OBJECTIVETo reveal the possible mechanism involved in patella-femoral degenerative arthritis (PFDA) in- duced by torsion-deformity of tibia via analyzing the relationship between torsion-deformity of the tibia in patients with PFDA and the disorder of patella-femoral joint under the static and dynamic conditions.

METHODSFrom October 2009 to October 2010, 50 patients (86 knees, 24 knees of male patients and 62 knees of female patients) with PFDA were classified as disease group and 16 people (23 knees, 7 knees of males and 16 knees of females) in the control group. The follow indexes were measured: the torsion-angle of tibia on CT scanning imagings, the patella-femoral congruence angle and lateral patella-femoral angle under static and dynamic conditions when the knee bent at 30 degrees of flexion. Based on the measurement results, the relationship between the torsion-deformity of tibias and the disorders of patella-femoral joints in patients with PFDA were analyzed. Finally,the patients were divided into three groups including large torsion-angle group, small torsion-angle group and normal group according to the size of torsion-angle, in order to analyze the relationship between torsion-deformity and disorders of patella-femoral joint, especially under the dynamic conditions.

RESULTSCompared with patients without PFDA, the ones with PFDA had bigger torsion-angle (30.30 ± 7.11)° of tibia, larger patella-femoral congruence angle (13.20 ± 3.94)° and smaller lateral patella-femoral angle (12.30 ± 3.04)°. The congruence angle and lateral patella-femoral angle under static and dynamic conditions had statistical differences respectively in both too-big torsion-angle group and too-small torsion-angle group. The congruence angle and lateral patella-femoral angle under static and dynamic conditions had no statistical differences in normal torsion-angle group.

CONCLUSIONTorsion-deformity of tibia is the main reason for disorder of patella-femoral joint in the patients with PFDA. Torsion-deformity of tibia is always accompanied by instability of patella-femoral joint,especially under the dynamic condition, thus causing PFDA. It can not only provide arrangement information and degenerative condition of patella-femoral joint,but also provide guidance through the analysis on the relationship for better clinical prevention and early treatment of degenerative bone and joint disease.

Adult ; Female ; Femur ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Osteoarthritis, Knee ; diagnostic imaging ; etiology ; Patella ; diagnostic imaging ; Radiography ; Tibia ; diagnostic imaging ; Torsion Abnormality ; complications ; diagnostic imaging

Disability Evaluation ; Femur/diagnostic imaging* ; Humans ; Lower Extremity

OBJECTIVE: To explore correlation between imaging classification of knee osteoarthritis (KOA) and axis angle of tibiofemoral and patellofemoral joints. METHODS: A retrospective analysis of 739 middle-aged and elderly patients with KOA (1 026 knee joints) who underwent vertical X-ray examination of both lower limbs and lateral knee joints from September 2018 to December 2020. Among them, 63 patients with K-L 0 grade (95 knee joints), 100 patients with K-L 1 grade (130 knee joints), 161 patients with K-L 2 grade (226 knee joints), 187 patients with K-L 3 grade (256 knee joints), and 228 patients of K-L 4 grade (319 knee joints). According to relative position of knee joint center and line between hip joint center and ankle joint center, the affected knee was divided into varus group(844 knees joints) and valgus group (182 knees joints). According to Install-Salvati method, the affected knee was divided into three groups, such as high patella (patella height>1.2 mm, 347 knees joints), median patella (patella height ranged from 0.8 to 1.2 mm, 561 knees joints), and low patella (patella height<0.8 mm, 118 knees joints). Lower femur angle, upper tibia angle, femoral neck shaft angle, femoral tibial angle, joint gap angle, hip-knee-ankle angle, patella-femoral angle and patella height among different groups were observed and compared. RESULTS: (1) In varus KOA group, there were statistical differnces in hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades (P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle and K-L grade were significantly positively correlated at 0.01(P<0.05);femoral neck shaft angle and K-L grade showed negative correlation at 0.01(P<0.05). (2) In valgus KOA group, hip-knee-ankle angle, there were statistical differences in tibiofemoral angle, inferior femoral angle, superior tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades(P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, and femoral neck shaft angle showed negative correlation with K-L grades at level of 0.01 (P<0.05);joint gap angle and K-L grades showed significantly positive correlation at level of 0.01(P<0.05). (3) In high patella group, there were statistically differences in patellar height and patellar femoral angle of different K-L grades(P<0.05);there were no statistical difference in patella height and patellar femoral angle of different K-L grades in median patella group. There was no significant difference in patella heightin low patella group with different K-L grades(P>0.05), and there was statistical difference in patellofemoral angle(P<0.05). Patellar height and patella-femoral angle of high patella group were significantly positively correlated with K-L grades at the level of 0.01 (P<0.05);patella height and patella-femoral angle were not correlated with K-L grades in median patella group(P>0.05). There was no correlation between height of patella and K-L grade in low patella group (P>0.05). There was significant negative correlation between patella-femoral angle and K-L grade at level of 0.05 (P<0.05). CONCLUSION Inferior femoral angle, tibiofemoral angle, joint gap angle, hip-knee-ankle angle, femoral neck shaft angle and high patella are related to K-L classification of varus KOA, which could be used for early diagnosis and provide objective data for efficacy analysis of conservative treatment.
Aged ; Middle Aged ; Humans ; Patellofemoral Joint/diagnostic imaging* ; Osteoarthritis, Knee/diagnostic imaging* ; Retrospective Studies ; Knee Joint ; Femur/diagnostic imaging* ; Tibia

Adult ; Enchondromatosis ; diagnosis ; diagnostic imaging ; Femur ; diagnostic imaging ; Humans ; Male ; Radiography

Diagnostic Errors ; Female ; Femoral Neck Fractures ; diagnosis ; diagnostic imaging ; Femur Neck ; diagnostic imaging ; injuries ; Humans ; Radiography ; Young Adult

OBJECTIVE: To explore the related factors of femoral stem anteversion (FSA) after total hip arthroplasty (THA), so as to provide reference for clinical design of FSA before operation and reduce the risk of hip dislocation after arthroplasty. METHODS: Ninty-three patients (103 hips) who underwent THA between October 2021 and September 2022 and met the selection criteria were selected as the study subjects. Among them, there were 48 males and 45 females with an average age of 58.5 years (range, 25-88 years). Body mass index was 18.00-37.84 kg/m ², with an average of 24.92 kg/m ². There were 51 cases (57 hips) of osteonecrosis of femoral head, 35 cases (39 hips) of hip osteoarthritis, and 7 cases (7 hips) of congenital hip dysplasia. Based on CT images, the following indicators were measured: preoperative femoral neck anteversion (FNA), preoperative femoral rotation angle (FRA), preoperative acetabular anteversion (AA), and preoperative combined anteversion (CA; the sum of preoperative FNA and AA); postoperative FSA and the change in femoral anteversion angle (the difference between postoperative FSA and preoperative FNA). Based on preoperative X-ray films, the following indicators were measured: femoral cortical thickness index (CTI) and canal flare index (CFI), the proximal femoral medullary cavity was classified according to Noble classification (champagne cup type, normal type, chimney type), neck-shaft angle (NSA), and femoral offset (FO). Pearson correlation analysis, one-way ANOVA, and Point-biserial correlation analysis were used to investigate the correlation between postoperative FSA, postoperative change in femoral anteversion angle, and patient diagnosis, proximal femoral medullary cavity anatomy type, gender, age, as well as preoperative FNA, FRA, AA, CA, NSA, FO, CTI, and CFI. FSA was used as the dependent variable and the independent variables that may be related to it were included for multiple linear regression analysis. RESULTS: Based on CT image measurement, preoperative FNA was (15.96±10.01)°, FRA (3.36±10.87)°, AA (12.94±8.83)°, CA (28.9±12.6)°, postoperative FSA (16.18±11.01)°, and postoperative change in femoral anteversion angle was (0.22±9.98)°. Based on preoperative X-ray films measurements, the CTI was 0.586±0.081; the CFI was 4.135±1.125, with 23 hips classified as champagne cup type, 68 hips as normal type, and 12 hips as chimney type in the proximal femoral medullary cavity anatomy; NSA was (132.87±7.83)°; FO was (40.53±10.11) mm. There was no significant difference between preoperative FNA and postoperative FSA ( t=-0.227, P=0.821). Pearson correlation analysis showed that postoperative FSA was positively correlated with preoperative FNA, preoperative CA, postoperative change in femoral anteversion angle, and age ( P<0.05), while negatively correlated with preoperative FRA ( P<0.05). The postoperative change in femoral anteversion angle were positively correlated with preoperative FRA and postoperative FSA ( P<0.05), and negatively correlated with preoperative CA and FNA ( P<0.05). One-way ANOVA analysis showed that the above two indicators were not correlated with diagnosis and the proximal femoral medullary cavity anatomy type ( P>0.05). Multiple linear regression analysis showed a linear correlation between FSA and FNA, CA, age, and FRA ( F=10.998, P<0.001), and the best fit model was FSA=0.48×FNA-2.551. CONCLUSION The factors related to FSA after THA include patient's age, preoperative FNA, CA, FRA and postoperative femoral anteversion, of which preoperative FNA is the most closely related. When designing a surgical plan before surgery, attention should be paid to the patient's preoperative FNA, and if necessary, CT around the hip joint should be scanned to gain a detailed understanding of the proximal femoral anatomical structure.
Female ; Male ; Humans ; Middle Aged ; Arthroplasty, Replacement, Hip ; Femur/diagnostic imaging* ; Femur Neck ; Femur Head ; Hip Joint

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 analysis and determine MR signs of Harris score ARCO stages 2-4 in osteonecrosis of femoral head (ONFH). METHODS: Thirty-four patients with ONFH of ARCO stages 2 to 4 who underwent routine MR, T2 mapping, 3D-SPACE sequence examination and Harris score were retrospectively collected from January 2019 to June 2020, and 3 patients were excluded, and 31 patients were finally included, including 23 males and 8 females, aged from 18 to 62 years old with an average of(40.0±10.8) years old. Among them 21 patients with bilateral femoral head necrosis, totally 52 cases, including 17 with ARCO stage 2 patients, 24 ARCO stage 3, and 11 ARCO stage 4. MR imaging signs (femoral head collapse depth, ONFH index, bone marrow edema, hyperplasia, grade and T2 value of cartilage injury, and joint effusion) were scored and measured on the picture archiving and communication system (PACS) workstation, and the cartilage quantitative parameter T2 value was calculated and measured on Siemens postprocessing workstation. Pearson correlation analysis was used to evaluate the correlation between various MR signs and Harris score, and then multiple linear regression analysis was used to examine impact of MR signs on Harris hip score. RESULTS: Femoral head collapse depth(r=-0.563, P=0.000), grade of cartilage injury(r=-0.500, P=0.000), and joint effusion (r=-0.535, P=0.000) were negatively correlated with Harris score by Pearson correlation analysis. Multiple linear regression analysis showed that joint effusion(β=-6.198, P=0.001) and femoral head collapse depth(β=-4.085, P=0.014) had a significant negative impact on Harris hip score. CONCLUSION Femoral head collapse depth and joint effusion both had significant negative relationship with Harris hip score. It is recommended to routinely evaluate femoral head collapse depth and joint effusion quantitatively and gradedly, so as to efficiently and accurately assist clinical diagnosis and treatment.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Femur Head Necrosis/diagnostic imaging* ; Retrospective Studies ; Femur Head/diagnostic imaging* ; Bone Transplantation/methods* ; Magnetic Resonance Imaging ; Treatment Outcome

Clear cell chondrosarcoma is a rare cartilaginous tumour of low-grade malignancy. Although it has a characteristic histological appearance, its radiological features and clinical presentation often mimic a benign lesion. Herein, we describe the case of a patient with a clear cell chondrosarcoma of the right proximal femur that had an atypical appearance of chronic avascular necrosis on initial plain radiographs, which made preoperative diagnosis a challenge. In addition, the tumour also had extensive areas of aneurysmal bone cyst-like changes, which is not only a rare histologic phenomenon in clear cell chondrosarcoma, but also a confounding factor in the interpretation of the radiologic findings.
Adult ; Bone Cysts, Aneurysmal ; complications ; diagnostic imaging ; Bone Neoplasms ; complications ; diagnostic imaging ; Chondrosarcoma ; complications ; diagnostic imaging ; Female ; Femur ; diagnostic imaging ; pathology ; Hip ; pathology ; Humans ; Magnetic Resonance Imaging ; Necrosis ; pathology ; Osteoarthritis ; diagnostic imaging ; Radiography ; Whole Body Imaging

This paper presents a unit free-form deformation (FFD) method applied to rapid three-dimensioanl (3D) bone reconstruction, which was based on traditional FFD. With the femur as an example, we reconstructed a 3D model of femur from two X-ray images and a standardized model by taking advantage of unit FFD algorithm. The X-ray images and its parameters were taken by C-arm device. Those parameters and X-ray contour are contributed to 3D reconstruction. The out contours of X-ray image and standard model were connected by point matching algorithm. The unit-FFD lattice was built to reconstruct standard model and finally made the contour of X-ray image and standard model exactly the same. Experiments on shape accuracy, robustness and time consuming, carried out by 35 specimen from cadaver, showed that mean error of shape (0. 52 mm) and mean construction time (112 s) were lower than those using traditional method (0.7-2.6 mm, 8-20 min). The method proposed in this paper shows a good prospect in clinical application and related research.
Algorithms ; Femur ; anatomy & histology ; diagnostic imaging ; Humans ; Imaging, Three-Dimensional ; Models, Anatomic ; Radiography