Knee Surg Relat Res.  2019 Jun;31(2):120-125. 10.5792/ksrr.18.059.

Time-Dependent Increase in Medial Meniscus Extrusion after Medial Meniscus Posterior Root Tear Analyzed by Using Magnetic Resonance Imaging

• Okazaki Y
• Furumatsu
• Shimamura
• Saiga K
• Ohashi H
• Uchino T
• Kamatsuki
• Okazaki Y
• Ozaki T

• KMID: 2451846
• DOI: http://doi.org/10.5792/ksrr.18.059

Abstract

PURPOSE
Medial meniscus posterior root tear (MMPRT) causes progression of medial meniscus extrusion (MME). This study aims to calculate the progression rate of MME based on findings in two preoperative magnetic resonance imaging (MRI) scans and determine the associated factors.
MATERIALS AND METHODS
We retrospectively reviewed 33 patients (27 females and 6 males; mean age, 60 years) who underwent MRI twice, at a mean interval of 48 days. We measured the medial meniscus body width, medial joint space width (MJSW), and MME. The MME progression rate was derived from regression analysis of the increase in MME (ΔMME) between the two MRI scans. In addition, the correlations of the MME increase rate with age, body mass index, femorotibial angle, and MJSW were evaluated.
RESULTS
The mean MME increased from 3.4 mm to 4.5 mm (p<0.001). A good correlation was observed between ΔMME and the interval of MRI scans (R²=0.621), and the MME progression rate was 0.020 mm per day. A moderate correlation was observed between the MME increase rate and the MJSW (R²=0.432).
CONCLUSIONS
The MME progression rate was rapid in MMPRT and narrowing of the MJSW was associated with the progression of MME. LEVEL OF EVIDENCE: V, Cross-sectional study

Keyword

Medial meniscus; Root tear; Extrusion; Magnetic resonance imaging; Risk factors

MeSH Terms

Body Mass Index
Cross-Sectional Studies
Female
Humans
Joints
Magnetic Resonance Imaging*
Male
Menisci, Tibial*
Retrospective Studies
Risk Factors
Tears*