Meniscal Ramp Lesions: Anatomy, Epidemiology, Diagnosis, and Treatment

Abstract

Injuries to the medial meniscus meniscocapsular junction, also known as ramp lesions, are common in the setting of anterior cruciate ligament injuries with a prevalence of 9% to 42%. Anatomically, ramp lesions involve disruption of the posterior meniscocapsular junction and meniscotibial ligaments. Biomechanically, ramp lesions are associated with an increase in anterior tibial translation and internal and external tibial rotation in anterior cruciate ligament-deficient cadaveric knees. Magnetic resonance imaging is useful in evaluating the meniscocapsular junction. Irregularity or increased signal near the posterior meniscocapsular junction and/or signal change indicative of posterior medial tibial plateau edema can suggest these injuries are present before surgical intervention. The current benchmark for diagnosis is arthroscopic visualization of the posterior medial meniscocapsular junction viewed through the intercondylar notch. Once a ramp lesion is identified, stability should be assessed by arthroscopic probing to determine the degree of anterior displacement. Optimal treatment has been debated in the literature, especially for stable ramp lesions, although good outcomes have been shown with and without repair. Repair is warranted for those lesions that are unstable to probing. Unfortunately, only limited literature available to guide clinicians on the optimal rehabilitation for ramp lesions. Meniscal tears are common in the setting of anterior cruciate ligament (ACL) tears, with a prevalence as high as 55% to 65%. 1 Meniscal ramp lesions were initially described as a type of meniscal injury involving the peripheral meniscosynovial attachment of the posterior horn of the medial meniscus seen in conjunction with an ACL tear. 2 Strobel et al coined the term ramp lesion to distinguish this injury from other types of posterior longitudinal meniscal tears because ramp lesions occur at the posterior periphery of the meniscal ramp on a sagittal MRI. 2 More recently, in addition to the peripheral meniscocapsular junction, disruption of the meniscotibial ligaments is also noted. 3 Injuries to this area are biomechanically relevant because they increase not only anterior tibial translation but also internal and external tibial rotation in ACL-deficient cadaveric knees. [4][5][6]

High prevalence of meniscal ramp lesions in anterior cruciate ligament injuries

“…Only the repair of meniscal ramp lesions is able to restore anterior and rotational laxity [ 12 , 37 ]. If meniscal ramp lesions are overlooked in patients with ACLR, anterior and rotational laxity persists [ 1 , 7 , 12 , 37 ].…”

Surgical Management of Discoid Lateral Meniscus With Anterior Peripheral Instability: Retaining an Adequate Residual Meniscus Volume

“…Studies have shown that saucerization with suture stabilization of the peripheral meniscal rim results in fewer degenerative changes compared with total or subtotal meniscectomy. 7 Although a 6-to 8-mm width of the remaining meniscus rims was recommended as an appropriate value in a previous study, 9 the longterm result of saucerization has been shown to be associated with the progression of lateral compartment arthritis in 68.5% of patients. 9 Moreover, Nishino et al 10 reported that the width of the anterior horn, midbody, and posterior horn decreased significantly from 3 to 24 months after surgery.…”

Effect of Tibiofemoral Rotation Angle on Graft Failure After Anterior Cruciate Ligament Reconstruction

“…Similarly, meniscal ramp lesions, which have also been associated with increased tibial rotation, were not investigated. 3 Despite these limitations, this study may make a case for the consideration of the TFA as a possible predictive measure for ACLR failure based on a robustly powered study sample of matched-pair patients with ACL injuries and graft failure.…”