The Effects of Anterior Cruciate Ligament Deficiency on the Meniscus and Articular Cartilage

Abstract

Background:Anterior cruciate ligament (ACL) injury increases the risk of meniscus and articular cartilage damage, but the causes are not well understood. Previous in vitro studies were static, required extensive knee dissection, and likely altered meniscal and cartilage contact due to the insertion of pressure sensing devices.Hypothesis:ACL deficiency will lead to increased translation of the lateral meniscus and increased deformation of the medial meniscus as well as alter cartilage contact location, strain, and area.Study Design:Descriptive laboratory study.Methods:With minimally invasive techniques, six 1.0-mm tantalum beads were implanted into the medial and lateral menisci of 6 fresh-frozen cadaveric knees. Dynamic stereo x-rays (DSXs) were obtained during dynamic knee flexion (from 15° to 60°, simulating a standing squat) with a 46-kg load in intact and ACL-deficient states. Knee kinematics, meniscal movement and deformation, and cartilage contact were compared by novel imaging coregistration.Results:During dynamic knee flexion from 15° to 60°, the tibia translated 2.6 mm (P = .05) more anteriorly, with 2.3° more internal rotation (P = .04) with ACL deficiency. The medial and lateral menisci, respectively, translated posteriorly an additional 0.7 mm (P = .05) and 1.0 mm (P = .03). Medial and lateral compartment cartilage contact location moved posteriorly (2.0 mm [P = .05] and 2.0 mm [P = .04], respectively).Conclusion:The lateral meniscus showed greater translation with ACL deficiency compared with the medial meniscus, which may explain the greater incidences of acute lateral meniscus tears and chronic medial meniscus tears. Furthermore, cartilage contact location moved further posteriorly than that of the meniscus in both compartments, possibly imparting more meniscal stresses that may lead to early degeneration. This new, minimally invasive, dynamic in vitro model allows the study of meniscus function and cartilage contact and can be applied to evaluate different pathologies and surgical techniques.Clinical Relevance:This novel model illustrates that ACL injury may lead to significant meniscus and cartilage abnormalities acutely, and these parameters are dynamically measurable while maintaining native anatomy.

Correlation of Meniscal Tear with Timing of Anterior Cruciate Ligament Reconstruction in Patients without Initially Concurrent Meniscal Tear

“…The result may explain the greater incidence of chronic MMT. 20 All the above results suggested a mechanism for the increased incidence of MMT observed in chronically ACL-deficient patients, which was observed in our and many other studies. Discoid tear 0 (0) 0 (0) 0 (0) Discoid tear 0 (0) 0 (0) 0 (0) T o t a l 7 3 5 1 2 2 T o t a l 5 1 3 6 1 5…”

Complete tear of the lateral meniscus posterior root is associated with meniscal extrusion in anterior cruciate ligament deficient knees

“…ACL insufficiency may lead to an abnormal anterior translation of the tibia and result in an incompatibility of the tibiofemoral contact mechanism . The relative position of the tibia to the femur becomes internally rotated in the ACL‐deficient knee .…”

“…ACL insufficiency may lead to an abnormal anterior translation of the tibia and result in an incompatibility of the tibiofemoral contact mechanism . The relative position of the tibia to the femur becomes internally rotated in the ACL‐deficient knee . These positional mismatches between the tibia and femur can induce degenerative changes in the meniscus and knee joint cartilage .…”

“…The relative position of the tibia to the femur becomes internally rotated in the ACL‐deficient knee . These positional mismatches between the tibia and femur can induce degenerative changes in the meniscus and knee joint cartilage . We previously demonstrated that preoperative positions of the MM and LM could be altered by ACL reconstruction using MRI assessments .…”

Different Kinematics of Knees with Varus and Valgus Deformities

“…16,[19][20][21] Even in in vitro studies, an inconsistent movement pattern was detected with posterior translation of both femoral condyles during knee flexion after TKA. 17,22,23 As demanded by implantation technique, we achieved balanced medial and lateral gaps in flexion and extension in both groups after implantation of the prosthesis. However, condylar liftoff was detected in the early stage of flexion (10 degrees) in patients with varus deformity and at mid-flexion of 50 degrees and more in patients with valgus deformity.…”