Abnormal tibial alignment is a risk factor for lateral meniscus posterior root tears in patients with anterior cruciate ligament ruptures

Abstract

Purpose The purpose of this study was to identify if abnormal tibial alignment was a risk factor for lateral meniscus posterior root tears (LMPRT) in patients with acute anterior cruciate ligament (ACL) ruptures. Methods The medical charts of 200 patients treated for ACL ruptures between 2013 and 2016 were retrospectively reviewed and evaluated. MRI images and reports were assessed for concurrent meniscal tears. Radiographs were reviewed for tibia vara and tibial slope angles and MRI reports identifying lateral root tears were compared to intraoperative reports to determine accuracy. Multiple logistic regression models were constructed to identify potential risk factors for LMPRTs. Results Of the 200 patients reviewed, a total of 97 individuals with concurrent meniscal injuries were identified. In patients sustaining a concurrent meniscal injury, there was a 4% incidence of medial meniscus posterior root tears and a 10.3% incidence of LMPRTs. Patients sustaining an ACL injury with an LMPRT were found to have greater tibia vara angles (4.2 ± 1.0 vs. 2.9 ± 1.7; p = 0.024), increased tibial slopes (12.6 ± 1.5 vs. 10.7 ± 2.9; p = 0.034), and higher BMIs (27.3 ± 2.9 vs. 25.3 ± 5.9; p = 0.034) when compared to patients without meniscus tears. There was low agreement between MRI and arthroscopic findings (kappa rate = 0.54). Multiple logistic regression analysis demonstrated that a tibia vara angle > 3 was associated with a 5.2-fold increase (95% CI 0.99-27.01; p = 0.050), and a tibial slope > 12 with a 5.4-fold increase (95% CI 1.03-28.19; p = 0.046) in LMPRTs. Conclusions Patients with greater tibia varus angles, increased tibial slopes, and higher BMIs were found to have an increased risk of LMPRTs when sustaining an ACL rupture. There was a low rate of agreement between MRI and arthroscopy in identifying LMPRTs. In patients with ACL ruptures who have abnormal tibial alignment or increased BMI, physicians should be watchful for lateral meniscus posterior root tears. Level of evidence 3.

The Natural History of Meniscus Tears

“…The question remains as to whether or not the meniscus is protective after one of those injuries or more likely that the meniscus is at risk when there is a ligamentous injury that is not treated. Malalignment problems such as increased rotation of the femur or tibia 19,20 or increase varus or valgus of the knee may contribute to problems with meniscus tears-either leading to tears, nonhealing of repairs, or contributing to arthritis after meniscal tears. 21,22 The Discoid Meniscus…”

Analysis of Risk Factors for Ramp Lesions Associated With Anterior Cruciate Ligament Injury

“…8,12,19,40,48 Moreover, it was recently reported that knee alignment might affect medial meniscal extrusion, which could increase the risk of developing osteoarthritis, 11,34 the tibiofemoral contact force, 46 and even the incidence of root tears in the lateral and medial menisci. 6,18,35 However, a paucity of literature on this subject makes it difficult to find an association between knee alignment and ramp lesions.…”

Incidence and Healing Rates of Meniscal Tears in Patients Undergoing Repair During the First Stage of 2-Stage Revision Anterior Cruciate Ligament Reconstruction

“…1,15 Specifically, lateral meniscus posterior root tears have a reported incidence ranging from 7% to 15% at the time of ACL reconstruction (ACLR). 11,17,19 However, there are limited outcome data regarding the success rates of first-stage meniscal repair healing in patients who undergo 2-stage revision ACLR. 2,3…”