The Relationship of Open- and Closed-Kinetic-Chain Rate of Force Development With Jump Performance Following Anterior Cruciate Ligament Reconstruction.

PURPOSE: To determine between-limbs differences in isometric rate of force development (RFD) measured during open- (OKC) and closed-kinetic-chain (CKC) strength testing and establish which method had the strongest relationship to single-leg vertical-jump performance and knee mechanics after anterior cruciate ligament (ACL) reconstruction. METHODS: Subjects (n = 19) 1 to 5 years from ACL reconstruction performed isometric knee extensions (OKC), unilateral isometric midthigh pulls (CKC), and single-leg vertical jumps on the ACL-involved and -noninvolved limbs. Between-limbs differences were assessed using paired t tests, and the relationship between RFD, jump performance, and knee mechanics was assessed using correlation coefficients (r; P ≤ .05). RESULTS: There were significant between-limbs differences in OKC RFD (P = .008, d = -0.69) but not CKC RFD. OKC RFD in the ACL-involved limb had a strong association with jump height (r = .64, P = .003), knee-joint power (r = .72, P < .001), and peak knee-flexion angle (r = .72, P = .001). CKC RFD in the ACL-involved limb had a strong association with jump height (r = .65, P = .004) and knee-joint power (r = .67, P = .002) but not peak knee-flexion angle (r = .40, P = .09). CONCLUSIONS: While both OKC and CKC RFD were strongly related to jump performance and knee-joint power, OKC RFD was able to detect between-limbs RFD asymmetries and was strongly related to knee-joint kinematics. These findings indicate that isometric knee extension may be optimal for assessing RFD after ACL reconstruction.

Gaussian Aquila optimizer based dual convolutional neural networks for identification and grading of osteoarthritis using knee joint images.

Degenerative musculoskeletal disease known as Osteoarthritis (OA) causes serious pain and abnormalities for humans and on detecting at an early stage, timely treatment shall be initiated to the patients at the earliest to overcome this pain. In this research study, X-ray images are captured from the humans and the proposed Gaussian Aquila Optimizer based Dual Convolutional Neural Networks is employed for detecting and classifying the osteoarthritis patients. The new Gaussian Aquila Optimizer (GAO) is devised to include Gaussian mutation at the exploitation stage of Aquila optimizer, which results in attaining the best global optimal value. Novel Dual Convolutional Neural Network (DCNN) is devised to balance the convolutional layers in each convolutional model and the weight and bias parameters of the new DCNN model are optimized using the developed GAO. The novelty of the proposed work lies in evolving a new optimizer, Gaussian Aquila Optimizer for parameter optimization of the devised DCNN model and the new DCNN model is structured to minimize the computational burden incurred in spite of it possessing dual layers but with minimal number of layers. The knee dataset comprises of total 2283 knee images, out of which 1267 are normal knee images and 1016 are the osteoarthritis images with an image of 512 × 512-pixel width and height respectively. The proposed novel GAO-DCNN system attains the classification results of 98.25% of sensitivity, 98.93% of specificity and 98.77% of classification accuracy for abnormal knee case-knee joint images. Experimental simulation results carried out confirms the superiority of the developed hybrid GAO-DCNN over the existing deep learning neural models form previous literature studies.

A Two-Degree-of-Freedom Knee Model Predicts Full Three-Dimensional Tibiofemoral and Patellofemoral Joint Motion During Functional Activity.

Six kinematic parameters are needed to fully describe three-dimensional (3D) bone motion at a joint. At the knee, the relative movements of the femur and tibia are often represented by a 1-degree-of-freedom (1-DOF) model with a single flexion-extension axis or a 2-DOF model comprising a flexion-extension axis and an internal-external rotation axis. The primary aim of this study was to determine the accuracy with which 1-DOF and 2-DOF models predict the 3D movements of the femur, tibia and patella during daily activities. Each model was created by fitting polynomial functions to 3D tibiofemoral (TF) and patellofemoral (PF) kinematic data recorded from 10 healthy individuals performing 6 functional activities. Model cross-validation analyses showed that the 2-DOF model predicted 3D knee kinematics more accurately than the 1-DOF model. At the TF joint, mean root-mean-square (RMS) errors across all activities and all participants were 3.4°|mm (deg or mm) for the 1-DOF model and 2.4°|mm for the 2-DOF model. At the PF joint, mean RMS errors were 4.0°|mm and 3.9°|mm for the 1-DOF and 2-DOF models, respectively. These results indicate that a 2-DOF model with two rotations as inputs may be used with confidence to predict the full 3D motion of the knee-joint complex.

The analysis on perioperative blood loss factors and effect of tranexamic acid on the amount of occult bleeding in total knee arthroplasty / 中国医师进修杂志

Objective:To explore the factors of perioperative blood loss during total knee arthroplasty (TKA), and to analyze the influence of tranexamic acid on the amount of occult bleeding.Methods:A total of 100 patients who underwent TKA surgery in the knee surgery department of Dingzhou People′s Hospital from August 2018 to August 2020 were selected as the research subjects. According to whether tranexamic acid was used or not, they were divided into tranexamic acid group (68 cases) and non-tranexamic acid group (32 cases). The influence of the age, presence or absence of comorbidities, tourniquet use time, body mass index (BMI), platelet count (PLT) levels, and tranexamic acid use on TKA perioperative occult blood loss were analyzed.Results:Univariate analysis showed that factors such as age, presence or absence of comorbidities, tourniquet use time, BMI and PLT levels had a significant effect on occult blood loss, and the difference between different groups was statistically significant ( P<0.05), while gender and disease type, operation side, operation time and blood transfusion type had no significant effect on occult blood loss ( P>0.05); The latent blood loss in the tranexamic acid group was significantly lower than that in the non-tranexamic acid group: (662.47 ± 65.82) ml vs. (733.86 ± 59.86) ml, P<0.05. The proportion of allogeneic blood transfusion in the tranexamic acid group was significantly lower than that in the non-tranexamic acid group: 45.49%(31/68) vs. 68.75% (22/32), P<0.05. Postoperative drainage volume and perioperative total blood loss in the tranexamic acid group were significantly lower than those in the non-tranexamic acid group: (211.54 ± 85.63) ml vs. (427.61 ± 103.08) ml, (995.38 ± 187.11) ml vs. (1 276.42 ± 236.84) ml, P<0.05. Multivariate analysis showed that age, comorbidities, and tourniquet use time, and BMI were independent risk factors affecting the increase of perioperative occult blood loss ( P<0.05), and tranexamic acid was a protective factor ( P<0.05). Conclusions:Old age, comorbidities, excessive use time of tourniquets, and obesity can all cause the increase of perioperative occult blood loss during TKA. The use of tranexamic acid can effectively reduce the occult blood loss.

[Choice of reconstructive operation in lesions of femoropopliteotibial segment and dubious outflow pathways]. / Vybor rekonstruktivnoi operatsii pri porazheniiakh arterii bedrenno-podkolenno-bertsovogo segmenta i somnitel'nykh putiakh ottoka.

We analysed the results of surgical treatment of 40 patients with lower limb critical ischaemia induced by atherosclerotic lesion of arteries of the femoropopliteotibial segment with dubious outflow pathways. The patients were divided into two groups of 20 each. Group One patients underwent autovenous femoropopliteal or tibial bypass grafting below the fissure of the knee joint and Group Two patients were subjected to profundoplasty with closure of the arteriotomic opening with an autovenous patch. The outflow pathway index in Group One amounted to 7.5±0.09 and in Group Two to 7.45±0.08. Our findings suggest that the use of profundoplasty as reconstructive operation in patients with dubious outflow pathways is pathogenetically substantiated, because it makes it possible to decrease the rate of early postoperative complications by 20% and that of late bypass thromboses by 25%, as well as to increase the level of the physical component of health by 12.1% and that of mental health by 3.2%. A conclusion drawn is that performing profundoplasty in this cohort of patients is appropriate and effective.

TheMRIevaluationandriskfactorsanalysisofchronicinjuryof medialcollateralligamentinpatientswithosteoarthritis / 实用放射学杂志

Objective Toexploretheriskfactorsofchronicinjuryofmedialcollateralligament(MCL)inpatientswithosteoarthritis(OA). Methods Thestudywasconductedretrospectivelyandatotalof191patientsinourhospitalfromFebruary2017toApril2018were collected,amongthem,86casesofOApatientswithchronicinjuryofMCLastheobservationgroup,42casesofpatientswithacute MCLinjurycausedbytraumaasthecontrolgroup1,63casesofOApatientswithoutMCLinjuryascontrolgroup2.TheMRImanifestationsof kneejointsintheobservationgroupandthecontrolgroup1werecompared,thedifferencesofthedamagemechanismsbetweenthe twogroupswereanalyzed.TheMRImanifestationsandrelatedclinicaldataoftheobservationgroupandthecontrolgroup2wereanalyzed,and thefactorsthatmightcausethechronicinjuryofMCL wereidentifiedbyunivariateregressionanalysis,thenwereincludedinthe non-conditional L o g istic regression m odel for m ultivariate analysis and the risk factors and protective factors of chronic injury of MCLwerefinallyscreenedout.Results Thedifferencesinthe MRImanifestationsbetweentheobservationgroupandthecontrol group1,includingthegradingoftheMCLinjury,thegradingandthedislocationofmedialmeniscus,thedistributionofbonemarrow edema,theanteriorandposteriorcruciateligamentinjuriesandthestenosistypesofthejointspacewerestatisticallysignificant(P<0.05).The resultsrevealedthatthechronicinjuryofMCLwasrelatedtoage,sex,medialmeniscusdislocation,thegradingofmedialmeniscus, osteophyte,anteriorcruciateligamentinjury,posteriorcruciateligamentinjury,andthestenosistypeofthejointspaceusingtheunivariateanalysis (P<0.05).Theresultsrevealedthatosteophyte(OR=38.231,95%CI:6.573-222.370),medialmeniscusdislocation (OR=6.504, 95%CI:1.508-28.046),anteriorcruciateligamentinjury(OR=7.236,95%CI:1.188-44.090)wereriskfactorsforchronicinjury ofMCLinOApatientsandlateraljointspacestenosis(OR=0.014, 95%CI:0.002-0.092)andpatella-femoraljointspacestenosis (OR=0.006,95%CI:0.000-0.071)wereprotectivefactorsusing multiple L o g istic regression model.Conclusion Thepathogenicfactorsaredifferentbetweenchronicinjuryof MCLin OA patients andacuteinjuryofMCL.Osteophyte,medialmeniscusdislocation,anteriorcruciateligamentinjuryareriskfactorsforchronicinjury ofMCLinOApatients,andlateraljointspacestenosisandpatella-femoralspacestenosisareprotectivefactors.

Thevalueof3DGSPACEsequencetodisplayposterolateralcomplexinthekneejoint / 实用放射学杂志

Objective Toinvestigatethediagnosticvalueof3DGSPACEsequencewith3Dreconstructiontechniqueinevaluationof posterolateralcomplexofthekneejoint.Methods 30kneejointsofhealthyvolunteersweresubjectedtoMRIconventionalsequences andSPACEsequencewith3Dreconstructiontechnique.AdoubleblindmethodwasusedtocompareMRIroutineand3DGSPACEsequence imagesontheposteriorlateralcomplexofthekneejoint.Theeffectoftwoscanningmethodsonthelateralcollateralligament,popliteal tendonandpoplitealligamentwasanalyzedbyrankandtest.Results Ithadstatisticaldifferencebetweentwogroupsindisplayof posterolateralcomplex(P＜0.01).Thedisplayeffecton3DGSPACEsequenceforthelateralcollateralligament,poplitealtendonand poplitealligamentwasbetterthanthatontheconventionalMRIsequence.Conclusion 3DGSPACEsequencewith3Dreconstruction techniquecancompletelydisplaytheconfigurationanddirectionofposterolateralcomplex,whichcanimprovetherateofshowingligament obviously.

[Electroacupuncture Intervention Improves Cartilage Degeneration and Subchondral Bone Osteoporosis of Knee-joint Possibly by Adjusting OPG/RANK/RANKL Signaling in Ovariectomized Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on histopathological changes of cartilage and subchondral bone and osteoprotegerin (OPG)，receptor activator of nuclear factor-κB (RANK), and RANK ligand (RANKL) (OPG/RANK/RANKL) signaling and the expression of matrix metalloproteinase-13 (MMP-13) in ovariectomized(OVX)rats, so as to explore its mechanism underlying improvement of osteoporosis. METHODS: Three-month female SD rats were randomly divided into sham operation, model and EA groups (n＝8 in each group). The ovoariectomy model was established by resection of bilateral ovaries. Rats of the sham group were treated by simple removal of a piece of adipose tissue around the bilateral ovaries. EA (3 Hz/15 Hz, 1 mA) was applied to bilateral "Sanyinjiao" (SP 6), "Yanglingquan" (GB 34), "Yinlingquan" (SP 9) and "Zusanli" (ST 36) for 30 min, once daily (except the weekends) for 12 weeks. The histopathological changes of the subchondral bone of the right knee-joint were observed after Saffron O dyeing and evaluated by Mankin's score, and its anatomical structure including the bone volume fraction (bone volume/tissue volume, BV/TV), trabecular bone number (Tb. N) and trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) was observed by using Micro CT imaging. The urine C-terminal cross-linking telopeptide of type Ⅰ collagen (CTX-Ⅰ), CTX-Ⅱ (two bone resorption markers) and serum estrogen (E 2) contents were assayed by ELISA, and the expression levels of OPG, RANKL and MMP-13 mRNAs in the cartilage tissue of the left knee-joint were detected by quantitative RT-PCR. RESULTS: Following modeling, the BV/TV, Tb. N and Tb.Th levels were significantly decreased (P<0.01) and Tb.Sp and Mankin's score obviously increased in the model group compared with the sham group (P<0.01), suggesting a formation of osteoporosis and degeneration of the cartilage tissue. The serum E 2 content and OPG mRNA level in the cartilagetissue were significantly down-regulated (P<0.01), and urine CTX-Ⅰ and CTX-Ⅱ contents and RANKL mRNA and MMP-13 mRNA expression levels cartilagetissue were considerably up-regulated in the model group relevant to the sham group (P<0.01). After EA intervention, modeling-induced decrease of BV/TV, Tb.N, Tb.Th, E 2 and OPG mRNA levels and OVX-induced increase of Tb.Sp, Mankin's score, CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels were all completely reversed in the EA group relevant to the model group (P<0.01，P<0.05)．. CONCLUSION: EA intervention can inhibit subchondral bone osteoporosis and articular cartilage degeneration of knee-joint in OVX rats, which is closely associated with its effects in inhibiting the down-regulation of serum E 2 and OPG mRNA expression and up-regulation of CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels, including adjusting OPG/RANK/RANKL signaling.

Electroacupuncture Intervention Improves Cartilage Degeneration and Subchondral Bone Osteoporosis of Knee-joint Possibly by Adjusting OPG/RANK/RANKL Signaling in Ovariectomized Rats / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) on histopathological changes of cartilage and subchondral bone and osteoprotegerin (OPG)，receptor activator of nuclear factor-κB (RANK), and RANK ligand (RANKL) (OPG/RANK/RANKL) signaling and the expression of matrix metalloproteinase-13 (MMP-13) in ovariectomized(OVX)rats, so as to explore its mechanism underlying improvement of osteoporosis. METHODS: Three-month female SD rats were randomly divided into sham operation, model and EA groups (n＝8 in each group). The ovoariectomy model was established by resection of bilateral ovaries. Rats of the sham group were treated by simple removal of a piece of adipose tissue around the bilateral ovaries. EA (3 Hz/15 Hz, 1 mA) was applied to bilateral "Sanyinjiao" (SP 6), "Yanglingquan" (GB 34), "Yinlingquan" (SP 9) and "Zusanli" (ST 36) for 30 min, once daily (except the weekends) for 12 weeks. The histopathological changes of the subchondral bone of the right knee-joint were observed after Saffron O dyeing and evaluated by Mankin's score, and its anatomical structure including the bone volume fraction (bone volume/tissue volume, BV/TV), trabecular bone number (Tb. N) and trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) was observed by using Micro CT imaging. The urine C-terminal cross-linking telopeptide of type Ⅰ collagen (CTX-Ⅰ), CTX-Ⅱ (two bone resorption markers) and serum estrogen (E 2) contents were assayed by ELISA, and the expression levels of OPG, RANKL and MMP-13 mRNAs in the cartilage tissue of the left knee-joint were detected by quantitative RT-PCR. RESULTS: Following modeling, the BV/TV, Tb. N and Tb.Th levels were significantly decreased (P<0.01) and Tb.Sp and Mankin's score obviously increased in the model group compared with the sham group (P<0.01), suggesting a formation of osteoporosis and degeneration of the cartilage tissue. The serum E 2 content and OPG mRNA level in the cartilagetissue were significantly down-regulated (P<0.01), and urine CTX-Ⅰ and CTX-Ⅱ contents and RANKL mRNA and MMP-13 mRNA expression levels cartilagetissue were considerably up-regulated in the model group relevant to the sham group (P<0.01). After EA intervention, modeling-induced decrease of BV/TV, Tb.N, Tb.Th, E 2 and OPG mRNA levels and OVX-induced increase of Tb.Sp, Mankin's score, CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels were all completely reversed in the EA group relevant to the model group (P<0.01，P<0.05)．. CONCLUSION: EA intervention can inhibit subchondral bone osteoporosis and articular cartilage degeneration of knee-joint in OVX rats, which is closely associated with its effects in inhibiting the down-regulation of serum E 2 and OPG mRNA expression and up-regulation of CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels, including adjusting OPG/RANK/RANKL signaling.

Metabolomic Study on Serum of Liver-Kidney Deficiency Syndrome of Knee-Joint Osteoarthritis Based on 1H-NMR / 中国中医药信息杂志

Objective To study the endogenous metabolites of liver-kidney deficiency syndrome in knee-joint osteoarthritis (KOA) and explore the metabolic profile of KOA liver-kidney deficiency syndrome. Methods Totally 50 cases of KOA with liver-kidney deficiency syndrome and 50 cases of KOA with non-liver-kidney deficiency syndrome were collected respectively, and 20 cases of healthy volunteers were collected as the normal group. The serum samples of subjects were collected after fasting for 8 h. Hydro-Nuclear Magnetic Resonance (1H-NMR) spectrometer was collected. Principal component analysis and partial least squares discrimination analysis were used to conduct multivariate statistical analysis. Results 1H-NMR could identify 23 kinds of metabolites, and there was statistical significance between KOA patients and healthy volunteers (P<0.05, P<0.01). There was statistical significance in cartilage matrix metabolism, energy metabolism, lipid metabolism, pain, inflammation-related metabolites in patients with KOA liver-kidney deficiency syndrome and patients with KOA non-liver-kidney deficiency syndrome (P<0.05). Conclusion Patients with KOA liver-kidney deficiency syndrome have a unique 1H-NMR metabolic profile, KOA syndrome has a metabolic material basis.

Observations on the Clinical Efficacy of Thumb-tack Needle Therapy for the Early and Middle Stages of Senile Knee Osteoarthritis / 上海针灸杂志

Objective To investigate the clinical efficacy of thumb-tack needle therapy for the early and middle stages of senile knee osteoarthritis.Method Sixty patients were allocated, using a random number table, to observation and control groups, 30 cases each.Thecontrol group took meloxicam tablets7.5 mg once daily and the observation group received thumb-tack needle therapy8 hrs once daily inaddition.Liangqiu(ST34), Xiyangguan(GB33), Neixiyan(Ex-LE4), Dubi(ST35), Yinlingquan(SP9),Yanglingquan(GB34)and Ashipoint were selected forthumb-tack needle therapy.Both groups were treated five times a week for two consecutive weeks.The WOMAC score and the Lysholm score were recorded before and after treatment.Theclinical therapeutic effects were evaluated.Result The total efficacy rate was 93.3% inthe observation group and 80.0% in the control group.It was higher inthe observation group thanin the control group and there was a statistically significant difference (P<0.05). The WOMAC score decreased and the Lysholm score increased in both groups after treatment; there were statistically significant pre-/post-treatment differences (P<0.05).after treatment, the WOMAC score and the Lysholm score improved more inthe observation group than in the control group; there were statistically significant differences (P<0.05).Conclusion Thumb-tack needle therapyhas a definite effect on the early and middle stages of senile knee osteoarthritis.It can relieve the pain and improveknee functionin the patients.

Naringenin regulates production of matrix metalloproteinases in the knee-joint and primary cultured articular chondrocytes and alleviates pain in rat osteoarthritis model

Inflammation of cartilage is a primary symptom for knee-joint osteoarthritis. Matrix metalloproteinases (MMPs) are known to play an important role in the articular cartilage destruction related to osteoarthritis. Naringenin is a plant-derived flavonoid known for its anti-inflammatory properties. We studied the effect of naringenin on the transcriptional expression, secretion and enzymatic activity of MMP-3 in vivo in the murine monosodium iodoacetate (MIA) osteoarthritis model. The assessment of pain behavior was also performed in the MIA rats. The destruction of knee-joint tissues was analyzed microscopically. Moreover, the effect of naringenin was also studied in vitro in IL-1β activated articular chondrocytes. The transcriptional expression of MMP-3, MMP-1, MMP-13, thrombospondin motifs (ADAMTS-4) and ADAMTS-5 was also studied in primary cultured chondrocytes of rats. Naringenin caused significant reduction in pain behavior and showed marked improvement in the tissue morphology of MIA rats. Moreover, a significant inhibition of MMP-3 expression in MIA rats was observed upon treatment with naringenin. In the in vitro tests, naringenin caused a significant reduction in the transcriptional expression, secretion and enzymatic activity of the studied degradative enzymes. The NF-κB pathway was also found to be inhibited upon treatment with naringenin in vitro. Overall, the study suggests that naringenin alleviated pain and regulated the production of matrix-metalloproteinases via regulation of NF-κB pathway. Thus, naringenin could be a potent therapeutic option for the treatment of osteoarthritis.

Phenotypical expression of reduced mobility during limb ontogeny in frogs: the knee-joint case.

Movement is one of the most important epigenetic factors for normal development of the musculoskeletal system, particularly during genesis and joint development. Studies regarding alterations to embryonic mobility, performed on anurans, chickens and mammals, report important phenotypical similarities as a result of the reduction or absence of this stimulus. The precise stage of development at which the stimulus modification generates phenotypic modifications however, is yet to be determined. In this work we explore whether the developmental effects of abnormal mobility can appear at any time during development or whether they begin to express themselves in particular phases of tadpole ontogeny. We conducted five experiments that showed that morphological abnormalities are not visible until Stages 40-42. Morphology in earlier stages remains normal, probably due to the fact that the bones/muscles/tendons have not yet developed and therefore are not affected by immobilization. These results suggest the existence of a specific period of phenotypical expression in which normal limb movement is necessary for the correct development of the joint tissue framework.

Angle-specific hamstring-to-quadriceps ratio: a comparison of football players and recreationally active males.

It is currently unclear how football participation affects knee-joint muscle balance, which is widely considered a risk factor for hamstrings injury. This study compared the angle-specific functional hamstring-to-quadriceps (H:Q) ratio (hamstrings eccentric torque as a ratio of quadriceps concentric torque at the same knee-joint angle) of football players with recreationally active controls. Ten male footballers and 14 controls performed maximal voluntary isometric and isovelocity concentric and eccentric contractions (60, 240 and 400° s(-1)) of the knee extensors and flexors. Gaussian fitting to the raw torque values was used to interpolate torque values for knee-joint angles of 100-160° (60° s(-1)), 105-160° (240° s(-1)) and 115-145° (400° s(-1)). The angle-specific functional H:Q ratio was calculated from the knee flexors eccentric and knee extensors concentric torque at the same velocity and angle. No differences were found for the angle-specific functional H:Q ratio between groups, at any velocity. Quadriceps and hamstrings strength relative to body mass of footballers and controls was similar for all velocities, except concentric knee flexor strength at 400° s(-1) (footballers +40%; P < 0.01). In previously uninjured football players, there was no intrinsic muscle imbalance and therefore the high rate of hamstring injuries seen in this sport may be due to other risk factors and/or simply regular exposure to a high-risk activity.

Subject-specific evaluation of patellofemoral joint biomechanics during functional activity.

Patellofemoral joint pain is a common problem experienced by active adults. However, relatively little is known about patellofemoral joint load and its distribution across the medial and lateral facets of the patella. In this study, biomechanical experiments and computational modeling were used to study patellofemoral contact mechanics in four healthy adults during stair ambulation. Subject-specific anatomical and gait data were recorded using magnetic resonance imaging, dynamic X-ray fluoroscopy, video motion capture, and multiple force platforms. From these data, in vivo tibiofemoral joint kinematics and knee muscle forces were computed and then applied to a deformable finite-element model of the patellofemoral joint. The contact force acting on the lateral facet of the patella was 4-6 times higher than that acting on the medial facet. The peak average patellofemoral contact stresses were 8.2±1.0 MPa and 5.9±1.3 MPa for the lateral and medial patellar facets, respectively. Peak normal compressive stress and peak octahedral shear stress occurred near toe-off of the contralateral leg and were higher on the lateral facet than the medial facet; furthermore, the peak compressive stress (11.5±3.0 MPa) was higher than the peak octahedral shear stress (5.2±0.9 MPa). The dominant stress pattern on the lateral patellar facet corresponded well to the location of maximum cartilage thickness. Higher loading of the lateral facet is also consistent with the clinical observation that the lateral compartment of the patellofemoral joint is more prone to osteoarthritis than the medial compartment. Predicted cartilage contact stress maps near contralateral toe-off showed three distinctly different patterns: peak stresses located on the lateral patellar facet; peak stresses located centrally between the medial and lateral patellar facets; and peak stresses located superiorly on both the medial and lateral patellar facets.

The Clinical Observation on the Influence of Guo's MaQian Decoction on Joint Flexion and Extension of Elbow and Knee Joints of Moderate Skeletal Fluorosis / 国际中医中药杂志

Objective To observe the degree of joint flexion and extension of elbow and knee joints of moderate skeletal fluorosis patients before and after treatment and to assess the effects of Gun's MaQian decoction in treating moderate skeletal fluorosis. Methods 54 moderate skeletal fluorosis patients were randomly recruited into a treatment group and a control group. The treatment group was treated with Gun's MaQian decoction initially, and changed to be treated with GuKangNing capsule after 8 weeks' treatment. The control group was treated with placebo at first, and also changed to be treated with GuKangNing capsule after 8 weeks. Results Joint flexion and extension of elbow was improved greatly in both groups after the treatment, while the treatment group showing better effects than the control group (P<0.05). The improvement of joint flexion and extension of knee had not showed a statistical significance after the treatment. A 24 weeks follow-up to the joint flexion and extension of both elbow and knee revealed obvious improvement and the difference between the two groups were significance (P<0.05). Conclusion Gun's MaQian decoction can improve the flexion and extension of elbow and knee in moderate skeletal fluorosis patients.

Arthroscopic reconstruction of posterior cruciate ligament using hamstring tendon transfer and e-val uation of its clinical evaluation / 中华骨科杂志

Objective The present was to report the methods of arthroscopic reconstruction of poste-rior cruciate ligament by a two-strand semitendinosus tendon autograft and evaluate its clinical results.Method From June1998through June2002,28cases had undergone arthroscopic restoration of a torn pos-terior cruciate ligament,including22female and6male patients with an average age of21years(range,18to31years).The time-interval between the sustained injury and the surgery was25days to3months.The causes of injury of posterior cruciate ligament were sport activity in6cases,traffic accident in18cases and fall down in4cases.All of the patients suffered from knee pain,knee laxity and atrophy of quadriceps femoris.The posterior drawer test was positive in26cases preoperatively,in which6cases were associated with positive anterior drawer test.The Lachmans test was positive in all of28cases preoperatively.The piv-ot shift test was positive in12cases preoperatively.The concomitant injuries consisted of anterior cruciate ligament injury in6cases,meniscal tear in8cases and medial collateral ligament injury in5cases.Results Follow-up period extended from27to48months (mean,33months).According to the international knee documentation committee(IKDC)activity grades,grade D were26cases,and grade C were2cases preoper-atively,while postoperatively,grade A were9cases,grade B16cases,and grade C3cases at the last fol-low-up.The clinical assessment judging by Lysholm knee functional scoring system,the average scores be-fore operation was65.5?3.6;however the scores increased to an average of92.7?3.6postoperatively.Con-clusion Arthroscopic reconstruction of injured posterior cruciate ligament using hamstring tendon transfer passes through the tunnel more smoothly than the bone-patellar tendon-bone because of no bone blocks,furthermore,the tunnel disappears after the screw is absorbed to avoid the impact of the ligament the inside tunnel and prevent the tunnel extending gradually to cause the ligament laxity and knee instability.The at-tachment of the tendon on the outlet of tibial tunnel and the rigid anchoring of ligament on the outlet of femoral tunnel could provide enough strength for constructed posterior cruciate ligament.So the patients could begin postoperative rehabilitation as soon as possible and recover functional activity earlier.