Agreement Between Clinical Examination and Magnetic Resonance Imaging in Acute Knee Trauma With Hemarthrosis

Objective:Hemarthrosis after knee trauma often indicates serious joint injury. Few studies have evaluated agreement between clinical examination and findings from magnetic resonance imaging (MRI). We aimed to describe the agreement between acute clinical examination and subacute MRI findings after acute knee trauma with hemarthrosis and the importance of the subspecialty of the examiner.Design:Longitudinal cohort study. Agreement with MRI findings was evaluated by logistic regression.Setting:Helsingborg hospital.Patients:Thousand one hundred forty-five consecutive patients with hemarthrosis after knee trauma.Interventions:Clinical examination and MRI.Main outcome measures:agreement between clinical examination and findings from MRI. We considered the radiologist's report as the gold standard.Results:Median time (25th, 75th percentile) from injury to clinical examination was 2 (1, 7) days, and from injury to imaging was 8 (5, 15) days. The overall sensitivity and specificity of clinical examination versus MRI for major ligament injury or lateral patella dislocation (LPD) were 70% [95% confidence interval 67-73) and 66% (61-72), respectively. Orthopedic subspecialist knee had the highest agreement with anterior cruciate ligament rupture (adjusted odds ratios were 1.7 (95% confidence interval 1.2-2.3), 1.9 (1.2-3.0) and 5.9 (3.7-9.5) for orthopedic trainees, orthopedic subspecialists other, and orthopedic subspecialist knee, respectively]. For other ligament injuries and LPD, we did not find statistically significant differences.Conclusions:Clinical diagnosis after acute knee injury is relatively unreliable versus MRI findings even when performed by orthopedic specialists. However, the agreement is improved when the examination is performed by an orthopedic knee subspecialist.