Non-traumatic Femoral Head Necrosis Research Articles

Relationship between lipid metabolism, coagulation and other blood indices and etiology and staging of non-traumatic femoral head necrosis: a multivariate logistic regression-based analysis

BackgroundTo analyze the relationship between lipid metabolism, coagulation function, and bone metabolism and the contributing factor and staging of non-traumatic femoral head necrosis, and to further investigate the factors influencing the blood indicators related to the staging of non-traumatic femoral head necrosis.MethodsThe medical records of patients with femoral head necrosis were retrieved from the inpatient medical record management system, and the lipid metabolism, bone metabolism, and coagulation indices of non-traumatic femoral head necrosis (including alcoholic, hormonal, and idiopathic group) were obtained according to the inclusion and exclusion criteria, including Low-Density Lipoprotein Cholesterol, Triglycerides, Non-High-Density Lipoprotein Cholesterol, Apolipoprotein A1, Apolipoprotein (B), Apolipoprotein (E), Uric Acid, Alkaline Phosphatase, Bone-specific Alkaline Phosphatase, Activated Partial Thromboplastin Time, Prothrombin Time, D-dimer, Platelet count. The relationship between these blood indices and the different stages under different causative factors was compared, and the factors influencing the stages of non-traumatic femoral head necrosis were analyzed using multivariate logistic regression.Results(i) Gender, Age and BMI stratification, Low-density Lipoprotein Cholesterol, Triglycerides, Non-High-density Lipoprotein Cholesterol, Apolipoprotein (B), Apolipoprotein (E), Uric Acid, Bone-specific Alkaline Phosphatase, Activated Partial Thromboplastin Time, Plasminogen Time, D-dimer, and Platelet count of the alcohol group were statistically different when compared among the different ARCO staging groups; (ii) The differences in Age and BMI stratification, Triglycerides, Non-High-density Lipoprotein Cholesterol, Apolipoprotein A1, Apolipoprotein B, Apolipoprotein E, Uric Acid, Bone-specific Alkaline Phosphatase, Activated Partial Thromboplastin Time, Plasminogen Time, D-dimer, and Platelet count were statistically significant when compared among the different phases in the hormone group (P < 0.05); (iii) The differences in Age and BMI stratification, Non-High-Density Lipoprotein Cholesterol, Apolipoprotein A1, Apolipoprotein (B), Apolipoprotein (E), Uric Acid, Activated Partial Thromboplastin Time, D-dimer, and Platelet count were statistically significant when compared among the different stages in the idiopathic group (P < 0.05); (v) Statistically significant indicators were included in the multivariate logistic regression analysis, excluding the highly correlated bone-specific alkaline phosphatase, and the results showed that Low-density lipoprotein was negatively correlated with changes in the course of ARCO, and Non-High-Density Lipoprotein cholesterol, Apo B, Activated Partial Thromboplastin Time, and Platelet count were significantly and positively correlated with disease progression.ConclusionAn abnormal hypercoagulable state as well as an abnormal hyperlipidemic state are risk factors for the progression of non-traumatic femoral head necrosis under various exposure factors, as indicated by Non-High-Density Lipoprotein Cholesterol, Apolipoprotein B, Activated Fractional Thromboplastin Time, and Platelet Counts.

Early adjunctive diagnostic value of contrast-enhanced ultrasound-related quantitative parameter and its relationship with micro-perfusion of nontraumatic necrosis of femoral head.

The aim of this study is to explore the early diagnostic value of contrast-enhanced ultrasound (CEUS)-related quantitative parameter and its relationship with the micro-perfusion of nontraumatic necrosis of the femoral head. According to the random and double-blind method, the patients with non-traumatic femoral head necrosis diagnosed and treated in our hospital from July 2019 to January 2022 were selected as the subjects (the research group). According to the staging of the International Society of Bone Circulation for Femoral Head Necrosis, 89 patients with stage Ⅱ and Ⅲ A were included (39 patients with stage Ⅱ and 50 patients with stage Ⅲ A). 25 patients who conducted physical examination in our hospital during the same time were taken as the control group. Quantitative parameters of CEUS were analyzed. The content of serum vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) were evaluated. The relationship among the quantitative parameters of CEUS, the expression of VEGF and BMP-2 in serum and the patient's condition, and the value for assisting the early diagnosis of nontraumatic femoral head necrosis were analyzed. The body mass, body mass index (BMI), blood lipid, and cholesterol levels were much higher in the research group than in the control group (p < 0.05). The research group had a markedly higher slope of ascending branch (AS), strength enhancement index (EI), and VEGF and obviously lower decay slope (DS), mean transit time (MTT), and time to peak (TTP) than the control group (p < 0.05). In the research group, compared to stage Ⅱ, the levels of AS, EI, and VEGF in stage Ⅲ A patients were memorably higher, and the levels of DS, MTT, TTP and BMP-2 were dramatically lower (p < 0.05). Pearson's correlation test showed that AS, EI, and VEGF were positively correlated with the patients' condition, while DS, MTT, TTP and BMP-2 were negatively correlated with the patients' condition (p < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the diagnostic area under the curve (AUC) of quantitative parameters of CEUS was 0.961, with sensitivity and specificity of 88.0% and 97.4%, respectively. The AUC of the combined detection of VEGF and BMP-2 was 0.945 with sensitivity and specificity of 82.3% and 87.5%, respectively, and the combined detection had a high diagnostic value (p < 0.05). The quantitative parameters of CEUS were of great value in the early diagnosis of nontraumatic necrosis of the femoral head with microvascular perfusion and the patients' condition, and provided a reference for the clinical treatment of non-traumatic necrosis of the femoral head. These parameters were expected to be useful indicators for judging the efficacy before and after treatment.

Comparisons of Ultrasound-Guided Platelet-Rich Plasma Intra-Articular Injection and Extracorporeal Shock Wave Therapy in Treating ARCO I-III Symptomatic Non-Traumatic Femoral Head Necrosis: A Randomized Controlled Clinical Trial.

Background and ObjectiveOsteonecrosis of the femoral head (ONFH) is a devastating disease, and there is some evidence that extracorporeal shock wave therapy (ESWT) and intra-articular platelet-rich plasma (PRP) injection might alleviate pain and improve joint function in individuals with ONFH. The objective of this study was to compare the effectiveness and safety of PRP and ESWT in symptomatic ONFH patients.MethodsA total of 60 patients aged 40–79 with unilateral ONFH at Association Research Circulation Osseous (ARCO) stages I, II, and III were randomly assigned to the PRP (N=30) or the ESWT group (N=30). Four treatment sessions were provided in both groups. Assessments were performed at baseline, and 1-, 3-, 6-, and 12-month. Primary outcomes were measured by the visual analogue scale (VAS), and pressure pain thresholds (PPTs). Secondary outcomes were assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS), and magnetic resonance imaging (MRI). The linear mixed-model analysis was used to evaluate the differences between groups and within groups and the “group by time” interaction effects.ResultsThere were significant differences between groups in terms of changes over time for VAS, PPTs, WOMAC, and HHS since 3-month and maintained up to 12-month (P<0.05, except for PPTs at 12-month). The simple main effects showed that the patients in PRP group had greater improvements in VAS (mean difference = −0.82, 95% CI [−1.39, −0.25], P=0.005), WOMAC (mean difference = −4.19, 95% CI [−7.00, −1.37], P=0.004), and HHS (mean difference = 5.28, 95% CI [1.94, 8.62], P=0.002). No related adverse events were reported.ConclusionThis study supported the effectiveness and safety of both the PRP injection and ESWT in treating ONFH patients. For symptomatic patients with ONFH, intra-articular PRP injection appeared superior to ESWT in pain relief and functional improvement.

Clinical Application of the Musculoperiosteal Iliac Flap for Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) often affects young, active patients, and the femoral head's preservation is the primary goal of treatment for this disease. Vascularized iliac crest bone grafting is one of the many vascularized procedures used in treating ONHF. In some cases, we selectively performed this procedure using the musculoperiosteal iliac flap with the ascending branch of the lateral femoral circumflex artery for ONFH treatment. Twelve patients (12 hips) with nontraumatic femoral head necrosis underwent musculoperiosteal iliac flap transfer with the ascending branch of the lateral femoral circumflex artery. The Harris Hip Score (HHS), visual analog scale score, and double-hip X-ray findings were used to analyze hip function changes within 10 days preoperatively and 6 and 12 months postoperatively. The mean HHS increased from 52.33 ± 3.34 preoperatively to 65.92 ± 5.04 6 months postoperatively and 79.75 ± 3.84 12 months postoperatively, and the data showed a statistical significance difference between preoperative and postoperative (F = 131.90, P < 0.01). The HHS at 6 and 12 months after surgery were significantly different (P < 0.01). The visual analog scale score showed the same trend. The x-ray of hip joints at 6 and 12 months after surgery showed that the femoral heads' shape and contour were good, femoral heads did not collapse, and the transferred bone flaps healed well. Musculoperiosteal iliac flap transfer with the ascending branch of the lateral femoral circumflex artery may be an effective method with a high clinical success rate for treating young patients with early to midstage ONFH.

Bone marrow aspirate: a viable source of stem cells for bone regeneration. A systematic review

This systematic review evaluated the effectiveness of bone marrow aspirate (BMA) to enhance bone repair in humans. Comprehensive survey of ramdomized clinical trials published up to June 2021 and listed in PubMed/MEDLINE, EMBASE, and Cochrane Library databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Two reviewers independently searched eligible studies, made a final article selection, and extracted the data of the selected studies to evaluate it qualitatively. Overall, 13 studies were included in the review. Experimental models involved Posttraumatical aseptic nonunions of long bones of the upper limb, alveolar ridges following tooth extraction, atrophic mandibular fracture, benign bone lesions, bilateral tibial lengthening, fracture of intracapsular neck femur, maxillary horizontal ridge augmentation, non-traumatic femoral head necrosis, and sinus maxillary augmentation. The analyses included radiography, tomography, biopsies, and clinical evaluations. Ten studies reported enahanced bone formation (primary outcome) with combined use or not of BMA with other biomaterials and three studies found no benefit resulting from the use of BMA to treat bony defects. Secundary outcomes related to the healing process were also evaluated and positive, such as postoperative complications and pain visual analogue score. Within the limits of the present study, it can be concluded that BMA can improve the early stages of bone healing process.

Органосохранное хирургическое лечение некроза головки бедренной кости нетравматического генеза

Introduction Hip-salvage treatment in femoral head necrosis has a great social and economic importance.The number of hip joint replacements in young patients has been increasing. Purpose To evaluate the results of hip-preserving surgical interventions in the treatment of patients with non-traumatic femoral head necrosis. Materials and methods The study included 42 cases treated by minimally invasive core decompression of the femoral head and bone grafting, 22 cases of decompression and introduction of autologous bone marrow and mesenchymal stem cells into the core of necrosis, and six cases of using a titanium locking mesh implant. Results The follow-up time after surgery was up to 5 years. The survival rate of hip-reserving operations using cell technology to stimulate osteoregeneration were noticeably better than using bone grafting only in disease stages I, IIA, IIB, IIC. For femoral head osteonecrosis in stage IIIA, a titanium locking femoral head implant has been developed. It promotes regeneration and performs a supporting function. Conclusion The analysis of long-term results of these minimally invasive technologies has proven their efficacy and safety along with a low rate of complications.

The value of the MTHFR polymorphisms in pathogenesis of nontraumatic necrosis of femoral head

Introduction. Among the etiological factors of non-traumatic avascular necrosis of the femoral head are the following: the prolonged use of corticosteroids, alcohol abuse, systemic lupus erythematosus, sickle cell anemia, the Legg Calve Perthes disease, ionizing radiation, cytotoxic agents, etc. At the same time necrosis of the femoral head might occur in the absence of the above factors (idiopathic necrosis). The reasons for idiopathic avascular necrosis could be a mechanical obstacle to the flow of blood, thrombotic occlusion of vessels, extravascular compression.&#x0D; The purpose of this study is to examine the role of C677T gene mutation of the MTHFR gene in the development of non-traumatic avascular necrosis of the femoral head.&#x0D; Materials and methods. During this study there was a comparative analysis of the frequency of the C677T gene allelic variants conducted in 41 patients with a verified diagnosis of non-traumatic avascular necrosis (main group) and 320 healthy individuals (control group). The survey program included the study of polymorphisms of MTHFR C677T gene by PCR.&#x0D; Results. Differences in the frequency of occurrence of C allele of C677T gene MTHFR in the heterozygous state in case of non-traumatic avascular necrosis and in its absence were not statistically significant (51.2% against 37.2% respectively, 2 = 3.014, p = 0.083). The genotype TT (T in the homozygous state) of the C677T MTHFR gene was detected in 19.5% of the main group patients. A similar index in the control group was two times lower and amounted to 9.0 percent, the differences between groups statistically significant, 2 = 4.314, p = 0.038.&#x0D; Conclusion. The study showed the importance of having the T C677T MTHFR gene in the pathogenesis of non-traumatic avascular necrosis of the femoral head. The data obtained and the analysis of the current literature suggests that this polymorphism is one of genetic predictors of non-traumatic avascular necrosis of the femoral head and other cardiovascular diseases as well.

CD41-deficient exosomes from non-traumatic femoral head necrosis tissues impair osteogenic differentiation and migration of mesenchymal stem cells

Non-traumatic osteonecrosis of the femoral head (ONFH) is clinically a devastating and progressive disease without an effective treatment. Mesenchymal stem cells (MSCs) transplantation has been used to treat ONFH in early stage, but the failure rate of this therapy is high due to the reduced osteogenic differentiation and migration of the transplanted MSCs related with pathological bone tissues. However, the mechanism responsible for this decrease is still unclear. Therefore, we assume that the implanted MSCs might be influenced by signals delivered from pathological bone tissue, where the exosomes might play a critical role in this delivery. This study showed that exosomes from ONFH bone tissues (ONFH-exos) were able to induce GC-induced ONFH-like damage, in vivo and impair osteogenic differentiation and migration of MSCs, in vitro. Then, we analyzed the differentially expressed proteins (DEPs) in ONFH-exos using proteomic technology and identified 842 differentially expressed proteins (DEPs). On the basis of gene ontology (GO) enrichment analysis of DEPs, fold-changes and previous report, cell adhesion-related CD41 (integrin α2b) was selected for further investigation. Our study showed that the CD41 (integrin α2b) was distinctly decreased in ONFH-exos, compared to NOR-exos, and downregulation of CD41 could impair osteogenic differentiation and migration of the MSCs, where CD41-integrin β3-FAK-Akt-Runx2 pathway was involved. Finally, our study further suggested that CD41-affluent NOR-exos could restore the glucocorticoid-induced decline of osteogenic differentiation and migration in MSCs, and prevent GC-induced ONFH-like damage in rat models. Taken together, our study results revealed that in the progress of ONFH, exosomes from the pathological bone brought about the failure of MSCs repairing the necrotic bone for lack of some critical proteins, like integrin CD41, and prompted the progression of experimentally induced ONFH-like status in the rat. CD41 could be considered as the target of early diagnosis and therapy in ONFH.

Repair of non-traumatic femoral head necrosis by marrow core decompression with bone grafting and porous tantalum rod implantation.

Objective:To compare the clinical effects of marrow core decompression with bone grafting and marrow core decompression with porous tantalum rod implantation in treating avascular necrosis of non-traumatic femoral head.Methods:This prospective study selected 60 patients (74 hips) with avascular necrosis of femoral head admitted to Daping Hospital from January 2018 to March 2019. According to treatment methods, the 60 patients were randomly divided into two groups, i.e. 30 patients in one group were treated by marrow core decompression with bone grafting, and the other 30 patients in the other group were treated with marrow core decompression and porous tantalum rod implantation.Results:All implantation treatments were successful. No significant difference was found in surgical duration, hemorrhage volume and duration of hospitalization stay between the two groups during follow-up. All Harris scores were significantly improved (P<0.05) following treatment compared to those before treatment. The Harris score of patients treated with porous tantalum rod implantation was higher than that of patients treated with bone grafting (P<0.05) after 12 months following treatment and such a difference was significant.Conclusion:The combination of marrow core decompression and porous tantalum rod implantation can better improve the functions of hip joints with early femoral head necrosis than marrow core decompression with bone grafting, and can also prevent articular cartilage from collapsing gradually.

Clinical effects of the implantation of porous tantalum rod under three-dimensional C-arm positioning in treating ARCO I-II non-traumatic necrosis of the femoral head

Objective To evaluate the clinical effects of the implantation of porous tantalum rod under three-dimensional (3D) C-arm positioning in the treatment of ARCO I and II non-traumatic femoral head necrosis. Methods Fifty patients (58 hips, 39 males and 11 females, mean age 33.52 years) with non-traumatic femoral head in ARCO I-II were included from January 2009 to December 2011. All patients received implantation of porous tantalum rod. The 3D C-arm X-ray positioning was used in 24 patients (29 hips), while traditional C-arm X-ray positioning was performed in the other patients. The visual analogue scale (VAS), Harris score and superior rate were evaluated at 0.5, 1, 2, and 4 years after the surgery. Total hip arthroplasty was regarded as the end event for survival rate. Results In the 3D C-arm X-ray positioning group, the VAS score decreased from 7.17±1.00 points preoperatively to 2.38±0.86 points at half year, to 2.10±1.40 points at 1 year, to 2.38±1.66 points at 2 years, and to 2.21±1.47 points at 4 years postoperatively (F=98.78, P=0.00). Meanwhile, the Harris score increased significantly from 73.97±3.49 points preoperatively to 89.90±1.93, 89.93±3.26, 89.21±5.83, 88.57±5.70 points at the follow up, respectively (F=84.35, P=0.00). According to the analysis of the pre-operative and post-operative image data, there was no significant difference in progress in the ARCO staging at 23 hips duration the follow-up. Four hips were developed to ARCO III and two hips to ARCO II. Thus, the success rate of operation was 79% (23/29). There were two hips underwent total hip arthroplasty, so the survival rate of femoral head was 93% (27/29). The trend of VAS score and Harris score in the C-arm X-ray positioning group was in accordance with the 3D C-arm X-ray positioning group but without statistically significant difference (P>0.05). The operation duration 31.38±3.96 min, blood loss 36.72±5.59 ml, the ratio of distance of metal rod to bone cortex in femoral neck 0.48±0.10, and the distance of mental rod to center of necrosis 0.18±0.07 cm in 3D C-arm X-ray positioning group was superior to C-arm X-ray positioning group (respectively 41.97±4.64 min, 41.49±4.46 ml, 0.46±0.06, 0.23±0.10 cm, P<0.05). Conclusion The implantation of tantalum rod in treating ARCO I-II non-traumatic femoral head necrosis can increase the function of hip joint, relieve the symptoms of necrosis of femoral head, alleviate the progress of femoral head necrosis in X-ray, and obtain a higher survival rate. The 3D C-arm positioning in surgical operation could improve the accuracy and safety of surgery. Key words: Femur head necrosis; Tantalum; Imaging, three-dimensional; X-rays; Radiography

A Human Chondrocyte-Derived In Vitro Model of Alcohol-Induced and Steroid-Induced Femoral Head Necrosis.

BackgroundWorldwide, femoral head necrosis (FHN), which is also known as avascular necrosis of the femoral head or osteonecrosis of the femoral head, affects millions of people. Excess alcohol intake and steroid use are two common associations with FHN, but their pathogenesis remains unknown. The aim of this study was to develop an in vitro model using human chondrocytes to study alcohol-induced and steroid-induced FHN.Material/MethodsIn this study, the in vitro model used a monolayer culture of articular chondrocytes derived from patients with non-traumatic FHN (Ficat and Arlet, Stage III). Normal chondrocytes were obtained from patients with femoral neck fracture resulting from road traffic accident (Garden, Stage IV). Alcohol-stimulated and steroid-stimulated articular chondrocytes were evaluated by a cell proliferation assay, measurement of calcium levels (alizarin red), measurement of alkaline phosphatase (ALP) levels, detection of glycosaminoglycan (GAG) secretion using safranin O histochemical staining, and analysis of cartilage-specific genes, ACAN, SOX9, OPG, TGF-β, RANKL, and RUNX2, using quantitative real-time polymerase chain reaction (qRT-PCR).ResultsBoth alcohol and steroids, but especially steroids, accelerated the degradation of cartilage by suppression of chondrogenesis while promoting chondrocyte hypertrophy and activating osteogenic differentiation, as assessed by cell proliferation assay, detection of glycosaminoglycan (GAG) secretion, and analysis of cartilage-specific genes.ConclusionsA human chondrocyte-derived in vitro model of alcohol-induced and steroid-induced FHN demonstrated chondrocyte hypertrophy and activated osteogenic differentiation.

Differential proteomic screening and identification for non-traumatic necrotic femoral osseous tissue.

Currently, there is a lack of effective early screening and detection methods for femoral head necrosis. Current research on most orthopedic diseases focuses on proteomics in the preliminary stage. The recent fluorescence differential in gel electrophoresis (DIGE) has advantages such as a high reproducibility, high sensitivity, high throughput, and high dynamic range. It is currently one of the most widely used quantitative proteomic research means. We conducted this study to investigate the pathogenesis of non-traumatic femoral head necrosis using the fluorescence DIGE to screen non-traumatic femoral head necrosis based on proteomics and provide a theoretical basis for screening possible biomarkers and molecular targeted treatment. The DIGE technique was used to separate the protein. An electrophoretogram was established on the basis of scanning and analysis. Identification and a bioinformatics analysis were conducted for the differential protein. The protein with differential expression of over 2-fold was excavated and ionized by means of substrate assisted laser desorption. The flight time was identified with a mass spectrometer (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, MALDI-TOF/TOF). The formation on sequences, structures and functions of these proteins were obtained through database retrieval. Western blot analysis was used to verify the differential protein expression and the reliability of the DIGE result was verified. DIGE was used to successfully separate 1,500±40 protein spots. There were 252 significant differential protein spots. The Ettan™ Spot Picker automatic work station was used to excavate 49 significant differential protein spots with expression difference over 2-fold. The MALDI-TOF/TOF mass spectrometer was used to identify these differential protein spots. Six proteins were identified in total, which include apolipoprotein A1 (APOA1), fibrous protein original chain, fibrous protein original chain, serum albumin, sulfur-oxygen protein peroxiredoxin 2 (PRDX2) and actin. APOA1 and PRDX2 were subject to western blot analysis detection; results were consistent with the DIGE result. Based on an analysis of the biological information, these proteins may be associated with the incidence and progression of femoral head necrosis.

Core Decompression and Autologous Bone Marrow Concentrate for Treatment of Femoral Head Osteonecrosis: A Randomized Prospective Study.

The aim of this study was to investigate the safety of injection of bone marrow aspirate concentrate during core decompression and to study its clinical (visual analogue scale; Harris-Hip-score) and radiological outcomes (magnetic resonance imaging). In this prospective and randomized clinical trial we evaluated 24 consecutive patients with non-traumatic femoral head necrosis (FHN) during a period of two years after intervention. In vitro analysis of mesenchymal stem cells was performed by evaluating the fibroblast colony forming units (CFU-Fs). Postoperatively, significant decrease in pain associated with a functional benefit lasting was observed. However, there was no difference in the clinical outcome between the two study groups. Over the period of two years there was no significant difference between the head survival rate between both groups. In contrast to that, we could not perceive any significant change in the volume of FHN in both treatment groups related to the longitudinal course after treating. The number of CFU showed a significant increase after centrifugation. This trial could not detect a benefit from the additional injection of bone marrow concentrate with regard to bone regeneration and clinical outcome in the short term.

S3-Leitline. Teil 1: Diagnostik und Differenzialdiagnostik der atraumatischen Femurkopfnekrose (aFKN) des Erwachsenen

Non-traumatic femoral head necrosis (FHN) is primarily a disease of the middle-aged adult. Early diagnosis, at a time with lacking or minimal clinical symptoms, is mandatory to consider conservative therapy or joint preserving operations as a therapeutic option. The new German S3 guideline about diagnosis and therapy of FHN is a cooperative effort of five professional medical societies, overall headed by the Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie (DGOOC). This review (part I/III) cites and explains the statements of the S3 guideline as agreed on the use of imaging methods for diagnosis of FHN. A diagnostic algorithm is presented. FHN clinically has to be considered in case of equivocal pain of a hip joint with a minimum of 6 weeks duration, when risk factors can be revealed, groin pain at clinical investigation, limping, pain or limitation of movement in case of load, and no obvious differential diagnoses. Is an FHN clinically suspected, primarily radiographs of the pelvis ap and a Lauenstein projection of the hip involved should be carried out. When the radiographs are normal, an MRI of the hips should follow routinely. MRI allows the diagnosis of FNH with high accuracy. Furthermore, MRI reveals the site and the size of the necrotic area involved and evaluates the integrity of the joint surface and subchondral fractures. When ARCO stage II (ARCO: Association Research Circulation Osseous) is diagnosed and MRI does not allow one to determine the joint surface with certainty, a CT of the hip joints should be performed. The S3 guideline explains and recommends the use of the ARCO classification. Although, this classification of 1993 is still largely based on radiographs, the pragmatic use of an "extended" version seems reasonable. Today, classical radiographic criteria like impression of the joint surface and subchondral fractures ("crescent sign") are better to be evaluated by MRI, in cases of subtle findings MRI is even surpassed by CT. The extent of the necrosis in the femoral head as well as the size of the surface area involved is best revealed with MRI. Additionally, in the era of cross sectional imaging a stage "0" seems obsolete. The guideline also addresses practically important considerations about the differential diagnosis of misleading MRI findings. This especially holds true for bone marrow oedema in the femoral head which may be misinterpreted. The differentiating features between FHN, transient bone marrow oedema and destructive arthropathy are discussed.

Increased risk of revision in patients with non-traumatic femoral head necrosis

Background and purpose Previous studies of patients who have undergone total hip arthroplasty (THA) due to femoral head necrosis (FHN) have shown an increased risk of revision compared to cases with primary osteoarthritis (POA), but recent studies have suggested that this procedure is not associated with poor outcome. We compared the risk of revision after operation with THA due to FHN or POA inthe Nordic Arthroplasty Register Association (NARA) database including Denmark, Finland, Norway, and Sweden.Patients and methods 427,806 THAs performed between 1995 and 2011 were included. The relative risk of revision for any reason, for aseptic loosening, dislocation, deep infection, and periprosthetic fracture was studied before and after adjustment for covariates using Cox regression models.Results 416,217 hips with POA (mean age 69 (SD 10), 59% females) and 11,589 with FHN (mean age 65 (SD 16), 58% females) were registered. The mean follow-up was 6.3 (SD 4.3) years. After 2 years of observation, 1.7% in the POA group and 3.0% in the FHN group had been revised. The corresponding proportions after 16 years of observation were 4.2% and 6.1%, respectively. The 16-year survival in the 2 groups was 86% (95% CI: 86–86) and 77% (CI: 74–80). After adjusting for covariates, the relative risk (RR) of revision for any reason was higher in patients with FHN for both periods studied (up to 2 years: RR = 1.44, 95% CI: 1.34–1.54; p < 0.001; and 2–16 years: RR = 1.25, 1.14–1.38; p < 0.001).Interpretation Patients with FHN had an overall increased risk of revision. This increased risk persisted over the entire period of observation and covered more or less all of the 4 most common reasons for revision.

Hüftkopfnekrose – Diagnostik und Differenzialtherapie

Femoral head necrosis is an ischaemic bone necrosis of traumatic or nontraumatic pathogenesis which can lead to hip joint destruction in young age. It is today the indication for 10 % of all the total hip joint replacements. Known aetiologies of nontraumatic femoral head necrosis are alcoholism, steroids, sickle cell anaemia, caisson, and Gaucher's disease. Further risk factors are chemotherapy, chronic inflammatory bowel disease, systemic lupus erythematosus, and multiple sclerosis, in which also steroids are involved. Gravidity is another risk factor, but still idiopathic pathogenesis is found. In diagnosis, the ARCO-classification of the Association for the Research of Osseous Circulation is essential. While stage 0 can only be found histologically, the reversible early stage 1 shows MR signal changes. In the irreversible early stage 2, first native x-ray changes are seen as lower radiolucency reflects new bone apposition on dead trabeculae. In stage 3, subchondral fracture follows, and in stage 4 secondary arthritis of the hip. Established therapy in stage 1 is core decompression, physiotherapy, and more and more also bisphosphonates. Sufficient data to support extracorporeal shock wave therapy are still lacking. Stem cell therapy seems to be a promising new therapy method in stage 2. In stage 2 and 3 mainly proximal femoral osteotomies and (non)vascularised bone transplantation are performed. In stage 4, depending on size and location of the necrotic zone and pathology of the adjacent bone, resurfacing or short stem hip arthroplasty can be performed. However, conventional THA is still golden standard. The problem and challenge, however, is the often young patient age in femoral head necrosis. Especially chemotherapy-associated osteonecrosis in leukaemia is found in patients in their second decade of life. Therefore, the hip should be preserved as long as possible.

Impeded Venous Drainage from the Bone Marrow of the Femoral Head: A Synthesis

This paper is a synthesis of the results of research on intraosseous circulation in the proximal end of the femur in children (Perthes' disease) and adults (degenerative osteoarthri tis, the intraosseous engorgement- pain syndrome, nontraumatic femor al head necrosis). These disorders are all characterized by more or less ex tensive degenerative bone lesions and pain. Bone cell death is generally caused by anoxemia, and the com monly held assumption is that most of these disorders are due to failure of arterial supply to the bone marrow ("avascular necrosis"). Impaired capillary flow may also be due, how ever, to high resistance on the venous side of the capillary bed. This mech anism is best known from the patho logic mechanism of the venous lower extremity ulcer. The findings re ported in this synthesis point to the disturbance of venous drainage from the bone marrow of the femoral head as an important factor in the patho logic mechanism probably responsi ble for both the characteristic pain and degenerative skeletal changes.

Selective digital subtraction arteriography in necrosis of the femoral head.

Selective digital subtraction arteriographic investigations of the arteries of the femoral head in 31 patients with traumatic and 34 patients with nontraumatic femoral head necrosis (FHN) were compared with investigations in a control group of 35 patients without hip disease. In the control group and in patients with nontraumatic FHN atypical arteriographic findings were found only in one third of cases. In traumatic FHN, however, vascular alterations could be detected in 97% of cases. This evidence suggests that damage to the femoral head vessels is a major etiological factor in traumatic, but not in nontraumatic, FHN. In late arterial phases of DSA a perinecrotic hypervascularization was the common feature in all nontraumatic necroses and could be observed in 71% of traumatic necroses. Its pathophysiological mechanism is discussed.