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Published on: July 6, 2022
Medial Meniscal Extrusion in Patients With Medial Meniscus Root Tears: A Systematic Review and Meta-analysis
Francis Jia Yi Fong1, Bryan Wei Loong Ong2, Yee Han Dave Lee2
1Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Background:
Medial meniscal extrusion (MME) has received significant interest because of its correlation with medial meniscus root tears (MMRTs), its potential as a diagnostic tool, and its significance in the progression of knee osteoarthritis (OA).
Purpose:
To (1) evaluate if MMRTs significantly increase MME compared with nonroot tears (NRTs) and no tears and (2) determine the clinical outcomes of increased MME.
Study Design:
Systematic review; Level of evidence, 4.
Methods:
Electronic database searches of PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were conducted on June 6, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist criteria. The searches were conducted using the keywords "meniscus tear" and "extrusion." No restrictions were placed on the date of publication. Quality and sensitivity assessments were conducted on included studies. Major MME was defined as an extrusion ≥3 mm.
Results:
Twenty-two studies involving 7882 knees were included. Compared with patients with NRTs, those with MMRTs had a 1.12-mm greater mean absolute meniscal extrusion (AME) and were 3.45 times more likely to have major MME (P < .001 for both). Compared with patients with no tears, those with MMRTs had a 2.13-mm greater AME (P < .001). Within patients with MMRT, those with widely displaced MMRT had a 1.01-mm greater AME compared with nondisplaced MMRT (P < .001). Patients with OA had a 0.73-mm greater AME and were 3.86 times more likely to have major MME compared with patients without OA (P < .001 for both). Within patients who were not stratified according to MMRT, NRT, or no tears, those who eventually developed OA had a 0.79-mm greater AME than those who did not have OA (P = .02).
Conclusion:
Patients with MMRTs had higher MME values compared with those with other types of meniscal tears and those without any meniscal tears. Patients with knee OA were more likely to have higher MME compared with those without OA.
Insights
Medial meniscus root tears (MMRTs) significantly increase medial meniscal extrusion (MME) compared to other tears or no tears. Increased MME is also associated with knee osteoarthritis (OA) progression.
Area of Science:
- Orthopedics
- Radiology
- Sports Medicine
Background:
- Medial meniscal extrusion (MME) is linked to medial meniscus root tears (MMRTs), potentially aiding diagnosis.
- MME's role in knee osteoarthritis (OA) progression is a significant area of research.
Purpose of the Study:
- To compare MME in patients with MMRTs versus non-root tears (NRTs) and healthy knees.
- To assess the clinical outcomes associated with elevated MME.
Main Methods:
- A systematic review of electronic databases (PubMed, Embase, Scopus, Web of Science, Cochrane) was performed.
- Included studies were assessed for quality and sensitivity, defining major MME as extrusion ≥3 mm.
Main Results:
- MMRTs significantly increased MME by 1.12 mm versus NRTs and 2.13 mm versus no tears.
- Patients with MMRTs were 3.45 times more likely to have major MME than those with NRTs.
- Knee OA patients showed higher MME (0.73 mm greater) and were 3.86 times more likely to have major MME.
Conclusions:
- MMRTs are associated with significantly higher MME than other meniscal tears or intact menisci.
- Elevated MME is more prevalent in patients with knee OA.
