Joint line tenderness and Mcmurray tests for the detection of meniscal lesions: What is their real diagnostic value?

摘要

Objectives: To assess the interobserver concordance of the joint line tenderness (JLT) and McMurray tests, and to determine their diagnostic efficiency for the detection of meniscal lesions. Design: Prospective observational study. Setting: Orthopedics outpatient clinic, university hospital. Participants: Patients (N=60) with suspected nonacute meniscal lesions who underwent knee arthroscopy. Interventions: Not applicable. Main Outcome Measures: Patients were examined by 3 independent observers with graded levels of experience (>10y, 3y, and 4mo of practice). The interobserver concordance was assessed by Cohen-Fleiss κ statistics. Accuracy, negative and positive predictive values for prevalence 10% to 90%, positive (LR+) and negative (LR-) likelihood ratios, and the Bayesian posttest probability with a positive or negative result were also determined. The diagnostic value of the 2 tests combined was assessed by logistic regression. Arthroscopy was used as the reference test. Results: No interobserver concordance was determined for the JLT. The McMurray test showed higher interobserver concordance, which improved when judgments by the less experienced examiner were discarded. The whole series studied by the "best" examiner (experienced orthopedist) provided the following values: (1) JLT: sensitivity, 62.9%; specificity, 50%; LR+, 1.26; LR-,.74; (2) McMurray: sensitivity, 34.3%; specificity, 86.4%; LR+, 2.52; LR-,.76. The combination of the 2 tests did not offer advantages over the McMurray alone. Conclusions: The JLT alone is of little clinical usefulness. A negative McMurray test does not modify the pretest probability of a meniscal lesion, while a positive result has a fair predictive value. Hence, in a patient with a suspected meniscal lesion, a positive McMurray test indicates that arthroscopy should be performed. In case of a negative result, further examinations, including imaging, are needed.