Poor correlation of clinical signs with patellar cartilaginous changes

PURPOSE: There is controversy between the symptoms and signs of chondromalacia. Patellar chondromalacia has several clinical tests, whose reliability as a parameter of chondral damage is unclear. The purpose of this prospective study was to correlate the sensitivity, specificity, predictive values and accuracy of clinical patellar tests with the findings at arthroscopy. Type of Study: In this prospective study, 100 consecutive knees that were subjected to arthroscopy were examined. METHODS: Because of missing data, 85 of the 100 knees were included in the final analysis. There were 41 male and 44 female patients with an average age of 39 and 44 years, respectively. The clinical tests were the tracking test, the apprehension test, the patellar inhibition test, and the flexion test. These tests were compared with the arthroscopic findings of the patellar cartilage. The classification of Outerbridge was used for evaluation of the condition of the patellar cartilage. RESULTS: At arthroscopy, there were no patellar cartilage changes in 33 knees. Patellar chondromalacia was seen in 52 knees. Grade I changes were found in 9 knees, grade II in 21 knees, grade III in 17 knees, and grade IV in 5 knees. Among the 4 clinical tests, the sensitivity was best for the tracking test (56%). The flexion test had the greatest specificity (85%), but a low sensitivity (35%). None of the tests showed acceptable results in terms of both sensitivity and specificity. The predictive values and the accuracy of a test were low, too. CONCLUSIONS: The sensitivity and specificity, predictive values, and accuracy of a test were generally low, except perhaps the specificity of the flexion test. The current clinical tests seem to have little value as indicators of patellar chondral pathology.