scholarly journals Mineralized Tissue Changes Within the Anterior Cruciate Ligament Entheses Following a Tear

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicholas Nguyen ◽  
Stephen Schlecht
Keyword(s):  
Bone Loss ◽  
Volume Fraction ◽  
Cruciate Ligament ◽  
Insertion Site ◽  
Young Patients ◽  
Post Injury ◽  
Bone Volume Fraction ◽  
Acl Graft ◽  
Cortical Regions

Background: Thirty-percent of patients under 20 years of age suffer a primary ACL graft failure. Young patients show significant bone loss at the femoral ACL-bone insertion site (enthesis). We hypothesize that active bone resorption during ACL graft fixation contributes to poor graft survival in the young.  We investigated distal femoral and entheseal bone morphology changes after injury in a novel mouse model to determine if previously reported post-injury patient condition anti-translates to the mouse. Confirmation of a similar condition across species will allow us to use this model to spatially and temporally track physiologic processes within this critical region.     Methods: We induced an in vivo ACL rupture in 24 10-week C57BL/6J female mice and sacrificed them at 7 and 28 post-injury. Both loaded ipsilateral and non-loaded contralateral knees were 3D imaged and distal femoral and ACL entheseal cortical regions have begun being analyzed. Traits analyzed include 1) cortical (Ct.) mean gray-value density, area (Ar.), thickness (Th.), and bone volume fraction (BV/TV) Statistics: two-way ANOVA and Tukey posthoc.    Results: So far, mice are temporally demonstrating bone differences between injured and non-injured knees similar to that of patients at the time of ACL reconstructive surgery. By 7 days there is a steep decline in whole distal femoral epiphysis and ACL femoral entheseal Ct.Ar (-19.84% and -11.46%, respectively) and Ct.Th (-8.09% and -3.52%, respectively). The trend in Ct.Ar loss holds at 28 days (-40.95% and -8.32%, respectively), but not in Ct.Th, which substantially increases (6.26% and 11.05%, respectively).    Conclusion: It appears bone loss is rapid following injury, and that by 28 days there is increased porosity within the cortex with new periosteal/endosteal bone formation counteracting this. If true, particularly within the entheseal region, this may prove problematic for long-term graft outcomes when surgery is performed at the time of significant macrophagic activity.   

scholarly journals AB0099 IN VIVO BONE MICROARCHITECTURE ANALYSIS IN A PSORIATIC ARTHRITIC PATIENT BEFORE AND AFTER ANTI-TNFΑ TREATMENT

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1078.3-1078
Author(s):  
E. Soldati ◽  
L. Escoffier ◽  
S. Gabrie ◽  
J. P. Mattei ◽  
S. Camilleri ◽  
...  
Keyword(s):  
Bone Loss ◽  
Volume Fraction ◽  
Bone Microarchitecture ◽  
Bone Volume ◽  
Normal Range ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Posterior Tibial ◽  
Before And After

Background:In psoriatic arthritis (PA), a systemic inflammatory phenomenon, mainly mediated by TNFα, is characterized by a bone loss due to osteoclastic stimulation. Anti-TNFα treatment should inhibit this phenomenon having a role on systemic bone loss. Ultra-high field MRI (UHF MRI) may be a tool of choice for the quantification of bone microarchitecture (BM) in vivo.Objectives:The purpose of the present study was to quantify BM using UHF MRI in a PA patient and to follow up changes related to anti-TNFα treatment.Methods:An 18 years-old untreated PA patient with knee arthritis and 7 gender-matched healthy controls [21.6±0.8 years] were scanned using a gradient echo sequence at UHF MRI (TR/TE = 15/4.36ms). After a year of Adalimumab treatment, the patient underwent a second UHF MRI. BM analysis was performed on sagittal planes in regions corresponding to tendon insertion: proximal and distal patellar, and posterior tibial. A PET-FNa imaging was also performed before and after treatment. BM was characterized using the bone volume fraction (BVF), the trabecular thickness (TbTh) and the spacing (TbSp) and number of trabeculae (TbN). Student T-test was used for the statistical analysis and a p-value < 0.01 was considered as significative.Results:PET-FNa recorded before the treatment illustrated hypermetabolic areas which resumed after the treatment while the patient was in remission. The BM parameters are shown in figure 1. The BM parameters quantified before the treatment were very different as compared to controls. BVF was significatively lower (-33±23%), TbSp and TbN were significatively distinct (-27±3% and +27±9%) for all ROIs but proximal patellar, while TbTh was in the normal range (-2±2%). After 1 year of treatment, BM parameters were significantly improved. BVF was no longer different than controls (-8±6%). Similarly, TbSp and TbN were in the normal range (+13±12% and -15±10%) for all ROIs but posterior tibial. TbTh (-5±3%) was only significantly decreased for the distal patella.Table 1. Data are presented as mean ± SD. “P.” refers as patient. BVF: Bone volume fraction, TbTh: Trabecular Thickness, TbSp: Trabecular Space, TbN: Trabecular number. * indicates a statistically significant difference (p < 0.01) with the Healthy reference values.Conclusion:Our results illustrated knee microstructure alterations in a PA patient and a normalization after a year of treatment. The abnormalities initially observed were not only localized in the hypermetabolic regions identified by PET-FNa, suggesting that the bone loss was global and not related to inflammatory sites.Using UHF MRI, we highlighted and quantified in vivo BM anomalies in a patient with an inflammatory rheumatism together with the reversibility after one year of treatment.Acknowledgements:All the authors declare no conflict of interest.ES has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No713750. Also, it has been carried out with the financial support of the Regional Council of Provence- Alpes-Côte d’Azur and with the financial support of the A*MIDEX (n° ANR- 11-IDEX-0001-02), funded by the “Investissements d’Avenir” project funded by the French Government, managed by the French National Research Agency (ANR). edgements to declare.Disclosure of Interests:None declared

scholarly journals The plate-to-rod transition in trabecular bone loss is elusive

2021 ◽  
Vol 8 (6) ◽  
pp. 201401
Author(s):  
A. A. Felder ◽  
S. Monzem ◽  
R. De Souza ◽  
B. Javaheri ◽  
D. Mills ◽  
...  
Keyword(s):  
Bone Loss ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Bone Volume ◽  
Continuous Measure ◽  
Bone Volume Fraction ◽  
Trabecular Bone Loss ◽  
Mouse Tibia ◽  
Disease Stages ◽  
The Relationship

Changes in trabecular micro-architecture are key to our understanding of osteoporosis. Previous work focusing on structure model index (SMI) measurements have concluded that disease progression entails a shift from plates to rods in trabecular bone, but SMI is heavily biased by bone volume fraction. As an alternative to SMI, we proposed the ellipsoid factor (EF) as a continuous measure of local trabecular shape between plate-like and rod-like extremes. We investigated the relationship between EF distributions, SMI and bone volume fraction of the trabecular geometry in a murine model of disuse osteoporosis as well as from human vertebrae of differing bone volume fraction. We observed a moderate shift in EF median (at later disease stages in mouse tibia) and EF mode (in the vertebral samples with low bone volume fraction) towards a more rod-like geometry, but not in EF maximum and minimum. These results support the notion that the plate to rod transition does not coincide with the onset of bone loss and is considerably more moderate, when it does occur, than SMI suggests. A variety of local shapes not straightforward to categorize as rod or plate exist in all our trabecular bone samples.

scholarly journals Retaining Residual Ovarian Tissue following Ovarian Failure Has Limited Influence on Bone Loss in Aged Mice

2010 ◽  
Vol 2010 ◽  
pp. 1-6
Author(s):  
Zelieann R. Craig ◽  
Samuel L. Marion ◽  
Janet L. Funk ◽  
Mary L. Bouxsein ◽  
Patricia B. Hoyer
Keyword(s):  
Bone Loss ◽  
Volume Fraction ◽  
Ovarian Tissue ◽  
Ovarian Failure ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Ct Analysis ◽  
Time Point ◽  
Young Mice

Previous work showed that retaining residual ovarian tissue protects young mice from accelerated bone loss following ovarian failure. The present study was designed to determine whether this protection is also present in aged animals. Aged (9–12 months) C57BL/6Hsd female mice were divided into: CON (vehicle), VCD (160 mg/kg; 15d), or OVX (ovariectomized). Lumbar BMD was monitored by DXA andμCT used to assess vertebral microarchitecture. BMD was not different between VCD and CON at any time point but was lower (P<.05) than baseline, starting 1 month after ovarian failure in VCD and OVX mice. FollowingμCT analysis there were no differences between CON and VCD, but OVX mice had lower bone volume fraction, trabecular thickness, and a trend for decreased connectivity density. These findings provide evidence that retention of residual ovarian tissue may protect aged follicle-depleted mice from accelerated bone loss to a lesser extent than that observed in young mice.

scholarly journals Effects of P-15 Peptide Coated Hydroxyapatite on Tibial Defect Repair In Vivo in Normal and Osteoporotic Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Rasmus Hestehave Pedersen ◽  
Marina Rasmussen ◽  
Søren Overgaard ◽  
Ming Ding
Keyword(s):  
Bone Formation ◽  
Bone Regeneration ◽  
Volume Fraction ◽  
Structure Type ◽  
Osteoporotic Bone ◽  
Bone Volume Fraction ◽  
Defect Repair ◽  
Paired Design ◽  
Tibia Defect

This study assessed the efficacy of anorganic bone mineral coated with P-15 peptide (ABM/P-15) on tibia defect repair longitudinally in both normal and osteoporotic rats in vivo. A paired design was used. 24 Norwegian brown rats were divided into normal and osteoporotic groups. 48 cylindrical defects were created in proximal tibias bilaterally. Defects were filled with ABM/P-15 or left empty. Osteoporotic status was assessed by microarchitectural analysis. Microarchitectural properties of proximal tibial defects were evaluated at 4 time points. 21 days after surgery, tibias were harvested for histology and histomorphometry. Significantly increased bone volume fraction, surface density, and connectivity were seen in all groups at days 14 and 21 compared with day 0. Moreover, the structure type of ABM/P-15 group was changed toward typical plate-like structure. Microarchitectural properties of ABM/P-15 treated newly formed bones at 21 days were similar in normal and osteoporotic rats. Histologically, significant bone formation was seen in all groups. Interestingly, significantly increased bone formation was seen in osteoporotic rats treated with ABM/P-15 indicating optimized healing potential. Empty defects showed lower healing potential in osteoporotic bone. In conclusion, ABM/P-15 accelerated bone regeneration in osteoporotic rats but did not enhance bone regeneration in normal rats.

How Cyclic Loading Affects the Migration of Radio-Opaque Markers Attached to Tendon Grafts Using a New Method: A Study Using Roentgen Stereophotogrammetric Analysis (RSA)

2004 ◽  
Vol 126 (1) ◽  
pp. 62-69 ◽  
Author(s):  
P. J. Roos ◽  
M. L. Hull ◽  
S. M. Howell
Keyword(s):  
Cyclic Loading ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
In Vivo Studies ◽  
Repeated Loading ◽  
Acl Graft ◽  
Anterior Laxity ◽  
Tendon Grafts ◽  
Anterior Cruciate

An increase in anterior laxity following reconstruction of the anterior cruciate ligament (ACL) can result from lengthening of the graft construct in either the regions of fixation and/or the region of the graft substance between the fixations. RSA could be a useful technique to determine lengthening in these regions if a method can be devised for attaching radio-opaque markers to soft tissue grafts so that marker migration from repeated loading of the graft is limited. Therefore, the objectives of this study were 1) to develop a method for attaching radio-opaque markers to an ACL graft that limits marker migration within the graft, 2) to characterize the error of an RSA system used to study migration, and 3) to determine the maximum amount of migration and the time when it occurs during cyclic loading of ACL grafts. Tendon markers were constructed from a 0.8-mm tantalum ball and a stainless steel suture. Ten double-looped tendon grafts were passed through tibial tunnels drilled in bovine tibias and fixed with a tibial fixation device. Two tendon markers were sewn to one tendon bundle of each graft and the grafts were cyclically loaded for 225,000 cycles from 20 N to 170 N. At specified intervals, simultaneous radiographs were obtained of the tendon markers and a radiographic standard of known length. The bias and imprecision in measuring the length of the radiographic standard were 0.0 and 0.046 mm respectively. Marker migration was computed as the change in distance between the two tendon markers along the axis of the tibial tunnel. Marker migration was greatest after 225,000 cycles with a root mean square (RMS) value of less than 0.2 mm. Because the RMS value indicates the error introduced into measurements of lengthening and because this error is small, the method described for attaching markers to an ACL graft has the potential to be useful for determining lengthening of ACL graft constructs in in vivo studies in humans.

scholarly journals In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement

2012 ◽  
Vol 83 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Nan Ru ◽  
Sean Shih-Yao Liu ◽  
Li Zhuang ◽  
Song Li ◽  
Yuxing Bai
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Root Resorption ◽  
Volume Fraction ◽  
Orthodontic Tooth Movement ◽  
Bone Volume ◽  
Structure Model ◽  
Bone Volume Fraction ◽  
Trabecular Thickness

ABSTRACT Objective: To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment. Materials and Methods: A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P &lt; .05. Results: From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading. Conclusions: Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

scholarly journals Voxel size dependency, reproducibility and sensitivity of an in vivo bone loading estimation algorithm

2016 ◽  
Vol 13 (114) ◽  
pp. 20150991 ◽  
Author(s):  
Patrik Christen ◽  
Friederike A. Schulte ◽  
Alexander Zwahlen ◽  
Bert van Rietbergen ◽  
Stephanie Boutroy ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Estimation Algorithm ◽  
Bone Volume ◽  
Micro Ct ◽  
Bone Volume Fraction ◽  
Voxel Size ◽  
Size Dependency ◽  
Bone Loading

A bone loading estimation algorithm was previously developed that provides in vivo loading conditions required for in vivo bone remodelling simulations. The algorithm derives a bone's loading history from its microstructure as assessed by high-resolution (HR) computed tomography (CT). This reverse engineering approach showed accurate and realistic results based on micro-CT and HR-peripheral quantitative CT images. However, its voxel size dependency, reproducibility and sensitivity still need to be investigated, which is the purpose of this study. Voxel size dependency was tested on cadaveric distal radii with micro-CT images scanned at 25 µm and downscaled to 50, 61, 75, 82, 100, 125 and 150 µm. Reproducibility was calculated with repeated in vitro as well as in vivo HR-pQCT measurements at 82 µm. Sensitivity was defined using HR-pQCT images from women with fracture versus non-fracture, and low versus high bone volume fraction, expecting similar and different loading histories, respectively. Our results indicate that the algorithm is voxel size independent within an average (maximum) error of 8.2% (32.9%) at 61 µm, but that the dependency increases considerably at voxel sizes bigger than 82 µm. In vitro and in vivo reproducibility are up to 4.5% and 10.2%, respectively, which is comparable to other in vitro studies and slightly higher than in other in vivo studies. Subjects with different bone volume fraction were clearly distinguished but not subjects with and without fracture. This is in agreement with bone adapting to customary loading but not to fall loads. We conclude that the in vivo bone loading estimation algorithm provides reproducible, sensitive and fairly voxel size independent results at up to 82 µm, but that smaller voxel sizes would be advantageous.

Non-Linear Viscoelastic Mechanics of Native and Engineered Ligaments and Tendons

2011 ◽  
Author(s):  
Jinjin Ma ◽  
Ellen M. Arruda
Keyword(s):  
Cruciate Ligament ◽  
Viscoelastic Behavior ◽  
Biomechanical Properties ◽  
Acl Graft ◽  
Non Linear ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic ◽  
Anterior Cruciate ◽  
Acl Replacement

Patellar tendon (PT) autografts and allografts are the most common methods currently used to replace a torn anterior cruciate ligament (ACL). The PT is not only much stiffer than the ACL it replaces it also exhibits qualitatively and quantitatively different non-linear viscoelastic behavior from those of the ACL. These mis-matched biomechanics may be contributing to the high incidence of early onset osteoarthritis suffered by patients who have had ACL surgeries. Thus there is a need for an ACL graft that can reproduce normal ligament biomechanics and knee function. This talk examines the inhomogeneous, non-linear viscoelastic response of native ACL and of a tissue engineered ACL graft designed to rapidly grow and remodel in vivo to restore the proper biomechanical properties of native ligament. The results using this graft as an ACL replacement are compared against those using a PT autograft for the ACL replacement. Uniaxial loading reveals that after nine months as an ACL replacement, the tissue-engineered graft develops a strain contour pattern closely resembling that of native ACL whereas the PT graft fails to similarly remodel in vivo.

A Preclinical Model to Study the Influence of Graft Force on the Healing of the Anterior Cruciate Ligament Graft

2018 ◽  
Vol 32 (05) ◽  
pp. 441-447
Author(s):  
Richard Ma ◽  
Mark Stasiak ◽  
Xiang-Hua Deng ◽  
Scott Rodeo
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
Tunnel Position ◽  
Anterior Cruciate Ligament Graft ◽  
Acl Graft ◽  
Anterior Cruciate ◽  
Femoral Graft

AbstractThe purpose of this study is to establish a small animal anterior cruciate ligament (ACL) reconstruction research model where ACL graft force can be varied to create different graft force patterns with controlled knee motion. Cadaveric (n = 10) and in vivo (n = 10) rat knees underwent ACL resection followed by reconstruction using a soft tissue autograft. Five cadaveric and five in vivo knees received a nonisometric, high-force femoral graft tunnel position. Five cadaveric and five in vivo knees received a more isometric, low-force graft tunnel position. ACL graft force (N) was then recorded as the knee was ranged from extension to 90 degrees using a custom knee flexion device. Our results demonstrate that distinct ACL graft force patterns were generated for the high-force and low-force femoral graft tunnels. For high-force ACL grafts, ACL graft forces increased as the knee was flexed both in cadaveric and in vivo knees. At 90 degrees of knee flexion, high-force ACL grafts had significantly greater mean graft force when compared with baseline (cadaver: 7.76 ± 0.54 N at 90 degrees vs. 4.94 ± 0.14 N at 0 degree, p = 0.004; in vivo: 7.29 ± 0.42 N at 90 degrees vs. 4.74 ± 0.13 N at 0 degree, p = 0.007). In contrast, the graft forces for low-force ACL grafts did not change with knee flexion (cadaver: 4.94 ± 0.11 N at 90 degrees vs. 4.72 ± 0.14 N at 0 degree, p = 0.41; in vivo: 4.78 ± 0.26 N at 90 degrees vs. 4.77 ± 0.06 N at 0 degree, p = 1). Compared with nonisometric ACL grafts, the graft force for grafts placed in an isometric position had significantly lower ACL graft forces at 15, 30, 45, 60, 70, and 90 degrees in both cadaveric and in vivo knees. In conclusion, we have developed a novel ACL reconstruction model that can reproducibly produce two ACL graft force patterns. This model would permit further research on how ACL graft forces may affect subsequent graft healing, maturation, and function.

scholarly journals The Ginsenoside Exhibits Antiosteoporosis Effects in Ketogenic-Diet-Induced Osteoporosis via Rebalancing Bone Turnover

2021 ◽  
Vol 11 ◽  
Author(s):  
Qi Liu ◽  
Jian Zhou ◽  
Zhou Yang ◽  
Chuhai Xie ◽  
Yan Huang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Ketogenic Diet ◽  
Cancellous Bone ◽  
Volume Fraction ◽  
Cathepsin K ◽  
Tartrate Resistant Acid Phosphatase ◽  
Protective Effects ◽  
Bone Volume Fraction ◽  
Ppar Γ ◽  
Ginsenoside Rb2

Ginsenoside is widely used in China for therapeutic and healthcare practice. Ginsenoside-Rb2 shows the antiosteoporosis effects in ovariectomized rodents. However, the protective effects on osteoporosis induced by ketogenic diet (KD) remain unknown. Therefore, this study aimed at evaluating the effects of ginsenoside-Rb2 on KD-induced osteoporosis. Thirty mice were randomly divided into three groups: sham, KD, and KD + Rb2. Bone microstructures, biomechanical properties, concentrations of serum bone alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase (TRACP), and protein expression of osteocalcin (OCN), peroxisome proliferation-activated receptor γ (PPAR-γ), cathepsin K, and TRAP were evaluated after a 12-week intervention. The results show that KD induced significant bone loss and biomechanical impairment. Ginsenoside-Rb2 attenuated significant bone loss and maintained biomechanics in cancellous bone. The bone volume fraction increased from 2.3 to 6.0% in the KD + Rb2 group than that in the KD group. Meanwhile, ginsenoside-Rb2 effectively maintained biomechanical strengths in cancellous bone, increased serum BALP and decreased TRACP, and upregulated OCN and downregulated TRAP, PPAR-γ, and cathepsin K in the KD mice. This study demonstrated that ginsenoside-Rb2 retards bone loss and maintains biomechanics with KD. The underlying mechanism might be that ginsenoside-Rb2 inhibits bone resorption process and induces osteogenic differentiation, providing evidence for ginsenoside as being an alternative option for osteoporosis induced by KD.

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