OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

Hemophilic arthritis(HA),caused by recurrent bleeding,can seriously affect patient quality of life and consumes extensive social and medical resources.There is thus a need to establish an animal model of HA for research;however,this is limited by ethical requirements.Here we review the recent literature and summarize research progress into animal models of HA at home and abroad,from the aspects of species selection,modeling method,histopathology,and imaging evaluation method.Species selection includes rodents such as mice,New Zealand rabbits,beagles,miniature pigs,and crab-eating macaques.Modeling method comprise gene knockout trauma models,gene knockout spontaneous models,and injection models.Among these,the gene knockout spontaneous model closely mimics the pathological process of spontaneous bleeding and concurrent arthritis in human HA,making it more relevant to human HA.However,due to high modeling costs,phenotypic instability,and low survival rates,this model is not the preferred choice for animal experimental studies.In contrast,gene knockout trauma models exhibit characteristics such as short modeling time,strong stability,and high success rates,thus being widely utilized in animal experimental research.Evaluation of HA models involves various imaging method including MRI,micro-CT,MSKUS/PD,in addition to various gross scoring method.By reviewing the progress of HA model research,more experimental evidence is provided for investigating the pathogenesis and validating the efficacy of HA treatments,thereby compensating for the lack of clinical data,particularly in the field of traditional Chinese medicine therapy.

Objective To explore the anti-inflammatory effect of Qingre Jiedu(QRJD)formula on mice with gout and its effect on gut microbiota.Methods Forty C57BL/6 mice weighing 20～22 g were divided into control(CON),model(MOD),allopurinol(ALLO),and QRJD formula(QRJD)groups,and i.g.10 g/0.1 mL carboxymethyl cellulose was administered to the CON every morning from 1 to 35 days.A hyperuricemia mouse model was prepared by intragastric injection of a potassium oxalic acid(500 mg/kg)and yeast extract(10 g/kg)suspension.On day 29,50 μL sterile carboxymethyl cellulose was injected into the right ankle of mice in the CON group under isoflurane-induced anesthesia,and a gouty arthritis model was prepared by injecting the same volume of sodium urate(50 mg/mL)into the right ankle of mice in the other groups.Each group was treated with corresponding drugs every day.On day 35,samples were collected from mice that had been fasted for 6 hours without water.Blood indexes,such as uric acid,creatinine,and urea nitrogen,were assessed.Hematoxylin-eosin and saffranine O-fast green staining was performed on ankle joints.Anti-inflammatory indexes of interleukin-10(IL-10)and transforming growth factor-β1(TGF-β1)were detected by ankle joints immunohistochemical assay.The cecum contents of mice were collected,and changes in gut microbiota were analyzed by high-throughput sequencing of 16S rDNA.Results(1)After 7 days of treatment,compared with the MOD group,QRJD formula effectively reduced the blood concentrations of uric acid(P＜0.001),creatinine(P＜0.01),and urea nitrogen(P＜0.05),and effectively protected renal functions.(2)Compared with the MOD group,HE staining showed that synovial hyperplasia and inflammatory cell infiltration were reduced in the QRJD formula group after treatment.The cartilage arrangement of the compound was more orderly than before,cartilage destruction was less than that in the MOD group,and no matrix loss was observed.(3)Immunohistochemical analysis of the ankle joint indicated that IL-10 and TGF-β1 were not significantly increased in CON and MOD groups.Compared with the MOD group,IL-10 and TGF-β1 expression in the QRJD formula group were increased(P＜0.05).(4)In terms of biodiversity,the number of MOD-specific OTUs increased by 75 compared to the CON group,while the QRJD was able to reduce the number of MOD-specific OTUs to more closely resemble the CON group;no significant difference was found in α-diversity among the four groups(P＜0.05),whereas β-diversity was more similar to the CON group(P=0.001).(5)Compared with the CON group,the MOD group exhibited increased abundances(P＜0.05)of Ruminococcaceae spp.,Dubosiella sp.,Tyzzerella sp.,Ileibacterium sp.,and Bacteroidales spp..In contrast to the MOD group,the QRJD formula group showed elevated abundances(P＜0.05)of Lactobacillus sp.,Ligilactobacillus sp.,and Bacteroides sp..Furthermore,an interaction network of gut microbiota indicated mutual interactions among these microorganisms.(6)In the correlation analysis between gut microbiota and renal functions as well as anti-inflammatory factors,the relative abundances of Dubosiella sp.,Tyzzerella sp.,and Bacteroidales spp.were significantly positively correlated to SUA and SCR(P＜0.05).However,Lactobacillus sp.,Ligilactobacillus sp.,and Mitochondria spp.exhibited a positive correlation to anti-inflammatory factors IL-10 and TGF-β1 with a more significant association observed for TGF-β1(P＜0.05).(7)COG function prediction suggested that the functions of the QRJD formula group were concentrated on inorganic ion transport and metabolism,and carbohydrate transport and metabolism.Conclusions QRJD effectively modulates immune inflammation and gut microbiota dysbiosis,thereby treating gout.Its mechanism of gout prevention and treatment may involve regulation of gut microbiota diversity and abundance,as well as the control of the abundance of differential bacterial species,such as Ruminococcaceae spp.,Dubosiella sp.,and Lactobacillus sp.,to achieve gout therapy.

BACKGROUND:Compound Shengmai Chenggu capsule has good therapeutic effects on early steroid-induced osteonecrosis of the femoral head,but the exact mechanism of treatment is not fully understood. OBJECTIVE:To observe the effect of compound Shengmai Chenggu capsule on fucosyltransferase 8,osteogenic gene and Wnt/β-catenin in bone tissue of rats with steroid-induced osteonecrosis of the femoral head. METHODS:Sixty Sprague-Dawley rats were randomized into blank group,model group,low-,middle-,and high-dose drug groups(n=12 per group).In the latter four groups,animal models of steroid-induced osteonecrosis of the femoral head were established by subcutaneous injection of imiquimod(once every 2 weeks,2 times in total)and gluteal muscle injection of methylprednisolone(once a week,4 times in total).The low-,middle-and high-dose drug groups were given 1.89,3.78 and 7.56 g/kg per day compound Shengmai Chenggu capsule solution by gavage respectively on the second day after the last modeling.The same amount of saline was given by gavage to the model group.Administration lasted 8 weeks.After the administration,micro-CT scan,histological staining,compression test,RT-qPCR and western blot were performed on the femoral head. RESULTS AND CONCLUSION:Micro-CT scan results showed that compared with the blank group,trabecular volume fraction,trabecular number and trabecular thickness were significantly decreased(P<0.05),while trabecular separation was increased in the model group(P<0.05).Compared with the model group,the compound Shengmai Chenggu capsule could increase trabecular volume fraction,trabecular number and trabecular thickness(P<0.05),and decrease trabecular separation(P<0.05)in a dose-dependent manner.Hematoxylin-eosin staining results showed that compared with the model group,the rate of empty bone lacunae was reduced in a dose-dependent group in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups(P<0.05).Immunohistochemical staining results showed that compared with the blank group,the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 was reduced in the model group(P<0.05);compared with the model group,the compound Shengmai Chenggu capsule increased the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 in a dose-dependent manner(P<0.05).Results from the compression test showed that there was a dose-dependent increase in the maximum load and elastic modulus of the femoral head in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).RT-qPCR and western blot results showed that the mRNA and protein expressions of fucosyltransferase 8,Runx2,alkaline phosphatase,osteocalcin,osteoblast-specific transcription factor and bone morphogenetic protein 2 were decreased in the model group compared with the blank group(P<0.05);compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of the above indicators in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).Compared with the blank group,the mRNA and protein expression of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin were decreased(P<0.05)and the mRNA and protein expressions of glycogen synthase kinase 3β were increased(P<0.05)in the model group;compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin(P<0.05)but a dose-dependent decrease in the mRNA and protein expressions of lycogen synthase kinase 3β(P<0.05)in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups.To conclude,the mechanism by which the compound Shengmai Chenggu capsule treats steroid-induced osteonecrosis of the femoral head may activate the Wnt/β-catenin signaling pathway through the up-regulation of fucosyltransferase 8,thereby promoting bone formation.

BACKGROUND:The majority of studies on developmental dysplasia of the hip focus on hip malformations,but there are few reports on the effects of acetabular dysplasia on the spine. OBJECTIVE:To investigate the compensation of spinopelvic parameters in coronal and sagittal views in patients with developmental dysplasia of the hip,and to explore the correlation between acetabular development and spinopelvic parameters. METHODS:A total of 101 patients with developmental dysplasia of the hip admitted to the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2018 to June 2022 were selected as the trial group,and 114 healthy subjects were selected as the control group during the same period.The spinopelvic parameters of the subjects were measured through the full-length X-ray films of the coronal and sagittal spines:lumbar lordosis,anterior pelvic tilt,thoracolumbar kyphosis,Cobb angle,and the distance between the C7 plumb line and the center sacral vertical line,sacral slope,pelvic incidence,and thoracic kyphosis.The differences in spinopelvic parameters were compared between the two groups.In addition,the differences in spinopelvic parameters in patients with unilateral,bilateral and different Crowe classifications of developmental dysplasia of the hip were compared.Pearson correlation analysis was used to explore the correlation between Sharp angle and spinopelvic parameters. RESULTS AND CONCLUSION:(1)In the sagittal view,the lumbar lordosis in the trial group was significantly lower than that in the control group(P<0.05).The pelvic tilt and kyphosis angle of the thoracolumbar segment in the trial group were significantly greater than those in the control group(P<0.05).In the coronary position,the Cobb angle and the distance between the C7 plumb line and center sacral vertical line in the trial group were significantly greater than those in the control group(P<0.05).There was no significant difference in the remaining spinopelvic parameters between the two groups(P>0.05).(2)The lumbar lordosis of patients with bilateral developmental dysplasia of the hip was significantly lower than that of patients with unilateral developmental dysplasia of the hip(P<0.05).The pelvic tilt,thoracolumbar kyphosis,Cobb angle and the distance between the C7 plumb line and center sacral vertical line in bilateral developmental dysplasia of the hip patients were significantly greater than those in unilateral developmental dysplasia of the hip patients(P<0.05).(3)The lumbar lordosis decreased with the increase of Crowe classification severity(P<0.05).The pelvic tilt increased with the severity of the Crowe classification(P<0.05).(4)Pearson correlation analysis showed that Sharp angle was negatively correlated with lumbar lordosis(P<0.05),while Sharp angle was positively correlated with anterior pelvic tilt,Cobb angle,C7 plumb line and center sacral vertical line(P<0.05).(5)It is concluded that the pelvic tilt,thoracolumbar kyphosis,Cobb angle and the distance between the C7 plumb line and center sacral vertical line increase,while lumbar lordosis decreases in developmental dysplasia of the hip patients.The degree of acetabular dysplasia was significantly correlated with lumbar lordosis,pelvic tilt,Cobb angle,C7 plumb line and center sacral vertical line.

BACKGROUND:Periprosthetic joint infection is one of the most unwanted complications for surgeons and patients after arthroplasty,and its recalcitrance and intractability have always been a headache for arthroplasty surgeons. OBJECTIVE:To review the latest domestic and international clinical treatments used in the treatment of periprosthetic joint infection after hip and knee arthroplasty in recent years,including antibiotic treatment,surgical treatment,biological treatment and Chinese medicine treatment,to promote the research progress in the treatment of periprosthetic joint infection in China. METHODS:The literature from January 2000 to October 2022 on CNKI,WanFang,VIP,and PubMed was retrieved by the first author.762 articles were obtained by reading the titles for initial screening,then 194 articles were obtained by reading the abstracts and excluding studies with duplicate contents,low data reliability,and outdated views.Finally,88 articles were included through intensive reading of the original text. RESULTS AND CONCLUSION:(1)Combined antibiotic regimens may help eradicate the infection in the treatment of periprosthetic infections.(2)Two-stage revision remained the golden indicator for the treatment of periprosthetic infection.(3)One-stage revision lacked large-sample clinical studies and required more clinical observation.(4)Phage therapy and newer drug delivery systems in biological therapy had been applied in small amounts in the clinic,showing their advantages in the prevention and eradication of periprosthetic infections.(5)Chinese medicine with antibiotics and surgical treatment methods can improve the prevention and treatment of periprosthetic joint infection,but high-level evidence-based medical evidence was lacking.

BACKGROUND:The sclerotic zone in the femoral head is an important imaging feature in the progression of steroid-induced femoral head necrosis,which is associated with disease prognosis.Peroxisome proliferator-activated receptor γ coactivator 1α(PGC-1α)has been shown to possess biological activities such as osteogenesis,angiogenesis and anti-mitochondrial apoptosis,which may be closely related to bone repair of steroid-induced femoral head necrosis. OBJECTIVE:To screen for the differential proteins in the sclerotic zone of steroid-induced osteonecrosis of the femoral head versus the normal zone,to screen for hub proteins in the sclerotic zone,and to verify the differential expression of hub proteins in the femoral head specimens following steroid-induced femoral head necrosis,and to to explore the repair pattern of the sclerotic zone following steroid-induced femoral head necrosis. METHODS:Femoral head samples were collected from patients with steroid-induced osteonecrosis of the femoral head receiving total hip arthroplasty.The differentially expressed genes in the sclerotic zone and the normal zone were screened by Tandem Mass Tags and analyzed by GO and KEGG signaling pathways to construct a protein-protein interaction network and screen hub genes.In addition,the expression of hub genes in the sclerotic zone was verified by immunohistochemistry and western blot. RESULTS AND CONCLUSION:Quantitative protein profiling by Tandem Mass Tags revealed that 609 proteins were significantly differentially expressed(Log2FC＞1.20,Log2FC＜0.84 and P＜0.05)in the sclerotic zone of the femoral head compared with the normal zone,of which 290 proteins were upregulated and 319 proteins were downregulated.The GO and KEGG pathway enrichment analyses revealed that among the top 10 enriched pathways,Wnt signaling pathway and life-cycle regulatory pathway were closely related to bone repair;in the life-cycle regulatory pathway,PGC-1α was one of the important proteins.In addition,western blot results verified the low expression of PGC-1α and NRF1 in the sclerotic zone and high expression of Cleaved Caspase-3 in the sclerotic zone compared with the normal zone of steroid-induced femoral head necrosis specimens.Light microscopic immunohistochemical results showed the distribution of PGC-1α,NRF1 and Cleaved Caspase-3 positive expression in the sclerotic and normal zones in the femoral head tissue specimens,indicating the presence of their expression in bone trabeculae,osteoblasts and bone marrow.In contrast,the brown area of the sclerotic zone of femoral head necrosis stained darker and showed more obvious expression of Cleaved Caspase-3.To conclude,in the sclerotic zone of steroid-induced femoral head necrosis,biological behaviors including activation of osteogenesis-related pathways such as Wnt and oxidative apoptosis characterized by low expression of PGC-1 are observed.Low expression of PGC-1α in the sclerotic zone of steroid-induced femoral head necrosis may be associated with the activation of oxidative apoptosis.

Objective To establish a PCR-based capillary electrophoresis(PCR/CE)to detect Survival Motor Neuron 1(SMN1)and Survival Motor Neuron 2(SMN2)genes and to evaluate its performance.Methods PCR/CE and Multiplex Ligation-dependent Probe Amplification(MLPA)for SMA gene diagnosis were used to blindly test the samples in sync.The performance of PCR/CE was assessed using MLPA results as the standard.Results A total of 336 samples were included in this study,consisting of 50 homozygous deletion types(14.9%),65 heterozygous deletion types(19.3%),and 221 non-deletion types(65.8%).The results of PCR/CE for detect-ing SMN1 and SMN2 copy numbers(0,1,2,3,≥4)were in complete agreement with the results of the MLPA.Conclusions PCR/CE for gene testing related to SMA could accurately detect copy numbers of exon 7 and exon 8 of the SMN1 and SMN2 genes(0,1,2,3,≥4).

OBJECTIVE: To establish finite element models of different preserved angles of osteonecrosis of the femoral head (ONFH) for the biomechanical analysis, and to provide mechanical evidence for predicting the risk of ONFH collapse with anterior preserved angle (APA) and lateral preserved angle (LPA). METHODS: A healthy adult was selected as the study object, and the CT data of the left femoral head was acquired and imported into Mimics 21.0 software to reconstruct a complete proximal femur model and construct 3 models of necrotic area with equal volume and different morphology, all models were imported into Solidworks 2022 software to construct 21 finite element models of ONFH with LPA of 45°, 50°, 55°, 60°, 65°, 70°, and 75° when APA was 45°, respectively, and 21 finite element models of ONFH with APA of 45°, 50°, 55°, 60°, 65°, 70°, 75° when LPA was 45°, respectively. According to the physiological load condition of the femoral head, the distal femur was completely fixed, and a force with an angle of 25°, downward direction, and a magnitude of 3.5 times the subject's body mass was applied to the weight-bearing area of the femoral head surface. The maximum Von Mises stress of the surface of the femoral head and the necrotic area and the maximum displacement of the weight-bearing area of the femoral head were calculated and observed by Abaqus 2021 software. RESULTS: The finite element models of ONFH were basically consistent with biomechanics of ONFH. Under the same loading condition, there was stress concentration around the necrotic area in the 42 ONFH models with different preserved angles composed of 3 necrotic areas with equal volume and different morphology. When APA was 60°, the maximum Von Mises stress of the surface of the femoral head and the necrotic area and the maximum displacement of the weight-bearing area of the femoral head of the ONFH models with LPA<60° were significantly higher than those of the models with LPA≥60° ( P<0.05); there was no significant difference in each index among the ONFH models with LPA≥60° ( P>0.05). When LPA was 60°, each index of the ONFH models with APA<60° were significantly higher than those of the models with APA≥60° ( P<0.05); there was no significant difference in each index among the ONFH models with APA≥60° ( P>0.05). CONCLUSION From the perspective of biomechanics, when a preserved angle of ONFH is less than its critical value, the stress concentration phenomenon in the femoral head is more pronounced, suggesting that the necrotic femoral head may have a higher risk of collapse in this state.
Adult ; Humans ; Femur Head/surgery* ; Finite Element Analysis ; Stress, Mechanical ; Femur/diagnostic imaging* ; Femur Head Necrosis/surgery*

OBJECTIVE: To analyze the femoral head collapse and the operation of osteonecrosis of the femoral head (ONFH) in different Japanese Investigation Commitee (JIC) types, in order to summarize the prognostic rules of each type of ONFH, and explore the clinical significance of CT lateral subtypes based on reconstruction of necrotic area of C1 type and verify their clinical effect. METHODS: A total of 119 patients (155 hips) with ONFH between May 2004 and December 2016 were enrolled in the study. The total hips consisted of 34 hips in type A, 33 in type B, 57 in type C1, and 31 in type C2, respectively. There was no significant difference in age, gender, affected side, or type of ONFH of the patients with differenct JIC types ( P>0.05). The 1-, 2-, and 5-year femoral head collapse and operation of different JIC types were analyzed, as well as the survival rate (with femoral head collapse as the end point) of hip joint between different JIC types, hormonal/non-hormonal ONFH, asymptomatic and symptomatic (pain duration >6 months or ≤6 months), and combined preserved angle (CPA) ≥118.725° and CPA<118.725°. JIC types with significant differences in subgroup surgery and collapse and with research value were selected. According to the location of the necrotic area on the surface of the femoral head, the JIC classification was divided into 5 subtypes in the lateral CT reconstruction, and the contour line of the necrotic area was extracted and matched to the standard femoral head model, and the necrosis of the five subtypes was presented by thermography. The 1-, 2-, and 5-year outcomes of femoral head collapse and operation in different lateral subtypes were analyzed, and the survival rates (with collapse of the femoral head as the end point) between CPA≥118.725° and CPA<118.725° hip in patients with this subtype were compared, as well as the survival rates of different lateral subtypes (with collapse and surgery as the end points, respectively). RESULTS: The femoral head collapse rate and operation rate in the 1-, 2-, and 5-year were significantly higher in patients with JIC C2 type than in patients with other hip types ( P<0.05), while in patients with JIC C1 type than in patients with JIC types A and B ( P<0.05). The survival rate of patients with different JIC types was significantly different ( P<0.05), and the survival rate of patients with JIC types A, B, C1, and C2 decreased gradually. The survival rate of asymptomatic hip was significantly higher than that of symptomatic hip, and the survival rate of CPA≥118.725° was significantly higher than that of CPA<118.725° ( P<0.05). The lateral CT reconstruction of type C1 hip necrosis area was selected for further classification, including type 1 in 12 hips, type 2 in 20 hips, type 3 in 9 hips, type 4 in 9 hips, and type 5 in 7 hips. There were significant differences in the femoral head collapse rate and the operation rate among the subtypes after 5 years of follow-up ( P<0.05). The collapse rate and operation rate of types 4 and 5 were 0; the collapse rate and operation rate of type 3 were the highest; the collapse rate of type 2 was high, but the operation rate was lower than that of type 3; the collapse rate of type 1 was high, but the operation rate was 0. In JIC type C1 patients, the survival rate of the hip joint with CPA≥118.725° was significantly higher than that with CPA<118.725° ( P<0.05). In the follow-up with femoral head collapse as the end point, the survival rates of types 4 and 5 were all 100%, while the survival rates of types 1, 2, and 3 were all 0, and the difference was significant ( P<0.05). The survival rate of types 1, 4, and 5 was 100%, of type 3 was 0, and of type 2 was 60%, showing significant difference ( P<0.05). CONCLUSION JIC types A and B can be treated by non-surgical treatment, while type C2 can be treated by surgical treatment with hip preservation. Type C1 was classified into 5 subtypes by CT lateral classification, type 3 has the highest risk of femoral head collapse, types 4 and 5 have low risk of femoral head collapse and operation, type 1 has high femoral head collapse rate but low risk of operation; type 2 has high collapse rate, but the operation rate is close to the average of JIC type C1, which still needs to be further studied.
Humans ; Femur Head/surgery* ; Femur Head Necrosis/surgery* ; Retrospective Studies ; Hip Joint ; Tomography, X-Ray Computed