In Vivo Measurement of Localized Tibiofemoral Cartilage Strains in Response to Dynamic Activity

Abstract

Introduction Altered local mechanical loading may disrupt normal cartilage homeostasis and play a role in the progression of osteoarthritis. Currently, there is limited data quantifying local cartilage strains in response to dynamic activity in normal or injured knees. Purpose The purpose of this study was to directly measure local tibiofemoral cartilage strains in response to a dynamic hopping activity in normal healthy knees. We hypothesize that local regions of cartilage will exhibit significant compressive strains in response to hopping, while overall compartmental averages may not. Study Design Controlled laboratory study. Methods Both knees of eight healthy subjects were MR imaged before and immediately after a dynamic hopping activity. Images were segmented and then used to create 3D surface models of bone and cartilage. These pre- and post-activity models were then registered using an iterative closest point technique to enable site-specific measurements of cartilage strain (defined as the normalized change in cartilage thickness before and after activity) on the femur and tibia. Results Significant strains were observed in both the medial and lateral tibial cartilage, with each compartment averaging a decrease of 5%. However, these strains varied with location within each compartment, reaching a maximum compressive strain of 8% on the medial plateau and 7% on the lateral plateau. No significant averaged compartmental strains were observed in the medial or lateral femoral cartilage. However, local regions of the medial and lateral femoral cartilage experienced significant compressive strains, reaching maximums of 6% and 3% respectively. Conclusion Local regions of both the femur and tibia experienced significant cartilage strains as a result of dynamic activity. An understanding of changes in cartilage strain distributions may help to elucidate the biomechanical factors contributing to cartilage degeneration after joint injury.

In Vivo Tibial Cartilage Strains in Regions of Cartilage-to-Cartilage Contact and Cartilage-to-Meniscus Contact in Response to Walking

“…Using an iterative closest point technique in a solid modeling software program (Geomagic Studio; Geomagic, Inc.; Cary, NC), pre- and post-activity bone models were registered to each other by aligning the model of the post-activity tibial surface to the entire pre-activity tibial surface. 9, 30, 47, 59 …”

“…Utilizing magnetic resonance (MR) imaging and three-dimensional (3D) modeling techniques 9, 12, 13, 30, 32, 48, 54, 59 to measure cartilage deformation in response to a hopping activity, previous work from our lab found increased tibial cartilage strains near the tibial spine compared to the peripheral regions in both tibial compartments. 47 This pattern was thought to be a result of the meniscus distributing loads across the tibial plateau. 47 Therefore, in the present study, we sought to compare cartilage strains in regions covered by the meniscus to strains in regions not covered by the meniscus.…”

Call for standardized definitions of osteoarthritis and risk stratification for clinical trials and clinical use

“…The physiologic aspect of disease is therefore an integral and important descriptor of OA. Physiologic measures that might be used to characterized and grade OA include evaluation of cartilage degeneration using indentation [11, 51], dynamic MRI [52] including site-specific variations in cartilage strain with activity [53] constituting a non-invasive in vivo cartilage “stress test”, and gait biomechanics [54]. Traditional OA risk factors, such as strength, joint stability (functional or structural), obesity, and age are all likely to impact joint physiology but could also impact molecular and anatomic indicators of disease.…”

Analysis of in-vivo articular cartilage contact surface of the knee during a step-up motion

“…Numerous studies have investigated the tibiofemoral cartilage contact using both in-vitro and in-vivo experimental set ups, including cadaveric knee tests (D'Agata et al, 1993; Guettler et al, 2005), in silico three dimensional (3D) knee joint modeling (Halonen et al, 2014; Shim et al, 2016), in-vivo imaging measurements (Bingham et al, 2008; Carter et al, 2015; Chan et al, 2016; Coleman et al, 2013; Eckstein et al, 2005; Henak et al, 2013; Kaiser et al, 2016; Lad et al, 2016; Liu et al, 2010; Sutter et al, 2015). While these studies have greatly advanced our knowledge on human knee joint biomechanics, no data has been reported on the articular surface geometry at the contact locations.…”