Anserine bursa palpation tenderness is a risk factor for knee osteoarthritis progression and arthroplasty: data from the Osteoarthritis Initiative.

Abstract

Anserine bursa pain (ABP) is defined as the presence of palpation tenderness medially below the joint line, which is 2cm from the tibial tuberosity. This study aimed to determine a link between ABP and three knee outcomes: frequent pain, joint space narrowing (JSN) progression, and total knee arthroplasty (TKA). Participants from the Osteoarthritis Initiative cohort were included in this study. Frequent ABP was defined as presenting thrice at four-time points. The Chi-square test and binary logistic regression analyses examined the associations between ABP and the three knee outcomes. Furthermore, Cox Proportional Hazards Model explored the association between ABP and TKA. Baseline ABP was linked to a higher risk of frequent pain (odds ratio (OR): 2.28, 95% confidence interval (CI): 1.76-2.97, P < 0 .001) and TKA (OR: 1.54, 95% CI 1.01-2.36, P = 0 .044) after adjusting for gender, baseline age, body mass index (BMI), and Kellgren-Lawrence (KL) grade. In the frequent ABP group from baseline to the 4-year follow-up (≥ 3 of four-time points), frequent pain (OR: 3.14, 95% CI: 2.34-4.22, P < 0 .001) and TKA (OR: 1.79, 95% CI: 1.11-2.90, P = 0 .017) had a high association with ABP after adjusting for gender, baseline age, BMI, and KL grade. This study highlights the association between ABP and knee outcomes; therefore, clinicians should pay closer attention during the physical examination, especially in middle-aged and older female patients. Moreover, understanding ABP cause aids in better diagnosis and treatment. Key Points • This is the first study to identify an association between anserine bursa palpation tenderness and symptomatic knee osteoarthritis. • As opposed to most studies, which focus on intra-articular symptoms and signs, this study focused on extra-articular symptoms and signs. • Clinically, anserine bursa palpation tenderness can be utilized to determine patients at risk for the progression of knee osteoarthritis, thereby aiding in providing early therapeutic intervention.