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Objective: To study the correlation between high-level free fat acids（FFA）and red blood cell (RBC) injury and to explore the pathological mechanism of hidden blood loss (HBL) after total knee arthroplasty (TKA).Methods: Perioperative blood indexes were tested in 120 patients underwent unilateral total knee replacement for end-stage knee osteoarthritis. Venous blood samples were collected before operation and 24h, 48h, 72h and 120 h after operations. The changes of FFA, hemoglobin (Hb) and red blood cell number in the blood samples were detected by automatic hematology analyzer. The activity of glutathion peroxidase (GSH-Px), total superoxide dismutase (T-SOD) and hydrogen peroxide (H2O2) levels in the blood were measured. Measurement of reactive oxygen species（ROS）was performed by flow cytometry. Meanwhile, the morphological changes of RBC were analyzed under microscope. Results: Significant hidden blood loss was observed for all patients. The Hb content, RBC and hematocrit（Hct）decreased significantly 24 h after surgery (P 2O2 levels significantly decreased compared with preoperative tested samples (P 2O2 levels increased as well. All tested parameters tended to return to normal levels five days after surgery.Conclusion: High levels of FFA in blood can induce oxidative stress and damage RBCs, which in turns causes HBL after surgery.

Trabecular bone, widely presented in the ends of long bones and chine, is a typically porous structure which provides a multifunction such as light weight, undertaking load, impact energy buffer and hosting marrow cells. The structure of trabecular is a dominant factor for the strength of cancellous bone. The prediction of the trabecular bone’s mechanical properties depending on the trabecular structure is very useful for the diagnosis and treatment of osteoporosis. The object of this study is to establish a relationship between the mechanical properties and topological, morphological parameters of trabecular bone. The 50 3-D data of cancellous bone are selected from the CT images of three caput femurs and disposed in BoneJ, through which the BV/TV, SMI and genus parameters of each samples are obtained. The deformation behaviors of trabecular bone are simulated in ABAQUS through uniaxial compression on the 3-D model derived from stack images. Then linear-regression analyses are conducted on the BV/TV, genus, SMI and apparent Young’s modulus, resulting a high correlation (R^2=0.84) between the Young’s modulus and the hybrid parameter derived from SMI and normalized genus, corresponding to morphological and topological parameter of the samples respectively. The result indicates that it’s promising to establish the relationship between mechanical properties of trabecular bone and their topological and morphological parameters.

Background Hidden blood loss (HBL) often occurs in the prosthetic replacement for joint, but the mechanism is still not clear. Materials and methods This study tried to establish an animal model of HBL by injecting arachidonic acid (AA) into the Sprague-Dawley rats. Different concentrations of AA were injected into the tail veins of the rats, and blood samples were collected before and after administration at 24, 48, and 72 h. A complete blood count was obtained by to find the hemoglobin (Hb) and red blood cell (RBC) count changes. The glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD) activities and hydrogen peroxide (H 2 O 2 ) levels were detected. The morphological changes of erythrocyte were observed under a polarizing microscope. The absorbance values of the blood samples were tested to determine the presence of ferryl Hb. Results HBL occurred in the experimental groups when the concentration of AA reached 10 mmol/L; Hb and RBC values decreased sharply at 24- and 48-h postinjection. This was followed by reduced activities of GSH-PX and T-SOD and decreased levels of H 2 O 2 . Moreover, the pathologic changes of red cell morphology mainly presented as pleomorphic RBC morphology, including cell rupture. The absorbance values of the blood samples were in accordance with ferryl Hb features. RBC and Hb values were relatively stable at 72 h. The GSH-PX and T-SOD activities and H 2 O 2 levels gradually increased up to a balanced state. Conclusions The study concluded that high concentrations of AA can induce oxidative stress reactions in the body, causing acute injury of RBCs, which is closely related to HBL.

The aim of the study was to investigate the mechanisms of human β-defensin 3 (HBD-3) regulation of the immune response and the lipopolysaccharide/Toll-like receptor-4 (LPS/TLR4)-mediated signaling pathway. A TLR4 extracellular gene fragment was cloned into the pET32a plasmid to determine its expression in Escherichia coli (E. coli) and purification. A dialysis labeling method was used to stain HBD-3 with fluorescein isothiocyanate (FITC). FITC-HBD-3 was used to induce the differentiation of human peripheral blood mononuclear cells (MNC) into immature dendritic cells (imDC) in vitro. Binding reactions were established using FITC-HBD-3 and sTLR4 into cell suspensions. Flow cytometry (FCM) was used to analyze the results. Western blot analysis confirmed the identity of nuclear factor-κB (NF-κB) and was used to quantify its nuclear translocation. The results showed that, HBD-3 bound to imDC in a Ca2+-dependent manner, and sTLR4 and LPS competitively inhibited the binding. HBD-3 competitively blocked the binding of LPS and imDC by binding to imDC. HBD-3 significantly decreased the translocation of LPS-induced NF-κB into the nucleus. In conclusion, HBD-3 can competitively inhibit the binding of LPS and imDC through its binding to TLR4 molecules, which are expressed in imDC, thereby preventing LPS from inducing the maturity of the imDCs.

OBJECTIVES: As promising alternative to current metallic biomaterials, the porous Mg scaffold with a 3‐D open‐pore framework has drawn much attention in recent years due to its suitable biodegradation, biocompatibility, and mechanical properties for human bones. This experiment's aim is to study the mechanical properties, biosafety, and osteogenesis of porous Mg‐Zn alloy. METHODS: A porous Mg‐2Zn‐0.3Ca (wt%) alloy was successfully prepared by infiltration casting, and the size of NaCl particles was detected by a laser particle size analyzer. The microstructure of the Mg‐2Zn‐0.3Ca alloy was characterized by the stereoscopic microscope and Sirion Field emission scanning electron microscope. X‐ray computerized tomography scanning (x‐CT) was used to create the 3‐D image. The degradation rate was measured using the mass loss method and the pH values were determined together. The engineering stress–strain curve, compressive modulus, and yield strength were tested next. The bone marrow stromal cells (BMSC) were cultured in vitro. The CCK‐8 method was used to detect the proliferation of the BMSC. Alkaline phosphatase (ALP) and alizarin red staining were used to reflect the differentiation effects. After co‐culturing, cell growth on the material's surface was observed by scanning electron microscope (SEM). The cell adhesion was tested by confocal microscopy. RESULTS: The obtained results showed that by using near‐spherical NaCl filling particles, the porous Mg alloy formed complete open‐cell foam with a very uniform size of pores in the range of 500–600 μm. Benefitting from the small size and uniform distribution of pores, the present porous alloy exhibited a very high porosity, up to 80%, and compressive yield strength up to 6.5 MPa. The degradation test showed that both the pH and the mass loss rate had similar change tendency, with a rapid rise in the early stage for 1–2 day's immersion and subsequently remaining smooth after 3 days. In vitro cytocompatibility trials demonstrated that in comparison with Ti, the porous alloy accelerated proliferation in 1, 3, 5, and 7 days (P < 0.001), and the osteogenic differentiation test showed that the ALP activity in the experimental group was significantly higher (P = 0.017) and has more osteogenesis nodules. Cell adhesion testing showed good osteoconductivity by more BMSC adhesion around the holes. The confocal microscopy results showed that cells in porous Mg‐based alloy had better cytoskeletal morphology and were larger in number than in titanium. CONCLUSIONS: These results indicated that this porous Mg‐based alloy fabricated by infiltration casting shows great mechanical properties and biocompatibilities, and it has potential as an ideal bone tissue engineering scaffold material for bone regeneration.

Dear Editor, First we would like to congratulate Bao et al. [1] on the publication of the article entitled “Lesser trochanteric osteotomy in total hip arthroplasty for treating CROWE type IV developmental dysplasia of hip”. Although the technique of lesser trochanteric osteotomy has been well described in this study, there are still three problems which need to be further addressed by the authors: The greater trochanter fracture. The technique of lesser trochanteric osteotomy includes sequential bone cutting at the level of the subtrochanteric diaphysis, while leaving the greater trochanter intact, as shown in Fig. 1 in [1] this article. It is likely to cause a greater trochanter fracture when the femoral stem is inserted, which is going to compromise the abductor attachment. How can the greater trochanter be protected from being broken? The soft tissue tension. Subtrochanteric osteotomy has been demonstrated to be a safe and effective technique for soft tissue release in performing total hip arthroplasty (THA) for high dislocated developmental dysplasia of the hip (DDH). The neurovascular tissue is well protected as the femur is shortened when the femoral head is distalised and reduced into the true acetabulum [2]. In the technique described, however, the femoral length is in fact not reduced or shortened to a much lesser extent compared as a result of subtrochanteric osteotomy. The soft tissue tension remains high after the reduction of the hip. How can the authors address the high soft tissue tension remaining and the low incidence of neurovascular injuries as reported in this article? The anteversion angle of the acetabular cup and femoral stem. Due to the deformity of the acetabulum and proximal femur, it is not easy to determine the anteversion angle of the prostheses which is of vital importance in preventing dislocation of the hip. How are the prostheses set at a proper angle to construct a stable articulation? We agree with the viewpoint that the lessor trochanteric osteotomy could be adopted to avoid subtrochanteric nonunion when performing the step-cut or oblique osteotomy, but the proximal femur and abductor protecting technique needs to be advanced in future studies.

To study the correlation between arachidonic acid (AA) and acute red blood cells damage in rats, and to build a model with hidden blood loss in vivo, and to explore the pathological mechenism of hidden blood loss.A total of 50 male adult Sprague-Dawley rats weighing (200 ± 20) g were randomly divided into five groups (n = 10): control group and four experimental groups. The rats in the experimental groups were given 0.5 ml different concentrations of AA dilu- ents, 5, 10, 20, 40 mmol/L respectively. The blood samples were collected from orbital venous at the beginning and 24, 48, 72 hours after administration. Then the changes of hemoglobin (Hb) ,red blood cell count (RBC), glutathione peroxidase (GSH- PX) activity, total superoxide dismutase (T-SOD) activity and hydrogen peroxide (H202) in the blood samples were tested.Significant hidden blood loss occurred when the concentration was 10 mmol/L in the experimental group, with the RBC and Hb sharply reduced in blood samples. The Hb and RBC were reduced in all the experimental groups and control group at 24 hours after administration, while in the experimental groups they changed more obviously. The GSH-PX activity, T-SOD activity and H₂O₂were also significantly reduced in all groups, and the changes showed significant differences. The Hb and RBC were relatively stable in the control group and the experimental groups at 48 hours after administration; while GSH-PX activity, T-SOD activity and H₂O₂were all significantly decreased, and the changes in the experimental groups were more notable.Elevated levels of AA in the blood causes oxidative stress in the red blood cells, leading to the damage of red blood cells and hemoglobin, which is responsible for hidden blood loss.

To systematically evaluate the efficacy and safety of preoperative administration of cyclooxygenase-2 (COX-2) inhibitor on pain occurring with total knee arthroplasty (TKA).We electronically searched PubMed, Cochrane Library, EMBASE, CNKI, CBM, Wanfang data from inception to March 15, 2014 and manual searched journal of library collection to identify randomized controlled trials (RCTs) about preoperative administration of COX-2 inhibitor on pain occurring with TKA. The methodological quality of the included RCTs was assessed and the data were extracted according to the Cochrane Handbook 5.1.0. Meta-analysis was performed by using RevMan 5.2 software.A total of 6 RCTs involving 228 patients were included. The results of meta-analyses showed that: (1) Efficacy: The visual analog scale (VAS) of post-operation at 12-hour (WMD = -0.60, 95% CI -0.83 to -0.37, P0.000 01) and 24-hour (WMD = -0.74, 95% CI -1.29 to - 0.19, P = 0.008) was decreased when COX-2 inhibitor was used before operation. And compared with control group, experimental group decreased the modified numerical pain rating scale (MNPRS) at 24-hour (WMD = -0.50, 95% CI -0.70 to -0.30, P0.000 01), 48-hour (WMD = -0.55,95% CI -0.65 to -0.45,P0.000 01) under quiescent conditions, and the same result at 24-hour (WMD = -0.82, 95% CI -1.26 to -0.38, P0.000 01), 48-hour (WMD = -0.71, 95% CI -0.82 to -0.60, P0.000 01) under active conditions. The morphine consumption postoperatively were fewer in experimental group at the first day (WMD = - 1.35, 95% CI -1.92 to -0.79, P0.000 01) and the second day (WMD = -1.60, 95% CI -2.68 to -0.52, P = 0.004). (2) Safety: COX-2 inhibitor could lessen the incidence of postoperative pruritus (RR = 0.35, 95% CI 0.15 to 0.84, P = 0.02), but not statistically decrease of nausea and vomiting (RR = 0.83, 95% CI 0.54 to 1.28, P = 0.40) and exhaustion (RR = 0.63, 95% CI 0.05 to 7.67, P = 0.72).The current evidence indicated that preoperative administration of COX-2inhibitor can effectively improve the effect of postoperative analgesia, reduce the consumption of morphine and lessen the incidence of pruritus. Due to the limited quantity of the included studies and the evidence with limited strength,further high-quality RCTs are needed to verify the aforementioned conclusion.

Total hip arthroplasty (THA) is a vital therapeutic tool for hip terminal disease. Frequently, hidden blood loss exists in the postoperation, which seriously affect the postoperative rehabilitation of patients. It is urgent need to solve the problem that how to fundamentally prevent and reduce hidden blood loss after THA. Although THA has its own operational reason in blood loss, and also relates to a variety of risk factors, the mechanism of hidden blood loss is not clear. Tranexamic acid has a significant role in preventing perioperative blood loss, and the correlation of hidden blood loss and fibrinolytic mechanism would be confirm necessarily in the future,which will produce positive significance in completing the mechanism of hidden blood loss.

To detect the clinical value of the ECT bone scan in evaluating of the situation of infection control after hip knee arthroplasty.The clinical data were retrospectively analyzed in 62 patients, including 34 males and 28 females with an average age of 68.8 years old ranging from 65 to 74 years. The results of ECT bone scan, erythrocyte sedimentation rate, C-reactive protein were used to assess periprosthetic infection. The patients with positive ECT and ESR on CRP were considered to have periprosthetic infection; however, the patients with two or more negative, indexes were considered to have no infection.The sensitivity, specificity, accurate rate of ECT were 75.0%, 88.9%, 87.1% respectively; ESR 50.0%, 72.2%, 69.4%; CRP 62.5%, 81.4%, 79.0%. The combination of the three methods were 87.5%, 96.3% and 95.2%,Compared with ESR and CRP, ECT is a more effective way in the diagnosis of periprosthetic infection, which has great value and is worth popularizing.

Study design To develop a high-accuracy, easy-manipulated, and low-cost cervical pedicle three-dimensional locator for guiding cervical pedicle screw placement. Objectives To improve the safety of cervical pedicle screw insertion, simplify its manipulation, and offer safety guarantees in clinical application. Summary of background data Because of the complicacy of the anatomic structure of cervical pedicle, clinical application of cervical pedicle screw remained hard to popularize. And recent advances on cervical pedicle location did not simplify the manipulation of procedure significantly. Without aid of locator, distance and angle errors were difficult to control. So far, the only instrument for the location of pedicle "computer-assisted image-guided surgical system" is too expensive for clinical use. Furthermore, it has not yet been documented on location instrument for insertion of cervical pedicle screws. Methods The high-accuracy three-dimensional locator, made of stainless steel was designed to aid cervical pedicle nail placement. The cadavers were inserted nails under guidance of the locator that has been input the corresponding parameters collected from CT images. Results were evaluated by CT scans. Results A total of 90 nails were inserted into cervical pedicles, 90% of which were found right in the pedicles; 10% had pedicle cortex breaches. Parallel offset error of the locator in cross-sectional and lateral CT image that was 0.56 +/- 0.70 and 1.04 +/- 0.99; angular offset error was 1.69 +/- 2.41 and 6.54 +/- 7.08. Conclusion Three-dimensional locator of cervical pedicle and its localization technique achieved good results for individuated screws insertion into cervical pedicles, having such advantages as easy manipulation, high accuracy, and low cost. The system presented safety guarantee to the application and advanced the prevalence of pedicle techniques. Its principium and design were demonstrated feasible.

Total knee arthroplasty (TKA) has been successfully applied for the treatment of the knee pathology at the end stage such as osteoarthritis and rheumatoid arthritis. Although TKA has became a very mature technology, some patients still suffer from the persistent pain after surgery. The cause of this pain have been recognized as the operation or technical error in most cases, and it usually requires a surgical intervention. Only when the cause of pain is judged accurately, can the operation and other factors be estimated correctly, determining the appropriate treatment methods. In the article, the causes of the post-operative pain after TKA are reviewed, which may be helpful to study the causes of the pain, and to decrease the occurrence incidence of pain.

Bidirectional Eph-Ephrin signaling as a focal point of research in cell-cell communications is critical for generation of nerves and vesssels as well as invation and metastasis of tumor cells. The roles for Ephrin-Eph bidirectional signaling in bone remodeling were important. EphrinB2 is expressed on osteoblasts and EphB4 is expressed on osteoclasts. Forward signaling through the EphB4 receptor into mesenchymal precursors promotes osteoblast differentiation, while reverse signaling through the EphrinB2 ligand into osteoclast suppresses differentiation. Signaling between the ligand EphrinB2 and the receptors EphB4 explains bidirectional signaling between osteoblasts and osteoclasts,bone absorption and remodeling, which may lay a theoretical foundation for identifying drug targeting and preventing and treating bone loss.

To investigate the principle and methods of preoperative and postoperative rehabilitation for simultaneous bilateral total knee arthroplasty.From January 2005 to June 2008, 72 patients (144 knees) were reviewed in the study, including 33 males and 39 females, ranging in age from 46 to 78 years, with an average age of 69 years. There were 54 patients with osteoarthritis, 17 patients with RA, and 1 patient with traumatic osteoarthritis, including 10 cases (15 knees) of fixed varus deformity more than 30 degree and 6 cases (8 knees) of fixed vagus deformity more than 15 degree. Rehabilitation protocol was made for preoperative, early postoperative and late postoperative stages. Patients were encouraged to initiate the exercises at the early postoperative stage on the premise of multimodal analgesia. Knee function and pain were evaluated using WOMAC and VAS pain scores. Lower limb embolism was determined by ultrasonic scan and pulmonary embolism was diagnosed by clinical manifestation and D-dimer level.Sixty-nine patiets (138 knees) were followed up at 2 d preoperatively and the second day, 1, 2, 8 and 24 weeks postoperatively. The average postoperative WOMAC and VAS score were significantly lower than preoperative levels,while the postoperative knee ROM and 6 min walking distance were evidently higher than the preoperative ones, respectively. One hundred and twenty-eight knees achieved full extension and flexion more than 90 degree at 2 weeks postoperatively, and 135 knees reached 110 degree in flexion. Unilateral lower limb embolism was found in 2 cases (2 knees) and bilateral ones were found in 1 case (2 knees). No pulmonary embolism was confirmed.Rehabilitation protocols should be made for preoperative, early postoperative and late postoperative stages of simultaneous bilateral knee arthroplasty. Patients should be encouraged to exercise at the early postoperative stage on the premise of multimodal analgesia, in order to improve knee function and reduce edema.

To explore the prognostic significance of hidden blood loss in total hip arthroplasty.From May 2008 to July 2009, Harris hip score was used to evaluate the functions of 71 patients undergoing single side total hip arthroplasty (including 47 males and 24 females with a mean age of 68.3 years, ranged from 48 to 75 years). The blood loss in the operation was analyzed to study the correlation between hidden blood loss and the functional rehabilitation.All 71 patients undergoing THA were involved in the result analysis. The mean total blood loss was 1473 ml and the hidden blood loss was 545 ml (37%). Hidden blood loss significantly correlated with functional rehabilitation (P = 0.001), but there were no correlations between functional rehabilitation and age, gender, operative limb of patients (P = 0.067, 0.527, 0.926, 0.072).Hidden blood loss maybe a useful prognostic information contributing to the functional rehabilitation of total hip arthroplasty.

To investigate the curative effect of treating infected nonunion with debridement and granulated cancellous bone autografting in a one-stage procedure.Between 1999 and 2005, 38 cases of infected nonunion were treated with immediate granulated cancellous bone autografting after debridement.At a mean follow-up of 44 months (range: 12 to 93), 33/38 (86.8%) had an excellent outcome, 5 (13.2%) developed infectious recurrent and/or persistent nonunion (1 case with infectious recurrence and persistent nonunion). Two patients suffered refracture after removing external fixator.The success rate of treating infected nonunion with debridement and granulated cancellous bone autografting in one-stage is high.

To analyze the complications of bipolar hemiarthroplasty for the treatment of intertrochanteric fractures.From Jan. 2004 to Dec. 2007, 62 patients over 80 years old with unstable interthochanteric fracture were treated with bipolar hemiarthroplasty, included 34 males and 28 females with an average age of 86.3 years ranging from 81 to 97 years. According to the Evans classification, there were 29 cases of Evans III, 26 of Evans IV and 7 of Evans V. The systemic and operation related complications were investigated.Among all the cases, 59 were followed up in outpatient department for 24 to 70 months (33 months on average). Systemic complications were found in 19 cases with no death during preoperative period and 5 deaths after leaving hospital. Operation related complications were found in 9 cases, included 3 cases of thigh pain, 1 iatrogenic fracture of proximal femur, 2 hip dislocations, 2 delayed union of fractures and 1 superficial infection. There were no aseptic loosening, peri-prosthetic infections,ectopic ossification or injuries of nerves and vessels.Bipolar hemiarthroplasty is indicated for patients over 80 years old with intertrochanteric fracture, thus the organic or systemic malfunctions should be corrected during perioperative period. Meanwhile, retaining of lesser trochanter and reconstruction of calcar femorale are important for improving periprosthetic biomechanics and reducing local complications.

To measure the concentration of osteoprotegerin (OPG) and receptor activator of NF-kappaB ligand (sRANKL) in peripheral blood among normal healthy people and investigate the relationship pf the concentration with age and sex.The peripheral blood samples of 220 normal healthy people (included 108 males and 112 females, aged from 35 to 70) were collected in the morning. The OPG and sRANKL concentration of blood serum were measured by ELISA.The concentrations in female peripheral blood were: OPG 21.95 to 315.47 pg/ml, sRANKL 10.25 to 370.20 pmol/L; while in male were: OPG 14.78 to 192.55 pg/ml, sRANKL 9.22 to 300.32 pmol/L. There was positive correlation between the OPG concentration and age in the females older than 46 years. And for female older than 57, the sRANKL concentration of peripheral blood increases obviously.Age and sex are the elements that affect the OPG and sRANKL concentration in peripheral blood. For female older than 46, the OPG concentration of peripheral blood increases with age, while the sRANKL concentration of peripheral blood increases for females older than 57.

To investigate the opportune time of secondary definitive surgery for patients with multiple injuries from earthquakes based on the acute physiology and chronic health evaluation II (APACHE II) score and the principles of damage control.Twenty-one patients with critical earthquake injuries were treated with damage control strategies, followed by medical support and surgical intervention to restore their physical potential in the intensive care unit (ICU). Successive APACHE II scoring was adopted to evaluate the patients'physiological status, and then, internal fixation of fractures and other definitive operations were performed.All the patients were effectively treated with few complications, low deformity rate and no death.Appropriate evaluation of patients?physiological potential, right decision on surgical time and proper operative method can reduce the rates of complications, disability and death for patients with critical earthquake injuries.

To avoid disadvantages of two-stage cancellus bone autograft, we investigated the feasibility of one-stage allograft for reconstructing the bone defect resulting from debridement of chronic osteomyelitis in limbs.Between Feb. 1999 and Apr. 2004, 35 cases of chronic osteomyelitis (8 cases of nonunion) underwent one-stage allograft after debridement in our hospital.Thirty-five cases were followed up for an average period of 28 months (range, 13 to 55 months), in which 32 cases (91.43%) were found no infection, and 3 cases (8.57%) were confirmed recurrence of infection. Four out of 8 cases of bone nonunion healed in 9.5 months on average (range, 3 to 12 months), and another case also acquired union after redebridement and autograft of ilium due to infection recurrence 35 days after surgery. Renonunion occurred in 3 cases, 2 out of whom healed after secondary operation with autograft. One case of renonunion and 2 cases of infection recurrence refused further treatment.A high rate of infection arrest can be attained when one-stage allograft is used to reconstruct the bone defect of chronic osteomyelitis after debridement in limbs. Therefore, chronic osteomyelitis should not be regarded as a contraindication to one-stage allogeneic bone grafting. Renonuion, however, achieves a relatively high rate, especially in cases of segmental bone defect.