Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures.

BACKGROUND: Hip fractures account for 23.8% of all fractures in patients over the age of 75 years. More than half of these patients are older than 80 years. Bipolar hemiarthroplasty (BHA) was established as an effective management option for these patients. Various approaches can be used for the BHA procedure. However, there is a high risk of postoperative dislocation. The conjoined tendon-preserving posterior (CPP) lateral approach was introduced to reduce postoperative dislocation rates. AIM: To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients. METHODS: We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA. The patients were followed up for at least 1 year. Among the 80 patients, 57 (71.3%) were female. The time to operation averaged 2.3 d (range: 1-5 d). The mean age was 80.5 years (range: 67-90 years), and the mean body mass index was 24.9 kg/m2 (range: 17-36 kg/m2). According to the Garden classification, 42.5% of patients were type Ⅲ and 57.5% of patients were type Ⅳ. Uncemented bipolar hip prostheses were used for all patients. Torn conjoined tendons, dislocations, and adverse complications during and after surgery were recorded. RESULTS: The mean postoperative follow-up time was 15.3 months (range: 12-18 months). The average surgery time was 52 min (range: 40-70 min) with an average blood loss of 120 mL (range: 80-320 mL). The transfusion rate was 10% (8 of 80 patients). The gemellus inferior was torn in 4 patients (5%), while it was difficult to identify in 2 patients (2.5%) during surgery. The posterior capsule was punctured by the fractured femoral neck in 3 patients, but the conjoined tendon and the piriformis tendon remained intact. No patients had stem varus greater than 3 degrees or femoral fracture. There were no patients with stem subsidence more than 5 mm at the last follow-up. No postoperative dislocations were observed throughout the follow-up period. No significance was found between preoperative and postoperative mean Health Service System scores (87.30 ± 2.98 vs 86.10 ± 6.10, t = 1.89, P = 0.063). CONCLUSION: The CPP lateral approach can effectively reduce the incidence of postoperative dislocation without increasing perioperative complications. For surgeons familiar with the posterior lateral approach, there is no need for additional surgical instruments, and it does not increase surgical difficulty.

Human Mesenchymal Stem Cells Improve Angiogenesis and Bone Formation in Severed Finger Rats through SIRT1/Nrf2 Signaling.

BACKGROUND: This study employed a severed finger rat model to analyze the effects of human mesenchymal stem cells (MSCs) on angiogenesis, inflammatory response, apoptosis, and oxidative stress, to evaluate the possible mechanism of the repair effect of MSCs on severed finger (SF) rats. METHODS: Sixty Sprague-Dawley (SD) rats were categorized into five groups (n = 12). The pathological changes of severed finger tissues were investigated by Hematoxylin and eosin (H&E) staining on day 14 after the rats were sacrificed. The levels of inflammatory factors and oxidative stress factors were detected by ELISA. Terminal Deoxynucleotidyl Transferase (TdT) dUTP Nick End Labeling (TUNEL) was employed to assess the apoptosis of chondrocytes in severed finger tissues. The expression of osteocalcin (OCN), osteopontin (OPN), Collagen I (Col-1), and CD31 were detected by immunohistochemistry or immunofluorescence assay, respectively. The expression levels of related proteins were determined by western blot. RESULT: Our study presented evidence that MSCs treatment improved pathological changes of skin and bone tissue, diminished the inflammatory response, prevented oxidative stress injury, suppressed chondrocyte apoptosis, and promoted angiogenesis, and bone formation compared to the model group. In addition, EX527 treatment attenuated the effect of MSCs, SRT1720 and ML385 co-treatment also attenuated the effect of MSCs. Importantly, the MSCs treatment increased the expression of Sirtuin 1(SIRT1)/Nuclear factor erythroid2-related factor 2(Nrf2) relate proteins. CONCLUSION: Our study indicated that the mechanism of the effect of MSCs on a severed finger was related to the SIRT1/ Nrf2 signaling pathway.

Knockdown of DAPK1 inhibits IL-1ß-induced inflammation and cartilage degradation in human chondrocytes by modulating the PEDF-mediated NF-κB and NLRP3 inflammasome pathway.

Osteoarthritis (OA) is a common joint disease that is characterized by inflammation and cartilage degradation. Death-associated protein kinase 1 (DAPK1) is a multi-domain serine/threonine kinase and has been reported to be involved in the progression of OA. However, its role and mechanism in OA remain unclear. Here, we found the expression of DAPK1 in OA cartilage tissues was higher than that in normal cartilage tissues. The expression of DAPK1 in chondrocytes was up-regulated by IL-1ß. Knockdown of DAPK1 promoted cell viability and anti-apoptotic protein expression, while it inhibited the apoptosis rate and pro-apoptotic protein expressions in IL-1ß-induced chondrocytes. In addition, DAPK1 inhibition reduced the levels of inflammatory cytokines and expressions of matrix metalloproteinases (MMPs), and increased the expressions of collagen II and aggrecan. The data of mechanistic investigation indicated that the expression of pigment epithelium-derived factor (PEDF) was positively regulated by DAPK1. Overexpression of PEDF attenuated the effects of DAPK1 knockdown on IL-1ß-induced cell viability, apoptosis, inflammation, and cartilage degradation. Furthermore, PEDF overexpression restored the activity of the NF-κB pathway and NLRP3 inflammasome after DAPK1 knockdown. Collectively, down-regulation of DAPK1 inhibited IL-1ß-induced inflammation and cartilage degradation via the PEDF-mediated NF-κB and NLRP3 inflammasome pathways.

Vascular endothelial growth factor B improves impaired glucose tolerance through insulin-mediated inhibition of glucagon secretion.

BACKGROUND: Impaired glucose tolerance (IGT) is a homeostatic state between euglycemia and hyperglycemia and is considered an early high-risk state of diabetes. When IGT occurs, insulin sensitivity decreases, causing a reduction in insulin secretion and an increase in glucagon secretion. Recently, vascular endothelial growth factor B (VEGFB) has been demonstrated to play a positive role in improving glucose metabolism and insulin sensitivity. Therefore, we constructed a mouse model of IGT through high-fat diet feeding and speculated that VEGFB can regulate hyperglycemia in IGT by influencing insulin-mediated glucagon secretion, thus contributing to the prevention and cure of prediabetes. AIM: To explore the potential molecular mechanism and regulatory effects of VEGFB on insulin-mediated glucagon in mice with IGT. METHODS: We conducted in vivo experiments through systematic VEGFB knockout and pancreatic-specific VEGFB overexpression. Insulin and glucagon secretions were detected via enzyme-linked immunosorbent assay, and the protein expression of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) was determined using western blot. Further, mRNA expression of forkhead box protein O1, phosphoenolpyruvate carboxykinase, and glucose-6 phosphatase was detected via quantitative polymerase chain reaction, and the correlation between the expression of proteins was analyzed via bioinformatics. RESULTS: In mice with IGT and VEGFB knockout, glucagon secretion increased, and the protein expression of PI3K/AKT decreased dramatically. Further, in mice with VEGFB overexpression, glucagon levels declined, with the activation of the PI3K/AKT signaling pathway. CONCLUSION: VEGFB/vascular endothelial growth factor receptor 1 can promote insulin-mediated glucagon secretion by activating the PI3K/AKT signaling pathway to regulate glucose metabolism disorders in mice with IGT.

Role of vascular endothelial growth factor B in nonalcoholic fatty liver disease and its potential value.

Nonalcoholic fatty liver disease (NAFLD) refers to fatty liver disease caused by liver injury factors other than alcohol. The disease is characterized by diffuse fat infiltration, including simple steatosis (no inflammatory fat deposition), nonalcoholic fatty hepatitis, liver fibrosis, and so on, which may cause liver cirrhosis, liver failure, and even liver cancer in the later stage of disease progression. At present, the pathogenesis of NAFLD is still being studied. The "two-hit" theory, represented by lipid metabolism disorder and inflammatory reactions, is gradually enriched by the "multiple-hit" theory, which includes multiple factors, such as insulin resistance and adipocyte dysfunction. In recent years, vascular endothelial growth factor B (VEGFB) has been reported to have the potential to regulate lipid metabolism and is expected to become a novel target for ameliorating metabolic diseases, such as obesity and type 2 diabetes. This review summarizes the regulatory role of VEGFB in the onset and development of NAFLD and illustrates its underlying molecular mechanism. In conclusion, the signaling pathway mediated by VEGFB in the liver may provide an innovative approach to the diagnosis and treatment of NAFLD.

Current and Novel Therapeutics for Articular Cartilage Repair and Regeneration.

Articular cartilage repair is a sophisticated process that has is being recently investigated. There are several different approaches that are currently reported to promote cartilage repair, like cell-based therapies, biologics, and physical therapy. Cell-based therapies involve the using stem cells or chondrocytes, which make up cartilage, to promote the growth of new cartilage. Biologics, like growth factors, are also being applied to enhance cartilage repair. Physical therapy, like exercise and weight-bearing activities, can also be used to promote cartilage repair by inducing new cartilage growth and improving joint function. Additionally, surgical options like osteochondral autograft, autologous chondrocyte implantation, microfracture, and others are also reported for cartilage regeneration. In the current literature review, we aim to provide an up-to-date discussion about these approaches and discuss the current research status.

Melatonin ameliorates osteoarthritis rat cartilage injury by inhibiting matrix metalloproteinases and JAK2/STAT3 signaling pathway.

OBJECTIVE: To observe the effect of melatonin intervention on rat knee osteoarthritis (KOA) model and explore its mechanism. METHODS: A total of 81 Sprague-Dawley (SD) rats were employed. Haematoxylin and eosin (H&E) staining and safranin o-solid green staining were used to observe the changes of pathology in KOA, and inflammation factors in serum were detected by enzyme-linked immunosorbent assay (ELISA), type II collagen (Col-II) was detected by immunohistochemistry, chondrocyte apoptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL). The expression of matrix metalloproteinases (MMPs) and JAK2/STAT3 signaling were detected by western blot. RESULTS: Melatonin treatment ameliorated the histomorphology of knee joint in rats compared to the model group. The contents of TNF-α, IL-6, and IL-1ß in serum were decreased after melatonin treatment. In addition, compared to the model group, the positive expression of Col-II increased, the chondrocyte apoptosis decreased after melatonin treatment. Interestingly, the expression levels of MMP3, MMP9, MMP13, p-JAK2 and p-STAT3 decreased (p < 0.05). Importantly, melatonin combined with AG490 is significantly ameliorates histomorphology of knee joint, reduced cartilage loss compared with melatonin treatment alone. CONCLUSIONS: Melatonin treatment can effectively diminish the cartilage injury. Its mechanism may be related to protect the articular cartilage by reducing the release of inflammatory factors, inhibit the expression of MMPs and JAK2/STAT3 signaling.

Breakage risk of different sacroiliac screws in unilateral sacral fractures a finite element analysis.

OBJECTIVE: To compare the breakage risk of lengthened sacroiliac screws and ordinary sacroiliac screws to treat unilateral vertical sacral fractures and provide a reference for clinical application. METHODS: A finite element model of Tile C pelvic ring injury (unilateral type Denis II fracture of the sacrum) was produced. The sacral fractures were fixed with a lengthened sacroiliac screw and ordinary sacroiliac screw in 6 types of models. The maximal von Mises stresses and stress distributions of the two kinds of screws when standing on both feet were measured and compared. RESULTS: The maximal von Mises stress of the lengthened screw was less than that of the ordinary screw. Compared with ordinary screw, the stress distribution in the lengthened screw was more homogeneous. CONCLUSIONS: The breakage risk of screws fixed in double segments is lower than that of screws fixed in single segments, the breakage risk of lengthened screws is lower than that of ordinary screws, and the breakage risk of screws fixed in S2 segments is lower than that of screws fixed in S1 segments.

An Efficient Voltammetric Sensor Based on Graphene Oxide-Decorated Binary Transition Metal Oxides Bi2O3/MnO2 for Trace Determination of Lead Ions.

Herein we present a facile synthesis of the graphene oxide-decorated binary transition metal oxides of Bi2O3 and MnO2 nanocomposites (Bi2O3/MnO2/GO) and their applications in the voltammetric detection of lead ions (Pb2+) in water samples. The surface morphologies, crystal structures, electroactive surface area, and charge transferred resistance of the Bi2O3/MnO2/GO nanocomposites were investigated through the scanning electron microscopy (SEM), power X-ray diffraction (XRD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques, respectively. The Bi2O3/MnO2/GO nanocomposites were further decorated onto the surface of a glassy carbon electrode (GCE), and Pb2+ was quantitatively analyzed by using square-wave anodic stripping voltammetry (SWASV). We explored the effect of the analytical parameters, including deposition potential, deposition time, and solution pH, on the stripping peak current of Pb2+. The Bi2O3/MnO2/GO nanocomposites enlarged the electroactive surface area and reduced the charge transferred resistance by significant amounts. Moreover, the synergistic enhancement effect of MnO2, Bi2O3 and GO endowed Bi2O3/MnO2/GO/GCE with extraordinary electrocatalytic activity toward Pb2+ stripping. Under optimal conditions, the Bi2O3/MnO2/GO/GCE showed a broad linear detection range (0.01-10 µM) toward Pb2+ detection, with a low limit of detection (LOD, 2.0 nM). The proposed Bi2O3/MnO2/GO/GCE electrode achieved an accurate detection of Pb2+ in water with good recoveries (95.5-105%).

Superlarge living hyaline cartilage graft contributed by the scale-changed porous 3D culture system for joint defect repair.

It is known that an excellent hyaline cartilage phenotype, an internal microstructure with safe crosslinking and available size flexibility are the key factors of cartilage grafts that allow for clinical application. Living hyaline cartilage grafts (LhCGs) constructed by phase-transfer hydrogel (PTCC) systems were reported to have a hyaline phenotype and bionic microstructure. By employing chondrocytes to secrete matrix in the hydrogel and then removing the material to obtain material-free tissuein vitro, LhCG technology exhibited superior performance in cartilage repair. However, PTCC systems could only produce small-sized LhCGs because of medium delivery limitations, which hinders the clinical application of LhCGs. In this study, we prepared three different noncrosslinked gelatin microspheres with diameters from 200 µm to 500 µm, which replaced the original pore-forming agent. The new PTCC system with the mixed and gradient porous structure was used for the preparation of superlarge LhCGs with a continuous structure and hyaline phenotype. Compared to the original technique, the porous gradient structure promoted nutrient delivery and cartilage matrix secretion. The small size of the microporous structure promoted the rapid formation of matrix junctions. The experimental group with a mixed gradient increased cartilage matrix secretion significantly by more than 50% compared to the that of the control. The LhCG final area reached 7 cm2without obvious matrix stratification in the mixed gradient group. The design of the scale-changed porous PTCC system will make LhCGs more promising for clinical application.

Vascular endothelial growth factor B inhibits insulin secretion in MIN6 cells and reduces Ca2+ and cyclic adenosine monophosphate levels through PI3K/AKT pathway.

BACKGROUND: Type 2 diabetes (T2D) is characterized by insufficient insulin secretion caused by defective pancreatic ß-cell function or insulin resistance, resulting in an increase in blood glucose. However, the mechanism involved in this lack of insulin secretion is unclear. The level of vascular endothelial growth factor B (VEGF-B) is significantly increased in T2D patients. The inactivation of VEGF-B could restore insulin sensitivity in db/db mice by reducing fatty acid accumulation. It is speculated that VEGF-B is related to pancreatic ß-cell dysfunction and is an important factor affecting ß-cell secretion of insulin. As an in vitro model of normal pancreatic ß-cells, the MIN6 cell line can be used to analyze the mechanism of insulin secretion and related biological effects. AIM: To study the role of VEGF-B in the insulin secretion signaling pathway in MIN6 cells and explore the effect of VEGF-B on blood glucose regulation. METHODS: The MIN6 mouse pancreatic islet ß-cell line was used as the model system. By administering exogenous VEGF-B protein or knocking down VEGF-B expression in MIN6 cells, we examined the effects of VEGF-B on insulin secretion, Ca2+ and cyclic adenosine monophosphate (cAMP) levels, and the insulin secretion signaling pathway. RESULTS: Exogenous VEGF-B inhibited the secretion of insulin and simultaneously reduced the levels of Ca2+ and cAMP in MIN6 cells. Exogenous VEGF-B also reduced the expression of phospholipase C gamma 1 (PLCγ1), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase (AKT), and other proteins in the insulin secretion pathway. Upon knockdown of VEGF-B, MIN6 cells exhibited increased insulin secretion and Ca2+ and cAMP levels and upregulated expression of PLCγ1, PI3K, AKT, and other proteins. CONCLUSION: VEGF-B can regulate insulin secretion by modulating the levels of Ca2+ and cAMP. VEGF-B involvement in insulin secretion is related to the expression of PLCγ1, PI3K, AKT, and other signaling proteins. These results provide theoretical support and an experimental basis for the study of VEGF-B in the pathogenesis of T2D.

Biomechanical comparison of three minimally invasive fixations for unilateral pubic rami fractures.

BACKGROUND: To compare the mechanical characteristics of a percutaneous superior pubic intramedullary screw, percutaneous bridging plate and percutaneous screw-rod system of the anterior ring for the treatment of unilateral vertical pubic fractures to provide a reference for clinical application. METHODS: A finite element model of pelvic anterior ring injury (unilateral vertical pubic fracture) was produced. The fractures were fixed with a percutaneous superior pubic intramedullary screw, percutaneous bridging plate and percutaneous screw-rod system of the anterior ring and their combinations in 5 types of models. The fracture stabilities under vertical, bilateral and anterior-posterior load were quantified and compared based on the displacement of the hip joints' midpoint as quantificational index of fracture stability. RESULTS: In the condition of bilateral and anterior-posterior load, the vertical, bilateral and anterior-posterior displacements of the hip joints' midpoint of different models were significantly different respectively. In general, the displacements of the 5 pelvic anterior ring fixations were ranked from maximum to minimum as follows: bridging plate, pelvic anterior screw-rod system, combination of bridging plate and pelvic anterior screw-rod system, superior pubic intramedullary screw and combination of superior pubic intramedullary screw and pelvic anterior screw-rod system. CONCLUSION: For the fixation in unilateral pubic fractures of pelvic ring injury, the percutaneous superior pubic intramedullary screw is optimal, the percutaneous pelvic anterior screw-rod system is the second choice, and percutaneous bridging plate ranks the third. The percutaneous pelvic anterior screw-rod system can significantly increase fixation stability of the percutaneous superior pubic intramedullary screw and the percutaneous bridging plate.

Effects of lifestyle interventions on rural patients with type 2 diabetes mellitus.

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) is rising rapidly in rural areas, and lifestyle interventions can effectively reduce the blood glucose levels of patients with T2DM. However, current dietary and exercise guidelines are still at experimental stages and are difficult for subjects to understand and implement. The Human Metabolism Analyzer provides real life interventions for the prevention and treatment of T2DM, and our pilot research has demonstrated its effectiveness and good compliance. AIM: To investigate the effect of and compliance with lifestyle interventions in rural patients with T2DM. METHODS: A total of ten rural villages were randomly selected in Chaoshui Township, Penglai City, Shandong Province, China, to conduct health screening among residents aged 50 years or older. Each rural village represented a group, and 12 patients with T2DM were randomly selected from each group (total: 120) to participate in this study and receive real life lifestyle interventions and medication guidance. Lifestyle interventions included changing the meal order (A), postprandial activities (B), resistance exercise (C), and reverse abdominal breathing (D). Diabetes education was conducted at least once a month with a weekly phone follow-up to monitor exercise and diet. Waist circumference, blood pressure, body mass index (BMI), motor function, body composition, fasting blood glucose, and glycated hemoglobin (HbA1c) were analyzed before and 3 mo after the intervention. Moreover, patient compliance and adjustments of hypoglycemic drugs were evaluated. RESULTS: A total of 109 subjects completed the study. The compliance rates for lifestyle interventions A, B, C, and D were 57.79%, 60.55%, 64.22%, and 75.23%, respectively. Among the subjects who received hypoglycemic drugs, the dose was reduced 2 to 3 times based on blood glucose in 54 (67.50%) subjects and was tapered and discontinued in 5 (6.25%) subjects within 3 mo, with no significant fluctuations in blood glucose after dose reduction and withdrawal. After lifestyle interventions, waist circumference, BMI, fasting blood glucose, and HbA1c significantly decreased (P < 0.001); motor function and body composition also significantly improved (P < 0.001). CONCLUSION: For patients with T2DM, compliance to real-life lifestyle interventions is good, and the interventions significantly improve metabolic indicators such as waist circumference, BMI, blood pressure, HbA1c, body composition, and motor function. Some patients are able to taper or discontinue hypoglycemic drugs.

The effect of robot-navigation-assisted core decompression on early stage osteonecrosis of the femoral head.

BACKGROUND: The aim of the current paper is to evaluate the effects of robot-navigation-assisted core decompression compared with conventional core decompression surgery for early-stage osteonecrosis of the femoral head. METHODS: Twenty patients with a total of 36 hips who were diagnosed with Association Research Circulation Osseous stage 2 avascular necrosis of the femoral head and who received core decompression with or without robotic assistance were reviewed. The Harris hip score and visual analog scale score were used to assess clinical function. Intraoperative radiation exposure and operation time were used to evaluate the effectiveness of the robot-assisted system. RESULTS: At a mean follow-up of 26.4 months (24-36 months), the Harris hip score, visual analog scale score, and survival rate of the patients were similar between the conventional and robot-assisted groups. The guidewire insertion time, number of guidewire attempts, and radiation exposure during guidewire insertion were all significantly lower in the robot-assisted group than in the conventional group. CONCLUSIONS: Robot-assisted core decompression of the femoral head is as safe and effective as a conventional core decompression surgery. It can reduce operation time and decrease intraoperative radiation exposure.

MicroRNA-874 inhibits cell proliferation and invasion by targeting cyclin-dependent kinase 9 in osteosarcoma.

MicroRNAs (miRNAs) perform important roles in the development and progression of human malignancy. miR-874, as a tumor suppressor, is decreased in malignant tumors, including osteosarcoma. However, the potential mechanism of miR-874 in osteosarcoma remains largely unknown. In the present study, a dual-luciferase reporter system supported cyclin-dependent kinase 9 (CDK9) as a direct target gene of miR-874. miR-874 mimics evidently repressed CDK9 expression in osteosarcoma. Furthermore, osteosarcoma tissues and cell lines exhibited increased expression of CDK9, and CDK9 expression levels were inversely correlated (R=-0.725) with that of miR-874 in osteosarcoma tissues. Finally, CDK9 overexpression reversed the potential effect of miR-874 on the proliferation and invasion of osteosarcoma cells. Overall, the results revealed that miR-874, as a tumor suppressor, is involved in osteosarcoma progression and metastasis by targeting CDK9, indicating that the miR-874/CDK9 pathway may serve as a potential therapeutic target for the treatment of osteosarcoma.

Anatomical relation between S1 sacroiliac screws' entrance points and superior gluteal artery.

BACKGROUND: To conduct radiologic anatomical study on the relation between S1 sacroiliac screws' entry points and the route of the pelvic outer superior gluteal artery branches with the aim to provide the anatomical basis and technical reference for the avoidance of damage to the superior gluteal artery during the horizontal sacroiliac screw placement. METHODS: Superior gluteal artery CTA (CT angiography) vascular imaging of 74 healthy adults (37 women and 37 men) was done with 128-slice spiral CT (computed tomography). The CT attendant-measuring software was used to portray the "safe bony entrance area" (hereinafter referred to as "Safe Area") of the S1 segment in the standard lateral pelvic view of three-dimensional reconstruction. The anatomical relation between S1 sacroiliac screws' Safe Area and the pelvic outer superior gluteal artery branches was observed and recorded. The number of cases in which artery branches intersected the Safe Area was counted. The cases in which superior gluteal artery branches disjointed from the Safe Area were identified, and the shortest distance between the Safe Area and the superior gluteal artery branch closest to the Safe Area was measured. RESULTS: Three cases out of the 74 sample cases were excluded from this study as they were found to have no bony space for horizontal screw placement in S1 segment. Among the remaining 71 sample cases, there are 32 cases (45.1%) where the deep superior branch of superior gluteal artery passes through the Safe Area of S1 entrance point. There was no distinguishing feature and rule on how the deep superior branches and the Safe Area overlapped. In the 39 cases in which superior gluteal artery branches disjointed from the Safe Area, the deep superior branches of superior gluteal artery were the branches closest to the Safe Area and the part of the branch closest to the Safe Area was located in front of the widest part of the Safe Area. The shortest distance between the deep superior branch and the Safe Area is 0.86 ± 0.84 cm. CONCLUSION: There is a high risk of accidental injury of the deep superior branches of superior gluteal artery in the process of S1 sacroiliac screw placement. Even if the entry points are located in the safe bony entrance area, the absolute secure placement cannot be assured. We suggest that great attention should be paid to make thorough preoperative plans.

Stacked Modalities' Thromboprophylactic Therapy for Patients Undergoing Total Knee Replacement Surgery.

Thromboprophylaxis is a controversial and challenging topic in joint replacement surgery. Mechanical prophylaxis in combination with the use of anticoagulants have been shown to have greater efficacy than single modalities. But the early use of anticoagulants has the potential to increases the risk of postoperative bleeding. The purpose of this study was to evaluate the thromboprophylactic effects of sequential combined method using early-mechanical compression with delayed rivaroxaban in total knee arthroplasty. A retrospective cohort study, including 369 patients receiving simultaneous combined mechanical and pharmacological thromboprophylactic modality and 385 patients receiving sequential combined modality with early-mechanical compression treatment followed by rivaroxaban 2 days later after primary total knee arthroplasty surgery was conducted. The incidence rates of proximal and distal deep vein thrombosis (DVT) on the 2nd day and the 5th week and the volume of wound drainage were compared postoperatively. On the 2nd postoperative day, the incidence rates of proximal and distal DVT in the sequential group (1.56, 4.16%) had no significant difference compared with those (1.08, 3.25%) in the simultaneous group (p = 0.569, 0.507, respectively). No difference was found in the incidence rate of proximal and distal DVT on the 5th week between groups. No pulmonary embolism occurred. The mean volume of wound drainage in the sequential group was 343 mL which was 98 mL lesser than in the simultaneous group (p < 0.001). The sequential combined method as called "stacked modalities" thromboprophylactic therapy following total knee arthroplasty was safe and effective. The use of the mechanical compression method alone during the early-postoperative 48 hours, then followed by rivaroxaban then until the 5th week had the same antithrombotic effects and reduced the postoperative wound drainage volume as compared with simultaneous combined modalities.

[Mathematical analysis of the influences of femoral and tibial bone cuts on the dynamic alignment in total knee arthroplasty].

OBJECTIVE: To investigate the influences of the distal femoral cut, the anterior and posterior femoral cuts, the proximal tibial cut on the dynamic alignment of the lower extremity in total knee arthroplasty. METHODS: Based on the three-dimensional geometric model, imitating the flexion movement of the knee without axial rotation after total knee arthroplasty, the influence of each of the three bone cuts on the dynamic alignment was analyzed with the assumption of standard bone cuts of the other two and equality of the medial and lateral soft tissue balancing. The dynamic alignment was defined as the angle between the mechanical axis of the tibia and the sagittal plane of the body when the knee was in any angle of flexion. With two of the three major bone cuts standard, the track of the tibial movement was established when the other one bone cut deviated from the ideal section of angle A. Based on the principle of geometry, the mathematical formula were established to present the influences of three bone cuts on the dynamic alignment of the lower extremity. RESULTS: All of the three kinds of bone cuts in total knee arthroplasty influenced the dynamic alignment of the lower extremity not just in one static position, but during the whole range of motion. At the θ angle of knee flexion, the alignment of the lower extremity was arcsin(cosθsinA) when the varus/valgus femoral component alignment was A; the alignment of the lower extremity was arcsin(sinθsinA) when the rotational femoral component alignment was A; the alignment of the lower extremity was A when the varus/valgus tibial component alignment was A. CONCLUSION: The influences of the distal femoral cut, the anterior and posterior femoral cuts, the proximal tibial cut on the dynamic alignment of the lower extremity in total knee arthroplasty are dynamically changed during the flexion movement of the knee.

Femoral rotation influences dynamic alignment of the lower extremity in total knee arthroplasty.

PURPOSE: Besides the long-leg standing X-ray film focusing on static standing mechanical alignment of the lower extremity, dynamic alignment from full extension to 90° flexion after total knee arthroplasty (TKA) is rarely mentioned. Computer-assisted surgical technology enables surgeons to measure and assess knee behaviour during surgery. This study was designed to analyse the influences of femoral rotation on dynamic alignment of the lower extremity in TKA. METHODS: Seventy-six consecutive patients with end-stage knee osteoarthritis were enrolled. External rotation osteotomy of the distal femur during TKA was completed according to the pre-operative external rotation angle (ERA), intra-operative transepicondylar axis (TEA) and anteroposterior (AP) line. Passive dynamic alignment of the lower extremity during knee flexion was recorded. The variation trend of hip-knee-ankle (HKA) alignment and the influences of femoral external rotation osteotomy were analysed. RESULTS: Postoperative deviation of HKA alignment from 0° to 90° flexion was associated with the rotational alignment of the femoral component (r = -0.769, p < 0.001). Variation trend of HKA alignment during knee flexion tended to be varus, valgus and neutral according to the selected angle of external rotation osteotomy of the distal femur. CONCLUSION: External rotation osteotomy of the distal femur played a crucial role in determining dynamic HKA alignment in TKA.