Summary

Medial meniscus root injury and meniscal extrusion

Abstract

Background

Increased mobility of the meniscus, generated by a meniscal root injury can promote and worsen meniscal extrusion. However, little is known about the correlation between concomitant meniscal root injury and injury to medial structures, such as the medial collateral ligament and meniscus extrusion.

Purpose

To evaluate patients with injuries to the posterior root of the medial meniscus and to correlate with their associated injuries, as well as to assess patient characteristics such as sex, weight, height, and degree of meniscal extrusion.
Study Design: Cross-Sectional Study. Level 3 Evidence.

Methods

The characteristics and associated injuries of 55 patients diagnosed with an injury of the root of the posterior horn of the medial meniscus, evaluated through MRI, were compared. Specifically age, sex, anthropometric data, meniscal extrusion, associated medial collateral ligament injury, and presence of associated bone edema were evaluated.

Results

There was a moderate positive correlation between the age of the patients and the degree of extrusion (r = 0.565; p < 0.0001). A greater degree of meniscal extrusion was observed in patients who had complete medial meniscus root injury (p = 0.008). Patients with medial collateral ligament (MCL) injury presented more pronounced meniscal extrusion when compared to individuals without MCL injury (p = 0.042). The incidence of bone bruising was higher in patients with a tear of the medial meniscus posterior horn (MMPH) with an associated MCL injury, when compared to patients without concomitant MCL injury (p=0.012).

Conclusion

Patients with a complete medial meniscus root injury had greater meniscal extrusion than patients with a partial root injury. The presence of a concomitant MCL injury significantly increased meniscal extrusion. The presence of associated bony edema did not influence meniscal extrusion, but was significantly more common in patients with partial meniscal root injury when there was an associated MCL injury compared to those without an associated MCL injury. In the case of total complete root injury, the presence of MCL was not associated with bony edema.