Phenotype-considered kinematically aligned total knee arthroplasty for windswept-deformity-associated osteoarthritis: surgical strategy and clinical outcomes.

BACKGROUND: Windswept deformity (WSD) in relation to advanced osteoarthritis (OA) presents a significant surgical challenge in total knee arthroplasty (TKA). The primary goal of this study is to investigate the Prevalance of WSD associated osteoarthritis who have undergone total knee arthroplasty. The secondary goal is to explore the causes of WSD and its association with spinal deformity or leg length discrepancy in these patients. Finally, we evaluate the surgical outcomes of phenotype-considered kinematically aligned TKA (KA-TKA) in treating patients with WSD. METHODS: A review was conducted on data from 40 knees of 33 WSD patients who underwent phenotype-considered KA-TKA from August 2016 to December 2020. Patient demographics, associated diseases, preoperative and postoperative knee alignment angles, range of motion (ROM), Oxford Knee Score (OKS), and Knee Society Score (KSS) were collected and analyzed. Subgroup analysis for comparing the results between valgus and varus knees were also performed. RESULTS: Within the studied cohort of WSD patients, a substantial 64% displayed concomitant coronal spinal imbalance and 21% evidenced leg length discrepancy. Postoperative improvements were notable in knee alignments, ROM, OKS, and KSS following the application of the phenotype-considered KA-TKA approach. There were significant differences in the knee alignment angles, including mHKA, LDFA, and MPTA, between the valgus and varus side of knees (P = 0.018). However, no statistically significant difference were observed in the functional scores, comprising ROM, OKS, and KSS, between valgus and varus knees. CONCLUSIONS: A high percentage of patients with WSD exhibited coronal spinal imbalance and leg length discrepancy. Phenotype-considered KA-TKA effectively provided alignment targets for the treatment of both varus and valgus knees in patients with WSD, achieving excellent short-term outcomes and acceptable knee alignment.

A Retrospective Comparison of Clinical Efficacy between Multimodal Analgesia and Patient-Controlled Epidural Analgesia in Patients Undergoing Total Knee Arthroplasty.

Background and Objectives: Adequate pain management during early rehabilitation is mandatory for improving the outcomes of patients undergoing total knee arthroplasty (TKA). Conventional pain management, mainly comprising opioids and epidural analgesia, may result in certain adverse effects such as dizziness, nausea, and motor blockade. We proposed a multimodal analgesic (MA) strategy involving the use of peripheral nerve block (NB), periarticular injection (PAI), and intravenous patient-controlled analgesia (IVPCA). This study compared the clinical efficacy and adverse effects of the proposed MA strategy and patient-controlled epidural analgesia (PCEA). Materials and Methods: We enrolled 118 patients who underwent TKA under spinal anesthesia. The patients followed either the MA protocol or received PCEA after surgery. The analgesic effect was examined using a numerical rating scale (NRS). The adverse effects experienced by the patients were recorded. Results: A lower proportion of patients in the MA group experienced motor blockade (6.45% vs. 22.98%) compared to those in the PCEA group on the first postoperative day. Furthermore, a lower proportion of patients in the MA group experienced numbness (18.52% vs. 43.33%) than those in the PCEA group on the first postoperative day. Conclusions: The MA strategy can be recommended for reducing the occurrence of motor blockade and numbness in patients following TKA. Therefore, the MA strategy ensures early rehabilitation while maintaining adequate pain relief.

Enhancement of Osteoblast Function through Extracellular Vesicles Derived from Adipose-Derived Stem Cells.

Adipose-derived stem cells (ADSCs) are a type of mesenchymal stem cell that is investigated in bone tissue engineering (BTE). Osteoblasts are the main cells responsible for bone formation in vivo and directing ADSCs to form osteoblasts through osteogenesis is a research topic in BTE. In addition to the osteogenesis of ADSCs into osteoblasts, the crosstalk of ADSCs with osteoblasts through the secretion of extracellular vesicles (EVs) may also contribute to bone formation in ADSC-based BTE. We investigated the effect of ADSC-secreted EVs (ADSC-EVs) on osteoblast function. ADSC-EVs (size ≤ 1000 nm) were isolated from the culture supernatant of ADSCs through ultracentrifugation. The ADSC-EVs were observed to be spherical under a transmission electron microscope. The ADSC-EVs were positive for CD9, CD81, and Alix, but ß-actin was not detected. ADSC-EV treatment did not change survival but did increase osteoblast proliferation and activity. The 48 most abundant known microRNAs (miRNAs) identified within the ADSC-EVs were selected and then subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The GO analysis revealed that these miRNAs are highly relevant to skeletal system morphogenesis and bone development. The KEGG analysis indicated that these miRNAs may regulate osteoblast function through autophagy or the mitogen-activated protein kinase or Ras-related protein 1 signaling pathway. These results suggest that ADSC-EVs enhance osteoblast function and can contribute to bone regeneration in ADSC-based BTE.

Validation and modification of the Coronal Plane Alignment of the Knee classification in the Asian population.

AIMS: The Coronal Plane Alignment of the Knee (CPAK) classification is a simple and comprehensive system for predicting pre-arthritic knee alignment. However, when the CPAK classification is applied in the Asian population, which is characterized by more varus and wider distribution in lower limb alignment, modifications in the boundaries of arithmetic hip-knee-ankle angle (aHKA) and joint line obliquity (JLO) should be considered. The purposes of this study were as follows: first, to propose a modified CPAK classification based on the actual joint line obliquity (aJLO) and wider range of aHKA in the Asian population; second, to test this classification in a cohort of Asians with healthy knees; third, to propose individualized alignment targets for different CPAK types in kinematically aligned (KA) total knee arthroplasty (TKA). METHODS: The CPAK classification was modified by changing the neutral boundaries of aHKA to 0° ± 3° and using aJLO as a new variable. Radiological analysis of 214 healthy knees in 214 Asian individuals was used to assess the distribution and mean value of alignment angles of each phenotype among different classifications based on the coronal plane. Individualized alignment targets were set according to the mean lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) of different knee types. RESULTS: A very high concentration, 191 from 214 individuals (89.3%), were found in knee types with apex distal JLO when the CPAK classification was applied in the Asian population. By using aJLO as a new variable, the high distribution percentage in knee types with apex distal JLO decreased to 125 from 214 individuals (58.4%). The most common types in order were Type II (n = 70; 32.7%), Type V (n = 55; 25.7%), and Type I (n = 46; 21.5%) in the modified CPAK classification. CONCLUSION: The modified CPAK classification corrected the uneven distribution when applying the CPAK classification in the Asian population. Setting individualized TKA alignment targets according to CPAK type may be a practical method to recreate optimal LDFA and MPTA in KA-TKA. Cite this article: Bone Jt Open 2022;3(3):211-217.

Total knee arthroplasty according to the original knee phenotypes with kinematic alignment surgical technique-early clinical and functional outcomes.

BACKGROUND: The kinematic alignment (KA) technique in total knee arthroplasty (TKA) aims to restore the native alignment of pre-disease knee joint anatomy. Determining the individualized alignment targets is crucial for pre-operative planning, which can be set according to different original knee phenotypes. Five most common knee phenotypes have been categorized for KA-TKA alignment target setting in our previous study. The purpose of this study was to investigate the distribution of the five phenotypes in advanced OA knee patients and evaluate the clinical outcomes of this phenotype-oriented KA-TKA using the generic instrument, with particular emphasis on alignment strategy, surgical technique, survivorship, radiographic and functional outcomes. METHODS: The clinical data of 123 patients (88 women, 35 men) who had undergone 140 TKAs in our hospital were reviewed. All the TKAs were performed with alignment targets set according to the original phenotypes of the knee, with the KA method, using the generic total knee instrument. The patients' demographics, preoperative and postoperative knee alignment angles, one-year postoperative range of motion (ROM), Oxford knee scores (OKS), Combined knee society score (CKSS) were collected and analyzed. RESULTS: The 3 years survivorship was 99.3% for all cause of revision, and 100% with revision other than infection as the endpoint. The preoperative phenotypes of the knee were as follows: neutral alignment 20.1% (type 1: 3.6%, type 2: 16.5%), varus alignment 71.2% (type 3: 46.0%, type 4: 25.2%), and valgus alignment (type 5: 8.6%). Using our protocol, patients with different knee phenotypes could get similar great functional improvement though the postoperative alignment parameters were significantly different between the knee phenotypes (P < 0.05). CONCLUSION: The early outcomes of this phenotype-oriented KA-TKA using generic total knee instruments are promising. Setting individualized alignment target according to original knee phenotype is rational and practical. The residual varus alignment did not cause any aseptic loosening in the 3 years follow-up. Long-term survivorship and functional outcomes need to be evaluated in future studies.

Comparison of implant failure rates of different plates for midshaft clavicular fractures based on fracture classifications.

BACKGROUNDS: The aim of our study was to investigate failure rates of reconstruction plate and non-reconstruction plate, and find the best strategy for implant selection for different fracture types for midshaft clavicular fractures. PATIENTS AND METHODS: Two hundred twenty-six consecutive patients with midshaft clavicular fractures who received open reduction and plate fixation during Jan 2012 to July 2017 were reviewed. The correlations between implant failure rates and risk factors including demographic data, fracture classifications, and implant types were analyzed. RESULTS: AO/OTA fracture classification and plate types are the most important factors affecting implant failure for midshaft clavicular fractures. Reconstruction plate had a significantly higher failure rate (53%) than that of non-reconstruction plates (3%) in comminuted midshaft clavicular (AO/OTA 15-2C) fractures (P value < 0.01). However, the difference was not significant in AO/OTA 15-2A and 2B classifications. CONCLUSION: Patients with comminuted midshaft clavicular (AO/OTA 15-2C) fractures treated with reconstruction plates had very high implant failure rates compared to non-reconstruction plates. We suggested that patients with comminuted midshaft clavicular (AO/OTA 15-2C) fractures treated with reconstruction plates need more protection and more frequent follow-up in the postoperative period.

Mismatch between femur and tibia coronal alignment in the knee joint: classification of five lower limb types according to femoral and tibial mechanical alignment.

BACKGROUND: Reasons for dissatisfaction with total knee arthroplasty (TKA) include unequal flexion or extension gap, soft tissue imbalance, and patella maltracking, which often occur with mismatch between femoral and tibial coronal bony alignment in the knee joint or extremely varus or valgus alignment. However, lower limb coronal alignment classification is based only on hip-knee-ankle angle (HKAA), leading to oversight regarding a mismatch between femoral and tibial coronal alignment. We aimed to classify alignment of the lower limbs according to the mechanical alignment of the femur and tibia in a healthy population. METHODS: All 214 normal triple films were reviewed retrospectively. HKAA, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), angle between the femoral anatomical axis and the mechanical axis (AA-MA), and knee alignment angle (KAA) were measured. Subjects were categorized into one of five types based on the mechanical alignment of femur and tibia. RESULTS: Mean HKAA, mLDFA, and mMPTA of all subjects were 1.2°, 87.3°, and 85.8°, respectively. All subjects were classified into one of five types with significant differences (p < 0.001). About 61% of subjects showed neutral alignment, of which nearly 40% were type 2 (valgus of the femur and varus of the tibia with oblique joint line: mLDFA 85.0° ± 1.4°, mMPTA 85.1° ± 1.2°, TJLA 2.7° ± 2.4°) and 60% exhibited neutral alignment with a neutral femur and tibia (type 1). In varus and valgus types, mismatch between the mechanical angle of the femur and tibia was common. Varus alignment, including types 3 (varus of the tibia: mLDFA 88.0° ± 1.4°, mMPTA 83.5° ± 1.6°) and 4 (varus of both the tibia and femur: mLDFA 91.4° ± 1.4°, mMTPA 85.2° ± 2.0°), was found in 30% of subjects. Valgus alignment (type 5 valgus of femur: mLDFA 84.6° ± 1.6°, mMPTA 88.8° ± 2.0°) accounted for 8.9% of all subjects. CONCLUSIONS: Mismatch between mechanical alignment of the femur and tibia was common in varus and valgus alignment types. Joint line obliquity was also observed in 40% of the neutral alignment population. This classification provides a quick, simple interpretation of femoral and tibial coronal alignment, and more detailed guidance for preoperative planning for TKA than the traditional varus-neutral-valgus classification.

Integrated risk scoring model for predicting dynamic hip screw treatment outcome of intertrochanteric fracture.

BACKGROUND: Dynamic hip screw (DHS) is a common device for treating intertrochanteric fracture (ITF). Various risk factors have been reported to be associated with the operative treatment outcome. However, an integrated risk scoring prediction model is lacking. In this study, we aimed to develop a prediction model for treatment outcome of intertrochanteric fracture. METHODS: We analyzed 442 AO/OTA 31-A1 and A2 fractures which were treated with DHS during the period January 2000 to June 2014 in a level I trauma center. Risk factors including age, gender, injured side, lag screw position, AO/OTA classification, tip-apex distance, postoperative lateral wall fracture, reduction patterns were analyzed to determine their influence on treatment outcome. Integrated risk scores of significant predictors were used to construct a prediction model. RESULTS: AO/OTA 31-A2 classification, postoperative lateral wall fracture, posteriorly inserted lag screw and varus reduction pattern were significant risk predictors for DHS failure. The failure risk for low- and high-risk groups were significantly different (P<0.001) CONCLUSION: AO/OTA 31-A2 classification, postoperative lateral wall fracture, posteriorly inserted lag screw and varus reduction pattern were significant risk predictors for DHS failure. We developed a model that integrates these factors to predict the treatment outcome, which had excellent prediction accuracy and discriminatory ability. The models may provide useful information for orthopedic doctors to identify patients who need early intervention as well as ITF patients who require more frequent follow-up in the postoperative period.

Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.

Clinical implantation of clavicle hook plates is often used as a treatment for acromioclavicular joint dislocation. However, it is not uncommon to find patients that have developed acromion osteolysis or had peri-implant fracture after hook plate fixation. With the aim of preventing complications or fixation failure caused by implantation of inappropriate clavicle hook plates, the present study investigated the biomechanics of clavicle hook plates made of different materials and with different hook depths in treating acromioclavicular joint dislocation, using finite element analysis (FEA). This study established four parts using computer models: the clavicle, acromion, clavicle hook plate, and screws, and these established models were used for FEA. Moreover, implantations of clavicle hook plates made of different materials (stainless steel and titanium alloy) and with different depths (12, 15, and 18 mm) in patients with acromioclavicular joint dislocation were simulated in the biomechanical analysis. The results indicate that deeper implantation of the clavicle hook plate reduces stress on the clavicle, and also reduces the force applied to the acromion by the clavicle hook plate. Even though a clavicle hook plate made of titanium alloy (a material with a lower Young's modulus) reduces the force applied to the acromion by the clavicle hook plate, slightly higher stress on the clavicle may occur. The results obtained in this study provide a better reference for orthopedic surgeons in choosing different clavicle hook plates for surgery.

Paper-based ELISA to rapidly detect Escherichia coli.

Escherichia coli is a generic indicator of fecal contamination, and certain serotypes cause food- and water-borne illness such as O157:H7. In the clinic, detection of bacteriuria, which is often due to E. coli, is critical before certain surgical procedures or in cases of nosocomial infection to prevent further adverse events such as postoperative infection or sepsis. In low- and middle-income countries, where insufficient equipment and facilities preclude modern methods of detection, a simple, low-cost diagnostic device to detect E. coli in water and in the clinic will have significant impact. We have developed a simple paper-based colorimetric platform to detect E. coli contamination in 5h. On this platform, the mean color intensity for samples with 10(5)cells/mL is 0.118±0.002 (n=4), and 0.0145±0.003 (P<0.01⁎⁎) for uncontaminated samples. This technique is less time-consuming, easier to perform, and less expensive than conventional methods. Thus, paper-based ELISA is an innovative point-of-care diagnostic tool to rapidly detect E. coli, and possibly other pathogens when customized as appropriate, especially in areas that lack advanced clinical equipment.

Biomechanical analysis of acromioclavicular joint dislocation treated with clavicle hook plates in different lengths.

PURPOSE: Clavicle hook plates are frequently used in clinical orthopaedics to treat acromioclavicular joint dislocation. However, patients often exhibit acromion osteolysis and per-implant fracture after undergoing hook plate fixation. With the intent of avoiding future complications or fixation failure after clavicle hook plate fixation, we used finite element analysis (FEA) to investigate the biomechanics of clavicle hook plates of different materials and sizes when used in treating acromioclavicular joint dislocation. METHODS: Using finite element analysis, this study constructed a model comprising four parts: clavicle, acromion, clavicle hook plate and screws, and used the model to simulate implanting different types of clavicle hook plates in patients with acromioclavicular joint dislocation. Then, the biomechanics of stainless steel and titanium alloy clavicle hook plates containing either six or eight screw holes were investigated. RESULTS: The results indicated that using a longer clavicle hook plate decreased the stress value in the clavicle, and mitigated the force that clavicle hook plates exert on the acromion. Using a clavicle hook plate material characterized by a smaller Young's modulus caused a slight increase in the stress on the clavicle. However, the external force the material imposed on the acromion was less than the force exerted on the clavicle. CONCLUSIONS: The findings of this study can serve as a reference to help orthopaedic surgeons select clavicle hook plates.

Single-blinded, randomised preliminary study evaluating the effects of 2†Hz electroacupuncture for postoperative pain in patients with total knee arthroplasty.

OBJECTIVE: To explore the point-specific clinical effect of 2 Hz electroacupuncture (EA) in treating postoperative pain in patients undergoing total knee arthroplasty (TKA), METHODS: In a randomised, partially single-blinded preliminary study, 47patients with TKA were randomly divided into three groups: control group (CG, n=17) using only patient-controlled analgesia (PCA); EA group (EAG, n=16) with 2 Hz EA applied at ST36 (Zusanli) and GB34 (Yanglingquan) contralateral to the operated leg for 30 min on the first two postoperative days, also receiving PCA; and non-point group (NPG, n=14), with EA identical to the EAG except given 1 cm lateral to both ST36 and GB34. The Mann-Whitney test was used to show the difference between two groups and the Kruskal-Wallis test to show the difference between the three groups. RESULTS: The time until patients first required PCA in the CG was 34.1±22.0 min, which was significantly shorter than the 92.0±82.7 min in the EAG (p<0.001) and 90.7±94.8 min in the NPG (p<0.001); there was no difference between the EAG and NPG groups (p>0.05). The total dosage of PCA solution given was 4.6±0.9 mL/kg body weight in the CG, 4.2±1.0 mL/kg in the EAG and 4.5±1.0 mL/kg in the NPG; there were no significant differences (p>0.05) among the three groups. CONCLUSIONS: In this small preliminary study, EA retarded the first demand for PCA in comparison with no EA. No effect was seen on the total dosage of PCA required and no point-specific effect was seen.

Trochanter stabilising plate improves treatment outcomes in AO/OTA 31-A2 intertrochanteric fractures with critical thin femoral lateral walls.

BACKGROUND: For AO/OTA 31-A2 fractures (A2 fractures) treated with dynamic hip screw (DHS), postoperative lateral wall fracture (PLWF) is thought to be a major cause of femoral medialisation and reoperation. Though trochanter stabilising plate (TSP) had been reported to have a good effect in preventing femoral medialization, its effects and indication in A2 fractures remain controversial. We hypothesized that TSP may improve treatment outcomes in patients with high risk of postoperative lateral femoral wall fractures. The purpose of this study was to investigate (1) the main risk factors predictive of PLWF in A2 fractures and, (2) whether TSP can improve treatment outcomes in patients with high risk of PLWF. METHODS: Two hundred and fifty-two A2 fractures treated with DHS or DHS and TSP (DHS-TSP) during January 2000 and June 2013 were enrolled in this study. Standard univariate and multivariate analyses were performed to determine statistically significant risk factors for PLWF in 205 patients who were treated with DHS alone. The risk factor found to be associated with PLWF was utilized to include 171 patients who were at high risk of PLWF. Standard univariate and multivariate analyses were performed to evaluate the effect of TSP on treatment outcomes. RESULTS: Lateral wall thickness was found to be the main risk factor for PLWF in A2 fractures. A lateral wall thickness of 2.24 cm was found to be the best cutoff point to determine which patients were at high risk for PLWF. In 171 patients with a lateral wall thickness less than 2.24 cm, patients treated with DHS-TSP had significantly decreased lag screw sliding distances, PLWF rate, and reoperation rate (P=0.028, <0.001 and P=0.003, respectively) compared to the corresponding values of those treated with DHS alone. In the multivariate analysis, TSP decreased the reoperation rate by 13 times compared to that of patients who were treated with DHS alone. CONCLUSION: Lateral wall thickness is the main risk factor for PLWF in A2 fractures treated with DHS. Use of TSP in A2 fractures with critical thin lateral wall thickness <2.24 cm can significantly decrease the lag screw sliding distances, PLWF rate and reoperation rate.

A potential role of myeloid DAP12-associating lectin (MDL)-1 in the regulation of inflammation in rheumatoid arthritis patients.

The pathogenic roles of myeloid DAP12-associating lectin-1(MDL-1) and DAP12 in human rheumatoid arthritis (RA) remain unknown. Frequencies of MDL-1-expressing monocytes in 22 active RA patients, 16 inactive RA patients, 12 osteoarthritis (OA) patients and 10 healthy controls (HC) were determined by flow-cytometry analysis. The mRNA expression levels of MDL-1 and DAP12 on PBMCs were evaluated by quantitative PCR, and their protein expression levels in the synovium were examined by immunohistochemistry. Significantly higher median percentages of circulating MDL-1-expressing monocytes were observed in active RA patients (53.6%) compared to inactive RA patients (34.1%), OA patients (27.9%), and HC (21.2%). Levels of MDL-1 and DAP12 gene expression in PBMCs and their protein expression in the synovium were significantly higher in active RA patients than in inactive RA or OA patients. MDL-1 levels were positively correlated with parameters of disease activity, articular damage, and levels of proinflammatory cytokines. MDL-1 activator (Dengue virus type 2 antigen) stimulation on PBMCs resulted in significantly enhanced levels of proinflammatory cytokines in RA patients compared to those in OA patients or HC, indicating that MDL-1 activation is functional. Frequencies of MDL-1-expressing monocytes and levels of MDL-1 and DAP12 gene expression significantly decreased after effective therapy. Concordant overexpression of MDL-1 and DAP12 were correlated with increased production of proinflammatory cytokines in RA patients, suggesting their roles in regulating articular inflammation.

Evaluation of methods and timing in nail dynamisation for treating delayed healing femoral shaft fractures.

INTRODUCTION: Dynamisation is a simple method for treating femoral shaft fractures (FSFs) in patients with delayed healing after intramedullary nailing. However, only around half of patients with a slow-healing FSF have been successfully treated with this strategy. Although it is thought that dynamisation with a screw preserved in the dynamic locking hole improves treatment outcome in these patients, to date, no studies have demonstrated empirical evidence supporting this technique. In this study, we investigated the effects of dynamisation with and without rotation and length control as well as timing of dynamisation on treatment outcomes in FSF patients with delayed healing. PATIENTS AND METHODS: Thirty-nine consecutive acute FSF patients with static locking intramedullary nails who subsequently underwent dynamisation were recruited between January 2000 and June 2011. The indication for dynamisation was the presence of gap caused by bone absorption or over-traction at the fracture site when the locking screws were placed. Age, gender, dynamisation method, fracture classification, duration from nail insertion to dynamisation (i.e., timing of dynamisation) and dynamisation outcome were included in the statistical analysis. RESULTS: Patients whose nail was dynamised with a screw preserved in the dynamic locking hole had a significantly higher successful bone union rate (14/15 vs. 14/24, p=0.028) compared with those with all screws removed from one end of the nail. The patients treated in 10-24 weeks had a significantly increased chance of bone union than those treated after 24 weeks (p=0.027). A significantly higher bone union rate (p=0.036) was observed in 10-24 weeks (83.3%) than after 24 weeks (33.3%) in the group of dynamisation with all screws removed from one end of the nail. No statistical difference in bone union success rate was found between patients at 10-24 weeks and after 24 weeks in the group of dynamisation with a screw preserved in the dynamic locking hole. There were no significant differences in outcome based on other variables. CONCLUSION: (1) Dynamisation with a screw preserved in the dynamic locking hole was associated with a higher success rate in bone union than all screws removed from one end of the nail for patients with delayed healing FSFs. (2) Early dynamisation (10-24 weeks) had a better outcome than late dynamisation (>24 weeks). Late dynamisation with all screws removed from one end of the nails resulted in a poor success rate. Alternative treatment should be considered if the latter approach is to be adopted.

Outcomes of arthroscopic double-bundle PCL reconstruction using the LARS artificial ligament.

The purpose of this study was to assess the outcomes of posterior cruciate ligament (PCL) reconstruction using the Ligament Augmentation and Reconstruction System (LARS) (JK Orthomedic Ltd, Dollard-des-Ormeaux, Quebec, Canada) artificial ligament. Compared with older artificial ligaments, the LARS, which has been used in Europe for 15 years, is more resistant to wear and tear, has satisfactory torsional fatigue resistance, and has good biocompatibility. The current is study included 38 double-bundle PCL reconstructions using the LARS artificial ligament in 38 patients. Mean patient age was 32.6 years, and mean time from injury to surgery was 6 months. Mean follow-up was 37 months (range, 30-68 months). The study endpoint was 2-year follow-up. Mean Tegner score improved from 3.4 ± 0.6 preoperatively to 6.0 ± 1.4 postoperatively (P<.001), and mean Lysholm score improved from 70.0 ± 11.0 pre-operatively to 91.7 ± 5.5 postoperatively (P<.001). Knee laxity decreased significantly postoperatively (P<.001), and no differences existed at 1- and 2-year follow-up. After surgery using the Y-type LARS artificial ligament, knee function and stability improved. Using the LARS artificial ligament for double-bundle reconstruction of the PCL avoids donor-site morbidity and disease transmission. The complication rate is low, and the results appear to be stable with time and comparable with those obtained with other grafts. Double-bundle PCL reconstruction with the LARS artificial ligament may be an alternative treatment option.

Adiponectin increases MMP-3 expression in human chondrocytes through AdipoR1 signaling pathway.

Articular adipose tissue is a ubiquitous component of human joints, and adiponectin is a protein hormone secreted predominantly by differentiated adipocytes and involved in energy homeostasis. The adiponectin is significantly higher in synovial fluid of patients with osteoarthritis and rheumatoid arthritis. Matrix metalloproteinases (MMP)-3 may contribute to the breakdown of articular cartilage during arthritis. We investigated the signaling pathway involved in MMP-3 caused by adiponectin in human chondrocytes. Adiponectin increased the secretion of MMP-3 in cultured human chondrocytes, as shown by qPCR, Western blot, and ELISA analysis. Adiponectin-mediated MMP-3 expression was attenuated by AdipoR1 but not AdipoR2 siRNA. Pretreatment with 5'-AMP-activated protein kinase (AMPK) inhibitor (araA and compound C), p38 inhibitor (SB203580), and NF-κB inhibitor (PDTC and TPCK) also inhibited the potentiating action of adiponectin. Activations of p38, AMPK, and NF-κB pathways after adiponectin treatment were demonstrated. Taken together, our results provide evidence that adiponectin acts through AdipoR1 to activate p38 and AMPK, resulting in the activations of NF-κB on the MMP-3 promoter and contribute cartilage destruction during arthritis.

Association between metabolic syndrome (MS) and bone mineral loss: a cross-sectional study in Puli Township in Taiwan.

Results of studies regarding the association between the MS and osteoporosis have been largely controversial. The objectives of this study were to measure bone mineral density (BMD) with and without the MS and evaluate the associations between bone mineral loss and the components of the MS. In all, 352 men (mean age 70.6+/-11.9 years) and 468 women (mean age 67.8+/-12.0 years) in Puli township, Taiwan, were enrolled. Height (cm), weight (kg), waist circumference (cm), and blood pressure (mmHg) were measured. Fasting plasma glucose (FPG) and blood lipids were determined. Calcaneal BMD was measured using the ultrasound pulse transmission method. The prevalence of MS was 33.0% in men and 44.2% in women. In subjects with the MS, lower diastolic blood pressure (DBP) in both sexes (p < 0.001), lower triglycerides (p = 0.016) and more central obesity in men (p = 0.011) predicted bone mineral loss. The MS was not associated with bone mineral loss in either of sexes (p = 0.550 in men; p = 0.628 in women).

Peptidoglycan enhances IL-6 production in human synovial fibroblasts via TLR2 receptor, focal adhesion kinase, Akt, and AP-1- dependent pathway.

Peptidoglycan (PGN), the major component of the cell wall of Gram-positive bacteria, activates the innate immune system of the host and induces the release of cytokines and chemokines. We investigated the signaling pathway involved in IL-6 production stimulated by PGN in rheumatoid arthritis synovial fibroblasts. PGN caused concentration- and time-dependent increases in IL-6 production. PGN-mediated IL-6 production was attenuated by TLR2 small interfering RNA and nucleotide-binding oligomerization domain 2 small interfering RNA. Pretreatment with PI3K inhibitor (Ly294002 and wortmannin), Akt inhibitor, and AP-1 inhibitor (tanshinone IIA) also inhibited the potentiating action of PGN. PGN increased the focal adhesion kinase (FAK), PI3K, and Akt phosphorylation. Stimulation of rheumatoid arthritis synovial fibroblast cells with PGN increased the accumulation of phosphorylated c-Jun in the nucleus, AP-1-luciferase activity, and c-Jun binding to the AP-1 element on the IL-6 promoter. PGN mediated an increase in the accumulation of phosphorylated c-Jun in the nucleus, AP-1-luciferase activity, and c-Jun binding to AP-1 element was inhibited by Ly294002, Akt inhibitor, and FAK mutant. Our results suggest that PGN increased IL-6 production in human synovial fibroblasts via the TLR2 receptor/FAK/PI3K/Akt and AP-1 signaling pathway.