ePoster #1254 - 2013 ISAKOS Biennial Congress

Ramp Lesion Associated with Anterior Cruciate Ligament Rupture

Kazuhisa Hatayama, MD, PhD, Maebashi, Gunma, JAPAN
Masashi Kimura, MD, PhD, Gumma, JAPAN
Atsuko Ogoshi, MD, Maebashi-City, GUNMA, JAPAN
Kenji Takagishi, MD, PhD, Prof., Maebashi, Gunma, JAPAN
Department of Orthopaedic surgery, Zenshukai Hospital, Maebashi, Gunma, JAPAN

FDA Status Cleared

Summary: The prevalence of the ramp lesion was 25% in ACL injured knee and more likely seen in younger patients. As the presence of ramp lesion can’t be always expected from MRI, arthroscopic posteromedial viewing during surgery should be performed so as not to overlook it.

Introduction: Longitudinal tear of the medial meniscus posterior horn around the meniscocapsular junction is commonly associated with ACL rupture and is termed a “ramp lesion”. However, its identification requires careful arthroscopic posteromedial viewing, and there are only few reports about epidemiologic characteristics of the ramp lesion. The purpose of this study was to determine the prevalence and characteristics of the ramp lesion.
Methods: We prospectively examined the presence of ramp lesion in consecutive 92 knees (52 males, 40 females) underwent ACL reconstruction. Even if the ramp lesion is present, the medial meniscus is not displaceable and is stable to probing, and the medial meniscus posterior horn seems normal in only standard anterior viewing. Therefore, we passed the 30° arthroscope from anterolateral portal through the intercondylar notch between the posterior cruciate ligament and the medial femoral condyle into the posterior recess and detected the ramp lesion. The effects of age, gender, and time from injury on the prevalence of ramp lesions were analysis. Preoperative MRI was performed in all knees. We retrospectively evaluated the characteristic MRI finding to predict the presence of the ramp lesion. Results: Red-white or white-white tear of medial meniscus and the ramp lesion were respectively seen in 27 knees (29%) and 23 knees (25%) during ACL reconstruction. The mean ages at the time of surgery in former and latter group were 32.2 and 20.1 years, a significant difference (P < .05). The gender and time from injury were not significantly different between groups. High signal irregularity of the capsular margin of the medial meniscus posterior horn on T2*-weighted gradient-echo sagittal image was found as characteristic finding of the ramp lesion in MRI. This finding was seen in 14 of the 23 knees with a ramp lesion. However, in 9 knees (39%), it was difficult to confirm a ramp lesion in preoperative MRI.
Conclusion: This study showed that the ramp lesion was more likely to be associated with younger patients. The degeneration of the meniscus body by ageing may be related with the difference of the zone of the medial meniscus tear. Because we can’t always expect the presence of ramp lesion in preoperative MRI, posteromedial viewing through the intercondylar notch during surgery should be routinely performed so as not to overlook it.