Charcot neuroarthropathy of the knee due to idiopathic sensory peripheral neuropathy.

BACKGROUND: Charcot neuroarthropathy is a systemic disease that generates pathological changes in the musculoskeletal system, causing instability, dislocations, and deformities. Charcot neuroarthropathy of the knee, due to either diabetes mellitus or syringomyelia, is anecdotally reported with the epidemic of the diseases. However, idiopathic sensory peripheral neuropathy can inflict osteoarticular structures directly, inducing a dysfunctional Charcot neuroarthropathy. An early diagnosis and effective relief of the symptomatic deformity is essential for the treatment. CASE PRESENTATION: We report the case of a patient with idiopathic sensory peripheral neuropathy who presented with a swelling right knee, as well as distorted and painless gait disorder, diagnosed as Charcot neuroarthropathy of the knee. Partial weight bearing with a hinged knee brace was used to correct the abnormal alignment and gait posture, and bisphosphonates were prescribed to decrease pathological bone resorption. Although the alignment and Knee Society Score got a gradual deterioration, the combination of orthosis and pharmacy could alleviate the symptom to a certain extent. CONCLUSION: The diagnosis of Charcot neuroarthropathy of the knee is rare that requiring early diagnosis. The presence of features, including painlessness, numbness, and deformed arthropathy following chronic-onset algesthesia loss should be taken carefully.

The Protective Effect of Cordycepin On Alcohol-Induced Osteonecrosis of the Femoral Head.

BACKGROUND: Alcohol abuse is known to be a leading risk factor for atraumatic osteonecrosis of the femoral head (ONFH), in which the suppression of osteogenesis plays a critical role. Cordycepin benefits bone metabolism; however, there has been no study to determine its effect on osteonecrosis. METHODS: Human bone mesenchymal stem cells (hBMSCs) were identified by multi-lineage differentiation. Alkaline phosphatase (ALP) activity, RT-PCR, western blots, immunofluorescent assay and Alizarin red staining of BMSCs were evaluated. A rat model of alcohol-induced ONFH was established to investigate the protective role of cordycepin against ethanol. Hematoxylin & eosin (H&E) staining and micro-computerized tomography (micro-CT) were performed to observe ONFH. Apoptosis was assessed by TdT-mediated dUTP nick end labeling (TUNEL). Immunohistochemical staining was carried out to detect OCN and COL1. RESULTS: Ethanol significantly suppressed ALP activity, decreased gene expression of OCN and BMP2, lowered levels of RUNX2 protein, and reduced immunofluorescence staining of OCN and COL1 and calcium formation of hBMSCs. However, these inhibitory effects were attenuated by cordycepin co-treatment at concentrations of 1 and 10 µg/mL Moreover, it was revealed that the osteo-protective effect of cordycepin was associated with modulation of the Wnt/ß-catenin pathway. In vivo, by micro-CT, TUNEL and immunohistochemical staining of OCN and COL1, we found that cordycepin administration prevented alcohol-induced ONFH. CONCLUSION: Cordycepin treatment to enhance osteogenesis may be considered a potential therapeutic approach to prevent the development of alcohol-induced ONFH.

Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis.

BACKGROUND Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo. MATERIAL AND METHODS Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1ß (IL-1ß) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment. RESULTS Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1ß and PGE2 concentrations. CAPE injections reversed the increased IL-1ß and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections. CONCLUSIONS Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis.

Reverse Transfer of the Proximal Vascularized Fibula to Reconstruct the Lateral Malleolus: A Case Report and Literature Review.

Defects of the lateral malleolus and distal fibula occur occasionally, mainly because of severe trauma or wide resection of fibular neoplasms. These bony defects should be reconstructed to avoid persistent pain and to prevent an abnormal gait induced by ankle instability. Various methods of repair have been developed, including allografting, autologous iliac crest transplantation, scapular apophysis transplantation, and arthrodesis and prosthetic reconstruction. A reverse transfer of the proximal vascularized fibula is also effective. Its morphologic advantage is apparent, and the surgery is simple and direct, with no need for vascular anastomosis. We treated recurrent fibrous dysplasia in the distal fibula of a young male with wide resection and reconstruction using reverse transfer of the proximal, vascularized fibula. At the 6-year follow-up examination, the patient had an American Orthopaedic Foot and Ankle Society ankle-hindfoot score of 100, without any apparent complications. Additionally, we critically reviewed other methods for reconstructing the lateral malleolus and distal fibula and have concluded that reverse transfer of the proximal vascularized fibula compares favorably and could be the treatment of choice.

Comparison of Borate Bioactive Glass and Calcium Sulfate as Implants for the Local Delivery of Teicoplanin in the Treatment of Methicillin-Resistant Staphylococcus aureus-Induced Osteomyelitis in a Rabbit Model.

There is growing interest in biomaterials that can cure bone infection and also regenerate bone. In this study, two groups of implants composed of 10% (wt/wt) teicoplanin (TEC)-loaded borate bioactive glass (designated TBG) or calcium sulfate (TCS) were created and evaluated for their ability to release TEC in vitro and to cure methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in a rabbit model. When immersed in phosphate-buffered saline (PBS), both groups of implants provided a sustained release of TEC at a therapeutic level for up to 3 to 4 weeks while they were gradually degraded and converted to hydroxyapatite. The TBG implants showed a longer duration of TEC release and better retention of strength as a function of immersion time in PBS. Infected rabbit tibiae were treated by debridement, followed by implantation of TBG or TCS pellets or intravenous injection with TEC, or were left untreated. Evaluation at 6 weeks postimplantation showed that the animals implanted with TBG or TCS pellets had significantly lower radiological and histological scores, lower rates of MRSA-positive cultures, and lower bacterial loads than those preoperatively and those of animals treated intravenously. The level of bone regeneration was also higher in the defects treated with the TBG pellets. The results showed that local TEC delivery was more effective than intravenous administration for the treatment of MRSA-induced osteomyelitis. Borate glass has the advantages of better mechanical strength, more desirable kinetics of release of TEC, and a higher osteogenic capacity and thus could be an effective alternative to calcium sulfate for local delivery of TEC.

Calcification of joints and arteries: second report with novel NT5E mutations and expansion of the phenotype.

Calcification of joints and arteries (CALJA; MIM 211800) is an extremely rare mendelian disorder of isolated calcification that is characterized by late onset calcification of the extremity arteries and hand and foot joint capsules. Mutations of NT5E, encoding cluster of differentiation 73, have been implicated in CALJA. Here we report on a Chinese family with CALJA and novel compound heterozygous mutations (c.1360G>A (p.Gly454Arg) and c.1387C>T (p.Arg463X)) in NT5E. Our study represents the second report on patients with CALJA associated with NT5E mutations. The clinical features expand the previously reported phenotype of NT5E mutations. The propositus has calcification of the lower extremity arteries and hand and foot joint capsules similar to those previously reported patients. However, he also has calcification of the upper extremity arteries. By protein structural modeling, we found the mutation p.Gly454Arg may disrupt the folding of ß-pleated sheet and destabilize the protein structure. Our findings will provide clues to the phenotype-genotype relations and may assist not only in the clinical diagnosis but also in the interpretation of genetic information used for prenatal diagnosis and genetic counseling.

Lentivirus-mediated Wnt10b overexpression enhances fracture healing in a rat atrophic non-union model.

Lentivirus vectors encoding Wnt10b gene (LV-Wnt10b) or luciferase gene (LV-luc) were constructed to determine whether Wnt10b overexpression improved fracture healing in a rat atrophic non-union model. After fracture, rats were injected with LV-Wnt10b or LV-luc. Luciferase signals were clearly detected. At 2 and 4 weeks, LV-Wnt10b group had 107 and 98% more proliferating cell nuclear antigen (PCNA) positive cells, respectively, and promoted expression of bone morphogenetic protein-2 (BMP-2) in the callus compared with controls. LV-Wnt10b injection significantly increased bone mass density and bone mineral content: 46-84 and 96-193%, respectively, at the site of fracturein the LV-Wnt10b group compared with controls. At 8 weeks, fractured femora were healed in the LV-Wnt10b group compared with atrophic non-unions formed in controls. Thus, Wnt10b overexpression associated with lentiviral gene therapy is effective in healing atrophic non-unions in rats.

Transarticular fixation by hook plate versus coracoclavicular stabilization by single multistrand titanium cable for acute Rockwood grade-V acromioclavicular joint dislocation: a case-control study.

BACKGROUND: Hook plate (HP) is popularly used for acute and severely displaced acromioclavicular (AC) dislocations. However, subacromial impingement and acromion osteolysis induced by transarticular fixation are notorious. The current case-control study was to compare transarticular fixation by HP to coracoclavicular (CC) stabilization by single multistrand titanium cable (MSTC). METHODS: Between January 2006 and August 2009, 24 patients with acute AC dislocations were surgically treated by open reduction and transarticular fixation with HP. These patients were matched to a series of 24 patients, who were managed by CC stabilization with MSTC in the same period. All AC dislocations were graded as Rockwood type V. Implant was removed 8-12 months after the primary operation in all patients, and 12 months at least were needed to assess the maintenance of AC joint. Functional results were evaluated before implant removal as well as in the last follow-up based on Constant-Murley criteria. RESULTS: There were no differences of demographic data including age, dominant gender and side, injury-to-surgery interval, operation time and follow-up period. In terms of functionality, Constant score was 95.8 ± 4.1 in MSTC group, while 76.7 ± 8.0 in HP group before implant removal (P < 0.001). In detail, MSTC was superior to HP in pain, ROM and activities. Constant score was significantly improved to 86.1 ± 5.7 after hardware removal for patients in HP (P < 0.001). Degenerative change of acromioclavicular joint presented in 16 patients (66.7%) in patients treated by HP, while it was found in only 3 patients (12.5%) treated by MSTC (P < 0.001). CONCLUSIONS: MSTC is superior to HP for the treatment of Rockwood type-V acromioclavicular dislocation both before and after removal of the implant. Hardware removal is of great benefits for functional improvement in patients treated by HP.

Late surgery for acetabular fractures in a Chinese level I trauma centre: surgical experience and outcomes.

PURPOSE: Delayed surgical management of acetabular fractures, often necessary due to life-threatening concomitant injuries, is a great challenge because delays may potentially increase complications and decrease outcomes. We report clinical outcomes of 61 acetabular fractures treated by delayed open reduction and internal fixation (ORIF) with an injury-to-surgery interval (ISI) of 22-399 days. METHODS: Operations were performed between April 2001 and December 2008. There were 61 cases (42 men 19 women), with an average age of 38 years. All patients were followed for an average of 82 months. Demographic data, fracture pattern, ISI, concomitant injuries, surgical approach, complications and clinical outcomes were recorded and analysed. There were 16 simple fractures (26.2%) and 45 associated fractures (73.8%). Matta criteria were used to evaluate reduction quality. The Merle d'Aubigné and Postel scoring system was employed to assess post-operative functionality. RESULTS: Anatomical reduction was achieved in 45 cases (73.8%). The clinical result was excellent in 38 cases, good in 13, fair in six and poor in four. Osteonecrosis of the femoral head was observed in three cases, and heterotopic ossification was found in 28 cases. Four patients had transient palsy of the sciatic nerve. CONCLUSIONS: ORIF for fresh acetabular fractures might yield a better prognosis; however, for delayed acetabular fractures, clinical outcomes are also predictable when sophisticated surgical techniques are employed. Our results indicate that delayed ORIF could yield satisfactory clinical outcomes in the majority of patients with acetabular fractures.

Combined approaches for fixation of Schatzker type II tibial plateau fractures involving the posterolateral column: a prospective observational cohort study.

INTRODUCTION: This study aimed to investigate the surgical techniques and the clinical efficacy of combined approaches for the treatment of Schatzker type II tibial plateau fractures involving the posterolateral column [lateral and posterolateral columns (LPCs) fractures] in a prospective cohort. MATERIALS AND METHODS: From January 2007 through December 2010, a total of 65 patients with LPCs underwent dual-plate fixation via a combined anterior and posterior approach. The anterior and posterior approaches were the conventional anterolateral approach and a posteromedial inverted L-shaped approach, respectively, with the patients in a floating position. RESULTS: Ultimately, 41 patients were followed up for a mean period of 52.5 months. All fractures healed. The mean time to radiographic bony union was 15.2 weeks and the mean time to full weight-bearing was 18.7 weeks. No parameter associated with knee alignment changed significantly between immediately postoperation and 2 years postoperation. No collapse of the reduced articular surface was detected. Two years postoperation, the mean Hospital for Special Surgery score was 92.3; the mean Short Form-36 score was 90.1, and the mean range of knee motion was 1.7°-123.6° (extension-flexion). Two patients suffered dehiscence of the anterolateral incision and another suffered partial necrosis at the margin of the posteromedial incision postoperatively. All healed in response conservative treatment. Another two patients experienced numbness in the posteromedial inferior region of the calf. No implant loosening, breakage, fixation failure, or other complication was observed during follow-up. CONCLUSIONS: LPCs are not uncommon. Careful preoperative analysis of computed tomography images and impeccable preparation are necessary to avoid neglecting a posterolateral column fracture. It is inappropriate to generalize one scenario for all Schatzker type II fractures: a single approach cannot address all subtypes of these fractures. Dual-plate fixation via a combined approach is an effective treatment for LPCs.

Simultaneous bilateral fractures of the femoral neck caused by high energy: A case report and literature review.

Simultaneous bilateral fractures of the femoral neck are rare injuries, which are reportedly induced by low-speed energy with predisposing factors including systemic diseases, medications and eclamptic seizures. Those caused by high energy are even rarer. High energy-induced bilateral fractures of the femoral neck conceive of high incidence of mortality and present great challenges in the early management. We report one case of a 52-year-old man with simultaneous bilateral fractures of the femoral neck which resulted from a motor pedestrian accident. One-stage closed reduction and internal fixation was done following the emergent resuscitation and neurosurgical management for concomitant brain injuries. The fractures united. There was no pain in the hips, and they had a normal range of motion. The treatment protocol, mechanism of the injury and possible postoperative complications were discussed to expand a comprehensive understanding about these infrequent types of fractures.

Subtrochanteric femur fracture treated by intramedullary fixation.

PURPOSE: To discuss surgical technique, operative efficacy and clinical outcome of intramedullary fixation in the treatment of subtrochanteric femur fractures. METHODS: From February 2011 to February 2013, 76 cases of subtrochanteric femur fractures were treated by intramedullary fixation in our hospital, including 53 males and 23 females, with the age range of 37 -72 years (mean 53.5 years). According to Seinsheimer classification, there were 2 cases of type I, 7 type II, 15 type III, 23 type IV and 29 type V. Firstly, all patients underwent closed reduction with the guidance of C-arm fluoroscopy in a traction table. Two cases of type I and 3 cases of type III fractures had ideal closed reduction followed by internal fixation. The others needed additional limited open reduction. Radiographic examination was used to evaluate callus formation and fracture healing in postoperative 1, 3, 6 and 12 months follow-up. Functional recovery was evaluated by Harris Hip Scoring (HHS) system. RESULTS: Patients were followed up for 6-12 months. All fractures were healed except one patient with delayed union. The average bone union time was 4.5 months. According to HHS system, 65 cases were considered as excellent in functional recovery, 8 good, 2 fair and 1 poor. The proportion of the patients with excellent and good recovery was 96.05%. CONCLUSION: Intramedullary fixation is feasible for the treatment of subtrochanteric femur fracture. The accuracy of intraoperative reduction and surgical skill are important for the clinical outcome and the patients' prognosis.

Prognostic significance of VEGF expression in osteosarcoma: a meta-analysis.

Vascular endothelial growth factor (VEGF) is considered as a prime mediator of angiogenesis and has been implicated in carcinogenesis and metastasis. Various studies examined the relationship between VEGF overexpression with the clinical outcome in patients with osteosarcoma but yielded conflicting results. Electronic databases updated to April 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between VEGF overexpression and survival of patients with osteosarcoma. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of eight studies that evaluated the correlation between VEGF overexpression and survival in patients with osteosarcoma. Combined hazard ratios suggested that VEGF overexpression had an unfavorable impact on overall survival (hazard ratio (HR) = 1.75, 95% confidence interval (CI): 1.21-2.28) in patients with osteosarcoma for overall populations, 2.37 (1.35-3.39) in Asian studies but not in non-Asian studies (HR = 1.51, 95% CI: 0.89-2.14). No significant heterogeneity was observed among all studies. VEGF overexpression indicates a poor prognosis for patients with osteosarcoma. However, the prognostic value of VEGF on survival in osteosarcoma patients still needs further large-scale prospective trials to be clarified.

Biomechanical study of modular hemipelvic endoprosthesis for Type I-IV defect of pelvic tumor.

BACKGROUND: The modular hemipelvic prosthesis has been used in patient of Type I-IV pelvic tumor with good outcomes, but how to keep the stability between the prosthesis and the residual sacrum is a problem. An additional screw-rod system seems to solve it, but its biomechanical characters are still not well understood, which need experimental evaluation. METHODS: Six pelvic specimens were prepared in three conditions (normal intact pelvis, "normal"; the pelvis of left Type I-IV defect and implanted with prosthesis without/with additional screw-rod system, "rod-" and "rod+"). Compressing biomechanical experiments (50-500N) were performed in these three conditions, respectively. RESULTS: The loadings during the experiments are in accordance with the linear elastic control mode. Under the increasing loading, the implanted pelvises displaced asymmetrically, unlike normal intact pelvis. The vertical displacement of "rod+" changed significantly, whereas "rod-" did not. For both implanted pelvis, right side displaced less than left side (P values <0.05). CONCLUSIONS: The implanted pelvis showed asymmetric displacement under loading, where healthy side displaced more. The implanted pelvis plus screw-rod system showed less displacement at implanted side but more at contralateral side in comparison with those without screw-rod system.

Possibility of the hamatum carpometacarpal joint as a new joint donor site for interphalangeal joint restoration.

OBJECTIVE: This research investigates the anatomic basis for the repair and reconstruction of hand joints using transposition of the carpometacarpal (CMC) joint of the hamatum. METHODS: The morphology and structure of the CMC joints of the hamatum and the base joints of the middle phalanx were observed on 22 freshly frozen wrist specimens at Shanghai 6th People's Hospital Research Institute of Microsurgery. The volar dorsal dia, radioulnar dia, depth of concave, and area of the joints were measured. Data were obtained through statistical analysis, and the resemblance of joints was compared in terms of morphology, structure, area, length, and diameter. RESULTS: The radioulnar dia of the CMC joints of the hamatum (13.54 ± 1.15 mm) did not exhibit any evident differences in the middle phalanx of the forefinger, middle finger, and ring finger, and in the distal phalanx of the thumb. The volar dorsal dia of the CMC joints of the hamatum (10.71 ± 0.93 mm) exhibited an evident difference in the middle phalanx of the ring finger. In all fingers, the depth of the ulnar and radial concave of the CMC joints of the hamatum (1.30 ± 0.08 and 0.95 ± 0.05 mm, respectively) and the area of the CMC joints of the hamatum (139.89 ± 5.44 mm(2)) showed an evident difference. CONCLUSION: The CMC joint of the hamatum could be considered a new and viable joint donor site that could be used to repair and reconstruct the base joints of the middle phalanx.

Single-cell multi-omics identify novel regulators required for osteoclastogenesis during aging.

Age-related osteoporosis manifests as a complex pathology that disrupts bone homeostasis and elevates fracture risk, yet the mechanisms facilitating age-related shifts in bone marrow macrophages/osteoclasts (BMMs/OCs) lineage are not fully understood. To decipher these mechanisms, we conducted an investigation into the determinants controlling BMMs/OCs differentiation. We performed single-cell multi-omics profiling on bone marrow samples from mice of different ages (1, 6, and 20 months) to gain a holistic understanding of cellular changes across time. Our analysis revealed that aging significantly instigates OC differentiation. Importantly, we identified Cebpd as a vital gene for osteoclastogenesis and bone resorption during the aging process. Counterbalancing the effects of Cebpd, we found Irf8, Sox4, and Klf4 to play crucial roles. By thoroughly examining the cellular dynamics underpinning bone aging, our study unveils novel insights into the mechanisms of age-related osteoporosis and presents potential therapeutic targets for future exploration.

Edaravone, a novel free radical scavenger, prevents steroid-induced osteonecrosis in rabbits.

OBJECTIVE: To investigate the efficacy of edaravone, a novel free radical scavenger, on preventing steroid-induced osteonecrosis (ON) in a rabbit model. METHODS: Thirty-six New Zealand white rabbits were divided into control (C; n = 6), steroid-administered (S; n = 15) and edaravone-administered groups (E; n = 15) after receiving an established protocol of steroid-induced ON. Before and after steroid administration, plasma levels of reduced glutathione (GSH) and lipid peroxidation (LPO) were measured for oxidative stress. Two weeks later bilateral proximal femurs were dissected for micro-CT-based micro-angiography, and the presence or absence of ON and intravascular thrombi were examined histopathologically. Immunohistochemical examination of oxidative injury in bone tissue was conducted using the anti-8-hydoxy-2'-deoxyguanosine and anti-malondialdehyde mAbs. RESULTS: The incidence of ON in the E group (20%) was significantly lower than in the S group (73%). Three to five days after steroid administration, the plasma GSH level was significantly higher and LPO level was significantly lower in the E group than the S group. Compared with the S group, there were significantly more small-sized perfusion vessels and fewer large-sized dilated vessels in the E group. Thrombosis incidence was significantly lower in the E group than the S group. Intraosseous vessels and haematopoietic cells that sustained oxidative injury were significantly fewer in the E group than the S group. CONCLUSION: Edaravone exerted beneficial effects on reducing incidence of steroid-induced ON by suppressing the accumulation of lipid peroxidative products and oxidative DNA damage in endothelial cells and haematopoietic cells.

A novel rat model of osteonecrosis of the femoral head induced by periarticular injection of vascular endothelial growth factor receptor 2 antibody.

BACKGROUND: Traditional methods to establish animal model of osteonecrosis of the femoral head (ONFH) are not satisfactory because of the undefined underlying mechanism, low rate of the disease, and high incidence of mortality. The present study was to induce ONFH in a rat model through periarticular injection of vascular endothelial growth factor (VEGF) receptor 2 antibody. MATERIALS AND METHODS: Eighty Sprague-Dawley rats were divided into four groups randomly and equally. VEGF receptor 2 antibody solution with a concentration of 50 µg/mL (group A), 25 µg/mL (group B), and 12.5 µg/mL (group C) was injected periarticularly to the capsular attachment to proximal femur, respectively. The injection lasted 4 continuous days, with a total volume of 2 mL. The rats in the fourth group were treated by saline for control (group D). Two weeks after the first injection, histologic and micro-computed tomographic examinations were used to investigate the presence of ONFH. RESULTS: Histologically, there were 90% of rats that developed ONFH in group A, 60% in group B, and 20% in group C, whereas no ONFH was found in group D. The density of intraosseous vessels was suppressed significantly by the antibody. Radiologically, the features of ONFH including deformation of the femoral head were revealed. There was no occurrence of lethal complications. CONCLUSIONS: VEGF receptor 2 antibody can induce ONFH in the rat with a high incidence of the disease. Local blockage of angiogenesis can be used as an effective method to establish animal model of ONFH.

Osteogenic induction protects rat bone marrow-derived mesenchymal stem cells against hypoxia-induced apoptosis in vitro.

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BMSCs) undergo hypoxia-induced apoptosis when cells are transplanted from a normoxic to a hypoxic microenvironment in vivo. The effect of the osteogenic microenvironment on BMSCs under hypoxic conditions has not yet been revealed. MATERIALS AND METHODS: In the current study, we investigated the effects on BMSCs of hypoxia and osteogenic induction (OI) individually and in combination. We isolated BMSCs from rat bone marrow and confirmed them by recognition of surface antigens using cytometry. After passaging the BMSCs to the third generation, we treated them with the following conditions: 1% oxygen and OI, normoxia and OI, and 1% oxygen without OI; normoxia without OI was the control condition. On days 3, 7, 14, and 21, we detected the expression levels of hypoxia inducible factor-1α and alkaline phosphate via Western blotting. Cellular apoptosis was detected by Hoechst staining and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine, 5'-triphosphate nick end labeling; caspase activity was also detected. RESULTS: The expression of hypoxia inducible factor-1α was induced and up-regulated when BMSCs were grown under 1% oxygen. The incidence of terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine, 5'-triphosphatenick end labeling-positive cells in the hypoxia plus OI group was much lower than that in the hypoxia group without OI. Caspase activity increased on days 3, 7, 14, and 21. The absolute value of caspase was statistically higher in the BMSC hypoxia group than in the other three groups, whose values were similar to each other. CONCLUSIONS: Osteogenic induction could protect BMSCs against hypoxia-induced apoptosis. Bone marrow-derived mesenchymal stem cells may be appropriate candidate cells for cytotherapy for skeletal diseases.