Time Dependent Increase in Medial Meniscus Extrusion may require Meniscal Repair in Partial Medial Meniscus Posterior Root Tears

Koki Kawada et al conducted a study to compare medial meniscus extrusion (MME) in patients with partial medial meniscus posterior root tears (MMPRTs) through magnetic resonance imaging (MRI) conducted at two-time points and to determine whether patient characteristics or MME measurements differ in patients who respond to nonoperative treatment compared with those who require surgical treatment.

The study was conducted at Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikata-cho, Kita-ku, Okayama, Japan. The study has been published in ‘Indian Journal of Orthopaedics.’

Medial meniscus posterior root tears (MMPRTs) occur frequently in middle-aged adults and cause painful posteromedial popping with descending actions, such as stairs or downhill. Recently, meniscal repair has been widely performed for MMPRTs and is more effective than conservative therapy or meniscectomy in preventing cartilage damage and reducing additional surgery.

37 patients with partial MMPRTs underwent two MRI scans during nonoperative management or before pull-out repair. Among these, 17 patients received nonoperative management, and 20 underwent pull-out repair. Partial MMPRTs were diagnosed based on the MRI findings. MME measurements were performed on both MRI scans. Statistical and receiver operating curve (ROC) analyses were performed.

Key findings of the study were:

• The duration from the onset to the first MRI scan (23.2±16.1 days vs. 23.9±37.8 days, p=0.200) and the follow-up duration (22.6 ± 12.2 months vs. 25.1 ± 12.8 months, p = 0.583) were not significantly different between the two groups.

• The duration between the two MRI scans was significantly shorter in the pull-out repair group than in the nonoperative management group.

• The increase in MME (ΔMME) on MRI scans was significantly greater in the pull-out repair group than in the nonoperative management group.

• Linear regression analysis revealed a weak correlation between the MRI interval and ΔMME in the nonoperative management group and a moderate correlation in the pull-out repair group.

• In the ROC construction, the cut-off value for ΔMME that requires surgical intervention was 0.41 mm, with a sensitivity and specificity of 85.0% and 52.9%, respectively.

The authors concluded – “Patients with partial MMPRTs requiring surgical treatment had greater MME progression in a shorter time and a time-dependent increase in MME. Therefore, a ΔMME of ≥0.41 mm may be useful in deciding surgical intervention based on MRI retests.”

Level of evidence III.  

Further reading:

Time Dependent Increase in Medial Meniscus Extrusion Predicts the Need for Meniscal Repair in Patients with Partial Medial Meniscus Posterior Root Tears: A Case–Control Study

Koki Kawada, Takayuki Furumatsu et al

Indian Journal of Orthopaedics (2023) 57:1633–1639

https://doi.org/10.1007/s43465-023-00987-3