Femoral Head Bone Research Articles

Avascular Necrosis of Femoral Head: A Retrospective Study of MRI Scan in A Orthopedic Hospital

Background : Avascular necrosis (AVN), also known as osteonecrosis of femoral head is a pathology in which many etiologies play role and cause decreased vascular supply to subchondral bone of femoral head which results in osteocyte death. MRI is the most sensitive modality for detection of AVN and is helpful for screening and detecting at early stage. Purpose: The aim of the study was to determine the prevalence pattern and stages of presentation of Avascular Necrosis (AVN) of the femoral head. Materials and Methods: This was a retrospective study carried out at the department of Radiology & Imaging, National Institute of Traumatology & Orthopedic Rehabilitation (NITOR), Dhaka where MRI of the hip joint was performed during our study period, only those patients which showed positive signs for avascular necrosis of femoral head were included and were analysed over a period of five years. The age, sex, laterally distribution, causative factors, staging according to Ficat and Arlet classification was done. Results: It was found that most commonly males of productive age group (21 to 40 years) were affected. Though most of them had unilateral involvement however number of bilateral cases were also significant. Mostly, patient presented with stage-IV disease accounting for 104 out of 152 patients (68.42%). Conclusion: Considering that the young males were commonly affected and presented with advanced stage disease at the time of diagnosis, it was recommended that screening MRI should be done in all patients presenting with hip complaints. Sir Salimullah Med Coll J 2022; 30: 180-185

The therapeutic effect of adipose-derived lipoaspirate cells in femoral head necrosis by improving angiogenesis.

Femoral head necrosis (FHN), one of the most popular joint diseases in the musculoskeletal system, is usually attributed to local ischemia of the femoral head. Thus, regenerating the vascularization capacity and restoring the local perfusion of the femoral head becomes an efficient therapeutic approach for FHN. We investigated the function of autologous lipoaspirate cells (LPCs) in regenerating circulation in FHN animal models and human subjects in this study. We also explored the mechanisms of why LPCs show a superior effect than that of the bone marrow-derived stem cells (BMSCs) in vascularization. Thirty-four FHN patients were recruited for the randomized clinical trial. Harris Hip Score (HHS) and digital subtraction arteriography (DSA) and interventional technique were used to compare the efficacy of LPCs treatment and vehicle therapy in improving femoral head circulation and hip joint function. Cellular mechanism that underlies the beneficial effect of LPCs in restoring blood supply and rescuing bone architecture was further explored using canine and mouse FHN animal models. We found that LPCs perfusion through the medial circumflex artery will promote the femoral head vascularization and bone structure significantly in both FHN patients and animal models. The HHS in LPCs treated patients was significantly improved relative to vehicle group. The levels of angiogenesis factor secreted by LPCs such as VEGF, FGF2, VEC, TGF-β, were significantly higher than that of BMSCs. As the result, LPCs showed a better effect in promoting the tube structure formation of human vascular endothelial cells (HUVEC) than that of BMSCs. Moreover, LPCs contains a unique CD44+CD34+CD31- population. The CD44+CD34+CD31- LPCs showed significantly higher angiogenesis potential as compared to that of BMSCs. Taken together, our results show that LPCs possess a superior vascularization capacity in both autonomous and paracrine manner, indicating that autologous LPCs perfusion via the medial circumflex artery is an effective therapy for FHN.

Protective effect of Kaempferol on endothelial cell injury in glucocorticoid induced osteonecrosis of the femoral head

To explore the effect of Kaempferol on bone microvascular endothelial cells (BMECs) in glucocorticoid induced osteonecrosis of the femoral head (GIONFH) in vitro. BMECs were isolated from cancellous bone of femoral head or femoral neck donated voluntarily by patients with femoral neck fracture. BMECs were identified by von Willebrand factor and CD31 immunofluorescence staining and tube formation assay. The cell counting kit 8 (CCK-8) assay was used to screen the optimal concentration and the time point of dexamethasone (Dex) to inhibit the cell activity and the optimal concentration of Kaempferol to improve the inhibition of Dex. Then the BMECs were divided into 4 groups, namely, the cell group (group A), the cells treated with optimal concentration of Dex group (group B), the cells treated with optimal concentration of Dex+1 μmol/L Kaempferol group (group C), and the cells treated with optimal concentration of Dex+5 μmol/L Kaempferol group (group D). EdU assay, in vitro tube formation assay, TUNEL staining assay, Annexin Ⅴ/propidium iodide (PI) staining assay, Transwell migration assay, scratch healing assay, and Western blot assay were used to detect the effect of Kaempferol on the proliferation, tube formation, apoptosis, migration, and protein expression of BMECs treated with Dex. The cultured cells were identified as BMECs. CCK-8 assay showed that the optimal concentration and the time point of Dex to inhibit cell activity was 300 μmol/L for 24 hours, and the optimal concentration of Kaempferol to improve the inhibitory activity of Dex was 1 μmol/L. EdU and tube formation assays showed that the cell proliferation rate, tube length, and number of branch points were significantly lower in groups B-D than in group A, and in groups B and D than in group C ( P<0.05). TUNEL and Annexin V/PI staining assays showed that the rates of TUNEL positive cells and apoptotic cells were significantly higher in groups B-D than in group A, and in groups B and D than in group C ( P<0.05). Scratch healing assay and Transwell migration assay showed that the scratch healing rate and the number of migration cells were significantly lower in groups B-D than in group A, and in groups B and D than in group C ( P<0.05). Western blot assay demonstrated that the relative expressions of Cleaved Caspase-3 and Bax proteins were significantly higher in groups B-D than in group A, and in groups B and D than in group C ( P<0.05); the relative expressions of matrix metalloproteinase 2, Cyclin D1, Cyclin E1, VEGFA, and Bcl2 proteins were significantly lower in groups B-D than in group A, and in groups B and D than in group C ( P<0.05). Kaempferol can alleviate the damage and dysfunction of BMECs in GIONFH.

The analysis of Modified Qing' E Formula on the differential expression of exosomal miRNAs in the femoral head bone tissue of mice with steroid-induced ischemic necrosis of femoral head.

ObjectiveTo investigate the differential expression of exosomal miRNAs in the bone marrow tissue of Modified Qing’ E Formula (MQEF) on steroid-induced ischemic necrosis of the femoral head (INFH) model.MethodsSteroid hormones were used to establish the INFH model and treated with MQEF. After successful modeling, femoral tissue exosomes were isolated for miRNA sequencing to obtain femoral tissue exosomal differential miRNAs. By GO analysis and KEGG analysis of the differential genes in both groups, the major exosomal miRNAs of MQEF exerting anti-INFH as well as the major signaling pathways were identified. Next, a quantitative metabolomic validation of MQEF with broad targeting was performed to obtain the main active components of MQEF and to perform biological analysis and signaling pathway prediction of the active components by network pharmacology. Finally, the sequencing results were validated by using RT-qPCR. The results of miRNA sequencing were verified by double examination of network pharmacology and RT-qPCR, and the exosomal miRNAs regulated by the anti-INFH effect of MQEF and the specific signaling pathway of the effect were clarified.ResultsA total of 65,389 target genes were predicted in the exosomes of two groups of mice, and 18 significant differentially expressed miRNAs were obtained, of which 14 were up-regulated and 4 down-regulated. GO enrichment analysis showed that these predicted target genes were enriched in 12371 biological processes, 1727 cell components, and 4112 molecular functions. KEGG analysis showed that the predicted miRNA target genes were annotated to 342 signal pathways, in which the highly enriched pathways closely related to bone metabolism were PI3K-Akt signal pathway, MAPK signal pathway, and Wnt signal pathway. The most significantly up-regulated miRNAs were miR-185-3p and miR-1b-5p and the most significantly down-regulated miRNAs were miR-129b-5p and miR-223-5p, of which the targeted genes were closely related to the PI3K-Akt signal pathway. MQEF aqueous decoction extract targeted metabolomics quantitatively combined with network pharmacology predicted targets also closely related to PI3K-Akt signaling pathway. Real-time quantitative PCR validation showed that miR-185-3p was up-regulated 7.2-fold and miR-129b-5p was down-regulated 2.2-fold in the treatment group, and the difference was significant (P < 0.05).ConclusionsMQEF can regulate exosomal miRNA expression in steroid-induced INFH models, miR-185-3p or miR-129b-5p/PI3K-Akt signal axis may be part of the mechanism of MQEF against steroid-induced INFH.

Radiographic and clinical outcome of tibial plateau fractures treated with bone allograft

BackgroundTo determine the clinical outcome of patients who had been treated with bone allografts during open reduction and internal fixation (ORIF) of tibial head fractures.MethodsPatients who suffered a medial, lateral, or bicondylar fracture of the tibial plateau and underwent surgical treatment by open reduction and internal fixation (ORIF) using human femoral head bone allografts were included. Patients were invited to provide information for the following: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EuroQol Five Dimension score (EQ-5D), Lower Extremity Functional Scale (LEFS) and Parker Mobility Score. Bone mineral density (BMD) of the allograft area and the healthy human bone tissue were measured by quantitative computed tomography.ResultsA total of 22 patients with a mean follow-up time of 2.88 ± 2.46 years were included in our study. The most common fractures observed in this study were classified as Schatzker II (11 patients, 50.0%) or AO/OTA 41.B3 (12 patients, 54.5%) fractures. Postoperative WOMAC total was 13.0 (IQR = 16.3, range 0–33). Median quality of life (EQ-5D) score was 0.887 ± 0.121 (range 0.361–1.000). Median Lower Extremity Functional Scale (LEFS) score was 57.5 ± 19.0 (range 33–79). Mean Parker Mobility Score was 9 (range 6–9). Median bone mineral density (BMD) for the whole group was 300.04 ± 226.02 mg/cm3 (range − 88.68 to 555.06 mg/cm3) for region of interest (ROI 5) (central), 214.80 ± 167.45 mg/cm3 (range − 7.16 to 597.21 mg/cm3) for ROI 1–4 (marginal zones: medial, lateral, ventral, dorsal) and 168.14 ± 65.54 mg/cm3 (range 17.47–208.97 mg/cm3) for healthy bone tissue (femur and tibia).ConclusionBased on WOMAC scores, LEFS, ambulatory status, and quality of life findings, it can be concluded that following tibial head ORIF with allograft bone patients has promising results.

Spatial links between subchondral bone architectural features and cartilage degeneration in osteoarthritic joints

Early diagnosis of osteoarthritis (OA), before the onset of irreversible changes is crucial for understanding the disease process and identifying potential disease-modifying treatments from the earliest stage. OA is a whole joint disease and affects both cartilage and the underlying subchondral bone. However, spatial relationships between cartilage lesion severity (CLS) and microstructural changes in subchondral plate and trabecular bone remain elusive. Herein, we collected femoral heads from hip arthroplasty for primary osteoarthritis (n = 7) and femoral neck fracture (n = 6; non-OA controls) cases. Samples were regionally assessed for cartilage lesions by visual inspection using Outerbridge classification and entire femoral heads were micro-CT scanned. Scans of each femoral head were divided into 4 quadrants followed by morphometric analysis of subchondral plate and trabecular bone in each quadrant. Principal component analysis (PCA), a data reduction method, was employed to assess differences between OA and non-OA samples, and spatial relationship between CLS and subchondral bone changes. Mapping of the trabecular bone microstructure in OA patients with low CLS revealed trabecular organisation resembling non-OA patients, whereas clear differences were identifiable in subchondral plate architecture. The OA-related changes in subchondral plate architecture were summarised in the first principle component (PC1) which correlated with CLS in all quadrants, whilst by comparison such associations in trabecular bone were most prominent in the higher weight-bearing regions of the femoral head. Greater articular cartilage deterioration in OA was regionally-linked with lower BV/TV, TMD and thickness, and greater BS/BV and porosity in the subchondral plate; and with thinner, less separated trabeculae with greater TMD and BS/BV in the trabecular bone. Our findings suggest that impairment of subchondral bone microstructure in early stage of OA is more readily discernible in the cortical plate and that morphological characterisation of the femoral head bone microstructure may allow for earlier OA diagnosis and monitoring of progression.

Effect of verapamil on bone mass, microstructure and mechanical properties in type 2 diabetes mellitus rats

BackgroundVerapamil was mainly used to treat hypertension, cardiovascular disease, inflammation and improve blood glucose in patients with diabetes, but its effects on bone mass, microstructure and mechanical properties were unclear. This study described the effects of verapamil on bone mass, microstructure, macro and nano mechanical properties in type 2 diabetic rats.MethodsRat models of type 2 diabetes were treated with verapamil at doses of 4, 12, 24 and 48 mg/kg/day by gavage respectively, twice a day. After 12 weeks, all rats were sacrificed under general anesthesia. Blood glucose, blood lipid, renal function and biochemical markers of bone metabolism were obtained by serum analysis, Micro-CT scanning was used to assess the microstructure parameters of cancellous bone of femoral head, three-point bending test was used to measure maximum load and elastic modulus of femoral shaft, and nano-indentation tests were used to measure indentation moduli and hardnesses of longitudinal cortical bone in femoral shaft, longitudinal and transverse cancellous bones in femoral head.ResultsCompared with T2DM group, transverse indentation moduli of cancellous bones in VER 24 group, longitudinal and transverse indentation moduli and hardnesses of cancellous bones in VER 48 group were significantly increased (p < 0.05). Furthermore, the effects of verapamil on blood glucoses, microstructures and mechanical properties in type 2 diabetic rats were dependent on drug dose. Starting from verapamil dose of 12 mg/kg/day, with dose increasing, the concentrations of P1NP, BMD, BV/TV, Tb. Th, Tb. N, maximum loads, elastic moduli, indentation moduli and hardnesses of femurs in rats in treatment group increased gradually, the concentrations of CTX-1 decreased gradually, but these parameters did not return to the level of the corresponding parameters of normal rats. Verapamil (48 mg/kg/day) had the best therapeutic effect.ConclusionVerapamil treatment (24, 48 mg/kg/day) significantly affected nano mechanical properties of the femurs, and tended to improve bone microstructures and macro mechanical properties of the femurs, which provided guidance for the selection of verapamil dose in the treatment of type 2 diabetic patients.

A new bone adhesive candidate- does it work in human bone? An ex-vivo preclinical evaluation in fresh human osteoporotic femoral head bone

IntroductionThe fixation of small intraarticular bone fragments is clinically challenging and an obvious first orthopaedic indication for an effective bone adhesive. In the present study the feasibility of bonding freshly harvested human trabecular bone with OsSticR, a novel phosphoserine modified cement, was evaluated using a bone cylinder model pull-out test and compared with a commercial fibrin tissue adhesive. MethodsFemoral heads (n=13) were collected from hip fracture patients undergoing arthroplasty and stored refrigerated overnight in saline medium prior to testing. Cylindrical bone cores with a pre-inserted bone screw, were prepared using a coring tool. Each core was removed and glued back in place with either the bone adhesive (α-tricalcium phosphate, phosphoserine and 20% trisodium citrate solution) or the fibrin glue. All glued bones were stored in bone medium at 37°C. Tensile loading, using a universal testing machine (5 kN load cell), was applied to each core/head. For the bone adhesive, bone cores were tested at 2 (n=13) and 24 (n=11) hours. For the fibrin tissue adhesive control group (n=9), bone cores were tested exclusively at 2 hours. The femoral bone quality was evaluated with micro-CT. ResultsThe ultimate pull-out load for the bone adhesive at 2 hours ranged from 36 to 171 N (mean 94 N, SD 42 N). At 24 hours the pull-out strength was similar, 47 to 198 N (mean 123 N, SD 43 N). The adhesive failure usually occurred through the adhesive layer, however in two samples, at 167 N and 198 N the screw pulled out of the bone core. The fibrin tissue adhesive group reached a peak force of 8 N maximally at 2 hours (range 2.8-8 N, mean 5.4 N, SD 1.6 N). The mean BV/TV for femoral heads was 0.15 and indicates poor bone quality. ConclusionThe bone adhesive successfully glued wet and fatty tissue of osteoporotic human bone cores. The mean ultimate pull-out force of 123 N at 24 hours corresponds to ∼ 300 kPa shear stress acting on the bone core. These first ex-vivo results in human bone are a promising step toward potential clinical application in osteochondral fragment fixation.

Three-dimensional deep neural network for automatic delineation of cervical cancer in planning computed tomography images.

PurposeRadiation therapy is an essential treatment modality for cervical cancer, while accurate and efficient segmentation methods are needed to improve the workflow. In this study, a three‐dimensional V‐net model is proposed to automatically segment clinical target volume (CTV) and organs at risk (OARs), and to provide prospective guidance for low lose area.Material and methodsA total of 130 CT datasets were included. Ninety cases were randomly selected as the training data, with 10 cases used as the validation data, and the remaining 30 cases as testing data. The V‐net model was implemented with Tensorflow package to segment the CTV and OARs, as well as regions of 5 Gy, 10 Gy, 15 Gy, and 20 Gy isodose lines covered. The auto‐segmentation by V‐net was compared to auto‐segmentation by U‐net. Four representative parameters were calculated to evaluate the accuracy of the delineation, including Dice similarity coefficients (DSC), Jaccard index (JI), average surface distance (ASD), and Hausdorff distance (HD).ResultsThe V‐net and U‐net achieved the average DSC value for CTV of 0.85 and 0.83, average JI values of 0.77 and 0.75, average ASD values of 2.58 and 2.26, average HD of 11.2 and 10.08, respectively. As for the OARs, the performance of the V‐net model in the colon was significantly better than the U‐net model (p = 0.046), and the performance in the kidney, bladder, femoral head, and pelvic bones were comparable to the U‐net model. For prediction of low‐dose areas, the average DSC of the patients’ 5 Gy dose area in the test set were 0.88 and 0.83, for V‐net and U‐net, respectively.ConclusionsIt is feasible to use the V‐Net model to automatically segment cervical cancer CTV and OARs to achieve a more efficient radiotherapy workflow. In the delineation of most target areas and OARs, the performance of V‐net is better than U‐net. It also offers advantages with its feature of predicting the low‐dose area prospectively before radiation therapy (RT).

The Hasselback technique: quick and easy preparation of femoral head bone graft for impaction.

The Hasselback technique: quick and easy preparation of femoral head bone graft for impaction.

Ankle-Hindfoot Reconstruction by Tibiotalocalcaneal (TTC) Arthrodesis Using Multiple Cannulated Screws: 32 Cases

Category:Ankle; Ankle ArthritisIntroduction/Purpose:Tibiotalocalcaneal (TTC) arthrodesis is a salvage procedure that can be used as an alternative to amputation for various pathologic conditions of the ankle-hindfoot. The aim of this study is to evaluate the clinical-radiological outcome of TTC arthrodesis performed using the multiple cannulated screws.Methods:From 2003 to 2018, 32 ankles (31 patients) underwent TTC arthrodesis. The mean follow-up period was mean 32.5 (12-92) months and the average patient age at surgery was 59.6 years (43-75). The etiologies of TTC arthrodesis included posttraumatic osteoarthritis (18.8%), Charcot arthropathy (18.8%), paralytic deformity (21.9%), failure of total ankle arthroplasty (9.4%), and failure of arthrodesis (9.4%). For all of 32 cases, transfibular approach was used with or without auto fibular cancellous bone graft. 7.3mm cannulated screws were used for fixation of arthodesis for all of 32 cases, and in 23 of 32 cases (71.9%), screw- fixation was used exclusively without any additional plate or Ilizarov fixator. Especially for 11 of 32 cases with large bony defect, fresh-frozen allo-femoral head structural bone graft was used. Pre- and postoperative visual analog scale (VAS) pain, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot functional score, and radiographs including CT images were assessed.Results:Overall union rate was 81.3% (26/32). Mean VAS score decreased from 6.92 preoperatively to 1.46 postoperatively and the AOFAS score improved from 27.0 to 53.7 (Max=68) at the final follow-up. Complication of TTC arthrodesis included nonunion (18.8%, 6/32), infection (12.5%, 4/32), and one case of skin necrosis. Most frequent nonunion site was tibiotalar joint (6/32). For 3 of 7 cases with nonunion, patients were painless and could ambulate without severe functional impairment. There were two cases with infective nonunion and one case with active Charcot arthropathy after artrhdesis. Union rate of two groups with/without allo-femoral head bone graft were similar to each other (81.8%, 81.0%, respectively), however, final AOFAS scores were significantly superior in 'without' femoral head bone graft group.Conclusion:This study achieved a fusion rate comparable to other previous studies and obtained favorable clinical outcomes. Realignment TTC arthrodesis using multiple cannulated screws is a valid surgical option as a salvage procedure for various deformed or arthritic conditions of ankle-hindfoot. Allo-femoral head structural bone graft can be selected as useful option for TTC arthrodesis with large bone defect.

Destructive Arthropathy of the Femoral Head

Destructive arthropathy of the hip refers to noninfectious arthropathy causing extensive femoral head bone destruction. It has been described in the surgical literature using a variety of diagnostic criteria, but it remains a poorly defined entity. Cases of destructive arthropathy diagnosed at our institution between July 1, 2015, and December 31, 2019, were identified by a free text search of the radiology database. The medical record of each case was reviewed for possible causes of femoral head destruction, clinical presentation, laboratory values, imaging studies, and pathologic diagnoses. Imaging studies and pathology specimens were retrospectively reviewed. Twenty femoral heads were identified in which there was 25% or greater destruction of the femoral head in the absence of infections, congenital disease, or inflammatory arthritis. Destructive arthropathy was characterized pathologically by fibromyxoid change of the marrow, aggregates of necrotic bone fragments, increased numbers of osteoclasts, increased trabecular destruction, and granuloma-like aggregates. The histologic findings were distinctive. We postulate that a variety of preexisting conditions set in motion a cascade of tissue factors that led to bone destruction.

Treatment of intertrochanteric nonunion after sliding hip screw fixation with a short cephalomedullary nail.

Intertrochanteric femur fracture nonunions are a rare complication that can be difficult to treat with limited evidence regarding treatment options. Revision fixation is typically reserved for well-aligned nonunions with sufficient femoral head bone stock. The most common implant used for revision fixation is a sliding hip screw implant. The use of a short cephalomedullary nail (CMN) for revision fixation has not been previously reported. This article presents a technique for reamed short CMN revision fixation of well-aligned nonunions with sufficient bone stock that is a simpler and potentially less morbid treatment option compared to open procedures with fixed-angle devices. For nonunions with poor femoral head bone stock and/or malaligned fractures, a fixed-angle implant, with or without a valgus osteotomy, may be necessary, while arthroplasty is reserved for nonunions with poor proximal femur bone stock that are not amenable to fixed-angle implant fixation.

Evaluation of femoral head bone quality by Hounsfield units: a comparison with dual-energy X-ray absorptiometry.

Osteoporosis is associated with decreases in bone mineral density (BMD) and is diagnosed using dual-energy X-ray absorptiometry (DXA). Computed tomography (CT), performed in routine practice, can also be used to evaluate bone quality without additional cost. To determine whether Hounsfield units (HU), a standardized CT attenuation coefficient, measured from the femoral head correlated with DXA-measured BMD. We evaluated 82 patients (14 men, 68 women; mean age, 67 years) undergoing femoral DXA and CT (non-enhanced abdominopelvic and hip scans) with 130 kV to determine whether HU correlated with T-scores. HU were measured by two radiologists using the largest spherical region of interest including the medullary bone of the femoral head from the junction point of the most caudal section of the femoral head with the femoral neck in 5-mm axial sections. The correlations of both sides' HU values with their ages and DXA femur T-score were evaluated. HU values obtained from both femoral heads showed significant variation between the osteoporotic and non-osteoporotic groups (both P = 0.000) and strongly correlated with each other and DXA femur T-scores (left r = 0.75, right r = 0.73, respectively). In ROC curve analysis, predictive power of left HU values in identifying patients with osteoporotic femur DXA T-score was 0.905, and for right HU values it was 0.924. Osteoporosis cutoff values were 198 HU and 204 HU for the left and right hips, respectively. HU obtained from CT performed in routine practice correlated with the DXA scores, thus providing an alternative method to determine regional bone quality without additional cost. This may be useful when choosing a fixation method, especially in trauma cases with already-performed abdominopelvic or pelvic CT in emergency services.

Clinical study on minimally invasive treatment of femoral head necrosis with two different bone graft materials.

To investigate the clinical efficacy and safety of two different bone graft materials in the minimally invasive treatment of early and middle stage femoral head necrosis. A total of 36 patients (39 hips) with avascular necrosis of the femoral head were divided into autologous iliac bone group (ABG) and bioceramics bone group (BBG). Both groups were treated with minimally invasive thick channel decompression to remove dead bone of femoral head. The ABG was treated with autologous iliac bone graft, and BBG was treated with β-tricalcium phosphate bone graft. The operation time, intra-operative blood loss, haemoglobin, and haematocrit were recorded at three and seven days post-operatively. The clinical efficacy and safety were evaluated by Harris score and imaging examination before, and after treatment and at follow-up stages. The patients were followed up for 24 to 45 (average 29.27 ± 3.56) months. The BBG was significantly better than the ABG in terms of operation time, intra-operative blood loss, haemoglobin, and haematocrit value at three days. Compared with pre-operative, theHarris score of the two groups at 12months after operation was significantly improved. The Harris score and the imaging evaluation of the last follow-up exhibited significantly better outcome in BBG than those of ABG. Bioceramics and autologous iliac bone minimally invasive treatment of early and medium-term femoral head necrosis exhibited satisfactory clinical efficacy in the short and medium-term. The bioceramics graft materials have the advantages of reducing trauma, bleeding, operation time, and quick recovery of post-operative functions.

Comparative analysis and study on the rehabilitation of cruciate ligaments before and after treatment with nano-biomaterials

This paper uses porous silicon carbide as a stent, and applies chemical vapour deposition technology to prepare a new type of porous tantalum metal material and conduct preliminary biological evaluation. An experimental study on the repair of anterior and posterior cruciate ligament composite of porous tantalum metal material is carried out, and it is used in clinical practice. To treat patients with anterior cruciate ligament injury, comprehensively evaluate the biological characteristics of new porous tantalum metal and its clinical effect in the treatment of anteroposterior cruciate ligament injury, and apply a new porous tantalum rod combined with anterior cruciate ligament combined with vascular pedicle iliac flap transfer. Young and strong patients with anterior and posterior cruciate ligament injury were treated with ligament-preserving surgery. Under the condition that it was clear that bone marrow stromal cells had a bone-promoting effect, and porous tantalum metal rods could induce bone growth and biomechanical support, and vascularised iliac bone flap metastasis was studied. Young and middle-aged patients with anterior and posterior cruciate ligament injuries were treated with satisfactory results. The research results found that a new porous tantalum rod combined with anterior and posterior cruciate ligament combined with vascular pedicle iliac flap transfer effectively removed the femoral head. Internal necrosis bone promotes the new femoral head bone regeneration and provides a reliable blood supply and biomechanical support. Prevention of further collapse occurred, to assist front and rear cruciate ligament rehabilitation, and did not increase surgical complications.

Osteoblasts/Osteocytes sirtuin6 Is Vital to Preventing Ischemic Osteonecrosis Through Targeting VDR-RANKL Signaling.

Ischemic osteonecrosis (ION) can produce permanent deformity and osteoarthritis in the femoral head and other joints. No biologic treatment has been established, and the molecular mechanisms involved in the pathogenesis of ION have not been elucidated. In this work, we found that treatment with sirtuin6 (Sirt6) suppressed inflammatory cytokines, bone resorption, progression of osteoarthritis, and reduced bone deformity in an ION mouse model. We used a deacetylase mutant adenovirus to confirm that those effects were caused by the deacetylase function of Sirt6. Among the osteoclastogenic factors of osteoblasts, only the receptor activator of NF-κb ligand (RANKL) level changed in response to Sirt6 knockout in primary osteoblasts. In particular, the vitamin D receptor physically interacted with Sirt6 and induced recruitment of Sirt6 around RANKL promoters. Finally, Tg mice overexpressing Sirt6 resisted osteocyte death, bone resorption, and progression of osteoarthritis after ischemic surgery, whereas osteoblast/osteocyte-specific Sirt6 knockout mice showed aggravated bone loss and severe deformity. Our findings demonstrate that administration of Sirt6 prevents bone loss and osteoarthritis in ischemic conditions. Activation of Sirt6 in osteoblasts/osteocytes could be a new therapeutic approach to treating ION of the femoral head and other bone regions. © 2020 American Society for Bone and Mineral Research (ASBMR).

Heterogeneous Strain Distribution in the Subchondral Bone of Human Osteoarthritic Femoral Heads, Measured with Digital Volume Correlation.

Osteoarthritis (OA) is a chronic disease, affecting approximately one third of people over the age of 45. Whilst the etiology and pathogenesis of the disease are still not well understood, mechanics play an important role in both the initiation and progression of osteoarthritis. In this study, we demonstrate the application of stepwise compression, combined with microCT imaging and digital volume correlation (DVC) to measure and evaluate full-field strain distributions within osteoarthritic femoral heads under uniaxial compression. A comprehensive analysis showed that the microstructural features inherent in OA bone did not affect the level of uncertainties associated with the applied methods. The results illustrate the localization of strains at the loading surface as well as in areas of low bone volume fraction and subchondral cysts. Trabecular thickness and connectivity density were identified as the only microstructural parameters with any association to the magnitude of local strain measured at apparent yield strain or the volume of bone exceeding yield strain. This work demonstrates a novel approach to evaluating the mechanical properties of the whole human femoral head in case of severe OA.

Dentin Sialophosphoprotein Deletion Leads to Femoral Head Cartilage Attenuation and Subchondral Bone Ill-mineralization.

Dentin sialophosphoprotein (DSPP), which expresses and synthesizes in odontoblasts of dental pulp, is a critical protein for normal teeth mineralization. Originally, DSPP was identified as a dentin-specific protein. In 2010, DSPP was also found in femoral head cartilage, and it is still unclear what roles DSPP play in femoral head cartilage formation, growth, and maintenance. To reveal biological functions of DSPP in the femoral head cartilage, we examined Dspp null mice compared with wild-type (WT) mice to observe DSPP expression as well as localization in WT mice and to uncover differences of femoral head cartilage, bone morphology, and structure between these two kinds of mice. Expression data demonstrated that DSPP had heterogeneous fragments, expressed in each layer of femoral head cartilage and subchondral bone of WT mice. Dspp null mice exhibited a significant reduction in the thickness of femoral head cartilage, with decreases in the amount of proliferating cartilage cells and increases in apoptotic cells. In addition, the subchondral bone mineralization decreased, and the expressions of vessel markers (vascular endothelial growth factor [VEGF] and CD31), osteoblast markers (Osterix and dentin matrix protein 1 [DMP1]), osteocyte marker (sclerostin [SOST]), and osteoclast marker (tartrate-resistant acid phosphatase [TRAP]) were remarkably altered. These indicate that DSPP deletion can affect the proliferation of cartilage cells in the femoral head cartilage and endochondral ossification in subchondral bone. Our data clearly demonstrate that DSPP plays essential roles in the femoral head cartilage growth and maintenance and subchondral biomineralization.

Topology of microfractures in osteonecrotic femoral heads at μCT and histology.

To assess the topology of bone and cartilage microfractures in osteonecrotic femoral heads. Sixteen resected human femoral heads with collapsed osteonecrosis (ON, n=11) or osteoarthritis (OA, n=5) were imaged at μCT with 12μ nominal resolution. Forty-seven histological sections and μCT reformats with (n=30) or without (8 from ON and 9 from OA femoral heads) osteonecrotic lesions were obtained and divided in 2×2 mm segments by a superposed grid. A radiologist and a pathologist separately assessed the presence of bone and cartilage microfractures in each segment on μCT and histological images, respectively. We determined the frequency and distribution of segments with bone microfractures according to a zonal distribution. Matrix analysis was performed by using Matlab to calculate the connectivity index and long/short axis ratios of clustered segments with microfractures. Segments with bone microfractures but not with cartilage microfractures were found more frequently in ON than in OA femoral heads. In the 38 matched μCT and histological images from ON femoral heads, 86%/82% of segments with cortical microfracture, 91%/96% of segments with trabecular microfractures involved ON lesions at μCT/histology. At histology, 83% of segments with cartilage microfractures involved ON lesions. In the 30 paired μCT and histological images containing necrotic lesions, the frequency of segments with trabecular microfractures in the superficial layers (55% at μCT/51% at histology) was statistically significantly higher than in the deep layer (25% P<0.0001/35%; P=0.0006). Clustered segments with cortical/trabecular microfractures, exclusively found in osteonecrotic lesions, had a connectivity index >2.0/20.0 and mean long/short axis ratio>2.35/2.2, respectively. Segments with bone microfractures predominate in necrotic lesions. Segments with trabecular microfractures form elongated clusters near the femoral head surface.