Meniscocapsular ramp lesions in the paediatric knee: A review of diagnosis and surgical management

Abstract

Meniscocapsular ramp lesions, which are tears of the posterior horn of the medial meniscus at the meniscocapsular junction, are increasingly recognised as associated injuries, particularly in the setting of anterior cruciate ligament injuries. While extensively studied in adults, their prevalence, diagnostic challenges, and management in the paediatric and adolescent populations remain areas of active investigation. This review synthesises current evidence regarding the epidemiology, biomechanical significance, diagnostic and treatment modalities for paediatric ramp lesions. We further evaluate surgical repair techniques, including all-inside and inside-out approaches, and discuss clinical outcomes. Despite the high prevalence of these lesions in children, significant gaps exist in long-term follow-up data and standardised treatment algorithms, underscoring the need for further research to optimise care for this vulnerable patient group.

Key Words: Ramp lesion; Knee; Paediatric; Anterior cruciate ligament reconstruction; Meniscus; Meniscocapsular separation

Core Tip: Ramp lesions are commonly encountered when systematically sought, with reported prevalence of 20%-27% in paediatric anterior cruciate ligament (ACL) injuries. This is lower than many adult series. It is highly dependent on surgeon vigilance and exploration technique; therefore, prevalence is likely detection-dependent and not reflective of true incidence. Systematic exploration should therefore be strongly considered in high-risk cases, such as patients undergoing delayed ACL reconstruction, high-grade instability, or suggestive magnetic resonance imaging features. Biomechanical evidence suggests that repair may contribute to improved stability and graft protection, although paediatric clinical confirmation is lacking.

INTRODUCTION

The incidence of anterior cruciate ligament (ACL) tears in the paediatric and adolescent population has risen significantly over the last two decades, largely attributed to increased participation in high-demand competitive sports at younger ages[1,2]. Concomitant meniscal injuries are present in a high percentage of these cases, with recent literature highlighting the “ramp lesion”, which is defined as a “longitudinal tear of the peripheral attachment of the posterior horn of the medial meniscus (PHMM)” as an important but often overlooked injury[3,4].

Ramp lesions have been described as having a surprisingly high false negative detection rate during routine magnetic resonance imaging (MRI), as well as standard anterolateral arthroscopic evaluation, requiring specific manoeuvres or accessory portals for identification[5,6]. In young patients, preserving meniscal tissue to preserve native knee biomechanics has the most impact, as these patients have the longest time with their native knees, and early-onset osteoarthritis would be devastating to active lifestyle and sports careers[7,8].

This review aims to synthesise and critically appraise the current literature on meniscocapsular ramp lesions in the skeletally immature knee which would be referred to simply as paediatric knee in this review, with particular focus on their epidemiology, biomechanical significance, diagnostic challenges, and contemporary surgical management strategies, while highlighting gaps in evidence, especially regarding long-term outcomes to inform future research and clinical practice.

LITERATURE REVIEWS

This narrative review synthesises the current literature on meniscocapsular ramp lesions, focusing specifically on the paediatric and adolescent populations. A literature search was conducted across PubMed, Scopus, and Web of Science databases, utilising the keywords “ramp lesion”, “meniscocapsular”, “paediatric”, “pediatric”, and “adolescent” on January 15^th, 2026. Titles and abstracts were first reviewed, followed by the full body text for relevance to be included. Studies were included if they addressed the epidemiology, biomechanics, diagnosis, surgical management, or outcomes of meniscal ramp lesions in paediatric patients.

Given the limited paediatric-specific literature, particularly regarding surgical techniques and long-term outcomes, high-quality systematic reviews and cohort studies focused on adult populations were also included to provide foundational and comparative context. Case reports, editorials, and non-English articles were excluded. The final selection of articles was critically appraised to identify prevailing themes, controversies, and significant findings, with particular attention paid to study limitations such as small cohort sizes and retrospective data. The heterogeneity of the studies, especially the extrapolation of adult data to the paediatric knee, is a key consideration discussed throughout this manuscript.

EPIDEMIOLOGY AND MECHANISM OF INJURY

The prevalence of ramp lesions in adult ACL-deficient knees is reported to be between 16% and 42%[9,10]. This is similar in recent paediatric and adolescent studies with a prevalence ranging from 20% to 27%[5,6,11]. The systematic review by Moran et al[4] also identified younger age and male sex as significant risk factors for these injuries in the paediatric setting.

The rising incidence of identified ramp lesions is likely multifactorial, as it not only reflects an increase in high-energy ACL injuries in young athletes due to the increasing popularity of youth sports, but also improved diagnostic awareness[1,2]. Systematic arthroscopic exploration of the posteromedial compartment, championed by clinicians like Sonnery-Cottet, has led to the increased identification of lesions that were previously overlooked[12,13].

Furthermore, delays in ACL reconstruction (ACLR), often due to concerns regarding physeal injury in paediatric patients, may contribute to a higher incidence of secondary ramp lesions as the knee remains unstable[14,15]. Tashiro et al[16] demonstrated that a longer delay between injury and surgery is associated with a higher incidence of ramp lesions, suggesting the lesion can be a progressive consequence of chronic instability.

BIOMECHANICAL SIGNIFICANCE

The primary mechanism of a ramp lesion is thought to involve excessive anterior tibial translation and rotational stress during the initial ACL rupture. This forces the PHMM to wedge against the posterior tibial plateau, causing a tear at the meniscocapsular junction due to injury to the meniscotibial ligament[17,18]. The meniscotibial ligament complex, which anchors the posterior horn to the tibial plateau, is critical for meniscal stability. An injury to this complex destabilises the meniscus, permitting increased anterior tibial translation and rotation, thereby increasing the risk of graft failure and joint degeneration[19,20].

The PHMM serves as a vital secondary stabiliser against anterior tibial translation. Biomechanical studies, on cadaveric models, have demonstrated that a ramp lesion significantly increases laxity in an ACL-deficient knee[17,21]. Failure to repair a ramp lesion during ACLR may lead to increased forces on the ACL graft, predisposing it to failure[22]. This is particularly relevant in children, who often have higher baseline ligamentous laxity, potentially amplifying the stabilising role of the meniscocapsular complex[7,20].

Anatomical factors may also predispose individuals to these injuries. Kim et al[23] found that an increased posterior tibial slope was a significant risk factor, with every 1-degree increase in the medial tibial slope conferring 28.9% greater odds of sustaining a ramp lesion. This suggests a bony predisposition that, combined with traumatic instability, contributes to the development of these tears.

DIAGNOSIS: CHALLENGES AND MODALITIES

MRI

MRI is the primary non-invasive diagnostic tool for suspected meniscal pathology. However, its sensitivity for detecting ramp lesions, particularly in children, is notoriously low, with reported rates ranging from 23% to 50%[6,24]. A systematic review by D’Ambrosi et al[25] confirmed that while MRI has good specificity, its sensitivity for paediatric ramp lesions is poor. This diagnostic challenge is compounded by the unique characteristics of the paediatric meniscus, with its high vascularity and normal physiological signal intensity, which can mimic tear patterns, leading to false positives or obscuring true lesions[3,26].

To improve diagnostic accuracy, Nguyen et al[11] proposed specific MRI criteria for meniscal ramp lesions in children, identifying several key associations, as summarised in Table 1.

Table 1 Summary of magnetic resonance imaging findings significantly associated with meniscal ramp lesions in paediatric anterior cruciate ligament injuries, adapted from Nguyen et al[11].

MRI finding	Incidence (ramp vs no ramp), %	P value	Association with ramp lesion
Junctional T2 high/fluid-like signal	77.1 vs 24.0	< 0.001	Strongly associated
Peripheral meniscal irregularity	74.3 vs 38.0	< 0.001	Strongly associated
Meniscocapsular ligament tear	57.1 vs 16.0	< 0.001	Strongly associated
Medial tibial plateau oedema (mid zone)	68.6 vs 46.0	0.04	Associated

Despite these criteria, the diagnostic challenge persists. But with novel imaging techniques like the 120-degree flexed knee MRI described by Nonaka et al[27], demonstrating significantly improved detection rates by opening the meniscocapsular junction. Their study found that the overall sensitivity increased from 69.4% in the near-extended position to 91.9% in the flexed position. This is even more pronounced for specific injury patterns (partial superior and double tears) which were from 0% to 75 and 77.8% respectively.

Although artificial intelligence and deep-learning models is not widely available in many clinical settings, it may further enhance detection, particularly after accounting for risk factors (age, posteromedial tibial bone marrow oedema, and lateral meniscal tears), which the deep-learning model was able to surpass a human radiologist with an accuracy of over 80%, compared to around 60%[28].

ARTHROSCOPIC EVALUATION

Arthroscopy remains the gold standard for both the diagnosis and treatment of ramp lesions[29]. Standard anterior portals, however, often fail to adequately visualise the posteromedial compartment, where the ramp lesion is located. This “hidden area” is obscured by the convexity of the medial femoral condyle, making direct visualisation from an anterior approach impossible. As a result, a high index of suspicion and a systematic approach are required.

Effective visualisation requires passing the arthroscope through the intercondylar notch into the posteromedial compartment - referred in literature as the modified Gilquist view or transcondylar view (Figure 1) to visualise this area, and if required, to establish an accessory posteromedial portal under direct visualisation for probing and instrumentation[13,29]. The work of Sonnery-Cottet et al[12] was instrumental in highlighting the prevalence of these “hidden lesions”. Their systematic three-stage exploration protocol revealed that 16.8% of all medial meniscal tears were completely hidden from the anterior view and were only discovered after establishing a posteromedial portal and probing the meniscosynovial layer. Malatray et al[6] similarly reported that over 40% of ramp lesions in children would be missed without this systematic posteromedial exploration. This stark discrepancy between MRI and arthroscopic findings underscores the necessity of meticulous surgical exploration during paediatric ACL reconstructions[30].

Figure 1 Intraoperative view of medial compartment view. A and B: Comparison of the intraoperative view of medial compartment view using anterior portal (A), and posterior horn of medial meniscus with the modified Gilquist view (B) which would not be easily visualised through standard portals.

Once identified, ramp lesions are typically classified based on their stability and location, according to the systems proposed by Thaunat et al[31] and Greif et al[32] (Table 2).

Table 2 Arthroscopic classification of ramp lesions by Thaunat et al[31].

Classification	Anatomical description (adapted from Thaunat et al[31])	Stability assessment
Type I	Meniscocapsular detachment, with meniscotibial ligament injury	Stable (meniscus remains reduced)
Type II	Partial superior tear of the PHMM with meniscotibial ligament injury	Stable (meniscus remains reduced)
Type III	Partial inferior tear of the PHMM with meniscotibial ligament injury. Also referred to as the hidden lesion as it may not be visualised by standard Gilquist view	Unstable on probing
Type IV	Complete tear of the PHMM with meniscotibial ligament injury	Unstable on probing
Type V	Complete double tear with meniscotibial ligament injury	Unstable (gross displacement)

PHMM: Posterior horn of the medial meniscus.

SURGICAL MANAGEMENT

The management of ramp lesions ranges from non-operative management for stable, partial tears to formal surgical repair for unstable lesion. In the paediatric population, the consensus leans heavily toward repair due to the excellent healing potential afforded by the rich vascular supply in the peripheral “red-red” zone of the meniscus[8,33]. The overarching goal is meniscal preservation to prevent the devastating long-term sequelae of meniscectomy, a principle strongly advocated by surgeons like Beaufils[8,33].

Adaptation of techniques and paediatric safety

Current surgical techniques for paediatric ramp repair are adapted from adult procedures[24,34]. However, surgeons must account for the unique anatomical considerations of the paediatric knee, such as the presence of open physes, smaller joint volume, and often tighter compartments[26,35].

To improve access to the posteromedial compartment, a controlled release of the deep fibres of the medial collateral ligament (MCL) using a “pie-crusting” technique can be employed[14]. This manoeuvre, performed percutaneously with a needle, enhances visualisation and instrumentation space without causing significant valgus instability[14]. Although no evidence exists detailing physeal injury with this technique, care should be taken given that 57% of adolescents treated still had open distal femoral physes[36].

Additionally, establishing a posteromedial portal requires careful attention to neurovascular structures. The saphenous nerve and its infrapatellar branch are at particular risk; their location can be estimated by placing the knee in 90° of flexion and using blunt dissection to create the portal between the semimembranosus tendon and the posterior aspect of the MCL[37].

Repair techniques

All-inside vs inside-out: The two primary techniques for repairing a ramp lesion are the all-inside and inside-out methods. A comparison of these techniques is summarised in Table 3[38-40].

Table 3 Comparison of all-inside and inside-out ramp repair techniques.

Techniques	All-inside[38,39]	Inside-out[40]
Advantages	Less invasive, no posterior incision required, potentially faster surgical time	Allows for multiple sutures, more precisely placed sutures, in either vertical or oblique mattress patterns, providing superior compression. Lower risk of iatrogenic meniscal damage from smaller needles
Disadvantages	Device size may be cumbersome in smaller paediatric knees	Requires a separate posteromedial incision and carries a higher risk of injury to the saphenous nerve
	Larger needle bores can cause a “cheese-wire” effect on the meniscus, although no evidence in literature details this; effects may be amplified in the softer, more vascularized pediatric meniscus. Risk of anchor-related complications (synovitis, chondral damage)
Technical Considerations	Requires knee flexion and valgus force to open the medial compartment	Careful posteromedial portal creation with transillumination to identify the saphenous vessel (and therefore nerve), and blunt dissection/introduction
	Precise needle depth control to avoid over-penetration

Outcomes and prognosis

The clinical evidence base for paediatric-specific outcomes following ramp repair remains limited and is adapted from adult studies[24,34]. While biomechanical data strongly support repair to restore knee stability, the clinical literature is more heterogeneous, and the optimal management strategy, particularly for stable lesions, is still debated[22,41].

The review by Kaiser et al[41] highlighted the scarcity of high-level evidence, finding only one prospective randomised trial by Liu et al[42] that compared outcomes of ACLR with and without ramp lesion repair. The trial found no significant difference in patient-reported outcome measures between the groups at two-year follow-up. However, the primary goal of meniscal preservation in children is not merely short-term symptomatic improvement but the long-term prevention of early-onset osteoarthritis, which has devastating consequences for a young knee[8,43]. A meniscectomy in a young patient significantly increases the risk of future knee replacement and accelerates joint degeneration[43].

While the overall patient-reported outcomes were encouraging, a 20% re-operation rate for secondary meniscal surgery was reported[1]. Notably, all re-operations occurred in patients who had initially received an all-inside repair, suggesting that inside-out techniques may offer greater durability in this high-demand population[1]. This finding is consistent with systematic reviews in adult athletes that have also reported higher failure rates for all-inside repairs compared to inside-out repairs[44]. Table 4 summarises key contemporary studies reporting on surgical techniques and outcomes.

Table 4 Summary of contemporary research reporting surgical techniques and their outcomes.

Ref.	Study design	Number of patients	Repair technique	Follow-up duration	Key findings
Moran et al[1], 2026	Multicenter cohort	124 (paediatric/adolescent)	All-inside/inside-out	5 years	20% re-operation rate, all in the all-inside repair group. Higher articular cartilage injury rate with repair highlights technical difficulty
Bernardini et al[5], 2021	Cohort study	103 (paediatric)	All-inside (FasT-Fix)	24 months	20% prevalence found; all-inside repair reported as effective in children
Malatray et al[6], 2018	Cohort study	56 (paediatric/adolescent)	Suture-based (various)	30 months	23.2% prevalence; 40% of lesions missed without systematic posteromedial exploration

Limitations and future directions

The existing literature on paediatric ramp lesions, while growing, suffers from several key limitations. The evidence base is predominantly composed of level III and IV retrospective cohort studies and case series, with a significant lack of high-level evidence such as randomised controlled trials to guide treatment[24,34]. Many systematic reviews on ramp lesions are heavily weighted by adult data, making direct extrapolation to the paediatric knee challenging[24,34]. Furthermore, cohort sizes in paediatric-specific studies are often small, which limits the generalisability of their findings. For instance, a study by Gülenç et al[45] reporting good outcomes with a simple suture technique included only 15 patients.

There is also a critical lack of long-term data. While adult studies with 10-year follow-up show high survivorship for repaired menisci, it is unknown if these results translate to children who face decades of high-impact activity[13]. The most significant unanswered question is whether repair truly prevents the long-term development of osteoarthritis. Prospective, multicentre studies with long-term follow-up (15+ years) extending into adulthood are therefore essential. Future research should also aim to compare different repair techniques (all-inside vs. inside-out) in a randomised fashion within the paediatric population and establish the true natural history of stable, unrepaired ramp lesions to determine if surgical intervention is always necessary as there is evidence to suggest smaller (< 1 cm) lesions can be non-operatively managed with a good outcome in adults[29].

CONCLUSION

Meniscocapsular ramp lesions are common but frequently underdiagnosed injuries in paediatric ACL-deficient knees. Their biomechanical importance in maintaining knee stability and the high healing potential in children mandate a high index of suspicion and systematic arthroscopic exploration of the posteromedial compartment. While current repair techniques are adapted from adult surgery with careful attention to paediatric safety, the evidence base for long-term outcomes remains sparse. Further high-quality, long-term research is critically needed to establish standardised, evidence-based treatment protocols to best protect the future health of these young knees.