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A ramp lesion is a longitudinal tear at the posterior meniscocapsular junction of the medial meniscus, frequently seen in association with Anterior cruciate ligament (ACL) injury.
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These tears often go unrecognized on routine MRI and may require dynamic arthroscopic probing for detection.
Key features:
| Feature | Description |
|---|---|
| Ramp lesion | A meniscocapsular separation or tear of the posterior horn of the medial meniscus (PHMM) at its capsular attachment |
| Location | Posteromedial corner of the knee |
| Associated structure | Semimembranosus–posterior horn complex, posterior oblique ligament |
| Mechanism | Shear force during rotational ACL injury, especially pivoting trauma |
Posterior medial meniscus anatomy, with its corresponding structures. In (a), an illustrated open view of the medial compartment of the knee, in (b), a zoomed view of the posteromedial capsular-meniscal unit, and in (c), the corresponding MRI appearance on sagittal PD-weighted fat suppressed: meniscocapsular ligament (thin arrow), meniscotibial ligament (curved arrow) and posterior capsular attachment (star)
Taneja, A.K., Miranda, F.C., Rosemberg, L.A. et al. Meniscal ramp lesions: an illustrated review. Insights Imaging 12, 134 (2021). https://doi.org/10.1186/s13244-021-01080-9
| Type | Description |
|---|---|
| Type 1 | Meniscocapsular tear (most common) |
| Type 2 | Partial-thickness tear of meniscal body |
| Type 3 | Complete longitudinal peripheral tear |
| Type 4 | Bucket-handle with ramp extension |
| Type 5 | Complex ramp with adjacent tissue detachment |
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Tear patterns of ramp lesions of the medial meniscus. (A) These tears can then further classified by their proximity to meniscus blood supply, namely, whether they are located in the capsulomeniscal junction (1), red-red (2), red-white (3), or white-white (4) zones. (B) Type 1: Capsulomeniscal junction lesions. Lesions are very peripherally located in the synovial sheath. Mobility at probing is very low. (C) Type 2: Partial superior lesions. It is stable and can be diagnosed only by the trans-notch approach. Mobility at probing is low. (D) Type 3: Partial inferior or hidden lesions. They are not visible with the trans-notch approach, but they may be suspected in case of mobility at probing, which is high because of the disruption of the meniscotibial ligament. (E) Type 4: Complete tear in the red-red zone. Mobility at probing is very high. (F) Type 5: Double tear.
Thaunat M, Jan N, Fayard JM, et al. Repair of Meniscal Ramp Lesions Through a Posteromedial Portal During Anterior Cruciate Ligament Reconstruction: Outcome Study With a Minimum 2-Year Follow-up. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2016;32(11):2269-2277. doi:https://doi.org/10.1016/j.arthro.2016.02.026
| Feature | Description |
|---|---|
| Common in | ACL-deficient knees |
| Incidence | Seen in ~15–40% of ACL tears |
| Age group | Young athletes, especially pivoting sports |
| Symptom | Description |
|---|---|
| Instability | Persistent instability despite ACL repair |
| Mechanical symptoms | Pain, popping, catching |
| Often asymptomatic | Especially if chronic |
| Failure to detect | Can lead to failure of ACL reconstruction |
MR imaging:
Findings are subtle and often missed.
| MRI Sign | Description |
|---|---|
| Disruption of meniscocapsular junction | Linear T2 hyperintensity between PHMM and capsule |
| Posterior medial tibial edema | Secondary sign, indicates traction or chronic stress |
| Meniscal irregularity | Blunting or separation of posterior horn margins |
| Fluid signal tracking | Linear fluid cleft extending toward capsule |
| PHMM lift-off | Separation of posterior horn from tibial plateau |