Summary

In this study, the joint line tenderness was highly useful in diagnosing meniscus tears, whereas the McMurray test was significantly useful for lateral meniscus tears when a click is palpable during the examination and showed limited usefulness in medial meniscus tears.

Abstract

Objectives:
The aim of this study was to investigate the validity and reliability of the McMurray test and joint line tenderness for diagnosing meniscus tears.

Methods

A retrospective study was carried out with 220 patients who underwent arthroscopic surgery for suspected meniscal tears between April 2017 and March 2022. Data regarding patient demographics, preoperative assessment including physical examination, imaging and arthroscopic findings were collected from the medical records. A definitive diagnosis of medial or lateral meniscus tear was made based on arthroscopic findings and compared with age, gender, BMI, and physical examination findings using univariate analysis. Logistic regression analysis was performed to evaluate factors related to injuries. Sensitivity, specificity, and likelihood ratios were calculated for the physical findings that were useful for diagnosing meniscus tears. The association between physical examination findings and meniscus tear patterns was also analyzed.

Results

Of the 235 knees in 220 patients, 111 had an injury involving the menial meniscus (MM) and 109 the lateral meniscus (LM). The mean age at surgery was 40.8 years. In univariate analysis, age (p<0.001) and joint line tenderness (p<0.001) were associated with the presence of MM tear. Age (p<0.001), loss of knee extension (p=0.019), joint line tenderness (p<0.001), and clicks on the McMurray test (p<0.001) were associated with the LM tear. In logistic regression analysis, age (OR: 1.06, p<0.001) and medial joint line tenderness (OR: 24.4, p<0.001) were associated with the MM tear. Age (OR: 0.97, p=0.025), lateral joint line tenderness (OR: 30.6, p<0.001), and clicks on the McMurray test (OR: 2.74, p=0.016) were associated with the LM tear. For the MM tear, joint line tenderness had a sensitivity of 81.1%, a specificity of 85.5%, a positive likelihood ratio of 5.58, and a negative likelihood ratio of 0.22. For the LM tear, joint line tenderness had 71.6%, 93.7%, 11.3 and 0.30, whereas clicks on the McMurray test had 52.1%, 80.5%, 2.68 and 0.59, respectively. In the analysis of tear patterns, horizontal tears were most common in MM (n=62), while longitudinal and horizontal tears were most common in LM (n=28). The true positive rate of clicks on the McMurray test was highest for complex tears in LM (69.2%), while in MM, it was highest for longitudinal tears but merely 30.8%.

Conclusions

The joint line tenderness is the most useful clinical sign of meniscus tears. The McMurray test is useful in diagnosing the LM tear when a click is present during the test, although its usefulness in diagnosing the MM tear is limited based on the findings of this study.