Perfil do paciente com osteoartrite sintomática de joelho: uma análise descritiva da localização e do padrão da dor, desfecho autorreportado e de capacidade física e força isométrica de quadríceps

Abstract

Introduction: Knee osteoarthritis (KOA) is a chronic and multifactorial condition characterized by persistent pain, functional limitation, and reduced quality of life. The assessment of KOA may include pain location using the Photographic Knee Pain Map (PKPM), functional performance tests, and quadriceps strength measurement. The objective of this study was to describe the clinical profile, pain location and patterns, patient-reported outcomes of physical function, physical performance, and quadriceps isometric strength. Methods: This cross-sectional and descriptive, between August 2014 and February 2021, with approval from the Institutional Ethics Committee (CAAE: 1.000.404). Participants with symptomatic KOA were included according to the clinical criteria of the American College of Rheumatology. Exclusion criteria included uncontrolled diabetes mellitus, uncontrolled systemic arterial hypertension, and recent use of medications or procedures that could interfere with the assessments. Pain was assessed using the Numerical Pain Rating Scale (NPRS) and the PKPM. Patient-reported outcomes included the Lequesne Algofunctional Index, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Short-Form Health Survey (SF-36). Functional performance was evaluated using the 30-Second Chair Stand Test (30s-CST) and the Timed Up and Go (TUG). Quadriceps isometric strength was measured with a handheld dynamometer. Data were analyzed using descriptive statistics with SPSS version 24.0 and R version 4.1.0.Results: A total of 166 patients participated, predominantly female (81.3%), with a mean age of 61.9 years and a mean BMI of 30.6 kg/m². Most presented bilateral pain with a mean symptom duration greater than seven years and reported low adherence to physical activity and physiotherapy. The most frequent pain locations were the medial joint line (56.6%), lateral joint line (52.4%), medial patella (51.8%), and lateral patella (50%). The most prevalent pain pattern was diffuse (51.8%). Functional test results showed reduced performance: an average of 6.4 repetitions in the 30s-CST and 15.3 seconds in the TUG test. Patient-reported scores indicated significant impairments: KOOS total (41.7), Lequesne Index (11.5), and low SF-36 scores in physical domains. Quadriceps isometric strength was reduced (0.3 Kgf/kg), with a mean Muscle Symmetry Index (MSI) of 91.6. Conclusion: The clinical profile of patients with symptomatic KOA was characterized by a predominance of women, advanced age, obesity, chronic bilateral pain, and low levels of physical activity. Pain was most frequently located in the medial and lateral joint lines and patellar regions, with the diffuse pattern being the most common. Functional tests revealed reduced performance, decreased quadriceps isometric strength, and a negative impact on quality of life. These findings highlight the relevance of a comprehensive and individualized physiotherapeutic assessment, guided by both functional tests and pain characterization, to support safer and more effective interventions.