Anterior cruciate ligament (ACL) tears account for 13% of knee injuries in children. Among the associated damage, meniscal ramp lesions in children remain underdiagnosed. How common are they really? Can MRI reliably detect them? A study published in The American Journal of Sports Medicine provides concrete answers: out of 50 children undergoing ACL reconstruction, 28% had a ramp lesion, yet MRI only detected just over half of them.
The information presented in this article is drawn from the study Prevalence and Detection of Meniscal Ramp Lesions in Pediatric Anterior Cruciate Ligament–Deficient Knees, conducted notably by Prof. Cavaignac. For a deeper understanding of each finding, we encourage you to consult the complete publication.
What is a ramp lesion and why it matters in children
A ramp lesion is a tear of the posteromedial capsule of the medial meniscus, at the point where it attaches to the joint capsule. It frequently occurs alongside an ACL rupture, as the rotational trauma destabilises this fragile area of the knee.
In adults, this type of injury is fairly well documented. In children and adolescents, data remain scarce, and reported prevalence varies considerably from one study to another. Prof. Cavaignac’s research was specifically designed to address this gap in the context of paediatric ACL tears and meniscal injuries.
Why diagnosis is a challenge in paediatric patients
The growing paediatric knee has distinct anatomical features. Missing a ramp lesion during ACL reconstruction can lead to residual instability and a higher risk of re-rupture. For young patients who are often highly active in sport, the long-term consequences are particularly significant.
One child in four has a ramp lesion during ACL reconstruction
The research team analysed videos from 50 consecutive arthroscopic ACL reconstructions in children (32 boys, 18 girls, mean age 14.2 years). During each procedure, surgeons systematically explored the posteromedial compartment by passing the arthroscope through the intercondylar notch. A needle was then introduced at the posteromedial portal site to unfold the meniscocapsular junction and reveal any hidden tears. Videos were blindly reviewed by a third surgeon independent of the operating team.
Key findings
| Data point | Value |
| Number of patients | 50 (32 boys, 18 girls) |
| Mean age | 14.2 years (range 8.5 to 17.6) |
| Ramp lesions confirmed by arthroscopy | 14 (28%) |
| Associated meniscal body tears | 22 in 20 patients (40%) |
The ramp lesion prevalence in children undergoing ACL reconstruction therefore exceeds one in four. This figure underscores the importance of systematic exploration. The full study details the diagnostic criteria used and the subgroups analysed.
MRI is not enough: a sensitivity of just 57%
One of the most significant contributions of this research concerns MRI reliability for detecting meniscal ramp lesions in the paediatric population. Two senior radiologists, working independently and blinded to surgical outcomes, reviewed all preoperative MRI scans with a specific focus on ramp lesions.
The results reveal a clear discrepancy between imaging and intraoperative findings:
- Of the 14 ramp lesions confirmed arthroscopically, only 8 had been identified on MRI (sensitivity of 57%).
- Conversely, 12 patients showed a ramp lesion on MRI that could not be confirmed during surgery.
- The positive predictive value reached only 40%.
What this means in practice
For clinicians managing ACL deficiency in the paediatric knee, these figures call for caution. Relying solely on MRI risks missing nearly one lesion in two. Direct exploration of the posteromedial compartment during surgery therefore remains essential, particularly in paediatric patients with ACL tears and suspected ramp lesions.
For the complete statistical data and detailed methodology, refer to the original study.
Key takeaways for clinical practice
Prof. Cavaignac’s study establishes several essential points for managing ramp lesions in children and adolescents:
- Ramp lesion prevalence among children undergoing ACL reconstruction reaches 28%.
- MRI has insufficient sensitivity (57%) for this diagnosis.
- Systematic exploration of the posteromedial compartment during arthroscopy is strongly recommended.
- Overlooking these lesions may contribute to persistent instability and higher re-rupture rates in young patients.
These conclusions reinforce the view that particular attention must be paid to the meniscus during every paediatric ACL reconstruction, and that diagnosis cannot rely on imaging alone.
Conclusion & Findings
This study sheds valuable light on a topic that remains under-researched in paediatric knee surgery. The high prevalence of ramp lesions and the limitations of MRI argue strongly in favour of rigorous, systematic arthroscopic exploration during every ACL reconstruction in children.
To delve further into this area, we invite you to explore the other scientific publications by Prof. Cavaignac, which actively contribute to advancing our understanding and management of knee pathologies.
Prof. Cavaignac, through his expertise in knee surgery and his commitment to clinical research, is one of the specialists worth considering for this type of condition.