scholarly journals Tissue Modification of the Lateral Compartment of the Tibio-Femoral Joint Following In Vivo Varus Loading in the Rat

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
M. L. Roemhildt ◽  
B. D. Beynnon ◽  
M. Gardner-Morse ◽  
K. Anderson ◽  
G. J. Badger
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Compressive Loading ◽  
Compressive Load ◽  
Lateral Compartment ◽  
Peripheral Region ◽  
Degenerative Changes ◽  
Medial Compartment ◽  
Compressive Loads

This study describes the first application of a varus loading device (VLD) to the rat hind limb to study the role of sustained altered compressive loading and its relationship to the initiation of degenerative changes to the tibio-femoral joint. The VLD applies decreased compressive load to the lateral compartment and increased compressive load to the medial compartment of the tibio-femoral joint in a controlled manner. Mature rats were randomized into one of three groups: unoperated control, 0% (sham), or 80% body weight (BW). Devices were attached to an animal’s leg to deliver altered loads of 0% and 80% BW to the experimental knee for 12 weeks. Compartment-specific material properties of the tibial cartilage and subchondral bone were determined using indentation tests. Articular cartilage, calcified cartilage, and subchondral bone thicknesses, articular cartilage cellularity, and degeneration score were determined histologically. Joint tissues were sensitive to 12 weeks of decreased compressive loading in the lateral compartment with articular cartilage thickness decreased in the peripheral region, subchondral bone thickness increased, and cellularity of the midline region decreased in the 80% BW group as compared to the 0% BW group. The medial compartment revealed trends for diminished cellularity and aggregate modulus with increased loading. The rat-VLD model provides a new system to evaluate altered quantified levels of chronic in vivo loading without disruption of the joint capsule while maintaining full use of the knee. These results reveal a greater sensitivity of tissue parameters to decreased loading versus increased loading of 80% BW for 12 weeks in the rat. This model will allow future mechanistic studies that focus on the initiation and progression of degenerative changes with increased exposure in both magnitude and time to altered compressive loads.

scholarly journals Effect of differences in mechanical stress in vivo on the onset and progression of knee osteoarthritis

2021 ◽  
Author(s):  
Kohei Arakawa ◽  
Kei Takahata ◽  
Yuichiro Oka ◽  
Kaichi Ozone ◽  
Sumika Nakagaki ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Bone Formation ◽  
Mechanical Stress ◽  
Compressive Stress ◽  
Subchondral Bone ◽  
Shear Force ◽  
Joint Instability ◽  
Cartilage Degeneration ◽  
Articular Cartilage Degeneration

Objective: The effect of the type of mechanical stress on OA onset has not been clarified. The aim of this study was to establish a new model that reproduces the type and increase and decrease of mechanical stress in vivo and to clarify the differences in the mechanism of knee OA onset and progression among the models. Design: To reproduce the difference in mechanical stress, we used the anterior cruciate ligament transection (ACL-T) model and the destabilization of the medial meniscus (DMM) model. In addition, we created a controlled abnormal tibial translation (CATT) model and a controlled abnormal tibial rotation (CATR) model that suppressed the joint instability of the ACL-T and DMM model, respectively. These four models reproduced the increase and decrease in shear force due to joint instability and compressive stress due to meniscal dysfunction. We performed joint instability analysis with soft X-ray, micro computed tomography analysis, histological analysis, and immunohistological analysis in 4 and 6 weeks. Results: Joint instability decreased in the CATT and CATR groups. The meniscus deviated in the DMM and CATR groups. Chondrocyte hypertrophy increased in the ACL-T and DMM groups with joint instability. In the subchondral bone, bone resorption was promoted in the ACL-T and CATT groups, and bone formation was promoted in the DMM and CATR groups. Conclusions: Increased shear force causes articular cartilage degeneration and osteoclast activation in the subchondral bone. In contrast, increased compressive stress promotes bone formation in the subchondral bone earlier than articular cartilage degeneration occurs.

High Fibular Osteotomy Ameliorates Medial Compartment Knee Osteoarthritis in a Rabbit Model

2021 ◽  
Author(s):  
Feihua Yan ◽  
Xujun Zhao ◽  
Shisheng Duan ◽  
Aini Maimaiti ◽  
Yong Qi ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Knee Osteoarthritis ◽  
Bone Remodeling ◽  
Western Blotting ◽  
Subchondral Bone ◽  
Rabbit Model ◽  
Medial Compartment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fibular Osteotomy ◽  
Tnf Α

Abstract Purpose Knee osteoarthritis (KOA) is a common and severe disease characterized by articular cartilage degeneration, subchondral bone remodeling and inflammation. This study aimed to investigate the therapeutic effects of high fibular osteotomy (HFO) in a KOA rabbit model and to examine the molecular mechanisms involved in medial compartment KOA protective effects.Methods A rabbit model of destabilization of the medial meniscus was used to induce post-traumatic KOA. The effectiveness of HFO on protection against KOA was tested. Hematoxylin and eosin staining, Safranin O/Fast green staining and micro-CT analysis were performed to evaluate structural and morphological changes. The expression of metalloproteinase (MMP)-1, MMP-3, MMP-13, collagen type II (Col2), a disintegrin and metalloproteinase domain with thrombospondin motifs (ADAMTS)-5, aggrecan, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α was assessed by real time PCR, western blotting and enzyme-linked immunosorbent assay. Additionally, western blotting was performed to test the expression of NFκB p65, phospho-IκBα and IκBα. Results HFO delayed the progression of articular cartilage damage and suppressed subchondral bone remodeling. HFO also decreased MMP-1, MMP-3, MMP-13 and ADAMTS-5 expression, and increased Col2 and aggrecan expression. In parallel, HFO attenuated the expression of IL-1β, IL-6 and TNF-α. Furthermore, the molecular mechanism underlying the protective effect of HFO in medial compartment KOA was related to the NFκB signaling pathway. Conclusion HFO may be a novel therapeutic approach to treating medial compartment KOA.

scholarly journals Deciphering an extreme morphology: bone microarchitecture of the hero shrew backbone (Soricidae: Scutisorex )

2020 ◽  
Vol 287 (1926) ◽  
pp. 20200457 ◽  
Author(s):  
Stephanie M. Smith ◽  
Kenneth D. Angielczyk
Keyword(s):  
Trabecular Bone ◽  
Sagittal Plane ◽  
Bone Microarchitecture ◽  
Compressive Load ◽  
Bone Architecture ◽  
Micro Computed Tomography ◽  
Vertebral Centra ◽  
Behavioural Patterns ◽  
Compressive Loads

Biological structures with extreme morphologies are puzzling because they often lack obvious functions and stymie comparisons to homologous or analogous features with more typical shapes. An example of such an extreme morphotype is the uniquely modified vertebral column of the hero shrew Scutisorex , which features numerous accessory intervertebral articulations and massively expanded transverse processes. The function of these vertebral structures is unknown, and it is difficult to meaningfully compare them to vertebrae from animals with known behavioural patterns and spinal adaptations. Here, we use trabecular bone architecture of vertebral centra and quantitative external vertebral morphology to elucidate the forces that may act on the spine of Scutisorex and that of another large shrew with unmodified vertebrae ( Crocidura goliath ). X-ray micro-computed tomography (µCT) scans of thoracolumbar columns show that Scutisorex thori is structurally intermediate between C. goliath and S. somereni internally and externally, and both Scutisorex species exhibit trabecular bone characteristics indicative of higher in vivo axial compressive loads than C. goliath. Under compressive load, Scutisorex vertebral morphology is adapted to largely restrict bending to the sagittal plane (flexion). Although these findings do not solve the mystery of how Scutisorex uses its byzantine spine in vivo , our work suggests potentially fruitful new avenues of investigation for learning more about the function of this perplexing structure.

In Vivo Contrast-Enhanced Cone Beam CT Provides Quantitative Information on Articular Cartilage and Subchondral Bone

2016 ◽  
Vol 45 (3) ◽  
pp. 811-818 ◽  
Author(s):  
Katariina A. H. Myller ◽  
Mikael J. Turunen ◽  
Juuso T. J. Honkanen ◽  
Sami P. Väänänen ◽  
Jarkko T. Iivarinen ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Cone Beam Ct ◽  
Quantitative Information ◽  
Cone Beam ◽  
Contrast Enhanced

scholarly journals In Situ Microindentation for Determining Local Subchondral Bone Compressive Modulus

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Mack G. Gardner-Morse ◽  
Nelson J. Tacy ◽  
Bruce D. Beynnon ◽  
Maria L. Roemhildt
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Reference Values ◽  
Material Properties ◽  
Indentation Test ◽  
Lateral Compartment ◽  
Polyurethane Foams ◽  
Compressive Modulus ◽  
Sprague Dawley ◽  
Indentation Tests

Alterations to joint tissues, including subchondral bone, occur with osteoarthritis. A microindentation technique was developed to determine the local compressive modulus of subchondral bone. This test, in conjunction with a cartilage indentation test at the same location, could evaluate changes of these material properties in both tissues. The accuracy of the technique was determined by applying it to materials of known moduli. The technique was then applied to rat tibial plateaus to characterize the local moduli of the subchondral bone. An established nanoindentation method was adopted to determine the modulus of subchondral bone following penetration of the overlying articular cartilage. Three cycles of repeated loadings were applied (2.452 N, 30 s hold). The slope of the load-displacement response during the unloading portion of the third cycle was used to measure the stiffness. Indentation tests were performed on two polyurethane foams and polymethyl-methacrylate for validation (n=15). Regression analysis was used to compare the moduli with reference values. Subchondral bone moduli of tibial plateaus from Sprague-Dawley rats (n=5) were measured for central and posterior locations of medial and lateral compartments. An analysis of variance was used to analyze the effects of compartment and test location. The measured moduli of the validation materials correlated with the reference values (R2=0.993, p=0.05). In rat tibial plateaus, the modulus of the posterior location was significantly greater than the center location (4.03±1.00 GPa and 3.35±1.16 GPa respectively, p=0.03). The medial compartment was not different from the lateral compartment. This method for measuring the subchondral bone in the same location as articular cartilage allows studies of the changes in these material properties with the onset and progression of osteoarthritis.

Post-Run T2 Mapping Changes in Knees of Adolescent Basketball Players

Cartilage ◽  
2021 ◽  
pp. 194760352110218
Author(s):  
Yigal Chechik ◽  
Eran Beit Ner ◽  
Oleg Lysyy ◽  
Sigal Tal ◽  
Neta Stern ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
T2 Mapping ◽  
Femoral Condyle ◽  
Weight Bearing ◽  
Lateral Compartment ◽  
Medial Compartment ◽  
Cartilage Defects ◽  
Mri Scan ◽  
Basketball Players ◽  
Mean Values

Objective: While articular cartilage defects are common incidental findings among adult athletes, the effect of running on the cartilage of adolescent athletes have rarely been assessed. This study aims to assess the variations in the articular cartilage of the knees in healthy adolescent basketball players using quantitative T2 MRI (magnetic resonance imaging). Design: Fifteen adolescent basketball players were recruited (13.8 ± 0.5 years old). Girls were excluded to avoid potential gender-related confounding effects. Players underwent a pre-run MRI scan of both knees. All participants performed a 30-minute run on a treadmill. Within 15 minutes after completion of their run, players underwent a second, post-run MRI scan. Quantitative T2 maps were generated using the echo modulation curve (EMC) algorithm. Pre-run scans and post-run scans were compared using paired t test. Results: Participants finished their 30-minute run with a mean running distance of 5.77 ± 0.42 km. Pre-run scans analysis found statistically significant ( P < 0.05) changes in 3 regions of the knee lateral compartment representing the cartilaginous tissue. No differences were found in the knee medial compartment. Post-run analysis showed lower T2 values in the medial compartment compared to the pre-run scans in several weight-bearing regions: femoral condyle central (pre/post mean values of 33.9/32.2 ms, P = 0.020); femoral condyle posterior (38.1/36.8 ms, P = 0.038); and tibial plateau posterior (34.1/31.0 ms, P < 0.001). The lateral regions did not show any significant changes. Conclusions: Running leads to microstructural changes in the articular cartilage in several weight-bearing areas of the medial compartment, both in the femoral and the tibial cartilage.

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