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Acrylamide (ACR) is a water-soluble chemical applied in industrial and laboratory processes. The neurotoxicity induced by acrylamide involves both peripheral and central nervous system. Hence, there is a growing urgency to investigate the mechanisms of acrylamide-induced neurotoxicity and search novel therapeutic target for the nerve repair. The effects of ACR on the proliferation, reactive oxygen species (ROS) and iron production of dorsal root ganglia (DRG) neurons and Schwann cells were determined. 5-Ethynyl-2′-deoxyuridine (EDU) staining and transwell assay were applied to detect the proliferation and migration capacity of DRG cells. Ferrostatin-1 (Fer-1) was used to suppress ferroptosis induced by ACR. RT-PCR analysis was performed to examine the expression of neurotrophic factors including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and glial cell line-derived neurotrophic factor (GDNF). Moreover, Iron, ROS, malondialdehyde (MDA) and glutathione (GSH) contents were measured to reveal the regulation of ferroptosis in ACR-related nerve injury. ACR inhibited the proliferation and migration of DRG neurons and the supplementation of Fer-1 reversed the effects induced by ACR. Besides, the treatment of Fer-1 effectively increased the expression of NGF, BDNF, VEGF and GDNF. Furthermore, ACR increased the iron level, MDA and ROS contents while inhibited the level of GSH. It was unveiled that ACR attenuated the proliferation, migration and neuron repair of DRG neurons through regulating ferroptosis. The modulation of ferroptosis might be a promising therapeutic strategy and provide references for future treatment of acrylamide-induced nerve damage.

To investigate gut microbiota and intestinal barrier function changes after orthopedic surgery in elderly patients with either normal cognition (NC) or a prodromal Alzheimer disease phenotype (pAD) comprising either subjective cognitive decline (SCD) or amnestic mild cognitive impairment (aMCI).Homeostatic disturbances induced by surgical trauma and/or stress can potentially alter the gut microbiota and intestinal barrier function in elderly patients before and after orthopedic surgery.In this prospective cohort study, 135 patients were subject to preoperative neuropsychological assessment and then classified into: NC (n=40), SCD (n=58), or aMCI (n=37). Their gut microbiota, bacterial endotoxin (lipopolysaccharide), tight junction (TJ) protein, and inflammatory cytokines in blood were measured before surgery and on postsurgical day 1, 3, and 7 (or before discharge).The short-chain fatty acid (SCFA)-producing bacteria were lower while the gram-negative bacteria, lipopolysaccharide and TJ were higher preoperatively in both the SCD and aMCI (pAD) groups compared with the NC group. After surgery, a decrease in SCFA-producing bacteria, and an increase in both gram-negative bacteria and plasma claudin were significant in the pAD groups relative to the NC group. SCFA-producing bacteria were negatively correlated with TJ and cytokines in pAD patients on postsurgical day 7. Furthermore, surgery-induced perioperative metabolic stress and inflammatory responses were associated with gut microbiota alterations.Surgery exacerbates both preexisting microbiota dysbiosis and intestinal barrier dysfunction in pAD patients, all of which may be associated with systemic inflammation and, in turn, may lead to further cognitive deterioration.

Background High fever, knee swelling and pain after knee arthroplasty are often considered as symptoms of acute prosthetic joint infection. However, similar symptoms can also present as primary manifestations of adult-onset Still’s disease, which creates some interference in differential diagnosis. To our knowledge, this is the first published case of misdiagnosis of adult Still’s disease after total knee arthroplasty, who was initially misdiagnosed as an prosthetic joint infection due to the above-mentioned symptoms. The symptoms of the knee infection was not relieve after several revisions and continous antibiotic treatment. Finally, after several consultations and repeated evaluation it was diagnosed as adult-onset Still’s disease. Case presentation A 77-year-old female who underwent bilateral total knee arthroplasty 6 years ago was admitted to our hospital with high fever, right knee effusion and painful knee. Based on the results of joint fluid aspiration and culture, we treated the right knee as acute hematogenous prosthetic joint infection. After three debridement and revision surgeries, the patient’s symptoms continued to persist. Subsequent manifestations of other symptoms such as typical rash and sore throat and laboratory examination suggested the possibility of adult-onset Still’s disease. So she underwent diagnostic steroid hormone therapy at the recommendation of a rheumatologist, and a final revision was performed after symptom was controlled. At the one-year follow-up, the patient’s symptoms completely resolved and the knee revision was functioning well. Conclusions When joint swelling and pain occurs after knee arthroplasty, the possibility of joint infection should not only be considered, but rheumatic autoimmune diseases should also be differentiated. Because the manifestations of joint infection and rheumatic immune disease sometimes overlap highly, when reasonable treatment over a period of time fails to relieve symptoms and signs, we should notice subtle differences in symptoms and laborotary tests and look for other diagnostic possibilities in time.

Background Hybrid Oxford unicompartmental knee arthroplasty (OUKA) consists of cementless femoral prostheses and cemented tibial prostheses. Although a hybrid OUKA has been used in clinical practice, the clinical outcome has not been reported. The purpose of this study was to compare the short-term clinical outcomes and rate of residual bone cement extrusion between hybrid and cemented prostheses and analyse the possible reasons for differences between outcomes. Methods A total of 128 knees (118 patients) with end-stage osteoarthritis were included in this study, of which underwent consecutive operations using unicondylar Oxford phase 3 implants from July 2017 and September 2019 in our centre. Follow-up was performed at 6 weeks, 3 and 6 months, 1 year and every year after operation, and complications and changes in the Oxford knee score (OKS) were recorded. The OKS of the two groups was analysed by the generalized estimating equation approach. Prosthesis-based standard fluoroscopy was performed in a timely manner after each operation, and the rate of residual cement extrusion of the two groups was estimated using T-tests and a multivariate regression analysis. Results Excluding the cases that lost follow-up, a total of 120 knees (65 in hybrid group and 55 in cemented group) were included in the analysis. There was no statistically significant difference in patient characteristics between the two groups (p > 0.05). The average follow-up time was 23.4 months (and ranged from 12 to 38 months). As of the last follow-up, there were no complications, such as dislocation, fracture, prosthesis loosening and subsidence, but one patient in the cemented group experienced symptoms caused by residual loose cement. Postoperative OKS in both groups improved significantly (p < 0.001). There was no significant difference in the OKS at any point during the follow-up or in the improvement of the OKS between the two groups (p > 0.05). Residual cement was mainly extruded behind the tibial prosthesis. The rate of hybrid periprosthetic residual cement extrusion was significantly lower in the hybrid group than in the cemented group, and the difference was statistically significant (OR = 3.38; p = 0.014). Conclusions Hybrid OUKA is as effective as cemented OUKA in the short term after operation and can significantly reduce the residual cement extrusion rate around the tibial prosthesis.

There are an increasing number of vascular complications after hip replacement, some of which can be life-threatening. However, there are few reports of lower limb ischemic symptoms after undergoing an otherwise uncomplicated classic total hip replacement. We report a patient with low weight who developed postoperative limb ischemia resulting from blood clots caused by insertion of a Hohmann retractor close to small anterior acetabular osteophytes. Ultrasonography and angiography revealed her symptoms to be the result of femoral artery intimal injury with lower extremity arterial thrombosis, which led to pain, numbness, and decreased skin temperature. The patient underwent timely percutaneous intervention with a femoral artery stent, which relieved her symptoms. The discussion reviews femoral artery injury during total hip arthroplasty. Keywords: Vascular injury, Limb ischemia, Total hip arthroplasty

INTRODUCTION Medial unicompartmental knee arthroplasty (mUKA) requires full-thickness cartilage in the lateral compartment, but slight damage of the cartilage surface can be ignored. However, as this statement lacks literature support, we investigated whether slight cartilage damages in the weight-bearing area of the lateral femoral condyle would affect the outcome of mUKAs. MATERIALS AND METHODS Outerbridge grading was performed on the cartilage in the weight-bearing area of the lateral femoral condyle intraoperatively. The patients, grouped as normal or as having lateral condyle cartilage of Outerbridge grade 1-2 (slight cartilage damage), underwent mUKA. Full-length lower extremity radiographs were taken and hip-knee-ankle angles (HKAAs) were measured both preoperatively and postoperatively. Using magnetic resonance imaging, the lateral meniscal extrusion distance was also measured. In addition, the Oxford Knee Score (OKS) was assessed preoperatively and at the last follow-up, in addition to the patient satisfaction assessment. RESULTS We enrolled 152 knees of 142 patients proposed for mUKAs. The mean age of participants was 69.5 years (51-89 years) and they were followed up for a mean of 25.4 months (15-44 months). There was no significant difference in preoperative (p = 0.746) and postoperative (p = 0.202) mean OKS between the normal, Outerbridge grade 1 and Outerbridge grade 2 groups. While the normal group had a higher change in OKS than the group with cartilage damage, this difference was not significant (p = 0.910). The UKA corrected the patients' mean HKAA from 171.1° (preoperatively) to 176.1° (postoperatively). From all patients, only four had slight lateral meniscus extrusion with MEDs of ≤ 0.25 mm. With the exception of one patient with a poor outcome in normal group, the rest were satisfied with the outcome of mUKA. No patients had prosthesis-related complications or revision surgery. CONCLUSIONS Cartilage damage of Outerbridge grade 1 and grade 2 in the weight-bearing area of the lateral femoral condyle will not compromise the short-term outcome of medial mobile-bearing UKA.

IntroductionUnicompartmental knee arthroplasty (UKA) is one of the most effective surgical procedures for treating isolated medial compartment knee osteoarthritis. However, previous studies have regarded patellofemoral osteoarthritis as a contraindication for UKA. In contrast, most current research shows that damage to the articular cartilage of the patellofemoral joint, even to the extent of full-thickness cartilage loss, has no influence on the outcome of UKA.Methods and analysisStudy settings: This study is a prospective cohort study that will compare the Forgotten Joint Score and Lonner patellofemoral joint score of patients who have undergone UKA; the patients will be divided into two groups (with and without patellofemoral joint osteoarthritis (PFJOA)). Primary objective: Long-term follow-up will be used to evaluate the effect of the operation on the above-mentioned scores in both the groups. Secondary objective: We will divide the patients from the with PFJOA group into three subgroups according to the localisation of patellofemoral cartilage lesions (medial zone, lateral zone and central zone). We aim to compare knee joint scores among these groups and clarify the impact of different wear sites on clinical efficacy. We will use CT to explore the potential mechanism through which UKA affects patellofemoral joint-related parameters (lateral patellar tilt, lateral patellar shift and tibia tuberosity-trochlear groove distance). We will also record mid-term/long-term post-surgery complications.Ethics and disseminationThis study’s protocol is in accordance with the Declaration of Helsinki. This study was approved by the Ethics Committee of Xuanwu Hospital. The results of this study will be disseminated in international peer-reviewed journals.Trial registration numberChiCTR2000030310.

Objective: This study aimed to investigate the brain functional alterations with resting-state functional magnetic resonance imaging (rs-fMRI) in older patients with knee osteoarthritis (KOA) before and after total knee arthroplasty (TKA) and to assess the causal relationship of the brain function and neuropsychological changes.Methods: We performed rs-fMRI to investigate brain function of 23 patients aged ≥65 with KOA and 23 healthy matched controls. Of the KOA patients, 15 completed postoperative rs-fMRI examinations. Analyzes of the amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) were used to estimate differences in brain functional parameters between KOA patients, postoperative patients, and the controls. The relationship between changes of pre- and post-surgical status in ALFF and neuropsychological test results was analyzed.Results: Compared with the controls, all patients with KOA exhibited decreased ALFF in the default mode network (bilateral angular gyrus, precuneus gyrus, medial superior frontal gyrus) and increased ALFF in the bilateral amygdala and cerebellum posterior lobe before surgery (P < 0.001). Altered ALFF persisted in the same brain regions 1 week postoperatively. The decreased ALFF in the left precuneus gyrus and middle temporal gyrus was found after surgery when compared with preoperative data (P < 0.01). Preoperatively, the KOA patients exhibited increased FC between the left precuneus gyrus and the right supplementary motor area compared to the controls (P < 0.001), but this connectivity became no significant difference after TKA. The left Cerebelum_9 was found to have decreased FC with the right precuneus gyrus postoperatively (P < 0.001) although this was not significantly different before surgery. The significantly altered ALFF values were not correlated with changes in cognitive assessment scores.Conclusion: In older patients with end-stage KOA, functional alterations in important brain regions were detected with the persistence and further changes observed at an early stage after knee replacement. Our data further our understanding of brain functional abnormalities and cognitive impairment in older patients following knee replacement, which may provide therapeutic targets for preventive/treatment strategy to be developed.Trial registration: Clinical Trial Registration: http://www.chictr.org.cn/index.aspx, ChiCTR1800016437; Registered June 1, 2018.

Background: To explore the effect of delirium on postoperative early prognosis of geriatric patients with hip fracture. Methods: According to whether postoperative delirium (POD) appeared in elderly patients with hip fracture, all cases were divided into two groups: delirium and non-delirium. General parameters, operative parameters, length of stay (LOS), and perioperative complications were recorded. Recurrent fracture, new stroke, and mortality within 1 year postoperatively were followed up and compared between the two groups. Results: Of 358 cases, 55 (15.4%) developed delirium. Compared with the non-delirium group, the delirium group had longer operative times (P=0.031); increased platelet (P=0.002) and C-reactive protein (PPP=0.040), albumin (PPP=0.019) levels. Complications occurred to some extent in 196 cases (54.7%). In the delirium group, complication rates of pulmonary infection (P=0.005), hypoalbuminemia (PPP=0.027), bedsore (P=0.012) and anemia (P=0.007) were higher. In addition, LOS was significantly longer (15.71 ± 4.72 vs 14.00 ± 5.30 days; P=0.026) in the delirium group. Within 1 year postoperatively, 31 individuals (8.7%) had died, 13 were treated for recurrent fracture, and 42 had a new stroke. In the delirium group, mortality within 1 year postoperatively was higher (27.3% vs 5.3%, PConclusions: The morbidity of POD is high in geriatric patients with hip fractures. There was longer surgery delay, higher complication rate, longer LOS, and increased mortality in the delirium group. Early intervention of POD has important clinical significance.

Objective This study was performed to investigate the influence of a standard Oxford vertical cut on the coronal coverage and rotation of the tibial component and determine whether a relationship exists between coverage and rotation. Methods We retrospectively analyzed 71 patients with anteromedial osteoarthritis of the knee treated by Oxford unicompartmental knee arthroplasty in one center from October 2016 to October 2017. The distance of coronal coverage was measured on a postoperative anteroposterior view of the tibial component. Two different reference lines between the lateral wall of the tibial component were defined as rotation angle α and β, respectively, on a computed tomography scan. Results The mean distance was 0.3 ± 1.1 mm. The mean angle α and β were 5.7° ± 4.6° and 8.4° ± 4.6°, respectively. There were no significant differences in the distance according to the tibial component rotation or in the α and β angles according to the coronal coverage. No significant correlation was found between the α and β angles and the distance. Conclusion A standard tibial vertical cut caused various changes in coronal coverage and rotation of the tibial component. The rotation of the tibial component did not affect coverage within a certain range.

IntroductionMany patients with knee osteoarthritis also suffer from diabetes mellitus and the possibility of deep venous thrombosis (DVT) is increased following unicompartmental knee arthroplasty (UKA). Therefore, we evaluated whether DVT occurrence increased 3 days following operation in diabetic patients undergoing UKA.Materials and methodsThe incidence of deep venous thrombosis between non-diabetic and diabetic patients who underwent UKA in our hospital from August 2018 to January 2020 was compared, and the effect of glycosylated hemoglobin levels on DVT was evaluated.ResultsOf the 84 patients, 25 (29.8%) had diabetes and 59 (70.2%) did not. Within 3 days after operation, DVT occurred in 12 cases (48.0%) in the diabetic group and 8 cases (13.6%) (p ConclusionThe incidence of DVT in diabetic patients within 3 days after UKA is significantly higher than that in non-diabetic patients. The higher the concentration of glycosylated hemoglobin, the greater the risk of DVT.

Background: Oxford Unicompartmental Knee Arthroplasty (UKA) has increased rapidly around the world, and the effectiveness and safety of a minimally invasive surgical approach for it demonstrate excellent outcome. Oxford UKA represents an interesting solution for older patients. The aim of our study is to evaluate the perioperative complications and short-term clinical outcome and analyze the safety for older patients who undergo Oxford UKA.Methods: A retrospective review was performed of all patients who underwent Oxford UKA between June 2015 and January 2018. We divided all patients into two groups (ages 60–80; age over 80). We used the HSS score and WOMAC score to evaluate the general condition of the patients’ knees. We also recorded perioperative complications and long-term complications. Result:130 patients (139 knees) between the ages of 60 and 80 (Group 1) and 65 patients (70 knees) over 80 years old (Group 2) were included in the study. The mean follow-up was 22.04 ± 11.04 and 21.76 ± 10.20 months in Group 1 and 2, respectively. At last follow-up, the patients in Group 2 showed lower function scores, but both the HSS score and the WOMAC score were significantly improved in both groups after surgery. The rate of perioperative complications and other complications in elderly patients is the same as in younger patients. Conclusion: Oxford UKA showed validity and safety for elderly patients in China. The knee joint pain symptoms of the elderly patients are relieved and the function is well restored, but the function is still poor compared with the younger patients.

Peripheral nerve injury is known to activate the hypoxia-inducible factor-1α (HIF-1α) pathway as one of pro-regenerative transcriptional programs, which could stimulate multiple injury-induced gene expression and contribute to axon regeneration and functional recovery. However, the role of HIF-1α in peripheral nerve regeneration remains to be fully elucidated. In this study, rats were divided into three groups and treated with sham surgery, surgery with cobalt chloride (CoCl2) and surgery with saline, respectively. Sciatic functional index, morphologic evaluations of muscle fibers, and never conduction velocity were performed to measure the functional recovery at 12 weeks postoperatively. In addition, the effects of CoCl2 on the expression of HIF-1α, glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined at mRNA levels; as well as HIF-1α, the dual leucine zipper kinase (DLK), the c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), BDNF and NGF were measured at protein level at 4 weeks postoperatively. Systemic administration of CoCl2 (15 mg/kg/day intraperitoneally) significantly promoted functional recovery of rats with sciatic nerve transection injury. This study demonstrated in rats treated with CoCl2, the expression of HIF-1α, GDNF, BDNF and NGF was significantly increased at mRNA level, while HIF-1α, DLK, p-JNK, BDNF and NGF was significantly increased at protein level.

Under the influence of a high-speed, interrupted-cutting impact load, a great difference is existed among the internal load propagation of a milling cutter. Furthermore, the cutter damage caused by partial particle severe vibration has restricted the improvement of a high-speed milling energy efficiency; thus, the essence of wave dynamics damage in milling cutter remains has yet to be revealed. In this paper, through the relation between the systematic whole vibration and the particle motion, the dynamic response of milling cutter’s particle to cutting force load can be solved by the particle motion differential equation which is constructed with a one-dimensional string dynamic system. A combination of Newton’s second law and the constitutive equation of milling cutter material establishes the wave dynamics equation of milling cutter components. An approach for solving the wave front position and wave velocity of milling cutter’s stress wave is proposed, and the propagation path of transient cutting force to the milling cutter is communicated. The attenuation model of stress wave reflection is established to provide a method for revealing the stress wave transmission and distribution in milling cutter. The constitutive relation of milling cutter components under the impact load is obtained by split Hopkinson pressure bar experiment. A force connection method is adopted to make the trans-scale correlation analysis between continuum medium mechanics and molecular dynamics, thereby revealing the wave dynamics damage characteristics of a high-speed milling cutter. The results show that the potential damage position and types of milling cutter can be distinguished by the above method.

Objective This study was performed to develop a prediction model for requiring manipulation under anesthesia (MUA) for flexion contracture after total knee arthroplasty (TKA) in patients of advanced age. Methods We retrospectively reviewed 269 patients of advanced age undergoing primary TKA in one center with a minimum 1-year follow-up. Patients who underwent postoperative MUA had flexion contracture of >10° after 4 weeks of postoperative rehabilitation, and their demographic data and preoperative clinical conditions [knee diagnosis, diabetes mellitus, hypertension, lumbar spinal disorders, hip disorders, ankle disorders, knee deformity (varus/valgus), preoperative flexion contracture (PFC), range of motion (ROM), and Hospital for Special Surgery (HSS) knee score] were compared with those of patients without MUA. All preoperative factors were collected to develop the predictive model. Results Thirty patients underwent MUA. Patients who underwent MUA after surgery had significant differences in PFC, higher HSS knee scores before surgery (59.10 ± 7.22 vs. 55.70 ± 13.09), and lower preoperative ROM (81.57 ± 30.86 vs. 95.47 ± 24.36) than those who did not undergo MUA. Conclusion A prediction model for MUA in advanced-age patients with flexion contracture was developed and mainly consisted of preoperative risk factors including PFC, HSS scores, and ROM.

It has been demonstrated that bone fracture is associated with the activation of autophagy, and upregulation of autophagy could promote fracture healing. Previous study by our group demonstrated that activating the HIF-1α pathway via administration of cobalt (II) chloride (CoCl(2)) could promote fracture healing in vivo. However, the role of hypoxia-inducible factor-1α (HIF-1α) in autophagy remains unknown. In the current study, rats were divided into two groups following tibial fracture and treated with echinomycin or dimethyl sulfoxide (DMSO). Rats were sacrificed at 7, 14, 28 and 42 days after fracture. The evaluation of fracture healing was performed by micro-computed tomography. In addition, the effects of echinomycin on microtubule-associated protein 1 light chain 3 (LC3 II), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), Unc-51-like autophagy activating kinase 1 (ULK1) and P62 were detected at the mRNA and protein levels by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. The results demonstrated that the expression of LC3 II was markedly decreased following systemic administration of echinomycin (0.05 mg/kg every other day for 42 days, intraperitoneally). Furthermore, the levels of Runx2, ALP and ULK1 were decreased, while those of P62 were increased, at the mRNA and protein levels in rats treated with echinomycin in vivo. In summary, the current study suggested that HIF-1α may serve an important role in fracture healing via the downregulation of autophagy.

Objectives Little is known about the roles of granzyme B in rheumatoid arthritis (RA). We aimed to evaluate the serum level of granzyme B in patients with RA and determine relationships with clinical features and joint destruction of RA. Methods We enrolled 100 patients with RA, 50 patients with osteoarthritis (OA), and 50 healthy controls (HC). Granzyme B serum concentrations were measured by ELISA; we then analyzed associations between granzyme B levels, clinical features, and joint destruction by calculating Sharp scores and disease activity as measured by Disease Activity Score-28 based on erythrocyte sedimentation rate (DAS28-ESR) in patients with RA. Results Compared with HC and patients with OA, serum granzyme B levels in patients with RA were remarkably elevated. Serum granzyme B levels did not differ between patients with OA and HC. Granzyme B levels correlated with ESR, rheumatoid factor, swollen joint counts, joint erosion scores, total Sharp scores, and DAS28-ESR. Moreover, patients with RA with high disease activity had higher granzyme B levels. Conclusions Serum granzyme B levels were elevated significantly in patients with RA and correlated positively with disease activity and joint destruction. Serum granzyme B may have potential applications in laboratory evaluation of patients with RA.

Background/Aims: Hypoxia has been reported to regulate osteoblastic differentiation of bone cells and cartilage development. However, information concerning the molecular mechanisms remains largely unknown. Methods: The expression of miR-429 was evaluated by quantitative real-time PCR analysis. To test whether miR-429 directly regulate the expression level of ZFPM2 at transcription level, dual-luciferase reporter gene assay was performed. Western blotting was performed to detect osteogenesis related protein expression. The cell proliferation, apoptosis, alkaline phosphatase activity and matrix mineralization were performed to assess the functions of miR-429 in vitro and in vivo the effects of miR-429 on fracture healing. Results: Expression of miR-429 was increased in MC3T3-E1 cells treated with 200 μM CoCl2 by qRT-PCR, and overexpression of miR-429 promoted cell differentiation, and enhanced alkaline phosphatase activity and matrix mineralization. Luciferase reporter assays suggested that miR-429 directly targets the 3'UTR of ZFPM2. In addition, knockdown of ZFPM2 could phenocopy the effects of miR-429 expression. Furthermore, overexpression of ZFPM2 in miR-429-expressing MC3T3-E1 cells suppressed cell differentiation. Conclusions: Our results provide valuable insight into the potential role of hypoxia in regulation of osteoblastic cell differentiation.

Fracture healing in elderly patients is an emerging public health concern. As non‑drug treatments, intermittent hypoxia training (IHT) and remote ischemic preconditioning (RIPC) are considered to have substantial advantages and to aid fracture healing in elderly patients. The purpose of the present study was to evaluate and compare the effects of IHT and RIPC on fracture healing. Micro‑computed tomography (micro‑CT) and biomechanical testing were used to assess the morphology and structural properties of bone callus dissected from aged rats with tibial fractures. In addition, hypoxia‑inducible factor‑1α (HIF‑1α) and its target gene, associated with the healing process, were investigated by reverse transcription‑quantitative polymerase chain reaction and western blot analyses. The micro‑CT‑based parameters, including bone mineral density and trabecular number, were measured, and significant differences were identified between the experimental and control groups. The IHT group exhibited superior bone formation and mineralization rates compared with the RIPC group. The biomechanical testing revealed that the ultimate loading and stiffness values were significantly higher in the IHT group compared with those in the RIPC group. In accordance with previous studies, RIPC exerted a similar effect in increasing the expression of HIF‑1α, and its downstream genes, throughout the course of healing. In addition, the IHT group exhibited increased expression levels of HIF‑1α compared with the RIPC group. Taken together, the results suggested that IHT and RIPC significantly enhanced fracture healing; however, IHT exhibited superior bone formation and healing effects compared with RIPC.

This study aims to assess the early effects of operatively and nonoperatively managed vertebral compression fractures (VCFs) in elderly polytrauma patients. A multi-center retrospective cohort study of operative treatment [vertebroplasty (VP) or kyphoplasty (KP)] versus nonoperative treatment (bed rest). A total of 40 patients received operative treatment and 59 patients received nonoperative treatment. The mean length of hospital stay was 15.53 ± 6.994 days in the operative and 19.54 ± 12.012 days in the nonoperative group (P = 0.039). The incidence of complication was higher in the nonoperative group than the operative group (P = 0.009), especially the incidence of bed rest complication (P = 0.024). Mortality rate was not significant difference between two groups (P = 0.172). For VCFs in elderly polytrauma patients, VP or KP can reduce length of hospital stay and complications, especially bed rest complication compared with nonoperative treatment.

Increasing evidence indicates that long non-coding RNA (lncRNA) is involved in a number of types of human cancer and functions as an oncogene or tumor suppressor. However, little is known about the role of lncRNA X-inactive specific transcript (XIST) in osteosarcoma. In the present study, the expression of lncRNA XIST was analyzed in 56 osteosarcoma tissues and their corresponding normal bone tissues by reverse transcription-quantitative polymerase chain reaction. Increased lncRNA XIST expression was observed in osteosarcoma tissues compared with the normal tissues and was positively associated with advanced Enneking stage. In addition, lncRNA XIST may be used as an independent risk factor for the overall survival of patients with osteosarcoma. Knockdown of lncRNA XIST inhibited cell proliferation, induced cell apoptosis and arrested the cell cycle. The inhibition of lncRNA XIST may also suppress cell migration and invasion in vitro. The present study suggested that lncRNA XIST acted as an oncogene in osteosarcoma, which may make it a novel therapeutic target for the treatment of osteosarcoma.

The main objective of total knee arthroplasty is to relieve pain, restore normal knee function, and improve gait stability. Significant flexion contractures can severely impair function after surgery. The purpose of this study is to evaluate the efficacy of implementing a continuous proximal sciatic nerve block in conjunction with aggressive physical therapy to treat patients with persistent flexion contractures that were recalcitrant to rehabilitation efforts following primary total knee arthroplasty (TKA).From December 2012 to January 2016, the following subjects were enrolled in this study: 20 patients (15 females and 5 males aged between 62 and 78 years old; median age = 65.7 y) with flexion contractures ranging from 15° to 25° (19.2°±5.6°) that persisted for at least 1.5 months following total knee arthroplasty and showed no significant improvement in response to conventional therapeutic methods. Demographic data, the passive range of motion, flexion contracture, pain score during stretching, and the Hospital for Special Surgery knee score were recorded. A portable motion analyzer was used to obtain the corresponding gait parameters from the flexion contractures group and control group. Repeated measurement ANOVA was used to compare the clinical results.In combination with 2 to 4 (2.5 ± 1.3) months of aggressive knee stretching exercises, 16 out of 18 knees achieved full extension, and 2 out of 18 improved to within 5° of the full extension. An average of the 12 to 48 (26.6 ± 10.7) month follow-up showed that this improved range of motion was maintained for all the corresponding patients, and that there were no reoccurrences of deformity. The mean Hospital for Special Surgery knee scores improved from 61.2 to 93.2 points (p 0.001). After six months of continuous proximal sciatic nerve blockage, all gait parameters for the flexion contractures group exhibited significant improvement.A continuous proximal sciatic nerve block could be a useful adjunct to a physical therapy regimen for patients with knee flexion contractures, especially for patients with difficult-to-treat cases of knee flexion contracture that are recalcitrant to conservative therapy.

Knee osteoarthritis (KOA) is the most common osteoarthritis in lower limbs, and gait measurement is important to evaluate walking function of KOA patients before and after treatment. The third generation Intelligent Device for Energy Expenditure and Activity (IDEEA3) is a portable gait analysis system to evaluate gaits. This study is to evaluate the accuracy and reliability of IDEEA3 for gait measurement of KOA patients. Meanwhile, gait differences between KOA patients and healthy subjects are examined. Twelve healthy volunteers were recruited for measurement comparison of gait cycle (GC), cadence, step length, velocity and step counts between a motion analysis system and a high-speed camera (GoPro Hero3). Twenty-three KOA patients were recruited for measurement comparison of former five parameters between GoPro Hero3 and IDEEA3. Paired t-test, Concordance Correlation Coefficient (CCC) and Intraclass Correlation Coefficient (ICC) were used for data analysis. All p-values of paired t-tests for GC, cadence, step length and velocity were greater than 0.05 while all CCC and ICC results were above 0.95. The measurements of GC, cadence, step length, velocity and step counts by motion analysis system are highly consistent with the measurements by GoPro Hero3. The measurements of former parameters by GoPro Hero3 are not statistically different from the measurements by IDEEA3. IDEEA3 can be effectively used for the measurement of GC, cadence, step length, velocity and step counts in KOA patients. The KOA patients walk with longer GC, lower cadence, shorter step length and slower speed compared with healthy subjects in natural speed with flat shoes.

Arterial thrombosis after total knee arthroplasty (TKA) is a rare but limb-threatening complication, and early diagnosis and intervention are critical. However, delayed diagnosis is not uncommon, even in high-volume joint replacement centers. Some studies have indicated that patients with preexisting vascular disease have an increased risk of vascular injury during TKA. Thus, we report two cases from our center, which were treated during a 4-month period, that developed acute popliteal artery thrombosis immediately after TKA, despite the absence of preoperative vascular abnormalities in the affected lower limbs. In both cases, absence of a foot pulse was detected in time to successfully manage the complication using endovascular stent deployment, rather than open surgery. After the second case, the complications were attributed to improper use of single-pronged retractors, which were applied to the posterior surface of the tibial plateau. No other cases with similar complications have occurred. Thus, these cases indicate that direct instrument-related blunt injury can cause popliteal arterial thrombosis after TKA, and that the thrombosis can be successfully treated using the endovascular approach.