Comparison of two models of post‐traumatic osteoarthritis; temporal degradation of articular cartilage and menisci

Abstract

The objective of this study was to compare longitudinal results from two models of combined anterior cruciate ligament (ACL) and meniscal injury. A modified ACL transection (mACLT) model and a traumatic impact (ACLF) model were used to create an ACL rupture and acute meniscal damage in a Flemish Giant animal model. The animals were euthanized at time points of 4, 8, or 12 weeks. The menisci were assessed for equilibrium and instantaneous compressive modulus, as well as glycosaminoglycan (GAG) coverage. The articular cartilage was mechanically assessed for thickness, matrix modulus, fiber modulus, and permeability. Articular cartilage GAG coverage, fissuring, tidemark integrity, and subchondral bone thickness were measured. Both models resulted in damage indicative of osteoarthritis, including decreased meniscal mechanics and GAG coverage, increased permeability and fissuring of articular cartilage, and decreased GAG coverage. The mACLT model had an early and lasting effect on the menisci mechanics and GAG coverage, while cartilage damage was not significantly affected until 12 weeks. The ACLF model resulted in an earlier change of articular cartilage GAG coverage and fissuring in both the 8 and 12 week groups. The menisci were only significantly affected at the 12 week time point in the ACLF model. We concluded the progression of post traumatic osteoarthritis was dependent on injury modality: a point to be considered in future investigations. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:486-495, 2017.

Maximum shear strain-based algorithm can predict proteoglycan loss in damaged articular cartilage

“…Furthermore, when the two commonly observed changes in PTOA [i.e., reduced collagen fibril integrity (Punzi et al 2016) and increased tissue permeability (Sauerland et al 2003)] were tested, the FCD loss was increased in both cases, as expected. Similar changes in tissue properties and decrease in GAG coverage (associated with FCD loss) have been observed in experimental models of PTOA (Fischenich et al 2017). In the injury model, the increased permeability led to more FCD loss near the lesion than decreased integrity of the collagen fibrils.…”

Characterization of Post‐Traumatic Osteoarthritis in Rats Following Anterior Cruciate Ligament Rupture by Non‐Invasive Knee Injury (NIKI)

“…In the last 10 years, multiple non‐invasive ACL rupture models have been developed. These models have primarily used mice and rabbits, with a limited number of studies involving rats . Despite being relatively understudied, there are advantages to establishing this injury model in rats, such as their amenability to behavioral tests and their larger size, which can accommodate certain imaging modalities and therapeutic interventions .…”

Comparison between in vitro and in vivo cartilage overloading studies based on a systematic literature review

“…Cartilage damage can also be induced in vivo by altering the animal model's joint kinematics, for example, by ACL transection, which induces joint instability, or meniscectomy, resulting in directly increased tibia‐femoral contact stresses, or repeated long‐term overloading by muscle stimulation . ACL transection, meniscectomy, and repeated long‐term overloading have been shown to induce cartilage degeneration over time in terms of surface fissuring, hypocellularity, loss of structural integrity, GAG increase followed by decrease, and overall tissue softening . In these models, the tibia is generally more severely or equally damaged compared to the femur, and less degeneration has been observed in the patella compared to the femur, indicating a greater effect on areas that receive the most stress during locomotion.…”

“…In these models, the tibia is generally more severely or equally damaged compared to the femur, and less degeneration has been observed in the patella compared to the femur, indicating a greater effect on areas that receive the most stress during locomotion. Fissuring and GAG loss tend to worsen over time, although occasionally the degenerative grade remains relatively stable between varying observation points . The rate of cartilage degeneration also varies with injury modality, that is, when the magnitude and duration of abnormal loading are higher there is an increased rate .…”

“…Fissuring and GAG loss tend to worsen over time, although occasionally the degenerative grade remains relatively stable between varying observation points . The rate of cartilage degeneration also varies with injury modality, that is, when the magnitude and duration of abnormal loading are higher there is an increased rate . Similarly, combining various damage modalities such as ACL transection, meniscectomy, and/or application of an impact increases the rate of cartilage degeneration …”