Is Edema at the Posterior Medial Tibial Plateau Indicative of a Ramp Lesion? An Examination of 307 Patients With Anterior Cruciate Ligament Reconstruction and Medial Meniscal Tears

Abstract

Background:Medial meniscal tears are commonly seen during anterior cruciate ligament reconstruction (ACLR). A subset of these injuries includes posterior meniscocapsular junction or “ramp” tears. One criterion that may correlate with a ramp lesion is the presence of posterior medial tibial plateau (PMTP) edema.Purpose:To compare patients with ramp lesions to patients with nonramp (meniscal body) medial meniscal tears and correlate PMTP edema on preoperative magnetic resonance imaging (MRI) to the incidence of ramp tears.Study Design:Case-control study; Level of evidence, 3.Methods:From 2006 to 2016, a total of 852 patients underwent ACLR and had operative reports available for review. Age, sex, laterality, mechanism of injury (contact/noncontact), sport, revision procedure, multiligament injury, time to MRI, and time to surgery were recorded. Preoperative MRI scans were reviewed for PMTP edema using axial, coronal, and sagittal T2 and proton-density sequences. Differences between groups were analyzed using a 2-sample t test and chi-square test. Univariate and multivariate logistic regression models examined correlations with tear type.Results:Overall, 307 patients had medial meniscal tears identified during ACLR (127 ramp lesions, 180 meniscal body lesions). The ramp group was 7.5 years younger than the meniscal body group (P < .01). The groups were not different regarding sex, contact injury, revision surgery, laterality, or multiligament injury. Patients with delayed ACLR were significantly more likely to have a meniscal body tear than a ramp lesion (odds ratio, 3.3 [95% CI, 1.9-5.6]; P < .01). The sensitivity of PMTP edema for a ramp tear was 66.3%, and 54.5% of patients with ACLR and a medial meniscal tear had PMTP edema. Patients with PMTP edema were significantly more likely to have a ramp tear than a meniscal body tear (odds ratio, 2.1 [95% CI, 1.1-4.1]; P < .03).Conclusion:The overall incidence of ramp tears in patients undergoing ACLR was 14.9%, and these tears were more prevalent in younger patients. Meniscal body tears were significantly more likely than ramp tears with delayed ACLR. In patients undergoing ACLR with an associated medial meniscal tear, the presence of PMTP edema demonstrated significantly greater odds for ramp lesions compared with meniscal body tears.

Diagnostic Performance of Magnetic Resonance Imaging for Detecting Meniscal Ramp Lesions in Patients With Anterior Cruciate Ligament Tears: A Systematic Review and Meta-analysis

“…Full texts of the 16 eligible articles were reviewed, and 8 studies 2,4,6,8,15,27-29 with insufficient data for generating 2 × 2 tables were excluded. Finally, 8 original research articles 1,13,16,18,19,23,30,36 comprising 883 patients were included in the meta-analysis. Hatayama et al 13 used 2 different cohorts to compare 2 different magnet strengths for diagnosing ramp lesion (first cohort, patients who underwent 1.5-T MRI; second cohort, patients who underwent 3.0-T MRI); thus, we evaluated 9 diagnostic performance studies from 8 original research articles.…”

“…However, all technical MRI parameters were not assessed because parameters such as receiver bandwidth, matrix, and field of view were not described in most studies. Fifth, a few studies 16,19,23 were not included in the individual comparisons portion of the meta-regression analysis because they reported insufficient data related to the MRI position and magnet strength. We noted that 2 studies 16,19 (203 patients; 23.0%) did not report knee position, and 2 studies 19,23 (234 patients; 26.5%) did not report magnet strength.…”

“…All studies were considered to have a low risk of bias for index test and reference standard domains. We noted that 2 studies 19,30 had ambiguous risk of bias due to absence of mean interval data between MRI and the reference standard. All studies exhibited low concerns regarding applicability to the research question in terms of patient selection, index test, and reference standard domains.…”

Ramp Lesions

“…However, most acute knee MRI evaluations are performed with the knee in full extension, which reduces the meniscocapsular gap, and can lead to false-negative tests. 29 The MRI detected presence of bone bruising in the postero-medial tibial plateau has also been associated with ramp lesions, at a rate that varies from 38.5% for Hatayama and colleagues, 28 66.3% for Kumar and colleagues, 30 and 72.0% for DePhillipo and colleagues. 27 Arthroscopy is considered gold standard for diagnosis of ramp lesions.…”

Ramp lesion of the medial meniscus

“… 28 – 31 In spite of this fact, radiologists continuously make attempts to set criteria for diagnosing MRL with MRI scan and increase its performance. 29 The most significant findings include peripheral irregularities and hyperintensity (posterior medial tibial plateau oedema) in adults, 30 , 32 whereas MRI scan in children may show medial meniscus and capsular ligament tears in addition to the aforementioned findings (all p < 0.05). 33 Moreover, in order to increase diagnostic accuracy, a knee should be placed in flexed position whenever feasible.…”