Comparison of Kinematics and Tibiofemoral Contact Pressures for Native and Transplanted Lateral Menisci

Abstract

Background:Lateral meniscus transplantation is a proven treatment option for the meniscus-deficient knee, yet little is known about meniscal kinematics, strain, and tibiofemoral contact pressure changes after transplantation or the effect of altered root position in lateral meniscus transplantation.Purpose:To compare the native lateral meniscal kinematics, strain, and tibiofemoral contact pressures to a best-case scenario meniscus transplant with perfectly matched size and position and to determine how sensitive these factors are to subtle changes in shape and position by using a nonanatomic meniscus transplant position.Study Design:Controlled laboratory study.Methods:The lateral menisci of 8 cadaveric knees were circumferentially implanted with radiopaque spherical markers. They were mounted to a testing apparatus applying muscle and ground-reaction forces. The meniscus was evaluated at 0°, 30°, 90°, and 115° of knee flexion using Roentgen stereophotogrammetric analysis (RSA), with a pressure sensor affixed to the lateral tibial plateau. Measurements were recorded for 3 states: the native lateral meniscus, an anatomic autograft transplant, and a nonanatomic autograft transplant with an anteriorized posterior root position.Results:After transplantation, there was less posterior displacement in both the anatomic and nonanatomic transplant states compared with the native meniscus, but this was not significant. The largest lateral translation in the native state was 2.38 ± 1.58 mm at the anterolateral region from 0° to 90°, which was increased to 3.28 ± 1.39 mm (P = .25) and 3.12 ± 1.18 mm (P = .30) in the anatomic and nonanatomic transplant states, respectively. Internal deformations of the transplant states were more constrained, suggesting less compliance. The native meniscus distributed load over 223 mm2, while both the anatomic (160 mm2) and nonanatomic (102 mm2) states concentrated pressure anteriorly to the tibial plateau centroid.Conclusion:This study is the first to characterize kinematics in the native lateral meniscus compared with a transplanted state utilizing RSA. Results demonstrate increased meniscal constraint and pressure concentrations even after an ideal size and position matched transplantation, which further increased with a nonanatomic posterior root position.Clinical Relevance:The results show that kinematics are similar in both transplanted states when compared with the native meniscus at various flexion angles. Because both transplanted states were more constrained with less deformation compared with the native state, this should allow for relatively safe postoperative range of motion. However, in the transplanted states, peak pressures were distributed over a smaller area and shifted anteriorly. This pattern was exacerbated in the nonanatomic state compared with anatomic. This could have detrimental effects with regard to articular cartilage degeneration, and ultimately result in a failed transplantation.

Influence of Menisci on Tibiofemoral Contact Mechanics in Human Knees: A Systematic Review

“…Modified material testing machines with customized loading setups are normally able to provide all six DOF during in vitro experiments ( Becker et al, 2005 ; Rodner et al, 2006 ; Schillhammer et al, 2012 ; Kim et al, 2013 ; Bryant et al, 2014 ; Goyal et al, 2014 ; Lee, 2014 ). The main components of custom-made vertical knee joint simulators, so-called Oxford-rig simulators ( Mcculloch et al, 2016 ; Steinbruck et al, 2016 ), are ankle and hip assemblies that also enable an unconstrained movement of the knee joint in all six DOF ( Zavatsky, 1997 ). In Oxford-rigs, a horizontal actuator normally simulates the flexion-extension movements without simulating an according axial or ground reaction force.…”

“…The fixed angles and pre-defined axial loads allow groups to investigate research questions and their effects on knee kinematics without additional expense or new machine investment. Complex setups like Oxford-rigs, by contrast, offer greater dynamics and the simulation of muscle forces and motion patterns ( Bryant et al, 2014 ; Mcculloch et al, 2016 ; Steinbruck et al, 2016 ; Schall et al, 2019 ).…”

Establishing Clinically Significant Outcomes After Meniscal Allograft Transplantation

“…Meniscal allograft transplantation (MAT) has been shown to restore force distribution lost by meniscus-deficient knees. 27,40 In appropriately selected candidates, MAT is a viable procedure for joint preservation, although future research will always be needed for methods to gain optimum results. 20,24,37 Given appropriate preliminary results, clinical practice guidelines must be constructed from research to provide the optimal methodology of MAT.…”

Lateral Capsular Stabilization in Lateral Meniscal Allograft Transplantation

“…Vedi et al 14 examined meniscal translation in healthy volunteers while weightbearing from full extension to 90° of flexion in vivo using open MRI and found that the anterior horn of the lateral meniscus translates posteriorly 9.5 mm, while the posterior horn translates 5.6 mm. Recently, McCulloch et al 10 measured normal posterior translation of the lateral meniscus from cadaveric knees using roentgen stereophotogrammetric analysis. They divided the lateral meniscus into 6 regions: anterior root, anteromedial, anterolateral, posterolateral, posteromedial, and posterior root.…”