Positive predictive value of maximal posterior joint-line tenderness in diagnosing meniscal pathology: a pilot study

OBJECTIVE: The purpose of this prospective study was to determine the positive predictive value (PPV) of the point of maximal posterior joint line tenderness (JLT), as a clinical sign, to diagnose underlying meniscal tears. METHODS: We conducted a prospective study of patients requiring arthroscopic surgery, who consecutively presented to the University of Calgary's Sport Medicine Centre. The femurotibial joint line was palpated for the point of maximal tenderness. We recorded the data on the arthroscopy report. A second examiner (orthopedic sport medicine surgical fellow or sport medicine physician) performed the same protocol. An arthroscopist documented the site of pathology as detected by arthroscopy. RESULTS: We found a PPV of 60.0% and a negative predictive value of 62.5%, suggesting that maximal posterior JLT may be predictive of meniscal pathology. The sensitivity and specificity were 84.6% and 31.2%, respectively (p = 0.155), with Fisher's exact test. The kappa score assessed interobserver reliability and was good at 0.48. Patients with maximal posterior JLT but no meniscal pathology did have other confounding pathology and patients with no maximal posterior JLT who had meniscal pathology usually had confounding knee pathology. CONCLUSIONS: We found a PPV of 60.0% of maximal posterior JLT and meniscal pathology located at the same anatomical site on arthroscopic examination.