A prospective study of the accuracy of clinical examination evaluated by arthroscopy of the knee.

The diagnostic accuracy of clinical examination for internal derangement of the knee were evaluated by arthroscopy in 195 patients (200 knees). Radiographs were available and 50 patients had magnetic resonance imaging. The clinical diagnosis was correct in 104 knees (52%), incomplete in 70 (35%) and incorrect in 26 (13%). When there was a single abnormality the diagnosis was correct in 70%, but when more than 3 lesions were discovered the figure was 28%. All individual lesions were diagnosed correctly in more than 90%. The lesions most difficult to diagnose were chondral fractures, partial tears of the anterior cruciate ligament and loose bodies. Knees with acute lesions and those with a single diagnosis were significantly easier to diagnose (p < 0.01). Age, sex, MRI and the surgeon were not significant.