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

The diagnostic accuracy of the clinical examination for intraarticular injuries of the knee was documented by arthroscopy over a 6-month period. Two-hundred ninety patients (296 knees) were evaluated by history, physical examination, and standard radiographs. Supplemental diagnostic studies included 41 magnetic resonance images, 2 arthrograms, and 1 previous arthroscopy that had been recently performed. Overall, the correct diagnosis was made in 165 knees (56%), an incomplete diagnosis in 92 (31%), and an incorrect diagnosis in 39 (13%). There were only 2 knees (0.07%) with no discernable lesions. When a single lesion was present in the knee, the diagnosis was made correctly in 72% of cases. When more than 2 were discovered, the diagnosis was correct in only 30%. However, all individual lesions were diagnosed with an accuracy of greater than 90%. The lesions most difficult to diagnose were chondral fractures, fibrotic fat pads, tears in the anterior cruciate ligament, and loose bodies. Knees with acute lesions and those with a single diagnosis proved to be significantly easier to diagnose (P < 0.01). The variables that proved to be insignificant were age, sex, magnetic resonance imaging, surgeon, workers' compensation, or pending litigation.