[The radiological assessment of the knee in the meniscectomy patient]

The increasing number of radiologic examinations performed on patients previously submitted to arthroscopic meniscectomy led us to analyze the types of lesion most frequently found in these patients and the prognostic factors related to meniscectomy. Thus, the radiographs, CT and MR examinations were reviewed of 34 symptomatic patients submitted to arthroscopy at least 1 year earlier and in whom symptoms had appeared no more than 3 months earlier, thus ruling out the symptoms related to surgical complications. Lesions were found in the menisci, in the meniscal stumps and in the articular ends. The lesions involving the menisci not submitted to previous arthroscopy were not studied in detail. As to meniscal stumps, CT and MRI exhibited the same diagnostic accuracy, in detecting lesion recurrence, in 50% of cases. In the remaining cases their results were similar, with some false negatives (CT) and some false positives (MRI). As to osteoarthritis, MRI proved superior in detecting the microscopic evidence of cartilage-bone erosions even though 20% of patients exhibited findings of such entity as to be visible at CT. As regards the macroscopic evidence of articular ends deformity, CT and MRI yielded the same results. To define the prognostic factors of meniscectomy, all patient was asked to define their activity level after meniscectomy, that is before the onset or recurrence of symptoms. A detailed questionnaire was used to this purpose, using the Tapper-Hoover rating scale, expressly developed to derive a functional knee score after meniscectomy. The results indicate that the functional knee score (related to prognosis) was lower in patients older than 40, in meniscectomy performed in older age, in long intervals between trauma and meniscectomy, after complex and horizontal-cleavage lesions and, finally, in sedentary activity.