Fc receptor-like 3 (-169T>C) polymorphism increases the risk of tendinopathy in volleyball athletes: a case control study.

BACKGROUND: Tendinopathy pathogenesis is associated with inflammation. Regulatory T (Treg) cells contribute to early tissue repair through an anti-inflammatory action, with the forkhead box P3 (FOXP3) transcription factor being essential for Treg function, and the FC-receptor-like 3 (FCRL3) possibly negatively regulating Treg function. FCRL3 -169T>C and FOXP3 -2383C>T polymorphisms are located near elements that regulate respective genes expression, thus it was deemed relevant to evaluate these polymorphisms as risk factors for tendinopathy development in athletes. METHODS: This case-control study included 271 volleyball athletes (146 tendinopathy cases and 125 controls) recruited from the Brazilian Volleyball Federation. Genotyping analyses were performed using TaqMan assays, and the association of the polymorphisms with tendinopathy evaluated by multivariate logistic regression. RESULTS: Tendinopathy frequency was 63% patellar, 22% rotator cuff and 15% Achilles tendons respectively. Tendinopathy was more common in men (OR = 2.87; 95% CI = 1.67-4.93). Higher age (OR = 8.75; 95% CI = 4.33-17.69) and more years of volleyball practice (OR = 8.38; 95% CI = 3.56-19.73) were risk factors for tendinopathy. The FCRL3 -169T>C frequency was significantly different between cases and controls. After adjustment for potential confounding factors, the FCRL3 -169C polymorphism was associated with increased tendinopathy risk (OR = 1.44; 95% CI = 1.02-2.04), either considering athletes playing with tendon pain (OR = 1.98; 95% CI = 1.30-3.01) or unable to train due to pain (OR = 1.89; 95% CI = 1.01-3.53). The combined variant genotypes, FCRL3 -169TC or -169CC and FOXP3 -2383CT or -2383TT, were associated with an increased risk of tendinopathy among athletes with tendon pain (OR = 2.24; 95% CI: 1.14-4.40 and OR = 2.60; 95% CI: 1.11-6.10). The combined analysis of FCRL3 -169T>C and FOXP3 -2383C>T suggests a gene-gene interaction in the susceptibility to tendinopathy. CONCLUSIONS: FCRL3 -169C allele may increase the risk of developing tendinopathy, and together with knowledge of potential risk factors (age, gender and years playing) could be used to personalize elite athletes' training or treatment in combination with other approaches, with the aim of minimizing pathology development risk.

Comparative analysis of quadriceps and hamstrings strength in knee osteoarthritis before and after total knee arthroplasty: a cross-sectional study.

OBJECTIVE: Compare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. METHODS: Volunteers were divided into five groups (n = 20): Control; Ahlbäck I and II; Ahlbäck IV; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. RESULTS: Significant differences in the peak torque of the quadriceps and hamstrings were found among the groups (p < 0.001). The Ahlbäck IV, six-month, and 12-month postoperative groups demonstrated lower values when compared to the Control and Ahlbäck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. CONCLUSION: Patients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.

OBJETIVO: Comparar a força muscular isocinética máxima dos músculos extensores e flexores do joelho entre pacientes com osteoartrite do joelho e pacientes submetidos à artroplastia total do joelho. MÉTODOS: Os voluntários foram divididos em cinco grupos (n = 20): Controle, Ahlbäck I e II; Ahlbäck IV; seis meses após artroplastia total do joelho; 12 meses após artroplastia total do joelho. O teste de força voluntária isocinética máxima foi feito para mensuração da força do quadríceps e isquiotibiais a 60/s. RESULTADOS: Foram achadas diferenças significativas entre o pico de torque do quadríceps e dos isquiotibiais (p < 0,001). Os grupos Ahlbäck IV, seis meses e 12 meses após cirurgia mostraram valores mais baixos quando comparados com os grupos controle e Ahlbäck I e II. Quando os valores percentuais foram comparados com o grupo Controle, as diferenças médias variaram de 7% a 41%. CONCLUSÃO: Os pacientes com joelhos saudáveis ou osteoartrite em estágio inicial apresentaram maior força no quadríceps e nos isquiotibiais do que pacientes em estágio mais avançado da doença, mesmo após a ATJ. Esses achados sugerem que os programas tradicionais de reabilitação não recuperam a força nos níveis observados em indivíduos sem osteoartrite do joelho.

Comparative analysis of quadriceps and hamstrings strength in knee osteoarthritis before and after total knee arthroplasty: a cross-sectional study / Análise comparativa da força do quadríceps e dos isquiotibiais na osteoartrite do joelho antes e após a artroplastia total do joelho: um estudo transversal

ABSTRACT Objective: Compare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. Methods: Volunteers were divided into five groups (n = 20): Control; Ahlbäck I and II; Ahlbäck IV; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. Results: Significant differences in the peak torque of the quadriceps and hamstrings were found among the groups (p < 0.001). The Ahlbäck IV, six-month, and 12-month postoperative groups demonstrated lower values when compared to the Control and Ahlbäck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. Conclusion: Patients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.

RESUMO Objetivo: Comparar a força muscular isocinética máxima dos músculos extensores e flexores do joelho entre pacientes com osteoartrite do joelho e pacientes submetidos à artroplastia total do joelho. Métodos: Os voluntários foram divididos em cinco grupos (n = 20): Controle, Ahlbäck I e II; Ahlbäck IV; seis meses após artroplastia total do joelho; 12 meses após artroplastia total do joelho. O teste de força voluntária isocinética máxima foi feito para mensuração da força do quadríceps e isquiotibiais a 60/s. Resultados: Foram achadas diferenças significativas entre o pico de torque do quadríceps e dos isquiotibiais (p < 0,001). Os grupos Ahlbäck IV, seis meses e 12 meses após cirurgia mostraram valores mais baixos quando comparados com os grupos controle e Ahlbäck I e II. Quando os valores percentuais foram comparados com o grupo Controle, as diferenças médias variaram de 7% a 41%. Conclusão: Os pacientes com joelhos saudáveis ou osteoartrite em estágio inicial apresentaram maior força no quadríceps e nos isquiotibiais do que pacientes em estágio mais avançado da doença, mesmo após a ATJ. Esses achados sugerem que os programas tradicionais de reabilitação não recuperam a força nos níveis observados em indivíduos sem osteoartrite do joelho.