Oxidative Stress and Abnormal Tendon Sonographic Features in Elite Soccer Players (A Pilot Study) / Estresse oxidativo e características ultrassonográficas do tendão anormal em jogadores de futebol de elite (um estudo piloto)

Abstract Objective Sound experimental data suggest that oxidative stress plays an important role in the pathogenesis of tendinopathies. However, this hypothesis in humans remains speculative given that clinical data are lacking to confirm it. Recently, a new methodology has allowed to quantify the oxidative stress in vivo by measuring the concentration of hydroperoxides of organic compounds, which have been utilized as an oxidative stressrelated marker in several pathologic and physiologic conditions. Given the reliability of this test and the lack of information in subjects with tendinopathies, the aim of the present study was to assess the oxidative stress status in elite professional soccer players with and without ultrasonographic features of tendon damage. Methods In 73 elite players, blood metabolic parameters were evaluated and oxidative stress was measured by means of a specific test (expressed as U-Carr units). Therefore, an ultrasonographic evaluation of the Achilles and patellar tendons was performed. Results No significant relationships were observed between metabolic parameters and oxidative stress biomarkers. The Achilles and patellar tendons showed a normal echographic pattern in 58 athletes, and sonographic abnormalities in 15. The athletes with ultrasonographic alterations, compared to those with normal US picture, showed significantly higher U-Carr levels (p = 0.000), body mass index (BMI) values (p = 0.03) and were older (p = 0.005). The difference in U-Carr values among the subjects remained significant also after adjustment for age and BMI. Conclusion The results of the present study support the hypothesis that oxidative substances, also increasedat systemicand notonlyat local level, mayfavor tendon damage. Level of Evidence IV (pilot study).

Resumo Objetivo Dados experimentais ultrassonográficos sugerem que o estresse oxidativo desempenha um papel importante na patogênese das tendinopatias. No entanto, essa hipótese permanece especulativa em humanos, dado que faltam dados clínicos para comprová-la. Recentemente, uma nova metodologia permitiu quantificar o estresse oxidativo in vivo medindo a concentração de hidroperóxidos de compostos orgânicos, que tem sido utilizada como um marcador relacionado ao estresse oxidativo em várias condições patológicas e fisiológicas. Dada a confiabilidade desse teste e a falta de informação em sujeitos com tendinopatias, o objetivo do presente estudo foi avaliar o status de estresse oxidativo em jogadores profissionais de elite com e sem características ultrassonográficas de dano tendinoso. Métodos Em 73 jogadores de elite foram avaliados parâmetros metabólicos e o estresse oxidativo foi medido por meio de um teste específico (expresso como unidades U-Carr). Por isso, foi realizada uma avaliação ultrassonográfica dos tendões de Aquiles e patelar. Resultados Não foram observadas relações significativas entre parâmetros metabólicos e biomarcadores de estresse oxidativo. Os tendões de Aquiles e patelar mostraram um padrão ecográfico normal em 58 atletas, e anormalidades ultrassonográficas em 15. Os atletas com alterações, em comparação com aqueles com quadro normal, apresentaram níveis significativamente mais elevados de U-Carr (p = 0,000), índice de massa corporal (IMC) (p = 0,03) e eram mais velhos (p = 0,005). A diferença nos valores de U-Carr entre os sujeitos permaneceu significativa também após ajuste por idade e IMC. Conclusão Os resultados deste estudo corroboram a hipótese de que as substâncias oxidativas, também aumentadas a nível sistêmico e não apenas a nível local, podem favorecer danos no tendão. Nível de Evidência IV (estudo piloto).

Ultrasound of entheses in ankylosing spondylitis patients: The importance of the calcaneal and quadriceps entheses for differentiating patients from healthy individuals

OBJECTIVES: To compare the ultrasonographic findings of entheses in ankylosing spondylitis (AS) patients with those of healthy control individuals and to assess the ability of ultrasound (US) to identify aspects related to the disease. METHODS: A cross-sectional study involving 50 patients with AS and 30 healthy controls was performed. Clinical assessment included the use of a visual analog scale for pain, assessment of swelling of the enthesis, global assessments for patients and physician, use of a disease activity index, mobility and dysfunctional indices, erythrocyte sedimentation rate and clinical enthesitis index. US was performed for the following entheses by two experienced musculoskeletal radiologists: brachial triceps, distal quadriceps, proximal and distal patellar tendons, calcaneal tendon, and plantar fascia; the total and subitems of the Madrid Sonographic Enthesitis Index were used for evaluations. RESULTS: Comparison between groups showed a statistically significant difference with worse scores in AS patients, with bone erosion of the calcaneal enthesis and bone erosion and thickening of the plantar fascia. The odds ratio for thickening of the plantar fascia in the AS group was 3.47, according to logistic regression analysis. The AS group also had worse scores regarding the presence of calcification in the quadriceps enthesis, with a fivefold increased risk. CONCLUSION: US analysis showed that only entheses of the foot and quadriceps were able to differentiate AS patients from healthy individuals.