect the survival and immune status of sarcoma patients. Therefore, p16, p53, and pcna could be used as potential biomarkers of prognosis and immune infiltration in human sarcoma and provide a possible therapeutic target for sarcoma.

L-Glutamine alleviates osteoarthritis by regulating lncRNA-NKILA expression through the TGF-ß1/SMAD2/3 signalling pathway.

Osteoarthritis (OA) is a heterogeneous condition characterized by cartilage degradation, subchondral sclerosis, and osteophyte formation, and accompanied by the generation of pro-inflammatory mediators and degradation of extracellular matrix. The current treatment for early OA is focused on the relief of symptoms, such as pain, but this treatment cannot delay the pathological process. L-Glutamine (L-Gln), which has anti-inflammatory and anti-apoptotic effects, is the most abundant amino acid in human blood. However, its role in OA has not been systematically studied. Therefore, the objective of this work was to explore the therapeutic effect and molecular mechanism of L-Gln on OA. In vitro, we found that L-Gln could up-regulate the expression of the long non-coding RNA NKILA, which is regulated by the transforming growth factor-ß1/SMAD2/3 pathway, and inhibit the activity of nuclear factor-κB, thereby decreasing the expression of nitric oxide synthase, cyclooxygenase-2, and matrix metalloproteinase-13 (MMP-13). This led to a reduction in the generation of nitrous oxide, prostaglandin E-2, tumour necrosis factor-α, and degradation of the extracellular matrix (i.e. aggrecan and collagen II) in rat OA chondrocytes. Moreover, intragastric administration of L-Gln reduced the degradation of cartilage tissue and expression of MMP-13 in a rat OA model. L-Gln also relieved the clinical symptoms in some patients with early knee joint OA. These findings highlight that L-Gln is a potential therapeutic drug to delay the occurrence and development of OA.

Complex proximal femoral fracture in a young patient followed up for 3 years: A case report.

BACKGROUND: Ipsilateral femoral neck and intertrochanteric fractures in young patients are extremely rare, and there is no reference for fracture classification and treatment options. CASE SUMMARY: We report a 27-year-old male patient who sustained ipsilateral femoral neck and intertrochanteric fractures and was treated with a proximal femoral locking compression plate (PFLCP). The literature on these fractures was also reviewed. At the last follow-up three years after surgery, the patient had no obvious pain in the hip, and the range of motion in the hip joint was slightly limited, but met the normal life and work needs. There were no complications such as necrosis of the femoral head. CONCLUSION: The PFLCP can be used to treat these complex proximal femoral fractures, and selection should be based on the patient's specific fractures.

Treatment of avulsion fracture of posterior cruciate ligament tibial insertion by minimally invasive approach in posterior medial knee.

Objective: The study aims to explore the feasibility and clinical effect of posterior minimally invasive treatment of cruciate ligament tibial avulsion fracture. Methods: Posterior knee minimally invasive approach was used to treat avulsion fracture of posterior cruciate ligament (PCL) tibia in 15 males and 11 females. The length of the incision, intraoperative blood loss, operation time, postoperative hospital stay, residual relaxation, and fracture healing time were analyzed to evaluate the curative effect, learning curve, and advantages of the new technology. Neurovascular complications were recorded. During the postoperative follow-up, the International Knee Joint Documentation Committee (IKDC), Lysholm knee joint score, and knee joint range of motion were recorded to evaluate the function. Results: All 26 patients were followed up for 18-24 months, with an average of 24.42 ± 5.00 months. The incision length was 3-6 cm, with an average of 4.04 ± 0.82 cm. The intraoperative blood loss was about 45-60 ml, with an average of 48.85 ± 5.88 ml. The operation time was 39-64 min, with an average of 52.46 ± 7.64 min. The postoperative hospital stay was 2-5 days, with an average of 2.73 ± 0.87 days. All incisions healed grade I without neurovascular injury. All fractures healed well with an average healing time of 9.46 ± 1.33 weeks (range, 8-12 weeks). The Lysholm score of the affected knee was 89-98 (mean, 94.12 ± 2.49) at 12-month follow-up. The IKDC score was 87-95 with an average of 91.85 ± 2.19, and the knee range of motion was 129-148° with an average of 137.08 ± 5.59°. The residual relaxation was 1-3 mm, with an average of 1.46 ± 0.65 mm. Conclusion: This minimally invasive method provides sufficient exposure for internal fixation of PCL tibial avulsion fractures without the surgical complications associated with traditional open surgical methods. The process is safe, less invasive, and does not require a long learning curve.

TiO2 nanotubes regulate histone acetylation through F-actin to induce the osteogenic differentiation of BMSCs.

Bone integration on the surface of titanium prosthesis is critical to the success of implant surgery. Good Bone integration at the contact interface is the basis of long-term stability. TiO2 nanotubes have become one of the most commonly used modification techniques for artificial joint prostheses and bone defect implants due to their good biocompatibility, mechanical properties and chemical stability. TiO2 nanotubes can promote F-actin polymerization in bone mesenchymal stem cells (BMSCs) and osteogenic differentiation. The possibility of F-actin as an upstream part to regulate GCN5 initiation of osteogenesis was discussed. The results of gene loss and functional acquisition assay, immunoblotting assay and fluorescence staining assay showed that TiO2 nanotubes could promote the differentiation of BMSCs into osteoblasts. The intervention of TiO2 nanotubes can make BMSCs form stronger F-actin fibre bundles, which can drive the differentiation process of osteogenesis. Our results showed that F-actin mediated nanotube-induced cell differentiation through promoting the expression of GCN5 and enhancing the function of GCN5 and GCN5 was a key regulator of the osteogenic differentiation of BMSCs induced by TiO2 nanotubes as a downstream mediated osteogenesis of F-actin, providing a novel insight into the study of osteogenic differentiation on surface of TiO2 nanotubes.

A lateral parapatellar approach with iliotibial band dissection from the Gerdy tubercle for total knee arthroplasty of the valgus knee.

Valgus knee, which causes severe dysfunction and seriously affects the quality of life of patients, is a condition affecting 10% of patients who undergo total knee arthroplasty (TKA). The best choice of surgical approach and the method of release of soft tissue, however, is still unclear. Therefore, the aim of the present study was to investigate the clinical efficacy of a lateral parapatellar approach with iliotibial band (ITB) dissection from the Gerdy tubercle for TKA in valgus knees. In total, 56 patients (25 males and 31 females) who underwent surgery via a lateral parapatellar approach with ITB dissection from the Gerdy tubercle for TKA due to valgus knee, with at least one-year follow-up, were retrospectively analyzed. Operation duration, length of time leg was raised post-surgery, prosthetic position, lower limb force line, visual analogue score for pain (VAS), range of movement (ROM), and Knee Society Scores (KSS; including knee score and functional score) were reviewed and analyzed. The data indicated that VAS, ROM and KSS were significantly improved after surgery compared with those before surgery. Additionally, no patient had a deviation in prosthetic position or limb alignment greater than 5˚. These results suggest that a lateral parapatellar approach with ITB dissection from the Gerdy tubercle for TKA is an effective technique to treat valgus knee, which can significantly improve pain and function without deviation of the lower limb mechanical axis or prosthesis position.

The Role of Knee Position in Blood Loss and Enhancement of Recovery after Total Knee Arthroplasty.

The study aimed to investigate the effects of postoperative position of knee on blood loss and functional recovery after total knee arthroplasty (TKA). We enrolled patients who underwent TKA from 2017 to 2019 in our department with osteoarthritis of the knee in this prospective and randomized study. The patients were randomly allocated to flexion or extension group. In the flexion group, the affected leg was elevated by 30 degrees at the hip and the knee was flexed by 30-degree, postoperatively, while in the extension group, the affected knee was fully extended postoperatively. Patients' data related to postoperative blood loss, Hospital for Special Surgery scores, pain intensity, usage of analgesic drugs, circumference of knee, and range of motion (ROM) of knee were recorded to assess the influence of postoperative leg position on clinical outcomes. Although the transfusion rate was similar between the two groups (p > 0.05), other parameters related to blood loss (including total blood loss, hidden blood loss, usage of analgesic drugs, and postoperative circumference of knee) were significantly lower in the flexion group than those in the extension group (p < 0.05). After 6 weeks and 6 months of rehabilitation, patients gained a similar ROM in the affected knee in both groups (p > 0.05). The length of hospital stay and medical expenses were similar in both groups. Incidence of wound infection and other complications was also similar in both groups (p > 0.05). Elevation of the hip by knee flexion of 30 degrees is an effective and simple method to reduce blood loss after TKA, and contributes to reduction of the dosage of analgesic drugs in the early postoperative period. The routine application of the present protocol also did not increase medical costs and length of hospital stay after TKA.

Total hip arthroplasty by direct anterior approach in the lateral position for the treatment of ankylosed hips.

OBJECTIVE: To investigate the clinical efficacy of total hip arthroplasty (THA) via the direct anterior approach (DAA) for the treatment of hip ankylosis in the lateral position. METHODS: A retrospective analysis was performed on the clinical data of 24 patients (39 hips) who underwent THA via the DAA in the lateral position for the treatment of hip ankylosis between January 2016 and December 2018. We performed bilateral THA for fifteen patients and unilateral THA for nine patients. Operation time, intraoperative blood loss, length of incisions, straight leg-raising time, length of postoperative hospital stay, operation-related complication, prosthesis position, radiological outcomes, postoperative pain relief (evaluated by VAS) and functional rehabilitation [evaluated by Harris hip score and range of motion (ROM)] were analyzed to determine clinical efficacy. These clinical data were compared and statistically analyzed with the clinical data of another 23 patients (28 hips) who underwent THA via the posterolateral approach (PLA) for the treatment of hip ankylosis in the lateral position. RESULTS: Follow-up was performed at 12-15 months. The incision length in the DAA group and the PLA group was (11.12 ± 1.69 vs. 14.36 ± 3.42) cm, the intraoperative blood loss was (371.25 ± 120.55 vs. 396.80 ± 101.21) ml, the operation time was (122.47 ± 25.40 vs. 138.47 ± 24.45) min, the postoperative hospital stay was (9.59 ± 4.62 vs. 12.08 ± 3.58) days, and the straight leg elevation time was (9.20 ± 2.12 vs. 12.34 ± 3.25) days, respectively. The prosthesis of the two groups was in a good position: The average angle of cup anteversion in the DAA group and the PLA group was (10.76 ± 2.84 vs. 15.36 ± 3.42)°, and the average angle of cup abduction in the DAA group and the PLA group was (40.00 ± 3.45 vs. 41.21 ± 2.85)° (P > 0.05). The VAS score, ROM and Harris score at different follow-up time points were significantly improved in the two groups compared with those before surgery. In the first 3 months after surgery, the VAS score, ROM and Harris score of the DAA group were significantly better than those of the PLA group (P < 0.05), but with the extension of the follow-up time, there was no significant difference in the above indicators between the two groups (P > 0.05). One case of greater trochanteric fracture occurred in the DAA group. Two cases of hip posterior dislocations occurred in the PLA group, and no dislocations occurred after manual closed reduction and hip fixation in bed for 1 month to the last follow-up. No complications such as infection, deep vein thrombosis, fat embolism, prosthesis loosening, limb length inequality or joint dislocation were reported. CONCLUSION: THA via the DAA for the treatment of hip ankylosis in the lateral position was safe and effective and had the advantage of reduced trauma, quicker recovery of hip function, lower incidence of postoperative dislocation and ability to expose the acetabulum fully and fit the prosthesis properly, providing satisfactory clinical efficacy.

Mechanical strain promotes osteogenic differentiation of mesenchymal stem cells on TiO2 nanotubes substrate.

Previous studies demonstrated cycle mechanical strain induced osteogenic differentiation of MSCs. But in general, MSCs are typically seeded on a flexible membrane or within a soft matrix. TiO2 nanotubes substrate topography plays a critical role in promoting the MSCs response and affects MSCs fate. Titanium implants surface modified by TiO2 nanotubes topography provides the opportunity to improve osseointegration by additionally regulating the MSCs fate. Titanium is one of most commonly used materials in the orthopedics and can undergo elastic deformation under certain mechanical stress. Therefore, for clinic trails, it is necessary to investigate the effect of mechanical strain on osteogenesis of MSCs on TiO2 nanotubes modified titanium substrate. But until now, there has been no research focused on the relationship between mechanical strain and osteogenesis of MSCs on the TiO2 nanotubes topography substrate. Here, we firstly applied the mechanical stress to the TiO2 nanotubes modified titanium specimen to investigate the effects of mechanical strain on the biological behaviors of MSCs. Our present study showed that mechanical strain promoted cell proliferation, spreading and increased vinculin expression of MSCs on the TiO2 nanotubes substrate. Additionally, mechanical strain enhanced the ALP activity and osteogenesis genes expression such as Runx2, BSP, ALP, OPN and OCN. Our results preliminarily demonstrated that mechanical strain enhanced the osteogenic differentiation of MSCs through the FAK-Erk1/2-Runx2 pathway on the TiO2 nanotubes substrate.