Arthroscopic prevalence of ramp lesion in 868 patients with anterior cruciate ligament injury.

BACKGROUND: A special type of repairable meniscal lesion involving the peripheral attachment of the posterior horn of the medial meniscus is commonly associated with anterior cruciate ligament deficiency and is termed a "ramp lesion." However, there are no previously published articles reporting the epidemiologic characteristics of ramp lesions.

HYPOTHESIS: The ramp lesion is a special type of medial meniscal tear with high prevalence associated with anterior cruciate ligament rupture; the prevalence increases with time from anterior cruciate ligament injury. Age and gender are risk factors affecting the prevalence of the ramp lesion.

STUDY DESIGN: Cross-sectional study; Level of evidence, 3.

METHODS: From April 2002 to October 2007, 868 consecutive knees were diagnosed as having an anterior cruciate ligament injury and received arthroscopic surgery for anterior cruciate ligament reconstruction. All the patients had verified tears of the ramp area under arthroscopy. The prevalence of the ramp lesion was evaluated retrospectively. Then, all cases were divided into different groups depending on the time interval from anterior cruciate ligament injury to anterior cruciate ligament reconstruction and other relevant risk factors such as age and gender. The effects of age, gender, and time from injury on the prevalence of ramp lesions were analyzed.

RESULTS: Among 868 knees that underwent surgery for anterior cruciate ligament reconstruction, 144 knees were diagnosed as having a ramp lesion. The mean age was 24.7 years; there were 113 male and 31 female patients. The mean time from injury to anterior cruciate ligament reconstruction was 27.2 months. The prevalence of ramp lesions was 16.6%, which was analyzed as a logarithmic correlation with time from injury. Patients younger than 30 years of age and male patients had a significantly higher prevalence of ramp lesions.

CONCLUSION: The ramp lesion is a common meniscal injury that can occur at the time of anterior cruciate ligament rupture or as a result of knee laxity associated with anterior cruciate ligament insufficiency. The prevalence of ramp lesion in this patient group was 16.6%, which increased with time until 24 months after initial injury. Patients younger than 30 years of age and male patients had a higher prevalence of ramp lesions.