<aside>
Meniscal flounce is a physiologic wavy appearance of the free inner edge of the meniscus—typically seen during arthroscopy or imaging—in the absence of a tear.
</aside>
Arthroscopic appearance of medial meniscus flounce
Gupta, Y., Mahara, D.P. & Lamichhane, A.P. Validity of flounce sign to rule out medial meniscus tear in knee arthroscopy. BMC Musculoskelet Disord 16, 337 (2015). https://doi.org/10.1186/s12891-015-0800-2
Key points:
| Feature | Description |
|---|---|
| Location | Usually the medial meniscus (more fixed, less mobile than lateral) |
| Appearance | Wavy or undulating edge on imaging or arthroscopy |
| Cause | Folding or buckling of the meniscus due to redundant inner margin |
| Clinical relevance | Benign and non-pathologic; important to distinguish from a tear |
| MRI mimicry | May resemble a horizontal tear on limited slices |
MRI Appearance:
| Sequence | Finding |
|---|---|
| T1/PD/T2 | Wavy or undulating contour at free edge of meniscus |
| No signal change | Within the meniscus itself (unlike in tears) |
| No extension to articular surface | Crucial to distinguish from true meniscal tear |
Radiologic Differentiation: Flounce vs Meniscal Tear
| Feature | Meniscal Flounce | Meniscal Tear |
|---|---|---|
| Signal within meniscus | None (normal low signal) | High signal extending to surface (Grade 3) |
| Morphology | Wavy free edge, no disruption | Clefts, truncation, displaced fragments |
| Reproducibility on slices | Seen only in one or two slices | Present on consecutive slices |
| Clinical symptoms | Usually asymptomatic | Pain, locking, swelling |
