OBJECTIVE: To investigate the correlation between the quadriceps cross-sectional area (CSA) and quadriceps muscle volume (QMV) at different horizontal levels from the upper edge of the patella, and to determine the best observation position. METHODS: Thigh magnetic resonance imaging (MRI) images of 22 Chinese young men [age: (29±6) years] with anterior cruciate ligament (ACL) rupture were examined. The CSA was measured at 18, 15, and 12 cm above the upper edge of the pate-lla (denoted by CSA-18, CSA-15 and CSA-12 respectively), and the QMV and CSA were determined by semiautomatic segmentation. A curve model was established to estimate QMV. Bland-Altman analysis was performed to determine the confidence limits of the volumes. RESULTS: On the unaffected side, the mean QMV was (1 944.45±323.77) cm³. The quadriceps CSA at the upper edge of the patella at 18, 15, and 12 cm was (80.80±12.16) cm², (77.53±12.03) cm², and (72.68±10.51) cm², respectively. The coefficients of determination (R²), ascertained using curve estimation models, for the 3 positions were 0.819, 0.755, and 0.684 (P < 0.001), and the standard deviations of the volume estimated value (SEE) were 7.4%, 8.7%, and 9.8%. The fitting equations of the three horizontal positions were all good, but the fitting degree of CSA-18 was the highest. The Bland-Altman scatter plot showed that the arithmetic means of the QMV at 18, 15 and 12 cm from the upper edge of the patella 0.8 cm³, -1.1 cm³, and 0.9 cm³ and 95% limits of agreement (LoA) were (-268.8, 270.5), (-315.2, 313.1), and (-355.7, 357.5), respectively. The estimated QMV was in good agreement with the measured value. The difference between the estimated CSA-18 and measured values was the smallest. The results on the affected side were consistent. CONCLUSION The correlation between QMV and CSA in the young men with the upper edge of patella as baseline was reliable and consistent. Among them, CSA-18 had the highest correlation with the QMV. However, different observation sites could be selected for different injuries of the quadriceps.
Adult ; Anterior Cruciate Ligament Injuries/surgery* ; Anterior Cruciate Ligament Reconstruction ; Humans ; Magnetic Resonance Imaging ; Male ; Patella ; Quadriceps Muscle/diagnostic imaging* ; Young Adult

OBJECTIVE: To construct a dynamic knee joint finite element model based on CT image data and verify the validity of the model. To provide a simulation model and basic data for biomechanical research of the knee joint by further finite element analysis. METHODS: The CT data of a healthy male knee joint was selected. With the help of Mimics 19.0 and Hypermesh 12.0 software, a high simulation finite element model of knee joint was established following steps, including geometric reconstruction, reverse engineering, meshing and material characterization. The dynamic knee flexion model was generated by determining the boundary conditions and torque loading, and the validity of themodel was confirmed. The biomechanical changes of the tibiofemoral and patellofemoral joints under different knee flexion angles were analyzed by applying the loads (500 N) to the finite element model during knee flexion. RESULTS: A finite element model of knee joint was established based on CT images and anatomical characteristics. The model included three-dimensional elements such as bone, ligament, cartilage, meniscus and patellar retinaculum. The different finite element models of knee flexion states were produced by applying different torques after establishing boundary conditions. According to equivalent conditions (knee flexion 30 degrees, quadriceps tendon under 200 N stretch), the peak stress value of patella was 2.209 MPa and the average Mises stress was 1.132 MPa; the peak stress value of femoral trochlear was 1.405 MPa and the average Mises stress was 0.936 MPa. The validity of the model was proved by the difference between the model and previous studies of 1% to 13.5%. Dynamic model loading showed that the Mises stressof tibiofemoral joint decreased with the increase of knee flexion angle, while the Mises stress of patellofemoral joint was positively correlated with knee flexion angle. The Mises stress of cartilage stress planes at different knee flexion angles was significantly different(<0.05). CONCLUSION The finite element model established in this study is more comprehensive and can effectively simulate the biomechanical characteristics of dynamic knee joint, which provides support for further simulation mechanics researches of the knee joint.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Knee Joint ; diagnostic imaging ; Male ; Patella ; Stress, Mechanical ; Tomography, X-Ray Computed

Objective To estimate sex based on patella measurements of Sichuan Han population by computed tomography three-dimensional volume reconstruction technique, and to explore the application value of patella in sex estimation. Methods CT three-dimensional volume reconstruction images of patella of 250 individuals were collected, the four measurement indicators including patellar length, patellar width, patellar thickness, and patellar volume were measured. The t-test was used to determine measurement indicators with sex differences. Fisher discriminant analysis was used to establish the sex discriminant function and the prediction accuracy was calculated by leave-one-out cross validation. Results The sex differences of the four measurement indicators had a statistical significance （P<0.05）. The accuracy rate of the univariate discriminant function established by the patellar length was the highest （82.0%）. The accuracy rates of the all indicators discriminant function and the stepwise discriminant function were 80.4% and 81.6%, respectively. Conclusion It is feasible and accurate to estimate sex of Sichuan Han population by patella measurements with CT three-dimensional volume reconstruction technique. The method may be used as an alternative for sex estimation of Sichuan Han population when other bones with higher accuracy are not available.
Discriminant Analysis ; Female ; Forensic Anthropology ; Humans ; Imaging, Three-Dimensional ; Male ; Patella/diagnostic imaging* ; Sex Determination by Skeleton ; Tomography, X-Ray Computed

A 20-year-old National Serviceman presented with left knee pain and swelling after training for his physical fitness test. Lateral knee radiography and magnetic resonance (MR) imaging showed patellar tendon-lateral femoral condyle friction syndrome (PT-LFCFS), on a background of patella alta and patellar malalignment. The patient was treated non-operatively with a course of physiotherapy and given advice on rest and activity modification. PT-LFCFS is a less well-recognised but important cause of anterior knee pain and represents an entity in a spectrum of disorders related to patellofemoral instability. We herein discuss the MR imaging findings specific to and associated with this condition, as well as briefly describing treatment options. In addition, we showcase a range of commonly encountered abnormalities that affect the infrapatellar fat pad and briefly discuss their specific MR imaging findings.
Adult ; Arthralgia ; diagnostic imaging ; Female ; Femur ; diagnostic imaging ; Humans ; Knee ; diagnostic imaging ; Knee Injuries ; diagnostic imaging ; therapy ; Knee Joint ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pain ; diagnostic imaging ; Patella ; diagnostic imaging ; Patellar Ligament ; diagnostic imaging ; Physical Therapy Modalities ; Radiography ; Young Adult

OBJECTIVETo evaluate long-term result of Scorpio posterior-stabilized total knee arthroplasty.

METHODSThere were 160 patients (240 knees) underwent Scorpio posterior-stabilized total knee arthroplasty between December 1998 and December 2000, which were performed by the same surgeon. Patients were followed up from June 2013 to December 2013. Knee Society Scoring (KSS), Hospital for Special Surgery (HSS) patellofemoral scoring, standard weight-bearing anteroposterior and patellar tangential radiographs were assessed. Satisfaction of outcome was requested. Alignment of components and presence of radiolucent lines were assessed by the radiographic scoring system of knee society. Paired t-test was used compared to the data between preoperation and the time of last follow-up.

RESULTSNinety-five patients (141 knees) (59.4%) were followed up. Average follow-up duration was 13.3 years (range 12 to 15 years). Eight knees were revised due to periprosthetic infection (4 knees), aseptic loosening of tibial tray (3 knees) and wear-out of polyethylene insert (1 knee). Compared with preoperative ones, KSS knee score, KSS functional score and range of motion improved significantly (pre-operation: 26±16, 34±18, 87°±25°; follow-up time: 93±8, 78±27, 114°±22°) (t=45.55, 15.60, 13.03, all P<0.01). In terms of KSS knee score and HSS patellofemoral score, 106 knees were rated as excellence respectively. Ninety-five knees had satisfaction with outcome for maximum. The presences of radiolucent lines occurred around 5 femoral and 11 tibial components with range less than 2 mm. The survival rate at 10 years was 94.5% with revision for any reason as the end point.

CONCLUSIONThe long-term study indicates that Scorpio posterior-stabilized knee system shows favorable clinical and radiological results.

Arthroplasty, Replacement, Knee ; methods ; Femur ; diagnostic imaging ; Follow-Up Studies ; Humans ; Knee Joint ; surgery ; Knee Prosthesis ; Patella ; diagnostic imaging ; Polyethylene ; Radiography ; Range of Motion, Articular ; Reoperation ; Tibia ; diagnostic imaging ; Treatment Outcome

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

Adolescent ; Diagnosis, Differential ; Humans ; Hyperoxaluria, Primary ; diagnosis ; Knee ; diagnostic imaging ; Lumbar Vertebrae ; diagnostic imaging ; Male ; Patella ; diagnostic imaging ; injuries ; Radiography

A 14-year-old girl presented with left knee pain and swelling after an injury. Magnetic resonance (MR) imaging showed a transient lateral patellar dislocation with patellar osteochondral fracture, medial patellofemoral ligament tear and underlying femoral trochlear dysplasia. Open reduction and internal fixation of the osteochondral fracture, plication of the medial patellar retinaculum and lateral release were performed. As lateral patellar dislocation is often clinically unsuspected, an understanding of its characteristic imaging features is important in making the diagnosis. Knowledge of the various predisposing factors for patellar instability may also influence the choice of surgical management. We also discuss signs of acute injury and chronic instability observed on MR imaging, and the imaging features of anatomical variants that predispose an individual to lateral patellar dislocation. Treatment options and postsurgical imaging appearances are also briefly described.
Adolescent ; Arthralgia ; diagnosis ; Female ; Fracture Fixation, Internal ; Fractures, Bone ; diagnostic imaging ; pathology ; Humans ; Joint Instability ; Knee Joint ; diagnostic imaging ; Ligaments, Articular ; injuries ; Magnetic Resonance Imaging ; Patella ; diagnostic imaging ; pathology ; Patellar Dislocation ; diagnosis

BACKGROUNDDue to racial differences in the morphology of the knee joint and due to most prostheses available in the market being designed using measurements from Caucasians, the objective of this study was to provide the morphometric data of the patella for the southern Chinese population for total knee arthroplasty (TKA), patellar resurfacing, and prostheses design.

METHODSThe CT slices of the knee joint were obtained from both knees of 40 Chinese volunteers (20 females, 20 males, and age from 20-25 years) by performing a computer tomographic scan. A 3D model was reconstructed by Mimics software based on the computed tomography images. Six metrical characteristics were measured by digital ruler. Statistical analysis was performed with the SPSS statistical program.

RESULTSThe mean, standard deviation and P values of measurements and ratios were calculated using SPSS. All dimensions showed a significant gender difference with P < 0.05, but the six variables of the left and right knees had no statistical significance with P > 0.05. In addition, we studied the relationship between six couples (H-W, H-T, H-HAF, W-T, W-HAF, T-HAF) of the four variables (H: height, W: width, T: thickness and HAF: height of articulating facet) that were measured, which showed a significant correlation.

CONCLUSIONSExamination of the southern Chinese population revealed that males have larger patellae than women. In both genders, comparing data between left and right knees shows no statistically significant difference. Compared with Westerners in previous studies, the patella in our study was thin and small. There was a good linear regression correlation between measurements of the patella. The indirect measurement method on 3D models makes it easy to obtain anatomical data, and the results can provide a region and gender specific database for morphometric measurements of the patella, and can be helpful for designing implants suited for southern Chinese patients.

Adult ; Arthroplasty, Replacement, Knee ; China ; Female ; Humans ; Male ; Patella ; diagnostic imaging ; Tomography, X-Ray Computed ; Young Adult

OBJECTIVETo observe the efficacy of Jianbu Tongluo Xunzheng Liquid (JTXL) in treating knee osteoarthritis (KOA), and to explore the correlation between changes of infrapatellar fat pad scanned by CT and the efficacy.

METHODSTotally 105 KOA outpatients were randomly assigned to three groups, i.e., the treatment group, the control group, and the combination group, 35 in each group. Patients in the treatment group were fumigated by JTXL, 30 min each time, once daily, 10 times as a course of treatment, 3 courses in total. Those in the control group received intra-articular injection of Sodium Hyaluronate Injection (SHI), 3 mL each time, once per 6 days, 5 times in total. Those in the combination group were treated by fumigation of JTXL + intra-articular injection of SHI in the same way as the aforesaid two groups. All patients were treated for 30 days. Their clinical efficacy and changes of infrapatellar fat pad scanned by CT were observed, and their correlation was analyzed.

RESULTSThe total effective rate was 88.57% in the combination group, better than that of the control group (74.29%) and the treatment group (80.00%; both P < 0.05). Besides, the score for knee joint functions at Hospital for Special Surgery (HSS) was better in the combination group than the other two groups (P < 0.05). The anteroposterior diameter, exterior-interior diameter, the superior-inferior diameter were shortened, and the density decreased in the treatment group and the combination group (P < 0.05). Besides, they were superior to those of the control group (P < 0.05).

CONCLUSIONSChanges of infrapatellar fat pad scanned by CT only existed in the combination group and the treatment group, indicating changes of CT scanning was only correlated with effect on changing physicochemical properties of infrapatellar fat pad. Treatment by Chinese medicine could omnipotently and balanced regulate functions and structures of every tissue. Therefore, CT could be taken as a better method for clinical efficacy observation by Chinese medicine.

Adipose Tissue ; diagnostic imaging ; Adult ; Aged ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Osteoarthritis, Knee ; diagnostic imaging ; drug therapy ; Patella ; diagnostic imaging ; Phytotherapy ; Tomography, X-Ray Computed