Understanding the Ramp Tears of the Knee Joint: Types, Consequences, and Treatment

Abstract

Ramp lesions or meniscocapsular separation are peripheral injuries that affect the posterior horn of the medial meniscus (PHMM) and the posteromedial capsule and are described as a tear or injury to the meniscocapsular junction or the meniscofemoral ligaments, particularly in the posteromedial aspect of the knee joint in the setting of pivot shift injuries. These almost always occur with a concomitant anterior cruciate ligament (ACL) tear. The meniscocapsular junction is the area where the peripheral attachment of the meniscus meets the joint capsule. In the context of ramp lesions, this region is susceptible to damage when there is an injury to the ACL. The medial meniscus serves as a firm attachment between the tibia and the femur, functioning as a stabilizer for the knee. It plays a crucial role in preventing anterior translation, particularly in knees with ACL deficiency, making it particularly prone to injuries. The ACL tear can cause the tibia to excessively translate anteriorly, leading to stress on the posterior aspect of the medial meniscus. Ramp lesions have significant biomechanical implications, and their occurrence is more prevalent than previously believed. Untreated ramp lesions may contribute to persistent knee symptoms, instability, and impaired function. These lesions are frequently underdiagnosed, leading to a lack of timely surgical intervention in standard knee arthroscopies. This limitation arises from the reliance on anterior portals, restricting a comprehensive evaluation of the posterior horn and attachment of the medial meniscus. Owing to its tendency to go unnoticed during magnetic resonance imaging interpretation and its blind spot in arthroscopic vision, achieving an accurate preoperative diagnosis is crucial. The objective of this article is to comprehensively present recent findings in the literature regarding meniscal ramp lesions, encompassing their anatomical, biomechanical, and diagnostic characteristics in an illustrative manner.