Meniscal movement

Abstract

We present the first study in vivo of meniscal movement in normal knees under load. Using an open MR scanner, allowing imaging in physiological positions in near to real-time, 16 young footballers were scanned moving from full extension to 90 degrees flexion in the sagittal and coronal planes. Excursion of the meniscal horns, radial displacement and meniscal height were measured. On weight-bearing, the anterior horn of the medial meniscus moves through a mean of 7.1 mm and the posterior horn through 3.9 mm, with 3.6 mm of mediolateral radial displacement. The height of the anterior horn increases by 2.6 mm and that of the posterior horn by 2.0 mm. The anterior horn of the lateral meniscus moves 9.5 mm and the posterior horn 5.6 mm, with 3.7 mm of radial displacement. The height of the anterior horn increases by 4.0 mm, and that of the posterior horn by 2.4 mm. In non-weight-bearing, the anterior horn of the medial meniscus moves 5.4 mm and the posterior horn 3.8 mm, with 3.3 mm of radial displacement. The anterior horn of the lateral meniscus moves 6.3 mm, and the posterior horn 4.0 mm, with 3.4 mm of radial displacement. The most significant differences between weight-bearing and non-weight-bearing were the movement and vertical height of the anterior horn of the lateral meniscus.

Medial Meniscus Posterior Root Tear: A Comprehensive Review

“…Chronic and repetitive hyper-flexion of the knee under weight-bearing may lead to excessive pressure on the meniscus posterior root and its subsequent impingement and degeneration4,11,14). A controlled clinical study is required to scientifically substantiate this hypothesis.…”

“…Posterior root tear tends to occur more in the medial than lateral meniscus. This may be because, during knee flexion, the lateral meniscus moves posteriorly by 19 mm on average, whereas more limited movement of an average of 4 mm occurs in the medial meniscus; thus, the latter becomes more vulnerable to impingement between the femoral condyle and tibial plateau, which, in turn, leads to an increased risk of meniscal damage4,15).…”

“…Of these, the most important function for the prevention of arthritis is the maintenance of hoop tension that allows correct intraarticular load transmission for which the medial meniscus is approximately 90% responsible and the lateral meniscus is approximately 70% responsible3,4). The medial meniscus posterior root tear (MMPRT) leads to loss of hoop tension and, thus, loss of load transmissibility of the meniscus, which results in a biomechanical condition much like total meniscectomy5).…”

Magnetic resonance analysis of loaded meniscus deformation: a novel technique comparing participants with and without radiographic knee osteoarthritis

“…In that study, both the ACL deficient and healthy control participants were found to have less than 2 mm of posterior movement of the posterior horns and those values are similar to those found within this study (Table 8). Another study done by Vedi et al [29] examined healthy participants that were standing in an open MRI at 0.5 T at full knee extension and 90 degrees of knee flexion. This study found that in the anterior-posterior direction the lateral meniscus moved more than the medial, and the anterior horns move more than the posterior horns.…”

The effects of knee joint kinematics on anterior cruciate ligament injury and articular cartilage damage

“…The subject was imaged early in the morning and had been unloaded for 30 minutes prior to imaging to minimize a full day of weight bearing. This was done to preserve the native geometry of the cartilage and menisci, as the geometries of these tissues have been reported to change due to body weight loading (Herberhold et al 1999;Vedi et al 1999;Gründer et al 2000;Nishii et al 2008). This may have prevented erroneous measurement of the ACL length at full knee extension, which is required in our subsequent analyses.…”