Association between Common Variants in VEGFA Gene and the Susceptibility of Primary Knee Osteoarthritis.

OBJECTIVES: This study aimed to analyze the relationship between vascular endothelial growth factor A (VEGFA) gene polymorphisms, plasma VEGFA, and the susceptibility of knee osteoarthritis (OA). DESIGN: A total of 404 subjects, 202 knee OA subjects and 202 healthy volunteers, were enrolled into the study. Four distinct polymorphisms of the VEGFA gene were evaluated using polymerase chain reaction-restriction fragment length polymorphism: -2578C/A (rs699947), -1154G/A (rs1570360), -634C/G (rs2010963), and +936C/T (rs3025039). Plasma VEGFA levels were analyzed using enzyme-linked immunosorbent assay. RESULTS: The most common nucleotides in both knee OA subjects and healthy controls were CC for -2578C/A, GG for -1154G/A, CG for -634C/G, and CC for +936C/T in the VEGFA gene. Genotype distribution and allele frequencies of VEGFA -2578C/A, -1154G/A, -634C/G, and +936C/T single nucleotide polymorphisms did not differ between OA patients and the controls. Plasma VEGFA levels showed no difference between OA patients and the controls. In contrast, plasma VEGFA levels of -634C/C genotype were significantly higher in OA patients than in the controls (P = 0.035). According to the -2578A/A genotype, patients with early stage OA had a higher odds ratio than those with advanced stage OA (P = 0.023). CONCLUSIONS: VEGFA -2578C/A (rs699947), -1154G/A (rs1570360), -634C/G (rs2010963), and +936C/T (rs3025039) polymorphisms may not be responsible for OA susceptibility in the Thai population. However, the OA patients with A/A genotype at the -2578C/A seemed to have a lower potential risk of developing severe OA than those with the C/A and C/C genotypes. These findings would help elucidate and facilitate a better understanding of the genetic fundamentals of OA.

Telomere shortening is associated with poor physical performance in knee osteoarthritis.

Telomere length is a hallmark characteristic of ageing and age-related diseases. Osteoarthritis (OA) is the most common cause of joint pain and physical disability in the elderly. Previous studies have revealed the role of telomere shortening in OA; however, the relationship between telomere length, muscle strength and physical performance in knee OA patients remains unknown. The aim of the present study was to investigate the association of telomere length and physical performance in patients with knee OA. A total of 202 patients with knee OA and 60 healthy controls were enrolled in the study. The quality of life was assessed using Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Short Form Health Survey. The skeletal muscle mass was examined using bioelectrical impedance analysis, while the muscle strength was analyzed using hand grip force and isometric knee extension force. The physical performance of patients with knee OA was also investigated using gait speed, Timed up and go test (TUGT), Sit to stand test and 6-min walk test (6MWT). Blood leukocyte relative telomere length (RTL) was assessed using real time quantitative PCR. The mean blood leukocyte RTL in knee OA subjects was significantly lower compared with healthy controls (P<0.001). Knee OA patients with RTL values in the lowest quartile had a slow gait speed (P=0.006) and prolonged TUGT time (P=0.03). Multivariate regression analyses and multiple logistic regression analyses adjusted for age, sex, waist circumference, body mass index, fat mass, skeletal muscle index and the total WOMAC demonstrated that gait speed, TUGT and 6MWT were associated with longer RTL (P-trend<0.05). These findings suggested that poorer physical performance was associated with shorter RTL. Therefore, leukocyte telomere length and physical performance tests, especially gait speed, TUGT and 6MWT, could predict the health status and quality of life in patients with knee OA.

Decreased Serum Adiponectin Reflects Low Vitamin D, High Interleukin 6, and Poor Physical Performance in Knee Osteoarthritis.

Obesity is a major contributor to deterioration of physical function toward sarcopenia in knee osteoarthritis (OA) due to its effect mediated through adipokines-derived molecules that have pro-/anti-inflammatory properties. This study aimed to investigate relationships of serum adiponectin, 25-hydroxyvitamin D (25(OH)D), interleukin (IL)-6, and physical performance in knee OA patients. A total of 175 knee OA patients and 52 healthy controls were recruited. Serum adiponectin, 25(OH)D, IL-6, biochemical markers, knee pain and functional scores, muscle strength, physical performance, metabolic parameters, and body composition were evaluated. Serum adiponectin levels were significantly higher in knee OA patients than that in controls, while its serum levels were significantly decreased in obese patients, especially those with sarcopenia. Furthermore, there were independent relationships of serum adiponectin with body composition parameters, knee pain scores, physical function tests, and metabolic parameters in knee OA patients. Besides, serum adiponectin levels were positively associated with 25(OH)D levels, and negatively correlated with C-reactive protein and IL-6 levels in knee OA. Additionally, low serum adiponectin could be used to distinguish knee OA patients with sarcopenic obesity from those without sarcopenic obesity. Circulating adiponectin levels may serve as a possible surrogate biomarker for exacerbated physical function in knee OA patients-particularly sarcopenic obesity.

Adiponectin gene rs1501299 polymorphism is associated with increased risk of anterior cruciate ligament rupture.

Anterior cruciate ligament (ACL) rupture is one the most common musculoskeletal soft tissue injuries of the knee. Although the exact mechanisms of this injury remain uncertain, genetic variants have been considered to be an intrinsic risk factor associated with ACL rupture. Therefore, the aim of the present study was to determine whether the adiponectin +276G/T polymorphism is associated with susceptibility to ACL rupture in a Thai population. Genotyping for rs1501299 was conducted in 98 participants with ACL rupture and 95 healthy controls by polymerase chain reaction-restriction fragment length polymorphism analysis. The results demonstrated that the GG genotype and G allele were significantly associated with an increased risk of ACL rupture [odds ratio (OR)=1.91, P=0.026; OR=1.89, P=0.004], whereas the TT genotype was significantly associated with a reduced risk of ACL rupture (OR=0.32, P=0.019). Furthermore, ACL injury patients with non-contact sports carrying the GG genotype and G allele exhibited a significantly higher risk of ACL rupture (OR=2.13, P=0.031; OR=1.84, P=0.029). In addition, overweight patients carrying the GG genotype and G allele had a significantly increased (8-fold) risk of ACL rupture (OR=8.00, P<0.001; OR=5.15, P<0.001), whereas overweight patients with the adiponectin +276G/T GT genotype had a significantly lower risk of ACL rupture (OR=0.13, P<0.001). Therefore, the adiponectin +276G/T polymorphism GG genotype and G allele were significantly associated with the risk of ACL rupture, particularly in overweight patients. These findings indicate that the adiponectin +276G/T polymorphism may play a role in the development of ACL rupture in the Thai population.

Functional and T Cell Receptor Repertoire Analyses of Peripheral Blood and Infrapatellar Fat Pad T Cells in Knee Osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a condition that features inflammation and immune responses of innate and adaptive immunity. The role of T cells in knee OA pathogenesis is still unclear. Our aim was to characterize T cell functions and their clonality in patients with knee OA in peripheral blood (PB) and infrapatellar fat pads (IPFP). METHODS: We isolated T cells from PB and IPFP of patients with knee OA and PB of healthy individuals and determined soluble mediators produced from these cells. In addition, we performed a clonal analysis of activated CD8+ T cells and compared the T cell receptor ß-variable gene chain (TRBV) usages between T cells in PB and IPFP of patients with knee OA. RESULTS: Our results suggest that in patients with knee OA, circulating T cells possess a more "cytotoxic" profile or rather impaired cytokine production, but the knee microenvironment allows for these T cells to produce proinflammatory cytokines [interleukin (IL)-1ß, IL-6, tumor necrosis factor], IL-17, and interferon-γ within IPFP. Activated CD8+ IPFP T cells carry different repertoire distribution from those present in PB of patients with knee OA. Shared TRBV usage of activated CD8+ IPFP T cells among the 3 patients with knee OA was also observed. CONCLUSION: Our study describes the nature of T cells in knee OA that may be due to "unhealthy" aging or other factors that drive healthy aging T cells into a state of imbalance, thus contributing to the pathogenesis of knee OA.

Effectiveness of Essence of Chicken on Cognitive Function Improvement: A Randomized Controlled Clinical Trial.

High-quality, adequately-powered clinical trials investigating the effect of Essence of Chicken (EC) on cognitive function are lacking. We conducted a randomized, double-blind, placebo-controlled clinical trial on healthy adult volunteers to determine the effect of EC on short-term memory, working memory, and selective and sustained attention. As a secondary objective, we evaluated baseline stress as a modifying factor by including treatment, stress and visit as main effects in a three-way ANOVA model. Cognitive function was evaluated at baseline, and Days 7 and 14. Data from 235 participants were analyzed on a per-protocol basis. The three-way interaction effect was significant (p = 0.020) in Digit Span Forward and further analyses showed EC improved test performance in moderate (p = 0.041) and severe stress (p = 0.065) but not in normal and mild stress subgroups. In Digit Span Backward, EC group showed greater improvement compared to placebo (p = 0.028), with 0.60 digits (8.50% improvement from baseline) more recalled on Day 7. No treatment or interaction effects were statistically significant in selective and sustained attention tests. Our findings support EC’s effect in improving mental processes used in working memory among healthy adults and short-term memory among healthy adults experiencing stress in daily life.

Association between leukocyte telomere length and angiogenic cytokines in knee osteoarthritis.

AIM: The aims of this study were to compare leukocyte relative telomere length (RTL) in knee osteoarthritis (OA) patients and healthy controls and to investigate associations between plasma angiogenic cytokine concentrations and leukocyte RTL. METHOD: Eighty knee OA patients and 60 age-matched controls were enrolled. Leukocyte RTL was assessed using real-time quantitative polymerase chain reaction (qPCR). Angiogenic cytokines were measured by a multiplex immunoassay. RESULTS: Leukocyte RTL in knee OA patients was significantly lower than that in healthy controls (1.1 ± 0.4 vs. 1.3 ± 0.6, P = 0.039). Plasma angiopoietin-2, follistatin, granulocyte-colony stimulating factor (G-CSF), hepatocyte growth factor (HGF), interleukin-8 (IL-8), platelet endothelial cell adhesion molecule-1 (PECAM-1), and vascular endothelial growth factor (VEGF) levels in knee OA patients were higher than those in controls (P < 0.01). Correlation analysis revealed significant negative correlations between leukocyte RTL and plasma levels of HGF (r = -0.377, P = 0.017), VEGF (r = -0.405, P = 0.009) and G-CSF (r = -0.347, P = 0.026). In contrast, plasma angiopoietin-2, follistatin, IL-8, leptin, platelet-derived growth factor-BB and PECAM-1 were not correlated with leukocyte RTL. CONCLUSION: Telomere length was shortened in knee OA patients compared to healthy controls. Plasma HGF, VEGF and G-CSF were negatively correlated with leukocyte RTL, suggesting involvement of telomere shortening and these cytokines in knee OA.

Association of adiponectin gene polymorphisms with knee osteoarthritis.

AIM: To investigate the possible relationship of adiponectin (ADIPOQ) gene polymorphisms, plasma adiponectin, and the risk of knee osteoarthritis (OA). METHODS: A total of 398 subjects, 202 knee OA patients and 196 healthy individuals, were enrolled in the case-control study. Genotyping at +45T/G (rs2241766) and +276G/T (rs1501299) loci was performed using polymerase chain reaction-restriction fragment length polymorphism. Plasma adiponectin levels were assessed using enzyme-linked immunosorbent assay. OA severity was determined using the Kellgren-Lawrence (KL) grading system. RESULTS: No significant associations were observed in the genotype distributions and allele frequencies at two loci of +45T/G and +276G/T polymorphisms in the ADIPOQ between knee OA patients and control subjects. There was a significant association between genotype distribution of +276G/T polymorphism and KL grade 2, 3 or 4 (P = 0.037, P = 0.046, P = 0.016, respectively). At +45T/G locus, the percentage of GG genotype was notably greater in control subjects (13.40%) compared with OA subjects (1.70%) (P = 0.023). Plasma adiponectin was markedly decreased in OA subjects compared with control subjects (P = 0.03). Likewise, circulating adiponectin in OA subjects was notably lesser than that in control subjects in GG genotype of +45T/G (P = 0.029) and +276G/T polymorphisms (P = 0.012). CONCLUSION: Polymorphisms +45T/G and +276G/T of the ADIPOQ gene might not be responsible for OA susceptibility among Thais.

Vitamin D Supplementation Improves Quality of Life and Physical Performance in Osteoarthritis Patients.

(1) Background: Lower levels of serum 25-hydroxyvitamin D (25(OH)D) are common in osteoarthritis (OA) patients. However, the effect of vitamin D supplementation on muscle strength and physical performance remains unclear. This study will investigate the effects of vitamin D2 supplementation on muscle strength and physical performance in knee OA patients; (2) Methods: One hundred and seventy-five primary knee OA patients with low levels of serum 25(OH)D (<30 ng/mL) received 40,000 IU vitamin D2 (ergocalciferol) per week for six months. Body composition, muscle strength, physical performance, serum 25(OH)D level, leptin, interlukin-6 (IL-6), parathyroid hormone (PTH), protein carbonyl, and metabolic profile were analyzed; (3) Results: Baseline mean serum 25(OH)D levels in knee OA patients was 20.73 ng/mL. Regarding baseline vitamin D status, 58.90% of patients had vitamin D insufficiency, and 41.10% had vitamin D deficiency. After vitamin D2 supplementation for six months, mean serum 25(OH)D level was 32.14 ng/mL. For post-supplementation vitamin D status, 57.10% of patients had vitamin D sufficiency and 42.90% had vitamin D insufficiency. From baseline to six months, there was a significant increase in mean serum 25(OH)D level (p < 0.001), while mean LDL cholesterol (p = 0.001), protein carbonyl (p = 0.04), and PTH (p = 0.005) all significantly decreased. Patient quality of life (SF-12) and pain (visual analog scale, VAS) both improved significantly from baseline to the six-month time point (p = 0.005 and p = 0.002, respectively). Knee OA patients demonstrated significant improvement grip strength and physical performance measurements after vitamin D2 supplementation (p < 0.05); (4) Conclusions: Vitamin D2 supplementation for six months reduced oxidative protein damage, decreased pain (VAS), improved quality of life, and improved grip strength and physical performance in osteoarthritis patients.

Elevated serum leptin levels are associated with low vitamin D, sarcopenic obesity, poor muscle strength, and physical performance in knee osteoarthritis.

CONTEXT: The associations between serum leptin, vitamin D status, sarcopenic obesity, muscle strength and physical performance in osteoarthritis (OA) remain uncertain. OBJECTIVE: To analyse the relationships between serum leptin, vitamin D status, muscle strength and physical performance in OA patients. METHODS: A total of 208 knee OA patients were enrolled. Serum leptin, vitamin D, muscle strength and physical performance were evaluated. RESULTS: OA patients with sarcopenic obesity had significantly higher serum leptin levels than those with non-sarcopenic obesity. In addition, knee OA patients with sarcopenic obesity displayed low grip strength and poor physical performance. Furthermore, high serum leptin was negatively associated with vitamin D and physical performance. CONCLUSIONS: Serum leptin levels were correlated with low vitamin D, reduced muscle strength and functional impairment, suggesting that serum leptin might serve as a biomarker reflecting physical performance in OA patients.

Plasma and synovial fluid inflammatory cytokine profiles in primary knee osteoarthritis.

OBJECTIVE: The objective of this study is to compare inflammatory cytokine levels in primary knee osteoarthritis (OA) patients and healthy controls. METHODS: A total of 32 knee OA patients and 14 healthy controls were enrolled. A multiplex immunoassay was utilized for 10 cytokines in plasma and synovial fluid. RESULTS: Plasma IL-2, IL-4, and IL-6 concentrations were significantly greater in knee OA patients than controls. Moreover, both plasma IL-4 and IL-6 were positively correlated with the radiographic severity of knee OA. CONCLUSIONS: Plasma IL-4 and IL-6 may serve as biomarkers reflecting the severity of OA.

Immune Mediators in Osteoarthritis: Infrapatellar Fat Pad-Infiltrating CD8+ T Cells Are Increased in Osteoarthritic Patients with Higher Clinical Radiographic Grading.

Osteoarthritis is a condition of joint failure characterized by many pathologic changes of joint-surrounding tissues. Many evidences suggest the role of both innate and adaptive immunity that interplay, resulting either in initiation or in progression of osteoarthritis. Adaptive immune cells, in particular T cells, have been demonstrated to play a role in the development of OA in animal models. However, the underlying mechanism is yet unclear. Our aim was to correlate the frequency and phenotype of tissue-infiltrating T cells in the synovial tissue and infrapatellar fat pad with radiographic grading. Our results show that CD8+ T cells are increased in osteoarthritic patients with higher radiographic grading. When peripheral blood CD8+ T cells were examined, we show that CD8+ T cells possess a significantly higher level of activation than its CD4+ T cell counterpart (P < 0.0001). Our results suggest a role for CD8+ T cells and recruitment of these activated circulating peripheral blood CD8+ T cells to the knee triggering local inflammation within the knee joint.

Upregulation of inducible nitric oxide synthase and nitrotyrosine expression in primary knee osteoarthritis.

BACKGROUND: To investigate nitrite and inducible nitric oxide synthase (iNOS) levels in the plasma and synovial fluid of patients with primary knee osteoarthritis (OA) and to determine protein nitrotyrosine in synovial tissue of OA patients. MATERIAL AND METHOD: Thirty patients and 30 healthy controls were recruited into the present study. Plasma and synovial fluid nitrite levels were measured using Griess reaction. Plasma and synovial fluid iNOS concentrations were analyzed by enzyme-linked immunosorbent assay. Nitrotyrosine was detected immunohistochemically in synovial tissue of OA patients. RESULTS: Plasma and synovial fluid nitrite concentration in the OA group were significantly higher than those in the healthy control group were (p = 0.007 and p = 0.012). Furthermore, plasma iNOS levels were significantly higher in the OA group than those in healthy control group were (p = 0.04). Moreover, nitrotyrosine was detected immunohistochemically in macrophages, synovial lining layer and synoviocytes of synovial tissue in the OA group. CONCLUSION: These findings indicate that reactive nitrogen species and nitrotyrosine-containing proteins may be involved in the joint destruction process, and play a potential role in the pathogenesis of knee osteoarthritis.

Angiogenic cytokine expression profiles in plasma and synovial fluid of primary knee osteoarthritis.

PURPOSE: The aim of this study was to compare angiogenic cytokine levels in knee osteoarthritis (OA) patients and healthy controls and to investigate the relationships between angiogenic cytokines and the OA severity. METHODS: Thirty-one knee OA patients and 15 healthy controls were recruited. Nine angiogenic cytokines (angiopoietin-2, follistatin, granulocyte-colony stimulating factor (G-CSF), hepatocyte growth factor (HGF), interleukin (IL)-8, leptin, platelet-derived growth factor-BB (PDGF-BB), platelet endothelial cell adhesion molecule (PECAM)-1, and vascular endothelial growth factor (VEGF)) in plasma and synovial fluid were measured using a multiplex immunoassay. RESULTS: PECAM-1, HGF, VEGF, angiopoietin-2, follistatin, G-CSF, and IL-8 concentrations in plasma were significantly higher in OA patients than those in controls. Plasma angiopoietin-2 was significantly greater in advanced OA than in early OA. Synovial fluid VEGF was positively correlated with the severity (r = 0.367, P = 0.04). Plasma follistatin was significantly lower in advanced knee OA than in early OA and was negatively correlated with the severity (r = -0.374, P < 0.05). CONCLUSIONS: Angiogenic cytokine concentrations in plasma can distinguish between controls and OA patients. Local and circulating levels of angiogenic cytokines could give an insight into the pathophysiology of OA. Follistatin, angiopoietin-2, and VEGF may have potential as biochemical markers for the assessment of OA severity.

Plasma and synovial fluid sclerostin are inversely associated with radiographic severity of knee osteoarthritis.

OBJECTIVE: The purpose of this study was to analyze sclerostin in plasma and synovial fluid of knee osteoarthritis (OA) patients and to investigate the association between sclerostin levels and radiographic severity. DESIGN AND METHODS: A total of 190 subjects (95 knee OA patients and 95 healthy controls) were recruited in the present study. Sclerostin levels in plasma and synovial fluid were assessed using an enzyme-linked immunosorbent assay. OA grading was performed using the Kellgren-Lawrence classification. RESULTS: Plasma sclerostin levels were significantly lower in OA patients than in healthy controls (P=0.004). Additionally, sclerostin levels in plasma were significantly higher with respect to paired synovial fluid (P<0.001). Moreover, sclerostin levels in plasma and synovial fluid demonstrated a significant inverse correlation with the radiographic severity of knee OA (r=-0.464, P<0.001 and r=-0.592, P<0.001, respectively). Subsequent analysis revealed that there was a positive correlation between plasma and synovial sclerostin levels (r=0.657, P<0.001). CONCLUSIONS: Sclerostin was significantly lower in OA plasma samples when compared with healthy controls. Plasma and synovial fluid sclerostin levels were inversely associated with the radiographic severity of knee OA. Therefore, sclerostin may be utilized as a biochemical marker for reflecting disease severity in primary knee OA.

Association of adiponectin +276G/T polymorphism with knee osteoarthritis.

Osteoarthritis (OA) is a prevalent, degenerative joint disorder leading to the destruction of articular cartilage, osteophyte formation and subchondral bone sclerosis. Genetic and environmental factors are involved in the development of OA. The role of adiponectin gene polymorphisms in OA has not yet been established. The aim of this study was to investigate the association of adiponectin +276G/T (rs1501299) gene polymorphism with knee OA. Genotype distributions and allelic frequencies of adiponectin gene, +276G/T polymorphism were determined in a total of 200 subjects (100 knee OA patients and 100 healthy controls). Single-nucleotide polymorphism (SNP) of the adiponectin +276G/T gene was genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis. The genotype distribution of +276G/T SNP was observed in the Hardy-Weinberg equilibrium for OA patients and controls. No statistically significant difference was identified between the two groups with respect to genotype distributions and allelic frequencies (P>0.05). The T- and G-allele frequencies were indicated as 24.5 and 75.5%, respectively, in OA patients, whereas the frequency was 23-70% in the control group. Findings of this study therefore suggest that the +276G/T SNP was not associated with susceptibility to knee OA.

Relationship of plasma and synovial fluid vascular endothelial growth factor with radiographic severity in primary knee osteoarthritis.

PURPOSE: Recent evidence suggests that angiogenesis and inflammation contribute to the development and progression of osteoarthritis (OA). The purpose of this study was to investigate vascular endothelial growth factor (VEGF) levels in plasma and synovial fluid of patients with knee OA and to determine the relationship of VEGF levels with disease severity in knee OA. METHODS: A total of 100 subjects were enrolled in this study (80 knee OA patients and 20 healthy controls). Plasma and synovial fluid VEGF levels were analysed using enzyme-linked immunosorbent assay. VEGF expressions in synovial membrane and articular cartilage samples were assessed using immunohistochemistry. RESULTS: VEGF level in synovial fluid of knee OA patients was tenfold higher than that in paired plasma (P < 0.001). Both plasma and synovial fluid VEGF exhibited a positive correlation with radiographic severity (r = 0.454 and r = 0.727, P < 0.001, respectively). VEGF expression was highly detectable in synovial lining cells and articular chondrocytes of knee OA patients. CONCLUSIONS: VEGF levels in both plasma and synovial fluid were positively correlated with the severity of knee OA. Therefore, VEGF may be useful for monitoring OA severity and could play a substantial role in the development and progression of knee OA.

Oxidative stress, vitamin e, and antioxidant capacity in knee osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a chronic progressive degenerative joint disorder which is characterised by strongly age-related regressive changes in articular cartilage. The objective of this study was to evaluate oxidative stress and antioxidant parameters in plasma and synovial fluid of patients with primary knee osteoarthritis. MATERIAL AND METHODS: Thirty-five OA patients and 35 healthy controls were recruited for this study. Nitrite, malondialdehyde (MDA), vitamin E, Trolox Equivalent Antioxidant Capacity (TEAC), and Ferric Reducing Antioxidant Power (FRAP) levels in plasma and synovial fluid were determined. RESULTS: Plasma nitrite levels in OA patients were significantly higher than those in healthy controls (p = 0.037). Furthermore, plasma MDA levels were significantly higher in OA patients than those in healthy controls (p < 0.001). Moreover, plasma vitamin E levels in OA patients were significantly lower than those in healthy controls (p < 0.001). Synovial fluid vitamin E levels of OA patients were significantly lower than paired plasma samples (p < 0.001). The total antioxidant capacities, as were measured by TEAC and FRAP assays in plasma of OA patients, were significantly lower than those in healthy controls (p < 0.01). MDA concentrations were positively correlated with nitrite concentrations but they were negatively associated with vitamin E and TEAC levels in synovial fluid of OA patients. CONCLUSION: The increased plasma levels of nitrite and MDA and the decreased plasma levels of vitamin E, TEAC, and FRAP indicated that oxidative stress was present in OA patients. These findings suggest that oxidative stress plays a potential role in pathophysiology of knee osteoarthritis.

Accuracy of computer-assisted total knee arthroplasty related to extra-articular tibial deformities.

OBJECTIVE: To compare the accuracy of postoperative mechanical alignment in computer-assisted total knee arthroplasties (CAS-TKA) related to various degrees of extra-articular tibial deformity. METHODS: We performed CAS-TKA on 30 knee models in which extra-articular proximal tibial deformities were preset to have malalignments ranging from 30° of varus to 30° of valgus. The knees were assigned to two groups, designated Group A (knees with ≤ 15° preoperative malalignment) and Group B (knees with > 15° preoperative malalignment), and the postoperative mechanical alignment in the two groups was compared using a computer-assisted surgery (CAS) system. Resected bone pieces from the distal femurs and proximal tibias were measured with a digital Vernier caliper and the results compared with the CAS calculations to evaluate the execution accuracy of the bone resection. RESULTS: There was no outlier in either group when a ± 3° deviation from neutral mechanical alignment was set as the acceptance criterion. Interestingly, Group B showed significantly more outliers when the acceptance criterion was a deviation of ± 2° (26.67%, p = 0.0317) or ± 1° (6.67%, p = 0.0007) from neutral alignment. There was no statistical difference between the groups in terms of the execution accuracy of the bone resection. DISCUSSION: The CAS-TKA approach provided significantly less alignment accuracy in tibia with greater preoperative frontal deformity, despite there being no outliers beyond ± 3°.

Association of MMP-3 (-1612 5A/6A) polymorphism with knee osteoarthritis in Thai population.

Osteoarthritis (OA) is a degenerative joint disorder resulting in destruction of articular cartilage, osteophyte formation, and subchondral bone sclerosis. In recent years, numerous genetic factors have been identified and implicated in causing osteoarthritis. One such genetic defect is a single nucleotide polymorphism at position -1612 of matrix metalloproteinase-3 (MMP-3) promoter region, known to lead to three possible genotypes, 5A/5A, 6A/6A, and 5A/6A. The purpose of this study was to investigate the association of MMP-3 -1612 5A/6A gene polymorphism with knee osteoarthritis in Thai population. Genotype distributions and allelic frequencies of MMP-3 -1612 5A/6A polymorphism were investigated in 200 participants (100 patients with knee osteoarthritis and 100 healthy controls). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. There was no statistically significant difference between the groups with respect to genotype distribution (P > 0.05). The 5A allele frequency was indicated as 15.5 %, and 6A allele was as 84.5 % in OA patients, whereas it was 10-90 % in the control group. Accordingly, the present study has indicated that the -1612 5A/6A polymorphism genotypes of MMP-3 gene promoter do not play a role in the development of osteoarthritis in the Thai population.