Abstract Introduction In chronic arthropathies, there are several mechanisms of joint destruction. In recent years, studies have reported the implication of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) in the process of activation and differentiation of osteoclasts, a key cell in the development of bone erosion. The RANKL/OPG ratio is increased in the serum of patients with malignant diseases and lytic bone disease, as well as rheumatoid arthritis (RA). The objective of this study was to measure and compare the concentrations of OPG and RANKL in the synovial fluid (SF) of patients with rheumatoid arthritis, spondyloarthritis (SpA) and osteoarthritis (OA). Methods This was an observational and cross-sectional study with 83 patients, 33 with RA, 32 with SpA and 18 with OA, followed up regularly in the outpatient clinics of the Rheumatology Department of the Clinics Hospital of the Ribeirão Preto Medical School-USP. All patients were assessed for indications for arthrocentesis by the attending physicians at the time of SF collection and were evaluated for demographic variables and medication use. Disease activity was assessed in individuals with RA and SpA. The quantification of SF OPG and RANKL levels was performed by ELISA, and the correlations of the results with clinical, laboratory and radiological parameters were assessed. Results We found no statistically significant difference in the RANKL and OPG levels among the groups. Patients with RA showed a positive correlation between the SF cell count and RANKL level (r = 0.59; p < 0.05) and the RANKL/ OPG ratio (r = 0.55; p < 0.05). Patients with OA showed a strong correlation between C-reactive protein (CRP) and the RANKL/OPG ratio (r = 0.82; p < 0.05). There was no correlation between the OPG and RANKL levels and markers of inflammatory activity or the disease activity index in patients with RA or SpA. Conclusion Within this patient cohort, the RANKL/OPG ratio was correlated with the SF cell count in patients with RA and with serum CRP in patients with OA, which may suggest a relationship with active inflammation and more destructive joint disease.

Objetivo: Avaliar o equilíbrio em tarefas dinâmicas e a qualidade de vida em idosas com e sem osteoartrite no joelho. Métodos: As idosas foram divididas em: Grupo 1 (n = 12), consistindo de idosas com osteoartrite bilateral no joelho (Grau Kellgreen-Lawrence 1 e 2); e Grupo 2 (n = 12), consistindo de controles. Foi empregada uma plataforma de força (EMG System do Brasil) para avaliar a oscilação postural em tarefas dinâmicas; já a qualidade de vida foi avaliada mediante a aplicação do questionário WHOQOL-Bref. Resultados: O teste t de Student não demonstrou diferença estatística durante as ações de ficar de pé e sentar em uma cadeira (p > 0,05). Contudo, a tarefa de subir escadas revelou diferença na velocidade de deslocamento (p < 0,05), enquanto a tarefa de descer escadas demonstrou diferenças tanto na velocidade como na amplitude do deslocamento (p < 0,05). No questionário, o Grupo 1 demonstrou valores mais baixos do que os obtidos no Grupo de controle, no que diz respeito ao domínio físico (p < 0,05). Conclusão: Aparentemente, idosas com osteoartrite no joelho tiveram mais dificuldade na tarefa de descer escadas e pior percepção de domínio físico. Esses achados foram observados no grupo com OA, mesmo nos estágios iniciais da doença, o que demonstra a importância de intervenções ainda mais precoces.

Objective: To assess the balance in dynamic tasks and in the quality of life in elderly women with and without knee osteoarthritis. Methods: Elderly women were divided into Group 1 (n = 12), consisting of participants with bilateral knee osteoarthritis (Kellgreen-Lawrence grade 1 and 2), and Group 2 (n = 12), consisting of controls. A force plate (EMG System do Brazil) was used to assess postural sway in dynamic tasks, whereas the quality of life was assessed by using the WHOQOL-Bref questionnaire. Results: Student's t-test showed no statistical difference during sitting down and standing up from the chair (p > 0.05). However, stair ascent revealed difference in displacement speed (p < 0.05), whereas stair descent showed differences in both displacement speed and amplitude (p < 0.05). In the questionnaire, Group 1 showed values lower than those in the control group regarding physical domain (p < 0.05). Conclusion: Elderly women with knee osteoarthritis seemed to have more difficulty on stair descent task and had perception of worst physical domain. These findings were observed in OA group, even in the early stages of the disease, which shows the importance of even earlier interventions.

OBJETIVOS: Comparar parâmetros estabilométricos de mulheres idosas com ou sem histórico de quedas associadas ou não à osteoartrite (OA) de joelhos. MÉTODOS: Cinquenta e seis idosas apresentando ou não histórico de quedas (Q) e OA de joelho unilateral e bilateral foram distribuídas da seguinte maneira: grupo QOA (n = 10), idosas com histórico de queda e OA de joelho; grupo QSOA (n = 11), idosas com histórico de queda e sem OA de joelho; grupo SQOA (n = 14), idosas sem histórico de quedas (SQ) e com OA de joelho; e grupo SQSOA (n = 21), idosas sem histórico de quedas e sem OA de joelho. Para análise do equilíbrio semiestático usando uma plataforma de força, foram avaliados os deslocamentos anteroposterior (DAP) e mediolateral (DML), as velocidades de oscilação anteroposterior (VAP) e mediolateral (VML) em quatro situações na postura ereta. As situações avaliadas foram as seguintes: 1) PFOA: sobre superfície fixa e olhos abertos; 2) PFOF: sobre superfície fixa e olhos fechados; 3) PIOA: sobre superfície instável e olhos abertos; 4) PIOF: sobre superfície instável e os olhos fechados. RESULTADOS: As idosas com OA de joelho apresentaram maior DAP em todas as situações analisadas (P < 0,05), ao passo que idosas com histórico de quedas apresentaram maior DML (P < 0,05). Não houve diferenças entre os grupos para VAP e VML (P > 0,05). CONCLUSÕES: A OA de joelho, por si, é um fator prejudicial no aumento de oscilação do centro de pressão (COP) na direção anteroposterior, enquanto o histórico de quedas, independente da presença de OA de joelhos, traz prejuízos ao controle postural na direção mediolateral.

OBJECTIVES: To compare stabilometric parameters of elderly female fallers and non-fallers associated or not with knee osteoarthritis (OA). METHODS: Fifty-six elderly female fallers and non-fallers diagnosed or not with unilateral or bilateral knee OA were divided into the following groups: FOA (n = 10), elderly female fallers with knee OA; FNOA (n = 11), elderly female fallers without knee OA; NFOA (n = 14), elderly female non-fallers with knee OA; and NFNOA (n = 21), elderly female non-fallers without knee OA. For analyzing semi-static balance on a force platform with the elderly females standing, the following parameters were assessed in four conditions: center of pressure (COP), anterior-posterior and mediolateral displacements (APD and MLD, respectively); and COP anterior-posterior and mediolateral displacement velocities (APV and MLV, respectively). The following conditions were assessed: 1) standing on a firm wooden surface with eyes open (WSEO); 2) standing on a firm wooden surface with eyes closed (WSEC); 3) standing on a foam surface with eyes open (FSEO); 4) standing on a foam surface with eyes closed (FSEC). RESULTS: The elderly females with knee OA showed greater APD in all four conditions assessed (P < 0.05), while the elderly female fallers showed greater MLD (P < 0.05). No difference between the groups was observed for APV and MLV (P > 0.05). CONCLUSIONS: Knee OA per se increases APD of the COP, while the history of falls, regardless of the presence of knee OA, hinders postural control in the ML direction.