Meniscal Ramp Lesions

Definition. A ramp lesion is a tear of the peripheral posterior horn of the medial meniscus at its meniscocapsular or meniscotibial junction, close to the posteromedial capsule.

The ACL association. Ramp lesions accompany around 17-23% of ACL tears in the series cited on this page. The familiar "40%" is 40% of the medial meniscal tears in Sonnery-Cottet's cohort, not of the ACL tears. Prevalence tends to rise with chronicity and is similar in adolescents and adults, so suspect a ramp lesion with any ACL injury.

The hidden lesion. Ramp lesions were historically under-recognised and are still easily missed: they are often invisible from the standard anterior portals, and about 17% stay hidden even at arthroscopy until a posteromedial portal and minimal debridement are used (Sonnery-Cottet 2014). Better arthroscopic technique and awareness mean they are now routinely identified during ACL surgery. That matters, because failure to address a ramp lesion may contribute to ACL graft failure and persistent rotational instability.

Risk factors. Suspicion rises with:

• Younger age (under 30)
• Male sex
• High-grade pivot shift
• Chronic ACL injury, with delayed presentation (over 6 months)
• Contact sport mechanism

The ramp. The name refers to the sloping posterior meniscocapsular junction of the medial meniscus, which connects the posterior horn to the posteromedial capsule. It sits in the peripheral third, the vascular red-red zone, supplied from the posteromedial capsule, the meniscocapsular vessels and the perimeniscal capsular plexus. That vascularity gives a repair a more favourable healing environment than a central avascular tear.

Two posterior attachments. The posterior horn is held by two attachments, and the distinction underpins both the classification and the biomechanics.

• Superior, meniscocapsular: the meniscosynovial or capsular junction joining the peripheral meniscus to the posteromedial capsule and the semimembranosus expansion. It is seen and probed from above and behind, through a trans-notch or posteromedial view.
• Inferior, meniscotibial (coronary) ligament: runs from the undersurface of the meniscus to the posterior tibial plateau. It is assessed by probing the meniscotibial face from the posteromedial portal.

What each restrains. The posterior medial meniscocapsular complex is a secondary stabiliser against anterior tibial translation. Disrupting the superior meniscocapsular attachment predominantly increases anterior translation: in Peltier's cadaveric study a ramp lesion added about 2.6mm to the ACL-deficient knee. Detaching the meniscotibial ligament is what adds internal and external rotatory laxity and drives the pivot shift (Peltier 2015, DePhillipo 2018).

What a lesion does, and what repair restores. A ramp lesion increases anterior translation, decreases rotational stability, compromises posterior horn function and increases the stress on an ACL graft; repair restores these. In DePhillipo's robotic study, ACL reconstruction alone restored anterior translation but not the pivot shift, which was eliminated only when both attachments were repaired alongside the reconstruction. Even then, internal and external rotation above 30° of flexion was not restored.

Mechanism. Ramp lesions occur through the same mechanisms as ACL injury. The pivot-shift mechanism combines knee flexion, valgus and internal tibial rotation, and the anterior tibial translation of ACL rupture shears the posterior meniscocapsular junction. The contact mechanism is a direct blow to the lateral knee with the foot planted.

Why the posterior horn. The posterior horn of the medial meniscus is fixed to the tibia by the coronary ligament. As the tibia translates anteriorly it pulls on the posterior horn, and the femoral condyle impinges on it, grinding it between condyle and tibial plateau. Add the rotational component, which shears the capsular attachment, and the meniscocapsular junction tears.

Natural history. Left unrepaired, a ramp lesion may lead to:

• Progressive meniscocapsular separation
• Increased knee laxity despite ACL reconstruction, with persistent rotational instability
• Increased stress on the ACL graft and a higher risk of re-rupture or graft failure
• Potentially accelerated cartilage degeneration
• Residual symptoms

The graft risk is why the posteromedial compartment is assessed at every ACL reconstruction and unstable lesions are repaired at the same sitting. Robust prospective evidence that repair reduces graft re-rupture is still incomplete (see Outcomes).

Thaunat (2016). The classification describes ramp tears by tear pattern, partial or full thickness, and by whether the meniscotibial ligament is disrupted. Most ramp lesions are peripheral meniscocapsular or meniscotibial separations in the vascular red-red zone, which gives them favourable healing potential.

Use the type to describe, not to decide. Type 4 is the complete tear, not the double-tear category, which is Type 5. The type describes what you see, and the decision to repair rests on stability on probing rather than on the type number alone.

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Assessing stability at arthroscopy. Stability is a functional finding, established by systematic probing of the whole posterior horn-capsule junction.

The gap. A measured gap may support the assessment, but no single gap threshold is independently validated. The classic "gap greater than 4mm on probing" is a pragmatic guide, not a validated cut-off. Probing technique, lesion length and meniscotibial-ligament integrity all influence the decision, and definitions of instability vary between surgeons.

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History. The mechanism is a pivot-shift injury, usually with an ACL tear, and the ramp lesion's symptoms are often masked by the ACL's. Pain, when present, is at the posteromedial joint line and may be subtle. Instability shows as giving way, especially rotational; note how long it has been since the ACL injury.

Examination. Posteromedial joint-line tenderness is subtle. Lachman and pivot shift are positive for the ACL; grade the pivot shift, because a higher grade carries a higher ramp risk. McMurray's test is often negative for a ramp lesion alone, and a deep squat may reproduce posterior pain.

MRI. The first-line test, with 3T preferred and dedicated sequences for the posterior horn. Sagittal images show the integrity of the posterior horn and the separation sign; coronal images show peripheral irregularity and increased signal at the meniscocapsular junction. Two indirect clues are useful: a posteromedial tibial bone bruise, and fluid interposed between the posteromedial tibial edge and semimembranosus, which should prompt deliberate review of the meniscocapsular and meniscotibial attachments.

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Sensitivity. MRI is poor at finding ramp lesions: about 27-46% overall in dedicated series. The split by location is the figure that matters, roughly 40-80% for tears in the red-red zone but 0-20% at the true meniscocapsular junction. The more peripheral the lesion, the blinder the scan, and the meniscocapsular junction is what the word "ramp" actually names. Inter-observer reliability was only fair to moderate. A negative MRI does not exclude a ramp lesion.

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Arthroscopy is the gold standard for diagnosis. Because MRI cannot be relied on to rule a lesion out, arthroscopic assessment is mandatory during every ACL reconstruction: view trans-notch and probe the posteromedial compartment systematically, with a 70° scope to improve visualisation.

The decision. Probe, describe, then decide. A vascular location supports healing, but it does not make fixation risk-free or mandatory. Whether every visualised ramp lesion should be repaired is debated: robotic data show small ramp lesions have little kinematic effect once the ACL is reconstructed (Deichsel 2024), which supports selective, stability-based repair rather than reflex fixation of every lesion.

Repair. The strong indications are:

• Frank instability or displacement on probing: the posterior horn displaces easily or lacks a firm endpoint
• A complete full-thickness or double-tear morphology
• Meniscotibial detachment that leaves the posterior horn mobile
• A repairable tear associated with symptomatic or reconstructable ACL deficiency

Repair is also generally favoured when tissue quality and tear morphology permit durable fixation, and when concomitant ACL reconstruction restores the environment for healing. The decision is modified by tear length, depth, vascular zone and tissue quality, by associated meniscal tears and the planned ACL procedure, and by the patient's activity goals and ability to follow rehabilitation restrictions.

Observation or biological stimulation. A selective option rather than a default, the stimulation by abrasion or trephination according to surgeon preference. It may be appropriate for:

• A short lesion that remains stable through systematic posteromedial probing
• A stable lesion found during ACL reconstruction
• A short, truly stable lesion with a firm endpoint after ACL reconstruction
• A lesion in which repair would sacrifice more viable tissue than it preserves
• A patient in whom fixation risk or rehabilitation burden outweighs the likely benefit

Choosing a construct. All-inside devices, inside-out sutures and single-portal suture-hook repair all have advocates. All-inside repair is a common option during ACL reconstruction, but high-quality comparative outcome data are limited, so the choice is driven by training, access and lesion morphology rather than proven superiority. Match the construct to the tear plane.

Visualisation comes first. The key to ramp repair is seeing the whole posterior horn-capsule junction. Use the 70° scope for the initial assessment; if repair is needed and the view is difficult, create a dedicated posteromedial viewing portal for direct access.

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All-Inside RepairSuture-Hook RepairInside-Out Repair

Surgical Steps

Step 1Visualisation

Use a 70° arthroscope through the anterolateral portal to view the posteromedial compartment, or create a posteromedial viewing portal. The entire posterior horn-capsule junction must be seen.

Step 2Preparation

Debride the tear edges minimally with a shaver. Rasp the meniscal and capsular surfaces to stimulate bleeding and a healing response. Do not over-debride.

Step 3Portal Creation

Create a posteromedial working portal, confirming the trajectory with a spinal needle. Entry is typically 1cm above the joint line, posterior to the MCL; stay anterior to sartorius to avoid the saphenous nerve.

Step 4Suture Passage

Use an all-inside meniscal repair device (FasT-Fix, ULTRA FasT-Fix, etc.), passing sutures through the meniscus and then into the capsule. Typically 1-3 sutures, depending on lesion length.

Step 5Tensioning

Tension the sutures to reduce the meniscus to the capsule. Confirm reduction with the probe: no gap should remain and the meniscus should be stable.

Pitfalls. Missing the lesion is avoided by probing systematically, and saphenous nerve injury by careful portal placement. Over-debridement loses tissue, the reduction should be checked after suturing, and an associated body tear must not be left unaddressed.

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Suture-Hook Repair Steps (Thaunat technique)

Step 1Visualise and localise

Establish a trans-notch or 70 degree posteromedial view. Localise the working portal with a spinal needle just above the joint line, posterior to the MCL and anterior to the sartorius, protecting the saphenous nerve.

Step 2Prepare the junction

Gently rasp the meniscal rim and the meniscotibial/capsular surface to a bleeding bed. Minimal debridement only - preserve tissue.

Step 3Pass the curved suture hook

Pass a curved suture-hook device (for example a 25 degree curved hook) through the capsule/meniscotibial junction and out through the meniscal leaf, placing the suture precisely at the true peripheral attachment.

Step 4Shuttle and repeat

Shuttle a repair suture with a relay, then place vertical sutures along the length of the tear. In a Type 5 double tear, inspect and address both clinically relevant tear planes.

Step 5Tie and confirm

Tie the knots arthroscopically on the capsular side and re-probe to confirm the meniscus is reduced and stable to the tibia.

When to prefer it. The hook places sutures at the true meniscotibial junction, which suits the most peripheral meniscotibial tears. Vertical sutures cross the circumferential meniscal fibres and can capture a concealed inferior component under direct vision, through a single working portal with no posterior open incision.

The trade-offs. The learning curve is steeper, demanding comfortable posteromedial portal skills and arthroscopic knot tying, and it is slower than deploying a rapid all-inside device. The posteromedial working space is crowded, and a misplaced portal puts the saphenous nerve at risk.

All-Inside for Speed, Suture-Hook for Precision

The all-inside device is efficient when its trajectory captures the tear securely. Prefer a single-portal suture-hook (Thaunat) technique when direct reduction of a peripheral meniscotibial component or precise vertical suture placement is required; an anchor that bridges the inferior leaf without reducing it is not an adequate repair.

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Inside-Out Steps

Step 1Posterior Incision

Small posteromedial incision for suture retrieval. Protect the saphenous nerve and vein.

Step 2Cannula Placement

Zone-specific cannula through the anteromedial portal, directed at the lesion.

Step 3Suture Passage

Needles passed through meniscus and capsule, retrieved through the posterior incision.

Step 4Tying

Sutures tied over the capsule with the knee in extension.

Why all-inside has largely replaced it. Inside-out is the traditional technique. All-inside repair needs no posterior incision, is faster and simpler, and carries a lower risk to the saphenous nerve, with similar healing outcomes.

A missed lesion carries the consequences set out under natural history, and systematic posteromedial probing in every ACL reconstruction is what prevents it.

With ACL reconstruction. The protocol follows ACL rehabilitation with minor modifications. Because ramp lesions sit in the red-red zone with excellent healing, the combined protocol is essentially the same as for the ACL alone, and no significant restriction is needed for the ramp repair itself.

Isolated ramp repair. Rare, because ramp lesions typically occur with ACL tears and are addressed together. When a ramp lesion is repaired without ACL reconstruction:

Healing. Repaired ramp lesions have generally high healing rates, the product of the peripheral red-red zone's vascularity and secure fixation; unrepaired lesions heal variably. Repair adds little time and morbidity to ACL reconstruction.

Stability and the graft. Biomechanically, repair best restores the pivot shift (DePhillipo 2018) and helps restore rotational stability, whereas an unrepaired lesion leaves increased laxity, and missed lesions are implicated in residual rotatory laxity. Repair may protect the graft, and an unrepaired lesion carries a potentially higher risk of ACL graft failure, but robust prospective clinical evidence that ramp repair reduces graft re-rupture remains incomplete.

Return to sport. After repair, return is similar to ACL reconstruction alone; an unrepaired lesion may leave instability, and repair is recommended.

Related pages: Meniscal Repair for repair technique and healing biology across all tear patterns, Meniscal Root Tears for the other peripheral attachment failure and its very different consequences, Meniscus Tears for the general classification and management, and Meniscus Structure and Function for the hoop-stress mechanics that explain why a peripheral tear matters.