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Time-Dependent Increase in Medial Meniscus Extrusion after Medial Meniscus Posterior Root Tear Analyzed by Using
Yoshiki Okazaki1, Takayuki Furumatsu1, Yasunori Shimamura1
1Department of Orthopaedic Surgery, Okayama University Graduate School, Okayama, Japan.
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 (R=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 (R=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.
Insights
Medial meniscus posterior root tears cause rapid progression of medial meniscus extrusion. Narrowing of the medial joint space width is linked to this extrusion progression.
Area of Science:
- Orthopedics
- Radiology
- Biomechanics
Background:
- Medial meniscus posterior root tears (MMPRT) are associated with medial meniscus extrusion (MME).
- Understanding the rate and factors influencing MME progression is crucial for patient management.
Purpose of the Study:
- To quantify the progression rate of medial meniscus extrusion (MME) in patients with MMPRT.
- To identify factors associated with MME progression using serial preoperative MRI scans.
Main Methods:
- Retrospective review of 33 patients with MMPRT who had two MRIs.
- Measurement of medial meniscus body width, medial joint space width (MJSW), and MME.
- Calculation of MME progression rate via regression analysis and correlation with clinical factors.
Main Results:
- Mean MME increased significantly from 3.4 mm to 4.5 mm (p<0.001).
- The MME progression rate was determined to be 0.020 mm per day.
- A moderate correlation was found between MME progression rate and medial joint space width (MJSW) (R=0.432).
Conclusions:
- Medial meniscus extrusion (MME) progresses rapidly in the setting of medial meniscus posterior root tears (MMPRT).
- Narrowing of the medial joint space width (MJSW) is a significant factor associated with MME progression.
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