['To [1] compare the frequency and severity of ultrasound (US) features in people with normal knees (controls), knee pain (KP), asymptomatic radiographic OA (ROA), and symptomatic OA (SROA), [2] examine relationships between US features, pain and radiographic severity, [3] explore the relationship between change in pain and US features over a 3-month period.', 'Community participants were recruited into a multiple group case-control study. All underwent assessment for pain, knee radiographs and US examination for effusion, synovial hypertrophy, popliteal cysts and power Doppler (PD) signal within the synovium. A 3-month follow-up was undertaken in over half of control and SROA participants.', '243 participants were recruited (90 controls; 59 KP; 32 ROA; 62 SROA). Effusion and synovial hypertrophy were more common in ROA and SROA participants. Severity of effusion and synovial hypertrophy were greater in SROA compared to ROA (P < 0.05). Severity of US effusion and synovial hypertrophy were correlated with radiographic severity (r = 0.6 and r = 0.7, P < 0.01) but the relationship between pain severity and US features was weak (r = 0.3, P < 0.01). In SROA participants, pain severity did not change in tandem with a change in synovial hypertrophy over time.'] Does synovial pathology detected on ultrasound correlate with the severity of radiographic knee osteoarthritis more than with symptoms?