N6 methyladenosine eraser FTO suppresses Staphylococcus aureus-induced ferroptosis of bone marrow mesenchymal stem cells to ameliorate osteomyelitis through regulating the MDM2/TLR4/SLC7A11 signaling pathway.

Osteomyelitis is a bone destructive inflammatory disease caused by infection. Ferroptosis is closely related to multiple inflammatory diseases, but the role of ferroptosis in Staphylococcus aureus (SA)-induced osteomyelitis remains unknown. In the present study, we found that SA treatment promoted the accumulation of iron, Fe2+ , lipid peroxide, and malondialdehyde, increased TFRC and reduced FTH1 and GPX4 to trigger ferroptosis in rat bone marrow mesenchymal stem cells (BMSCs). Interestingly, increased level of N6 methyl adenosine (m6A) modification along with decreased expression level of m6A eraser FTO were observed in SA-induced BMSCs, while upregulating FTO alleviated SA-triggered ferroptosis and protected cell viability in BMSCs. Mechanistically, MDM2 was identified as a target of FTO-mediated m6A demethylation, and FTO upregulation promoted MDM2 instability to downregulated TLR4 signal and elevate the expression of SLC7A11 and GPX4 in SA-induced BMSCs. Functional recovery experiments verified that overexpressing MDM2 or TLR4 reversed the inhibiting effect of FTO upregulation on ferroptosis in SA-treated BMSCs. Additionally, FTO upregulation restrained ferroptosis and pathological damage to bone tissue in SA-induced osteomyelitis model rats. Altogether, m6A eraser FTO alleviates SA-induced ferroptosis in osteomyelitis models partly through inhibiting the MDM2-TLR4 axis.

Management of infected bone defects of the femoral shaft by Masquelet technique: sequential internal fixation and nail with plate augmentation.

BACKGROUND: To evaluate the effectiveness of a sequential internal fixation strategy and intramedullary nailing with plate augmentation (IMN/PA) for bone reconstruction in the management of infected femoral shaft defects using the Masquelet technique. METHODS: We performed a retrospective descriptive cohort study of 21 patients (mean age, 36.4 years) with infected bone defects of the femoral shaft treated by the Masquelet technique with a minimum follow-up of 18 months after second stage. After aggressive debridement, temporary stabilisation (T1) was achieved by an antibiotic-loaded bone cement spacer and internal fixation with a bone cement-coated locking plate. At second stage (T2), the spacer and the locking plate were removed following re-debridement, and IMN/PA was used as definitive fixation together with bone grafting. We evaluated the following clinical outcomes: infection recurrence, bone union time, complications, and the affected limb's knee joint function. RESULTS: The median and quartiles of bone defect length was 7 (4.75-9.5) cm. Four patients required iterative debridement for infection recurrence after T1. The median of interval between T1 and T2 was 10 (9-19) weeks. At a median follow-up of 22 (20-27.5) months, none of the patients experienced recurrence of infection. Bone union was achieved at 7 (6-8.5) months in all patients, with one patient experiencing delayed union at the distal end of bone defect due to screws loosening. At the last follow-up, the median of flexion ROM of the knee joint was 120 (105-120.0)°. CONCLUSIONS: For infected femoral shaft bone defects treated by the Masquelet technique, sequential internal fixation and IMN/PA for the reconstruction can provide excellent mechanical stability, which is beneficial for early functional exercise and bone union, and does not increase the rate of infection recurrence.

Cartilage defect repair in a rat model via a nanocomposite hydrogel loaded with melatonin-loaded gelatin nanofibers and menstrual blood stem cells: an in vitro and in vivo study.

Cartilage damage caused by injuries or degenerative diseases remains a major challenge in the field of regenerative medicine. In this study, we developed a composite hydrogel system for the delivery of melatonin and menstrual blood stem cells (MenSCs) to treat a rat model of cartilage defect. The composite delivery system was produced by incorporation of melatonin into the gelatin fibers and dispersing these fibers into calcium alginate hydrogels. Various characterization methods including cell viability assay, microstructure studies, degradation rate measurement, drug release, anti-inflammatory assay, and radical scavenging assay were used to characterize the hydrogel system. MenSCs were encapsulated within the nanocomposite hydrogel and implanted into a rat model of full-thickness cartilage defect. A 1.3 mm diameter drilled in the femoral trochlea and used for the in vivo study. Results showed that the healing potential of nanocomposite hydrogels containing melatonin and MenSCs was significantly higher than polymer-only hydrogels. Our study introduces a novel composite hydrogel system, combining melatonin and MenSCs, demonstrating enhanced cartilage repair efficacy, offering a promising avenue for regenerative medicine.

First Report of Dickeya dadantii Causing Potato Blackleg in Fujian Province China.

Blackleg and soft rot are harmful diseases in potato (Solanum tuberosum) caused by Pectobacterium spp. and Dickeya spp. (Czajkowski et al. 2015). The occurrence of potato blackleg was serious in potato-producing areas around Xiapu County in Fujian Province, China, in 2021 (6 ha) and 2022 (7 ha), with an incidence of approximately 5%, which reached nearly 23%. Three diseased plants were collected to isolate the pathogen. Single colonies from each sampled plant were isolated and streaked onto fresh plates. DNA from three colonies from different plants was PCR amplified with primer pair 27F/1492R (Lane 1991) for the 16S rRNA gene. Since the sequences were identical, we selected strain M2-3 for further analysis. The strain M2-3 was gram-negative, pectolytic on CVP, grew at 37°C and 5% NaCl. The bacterium was positive for phosphatase activity, erythromycin sensitivity, indole production, gelatin liquefaction, malonic utilization, and acid production from, melibiose, raffinose, and arabinose. The bacterium was negative for sucrose, α-methyl glucoside, sorbitol, trehalose, lactose, and sodium citrate (Fujimoto et al. 2018;),although sucrose and lactose did not provide the expected results, there are exception in all species. The genome of strain M2-3 was sequenced and deposited in the NCBI database under accession numbers: CP077422. An Average Nucleotide Identity (ANI) analysis showed that M2-3 clustered with other D. dadantii strains and has a 98.39% identity with D. dadantii strain DSM 18020 (CP023467). The housekeeping genes (recA, dnaX, acnA, gapA, icd, mdh, mtlD and pgi) were amplified with primer pairs designed previously(Fujimoto et al. 2018; Ma et al. 2007) and sequenced. A multilocus sequence analysis (MLSA) was performed by concatenating the 8 gene sequences and constructing a maximum likelihood phylogenetic tree using PhyloSuite version 1.2.1 (Zhang et al. 2020) and IQ-tree version 1.6.8 (Nguyen et al. 2015) software. Strain M2-3 was clustered together with Dickeya dadantii. For the pathogenicity test, three plants per treatment, totaling nine plants, were used. Bacterial suspensions (1×10^8 CFU/mL) were made in a 10mM PBS buffer. 10 µL of M2-3, D. dadantii type strain 18020 (positive control), and buffer (negative control) were injected into the plant stems near the base. Water stains appeared at the site of inoculation after 2 days and they gradually became black and rotten. The leaves became yellow and wilted, and the petiole base rotted within 5 days of inoculation completing the Koch postulate. According to average nucleotide identity and housekeeping gene sequence analysis, strain M2-3 was identified as Dickeya dadantii. Previous studies have reported several pathogens that cause potato blackleg in China, including P. atrosepticum, P. carotovorum, P. brasiliense, P. parmentieri, P. polaris, and P. punjabense (Li-ping et al. 2020; Wang et al. 2021). To the best of our knowledge, this study is the first to report potato blackleg disease caused by Dickeya dadantii in Fujian Province, China. This finding suggests that this pathogen may cause a threat to potato production in Fujian Province.

A Study on the Functional Identification of Overexpressing Winter Wheat Expansin Gene TaEXPA7-B in Rice under Salt Stress.

Expansin is a cell wall relaxant protein that is common in plants and directly or indirectly participates in the whole process of plant root growth, development and morphogenesis. A well-developed root system helps plants to better absorb water and nutrients from the soil while effectively assisting them in resisting osmotic stress, such as salt stress. In this study, we observed and quantified the morphology of the roots of Arabidopsis overexpressing the TaEXPAs gene obtained by the research group in the early stage of development. We combined the bioinformatics analysis results relating to EXPA genes in five plants and identified TaEXPA7-B, a member of the EXPA family closely related to root development in winter wheat. Subcellular localization analysis of the TaEXPA7-B protein showed that it is located in the plant cell wall. In this study, the TaEXPA7-B gene was overexpressed in rice. The results showed that plant height, root length and the number of lateral roots of rice overexpressing the TaEXPA7-B gene were significantly higher than those of the wild type, and the expression of the TaEXPA7-B gene significantly promoted the growth of lateral root primordium and cortical cells. The plants were treated with 250 mM NaCl solution to simulate salt stress. The results showed that the accumulation of osmotic regulators, cell wall-related substances and the antioxidant enzyme activities of the overexpressed plants were higher than those of the wild type, and they had better salt tolerance. This paper discusses the effects of winter wheat expansins in plant root development and salt stress tolerance and provides a theoretical basis and relevant reference for screening high-quality expansin regulating root development and salt stress resistance in winter wheat and its application in crop molecular breeding.

Iva xanthiifolia leaf extract reduced the diversity of indigenous plant rhizosphere bacteria.

BACKGROUND: Iva xanthiifolia, native to North America, is now widely distributed in northeastern China and has become a vicious invasive plant. This article aims to probe the role of leaf extract in the invasion of I. xanthiifolia. METHODS: We collected the rhizosphere soil of Amaranthus tricolor and Setaria viridis in the invasive zone, the noninvasive zone and the noninvasive zone treated with extract from I. xanthiifolia leaf, and obtained I. xanthiifolia rhizosphere soil in the invasive zone. All wild plants were identified by Xu Yongqing. I. xanthiifolia (collection number: RQSB04100), A. tricolor (collection number: 831,030) and S. viridis (collection number: CF-0002-034) are all included in Chinese Virtual Herbarium ( https://www.cvh.ac.cn/index.php ). The soil bacterial diversity was analyzed based on the Illumina HiSeq sequencing platform. Subsequently, taxonomic analysis and Faprotax functional prediction were performed. RESULTS: The results showed that the leaf extract significantly reduced the diversity of indigenous plant rhizosphere bacteria. A. tricolor and S. viridis rhizobacterial phylum and genus abundances were significantly reduced under the influence of I. xanthiifolia or its leaf extract. The results of functional prediction showed that bacterial abundance changes induced by leaf extracts could potentially hinder nutrient cycling in native plants and increased bacterial abundance in the A. tricolor rhizosphere related to aromatic compound degradation. In addition, the greatest number of sensitive Operational Taxonomic Units (OTUs) appeared in the rhizosphere when S. viridis was in response to the invasion of I. xanthiifolia. It can be seen that A. tricolor and S. viridis have different mechanisms in response to the invasion of I. xanthiifolia. CONCLUSION: I. xanthiifolia leaves material has potential role in invasion by altering indigenous plant rhizosphere bacteria.

DNMT1-mediated DNA methylation in toll-like receptor 4 (TLR4) inactivates NF-κB signal pathway-triggered pyroptotic cell death and cellular inflammation to ameliorate lipopolysaccharides (LPS)-induced osteomyelitis.

Toll-like receptor 4 (TLR4) plays a critical role in various human diseases, and was associated with pyroptotic cell death and inflammatory responses. DNA methylation, which has stable and reversible properties, has been reported to alter the expression of target genes, including TLR4. However, the role of methylated TLR4 in osteomyelitis (OM) and the underlying molecular mechanisms remain unclear. RNA sequencing was used to identify differentially expressed genes and associated signaling pathways. RT-qPCR, Western blot, emzyme-linked immunosorbent assay (ELISA), cell counting kit-8 (CCK-8) and LDH assay kit were used to detect mRNA and protein expression of relevant genes, cell viability and the LDH activity, respectively. TLR4 methylation was detected by methylation-specific PCR (MSP) and verified by Chromatin immunoprecipitation (ChIP). Here, we found that DNA methyltransferase-1 (DNMT1)-mediated TLR4 demethylation significantly suppressed lipopolysaccharides (LPS)-induced pyroptosis and inflammatory response by inhibiting the TLR4/nuclear transcription factor-kappa B (NF-κB) axis. First, we confirmed TLR4 as the study target by mRNA transcriptome sequencing analysis, and TLR4 was observably high-expressed in both OM patients and LPS-treated osteoblastic MC3T3-E1. Then, we found that downregulation of DNMT1 blocked TLR4 promoter methylation modification, resulting in upregulation of TLR4. Simultaneously, functional experiments indicated that suppression of TLR4 or overexpression of DNMT1 promoted cell proliferation and inhibited cell pyroptosis and inflammation in LPS-induced MC3T3-E1, while upregulation of TLR4 restored the effects of DNMT1 silencing on OM progression. In addition, TLR4 elevated phosphorylation of IκB-α and NF-κB p65 in the NF-κB signal pathway, and inhibition of TLR4 or the NF-κB inhibitor PDTC reversed the influence of inhibition of DNMT1. In conclusion, our study demonstrated that DNMT1-mediated TLR4 DNA methylation alleviated LPS-induced OM by inhibiting the NF-κB signaling pathway.

Overloaded axial stress activates the Wnt/ß-Catenin pathway in nucleus pulposus cells of adult degenerative scoliosis combined with intervertebral disc degeneration.

BACKGROUND: Intervertebral disc degeneration (IVDD) is the initiating factor of adult degenerative scoliosis (ADS), and ADS further accelerates IVDD, creating a vicious cycle. Nevertheless, the role of the Wnt/ß-Catenin pathway in ADS combined with IVDD (ADS-IVDD) remains a mystery. Accordingly, this study was proposed to investigate the effect of axial stress on the Wnt/ß-Catenin pathway in nucleus pulposus cells (NPCs) isolated from DS-IVDD patients. METHODS: Normal NPCs (N-NPC) were purchased and the NPCs of young (25-30 years; Y-NPC) and old (65-70 years; O-NPC) from ADS-IVDD patients were primary cultured. After treatment of NPC with overloaded axial pressure, CCK-8 and Annexin V-FITC kits were applied for detecting proliferation and apoptosis of N-NPC, Y-NPC and O-NPC, and western blotting was performed to assess the expression of Wnt 3a, ß-Catenin, NPC markers and apoptosis markers (Bax, Bcl2 and Caspase 3). RESULTS: N-NPC, Y-NPC and O-NPC were mainly oval, polygonal and spindle-shaped with pseudopods, and the cell morphology tended to be flattened with age. N-NPC, Y-NPC and O-NPC were capable of synthesizing proteoglycans and expressing the NPC markers (Collagen II and Aggrecan). Notably, the expression of Wnt 3a, ß-Catenin, Collagen II and Aggrecan was reduced in N-NPC, Y-NPC and O-NPC in that order. After overload axial stress treatment, cell viability of N-NPC and Y-NPC was significantly reduced, and the percentage of apoptosis and expression of Wnt 3a and ß-Catenin were significantly increased. CONCLUSIONS: Overloaded axial pressure activates the Wnt/ß-Catenin pathway to suppress proliferation and facilitate apoptosis of NPC in ADS-IVDD patients.

Three-Dimensional Digitalized Virtual Planning of Free Anterior Tibial Artery Perforator Flap for Repairing Soft Tissue Defects in Extremities.

BACKGROUND: Traditional research methods have limited the application of anterior tibial artery perforator flap due to incomplete knowledge of the perforator. This study aimed to investigate the feasibility of three-dimensional digitalized virtual planning of free anterior tibial artery perforator flap for repairing soft tissue defects in extremities. METHODS: A total of 11 patients with soft tissue defects in extremities were included. The patient underwent computed tomography angiography (CTA) of bilateral lower limbs, and then the three-dimensional models of bones, arteries, and skin were constructed. Septocutaneous perforators with appropriate length and diameter were selected to design anterior tibial artery perforator flaps in software, and the virtual flaps were superimposed onto the patient's donor site in a translucent state. During the operation, the flaps were dissected and anastomosed to the proximal blood vessel of the defects as designed. RESULTS: Three-dimensional modeling showed clear anatomical relationships between bones, arteries, and skin. The origin, course, location, diameter, and length of the perforator obtained during the operation were consistent with those observed preoperatively. Eleven anterior tibial artery perforator flaps were successfully dissected and transplanted. Postoperative venous crisis occurred in one flap, partial epidermis necrosis occurred in another flap, while the remaining flaps completely survived. One flap was treated with debulking operation. The remaining flaps maintained aesthetic appearance, which did not affect the function of the affected limbs. CONCLUSIONS: Three-dimensional digitalized technology can provide comprehensive information on anterior tibial artery perforators, thus assisting in planning and dissecting patient-specific flaps for repairing soft tissue defects in extremities.

Mechanical properties evaluation of metacarpophalangeal joint prosthesis with new titanium-nickel memory alloy: a cadaver study.

OBJECTIVE: Ni-Ti memory alloys are unusual materials for hard-tissue replacement because of their unique superelasticity, good biocompatibility, high strength, low specific gravity, low magnetism, wear resistance, corrosion resistance and fatigue resistance. The current study aims to evaluate its mechanical properties and provide biomechanical basis for the clinical application of the prosthesis. METHODS: Ten adult metacarpophalangeal joint specimens were randomly divided into a prosthesis group (n = 5, underwent metacarpophalangeal joint prosthesis) and a control group (n = 5, underwent sham operation). Firstly, the axial compression strength was tested with BOSE material testing machine to evaluate its biomechanical strength. Secondly, these specimens were tested for strain changes using BOSE material testing machine and GOM non-contact optical strain measurement system to evaluate the stress changes. Thirdly, fatigue test was performed between groups. Lastly, the mechanical wear of the metacarpophalangeal joint prosthesis was tested with ETK5510 material testing machine to study its mechanical properties. RESULTS: Axial compression stiffness in the prosthesis group was greater than that in the control group in terms of 30 ° and 60 ° flexion positions (P < 0.05). There was no statistically significant difference between two groups with regards to axial compression stiffness and stress change test (P > 0.05). In the fatigue wear test, the mean mass loss in the prosthesis group's prosthesis was 17.2 mg and 17.619 mm3, respectively. The mean volume wear rate was 0.12%. There was no statistically significant difference in the maximum pull-out force of the metacarpal, phalangeal, and polymer polyethylene pads between the prosthesis group and the control group specimens. CONCLUSIONS: Ni-Ti memory alloy metacarpophalangeal joint prosthesis conforms to the biomechanical characteristics of metacarpophalangeal joints without implants, and the fatigue strength can fully meet the needs of metacarpophalangeal joint activities after joint replacement.

Study on the Effect of Pain Programmed Care Based on the Concept of Prehabilitation on the Recovery of Joint Function and WHOQOL-BREF Score in Elderly Patients after Total Hip Arthroplasty.

Objective: To assess the impact of pain-programmed care, utilizing the concept of prehabilitation, on the postoperative recovery of joint function and WHOQOL-BREF score in elderly patients following total hip arthroplasty. Methods: Ninety cases of elderly patients with total hip arthroplasty admitted to our hospital from January to December 2022 were selected as the observation sample, and the 90 elderly patients with total hip arthroplasty were divided into 45 control groups and 45 control groups by random number table method. The pain assessment, functional exercise compliance, hip joint function and quality of life of the two groups were compared after the intervention. Results: The nursing intervention led to a significant reduction in pain scores and improvement in quality of life for elderly patients undergoing total hip joint replacement. The observation group showed a greater reduction in resting pain scores (6.20 ± 0.63 vs. 3.78 ± 0.67, P < .05) and activity pain scores (8.78 ± 0.64 vs. 4.89 ± 0.68, P < .05) compared to the control group. Additionally, the observation group demonstrated significant improvements in physiology (55.73 ± 2.14 vs. 71.87 ± 21.59, P < .05), psychology (55.71 ± 2.13 vs. 72.60 ± 2.20, P < .05), social relations (55.73 ± 2.13 vs. 71.96 ± 1.57, P < .05), and environmental effect (55.60 ± 2.15 vs. 68.62 ± 1.51, P < .05) after care, whereas the control group exhibited lesser improvements in these areas (physiology: 55.60 ± 2.24 vs. 64.53±2.02, P < .05; psychology: 55.60 ± 2.22 vs. 66.33±1.99, P < .05; social relations: 55.82 ± 2.09 vs. 67.84 ± 1.73, P < .05; environmental effect: 55.89 ± 2.18 vs. 62.09 ± 51.49, P < .05). These findings demonstrate the significant impact of nursing intervention on pain reduction and improved quality of life for elderly patients undergoing total hip joint replacement. Conclusion: Pain programmed care based on the concept of prehabilitation for elderly patients undergoing total hip arthroplasty has a significant positive impact on pain control, compliance with functional exercise, recovery of hip function, and improvement of quality of life. These findings highlight the benefits of implementing pain management strategies and rehabilitation programs in the field of total hip arthroplasty and elderly care.

Genome Sequence Resource of Pectobacterium polaris QK413-1 that Causes Blackleg on Potato in Fujian Province, China.

The Pectobacterium pathogens cause soft rot and blackleg diseases on many plants and crops, including potatoes. Here, we first report a high-quality genome assembly and announcement of the P. polaris strain QK413-1, which causes blackleg disease in potatoes in China. The QK413-1 genome was sequenced and assembled using the PacBio Sequel II and Illumina sequencing platform. The assembled genome has a total size of 5,005,507 bp with a GC content of 51.81%, encoding 4,782 open reading frames, including 639 virulence genes, 273 drug resistance genes, and 416 secreted proteins. The QK413-1 genome sequence provides a valuable resource for the control of potato blackleg and research into its mechanism.

Metacarpal Lengthening Using a Mini-Ring Ilizarov Device for Thumb Reconstruction.

PURPOSE: To explore the results of using the mini-ring Ilizarov external fixator for thumb metacarpal lengthening and its compatibility with a simultaneous groin flap. METHODS: From May 2016 to June 2019, 17 adult patients with thumb loss were treated with metacarpal lengthening using a mini-ring Ilizarov device. The device was composed of 2 rings, threaded rods, nuts, and K-wires (diameter, 1.5 mm). Of these patients, 6 also underwent simultaneous groin flap transfer. Lengthening was started 3 days after surgery at a rate of 0.66 mm/d. The pedicle of the groin flap was divided 1 month after the surgery. The healing index (days per cm), which denotes the number of days the external fixator is attached to the bone per centimeter of length gained, was used to evaluate the lengthening efficiency. RESULTS: The patients were observed for 21.9 ± 9.0 months. The lengthening continued for 29.1 ± 4.5 days, resulting in an additional length of 1.9 ± 0.3 cm. CONCLUSIONS: The mini-ring Ilizarov external fixator is a simple device for primary metacarpal lengthening. This device can be used with a groin flap for single-stage lengthening of injured thumbs with bone exposure. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Anterolateral thigh flow-through flap: A versatile method for reconstruction of complex extremity defects.

BACKGROUND: Flow-through flaps have been widely applied only for the reconstruction of complex defects in the extremities because they can be used for arterial reconstruction and soft tissue coverage simultaneously. This report attempts to fully demonstrate the role of the anterolateral thigh (ALT) flow-through flap as a versatile method for reconstructing complex defects in the extremities. METHODS: From February 2011 to March 2017, we retrospectively analyzed the use of a reconstructive surgical technique based on the ALT flow-through flap to treat complex extremity defects in 87 patients (trauma, n = 79; diabetic ulcers, n = 5; squamous cell carcinoma, n = 3). Emergency surgery was performed in 12 patients to bridge a major artery gap and was followed by elective reconstruction in the remaining patients. Applications of the ALT flow-through flap included bridging major artery gaps, preserving recipient blood vessel integrity, reconstructing blood vessel continuity, protecting vascular anastomoses, avoiding difficult end-to-side anastomoses in the recipient area, and balancing blood flow, as well as combined application with an additional flap. RESULTS: The flap size ranged from 6 × 3 cm to 17 × 9 cm. ALT flow-through flaps were used in combination with an additional flap (n = 4) and in vascular reconstruction (n = 83). Three patients required of the microvascular anastomostic reexploration for venous congestion, total necrosis occurred in two patients, and partial necrosis occurred in one patient. At the donor site, there were three cases of infection and two cases of wound dehiscence. At the recipient site, one case of infection and two cases of wound dehiscence were observed. One patient presented with deep infection secondary to renal failure and underwent amputation. During the follow-up period (range, 1-33 months), all other flaps (84 cases) survived uneventfully, with normal texture and color. CONCLUSION: The ALT flow-through flap plays many roles as it is a versatile method for reconstructing complex defects of the extremities and serves various other clinical purposes.

Radiographic Assessment of Relationship Between Medial Cuneiform Obliquity and Hallux Valgus.

The research results are inconsistent that assessing whether the increased obliquity of the distal articular surface of the medial cuneiform leads to an increase in hallux valgus angle. Thus, this study investigated the relationship between distal medial cuneiform obliquity and hallux valgus by measuring various angles in weightbearing anteroposterior radiographs of the foot. In total, 679 feet of 538 patients with the radiographs were included in the study. We measured radiographic parameters including hallux valgus angle, first to second intermetatarsal angle, metatarsus adductus angle, first metatarsus cuneiform angle, distal medial cuneiform angle, and first proximal metatarsal articular angle. The surface morphology (flat or curved) of the first tarsometatarsal joint was also recorded. Our results analysis revealed a weak negative correlation between distal medial cuneiform angle and both hallux valgus angle and first to second intermetatarsal angle, contrary to our assumption. So we believe that distal medial cuneiform angle was relatively constant and it cannot be used as a characteristic angle for quantifying hallux valgus. First metatarsus cuneiform angle was a characteristic indicator of hallux valgus and was positively correlated with its severity (p < .000), indicating that it can be used to measure the size of hallux valgus. It can also be used as a reference factor for the first metatarsal osteotomy in clinical bunion orthopedics. First tarsometatarsal joint morphology was unrelated to hallux valgus, whereas metatarsus adductus angle, and first proximal metatarsal articular angle should be considered in hallux valgus.

CHI3L1 promotes Staphylococcus aureus-induced osteomyelitis by activating p38/MAPK and Smad signaling pathways.

AIMS: Staphylococcus aureus (S. aureus) is the most common causative bacterial pathogen involved in promoting infection-induced osteomyelitis, a disease resulting in severe bone degradation. In this study, we aimed to identify the mechanism behind inhibition of osteoclast survival and differentiation by CHI3L1, a lectin previously reported to regulate S. aureus-induced osteomyelitis. MAIN METHODS: The role of CHI3L1 in osteoclast survival, proliferation, and differentiation was studied ex vivo using primary human bone marrow derived stem cells (HBMSCs) and transducing them with lentiviral expression vectors or shRNA knockdown constructs. Cell apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/propidium iodide staining. Cell proliferation was assessed using alkaline phosphatase, Alcian Blue, and TRAP staining. The qRT-PCR was used to measure mRNA levels of osteoclast maturation markers, and western blotting was used to analyze protein expression. An in vivo murine model for osteomyelitis and microcomputed tomography analyses of infected femurs were used to study the effects of CHI3L1 on bone erosion. KEY FINDINGS: Overexpression of CHI3L1 significantly reduced HBMSC cell viability, proliferation, and differentiation, and knockdown improved these effects in the presence of S. aureus infection. More specifically, CHI3L1 constitutively activated the p38/MAPK pathway to promote apoptosis. Furthermore, CHI3L1 induced activation of the Smad pathway by promoting phosphorylation of Smad-1/5 proteins. Finally, overexpression of CHI3L1 significantly induced bone erosion upon S. aureus infection in a murine osteomyelitis model, and knockdown of CHI3L1 significantly alleviated this effect. SIGNIFICANCE: CHI3L1 played a vital role in osteoblast differentiation and proliferation by regulating the p38/MAPK and Smad signaling pathways to promote S. aureus-induced osteomyelitis.

Microsurgical Anterolateral Thigh Flap for Reconstruction of Extremity Soft Tissue Defects in Pediatric Patients.

BACKGROUND: The anterolateral thigh flap is one of the most widely used flaps because it has the advantages of less damage to the donor site, no sacrifice of main blood vessels, and abundant soft tissue. However, the application of anterolateral thigh flap in children is relatively rare because of small blood vessels and rapid physiological changes. The aim of this study was to explore the effectiveness and characteristics of free anterolateral thigh flaps for the reconstruction of extremity soft tissue defects in pediatric patients. PATIENTS AND METHODS: This study included 26 pediatric patients, with an average age of 6.7 years (range, 2-13 years). There were 5 cases of upper limb defects and 21 cases of lower limb defects, all of which were accompanied by exposed bones or tendons. The causes of defects included traffic injury in 9 cases, mechanical injury in 7 cases, collision injury in 4 cases, spoke injury in 3 cases, cicatricial contracture in 2 cases, and fibroma in 1 case. All defects were reconstructed with free anterolateral thigh flaps. RESULTS: Twenty-six anterolateral thigh flaps were harvested, including 15 fasciocutaneous flaps and 11 musculocutaneous flaps. The mean size of the flap was 73.4 cm 2 (range, 4 × 3 to 24 × 8 cm). The donor sites were sutured directly in 19 cases and underwent split-thickness skin grafting in 7 cases. There were 3 cases of vascular crisis, 3 cases of flap edge necrosis, 3 cases of infection, 1 case of pressure ulcer, and 1 case of dehiscence after surgery. Eleven patients had scar hyperplasia in the donor site. A total of 34 reoperations were performed, including 14 flap debulking, 7 debridement, 4 skin graft, 3 vascular crisis re-exploration, and 6 other procedures. CONCLUSIONS: Free anterolateral thigh flap was a safe and reliable option for reconstructing soft tissue defects of extremities in pediatric patients. Notably, the incidence of scar hyperplasia in the donor site and the possibility of reoperation in pediatric patients were higher than those in adult patients.

Treatment of inferior pole fracture of the patella with tension-free external immobilization.

BACKGROUND: Inferior pole fracture of the patella (IPFP) has small and comminuted fracture blocks that are hard to immobilize, and early mobilization may lead to loss of fracture reduction and immobilization failure. Therefore, a difficulty of treatment is to achieve rigid immobilization with early functional exercise. Here, a new treatment method of tension-free external immobilization is put forward. METHODS: The clinical data of 11 IPFP patients treated with tension-free external immobilization from May 2016 to June 2019 were retrospectively analyzed. There were six males and five females aged 39.0 ± 12.8 years (range 18-53 years). IPFP was caused by traffic accidents in five cases and falls in six cases. All cases had unilateral closed injuries, including four in the left knee and seven in the right knee. The preoperative range of motion of the knee was 22.0 ± 7.5° (10-30°). The time from injury to operation was 4.5 ± 1.3 d (3-7 d). The operation-related indices were recorded, and the function of the affected knee was assessed by the Böstman score. RESULTS: All operations were successful. The operation time was 56.4 ± 8.4 mi (45-70 min), the intraoperative blood loss was 54.1 ± 14.6 mL (40-80 mL), and the length of hospital stay was 7.5 ± 1.9 d (5-11 d). The mean follow-up time was 20.4 ± 7.6 months (12-36 months), the duration of fracture healing was 8.9 ± 1.5 weeks (7-12 weeks), and the removal time of the external immobilization device was 10.4 ± 0.9 weeks (9-12 weeks). At the last follow-up, the range of motion had no significant difference between the affected knee (129.7 ± 3.3°, range 125-135°) and the unaffected knee (130.8 ± 3.8°, range 126-137°) (t = 0.718, p < 0.05). The Böstman score of the knee was 29.2 ± 1.0 points (27-30 points), including 10 excellent cases (90.9%) and one good case (9.1%). CONCLUSION: Tension-free external immobilization is a feasible treatment for IPFP. It can help with early functional exercise and achieve a satisfactory clinical effect.

A modified surgical method for the treatment of ONFH: quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) can lead to pain and loss of function of the hip joint, which places a great burden on patients and society. Surgery is the main treatment for osteonecrosis of the femoral head, and quadratus femoris muscle pedicle bone grafting has a definite therapeutic effect as one method of surgery for the treatment of ONFH. However, the posterior superior retinacular artery is often injured during quadratus femoris muscle pedicle bone graft surgery. There is evidence that this artery is extremely important to the femoral head, as injury to this artery will seriously affect the blood supply of the femoral head. Therefore, this situation restricts the clinical application of quadratus femoris muscle pedicle bone grafts. We aimed to explore a new surgical method of quadratus femoris muscle pedicle bone grafting that can preserve the integrity of the posterior superior retinacular artery. METHODS: We modified the traditional quadratus femoris muscle pedicle bone graft and preserved the integrity of the posterior superior retinacular artery. To explore the safety and feasibility of the operation, we simulated the operation on 6 fresh frozen cadavers (12 hips) and measured the related data. We also tried this modified surgical method in the clinic and collected detailed data from the patients. RESULTS: By simulating the modified quadratus femoris muscle pedicle bone graft on the hip joints of fresh frozen cadavers, we found that the posterior superior retinacular artery existed in all cadaver specimens and that the sources may be different (MFCA or IGA). In the modified operation, the joint capsule did not need to be cut during the operation; therefore, the integrity of the posterior superior retinacular artery was preserved. The quadratus femoris muscle was exposed via the posterior approach of the hip joint, and then the quadratus femoris muscle pedicle bone flap was chiseled. After the pedicle of the quadratus femoris muscle was loosened properly, the migration distance of the quadratus femoris muscle pedicle bone flap reached 5.89 ± 0.45 (χ ± s) cm. The bone flap was trimmed properly and placed on one side. Next, we drilled a bone tunnel from the external intertrochanteric aspect of the capsule of the hip joint, and the bone tunnel broke through the sclerosing zone and proceeded straight to the necrotic area of the femoral head. Next, the necrotic bone was removed with a ring saw and arc bone knife, autogenous bone or allogeneic bone was filled into the bone groove according to the situation, and the cancellous bone in the bone groove was tamped by percussion. Then, the bone flap was inserted into the bone groove, and appropriate pressurization was performed. The depth of the bone groove was determined by the location of ONFH. We found that the furthest distance between the bone groove and the femoral head was 4.76 ± 0.07 (χ ± s) cm and that the length of the bone flap was (4.91 ± 0.23) (χ ± s) cm. This means that when the depth of the bone groove reached the area of ONFH, the quadratus femoris muscle pedicle bone flap had a sufficient length and migration distance to be embedded in the area of ONFH and firmly fixed, and the quadratus femoris did not have much tension. The closest distance between the posterior superior retinacular artery and the bone groove was (1.11 ± 0.96) (χ ± s) cm. When the bone groove was created in this area, the edge of the bone groove had a safe distance of at least 1 cm from the posterior superior retinacular artery of the femoral head. We attempted to implement this modified operation clinically. During the procedure, the quadratus femoris muscle pedicle bone flap was embedded into the drilled bone groove and fixed with a magnesium nail. There was no sliding of the bone flap after the operation, and the posterior superior retinacular artery was intact. We followed the patient for 3 months and found that the patient recovered well with no weight-bearing by the affected limb. The duration of the modified operation was shorter than that of the traditional quadratus femoris muscle pedicle bone graft, the amount of bleeding was significantly reduced, the postoperative pain was lessened, and no special discomfort was reported. Postoperative imaging examination showed that the collapse of the femoral head had been partially corrected and that the bone flap had gradually fused with the surrounding bone. CONCLUSIONS: Through this experimental study, we confirmed the feasibility of the modified method for quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery. This modified operation not only retains the integrity of the posterior superior retinacular artery of the femoral head but also reduces the difficulty of the operation and shortens the surgical time, which is of great clinical significance.

Treatment of symptomatic hip dysplasia by posterolateral small incision assisted Bernese periacetabular osteotomy.

BACKGROUND: For periacetabular osteotomy, traditional approaches usually have a long learning curve. We aimed to evaluate the postoperative results and complications of periacetabular osteotomy under a new double-incision approach. METHODS: The records of 58 consecutive patients (65 hips) who underwent periacetabular osteotomy using the new approach were retrospectively reviewed and evaluated. There were 52 women and 6 men with a mean age of 28.1 years at the time of surgery. RESULTS: The average follow-up period was 35.2 months, during which no patients were converted to total hip arthroplasty. Complications included 6 hips (9.2%) with nerve dysesthesias and 1 hip (1.5%) with delayed wound healing. The mean operative time and intraoperative blood loss were 88.6 min and 402.8 ml, respectively. The mean modified Harris hip score had improved from 72.2 points preoperatively to 91.3 points at the last follow-up. Fifty-five patients (62 hips, 95.4%) were satisfied to their outcomes, and good preoperative functional score was associated with a satisfactory outcome. Furthermore, the average lateral center-edge angle, anterior center-edge angle and acetabular index angle were corrected well after surgery. CONCLUSION: Periacetabular osteotomy using modified Smith-Petersen or Bikini approach with posterolateral assisted small incision can be performed safely and with satisfactory results. In addition, this technique shortens the learning curve, and reduces the operating complexity, especially for beginner.