scholarly journals Evaluation of hydroxyapatite ceramic vertebral spacers with different porosities and their binding capability to the vertebral body: an experimental study in sheep

2007 ◽  
Vol 6 (5) ◽  
pp. 431-437 ◽  
Author(s):  
Manabu Ito ◽  
Yoshihisa Kotani ◽  
Yoshihiro Hojo ◽  
Kuniyoshi Abumi ◽  
Tsuyoshi Kadosawa ◽  
...  
Keyword(s):  
Bone Ingrowth ◽  
Histological Study ◽  
Biomechanical Testing ◽  
Histological Evaluation ◽  
Micro Computed Tomography ◽  
Hydroxyapatite Ceramic ◽  
Sheep Model ◽  
Spinal Reconstruction ◽  
Computed Tomography Scans ◽  
The Ideal

Object The aim of this study was to evaluate the degree of bone ingrowth and bonding stiffness at the surface of hydroxyapatite ceramic (HAC) spacers with different porosities in an animal model and to discuss the ideal porous characteristics of these spacers for anterior spinal reconstruction. Methods Twenty-one adult sheep (age 1–2 years, mean weight 70 kg) were used in this experiment. Surgery consisted of anterior lumbar interbody fusion at L2–3 and L4–5, insertion of an HAC spacer (10 × 13 × 24 mm) with three different porosities (0, 3, and 15%), and single-rod anterior instrumentation. At 4 and 6 months postoperatively, the lumbar spines were harvested. Bonding conditions at the bone–HAC spacer interface were evaluated using neuroimages and biomechanically. A histological evaluation was also conducted to examine the state of bone ingrowth at the surface of the HAC spacer. Biomechanical testing showed that the bonding strength of HAC at 6 months postoperatively was 0.047 MPa in 0% porosity spacers, 0.39 MPa in 3%, and 0.49 MPa in 15% porosity spacers. The histological study showed that there was a soft-tissue layer at the surface of the HAC spacer with 0% porosity. Direct bonding was observed between bone and spacers with 3 or 15% porosity. Micro–computed tomography scans showed direct bonding between the bone and HAC with 3 or 15% porosity. No direct bonding was observed in HAC with 0% porosity. Conclusions Dense (0%) HAC anterior vertebral spacers did not achieve direct bonding to the bone in the sheep model. The HAC vertebral spacers with 3 or 15% porosity showed proof of direct bonding to the bone at 6 months postoperatively. The higher porosity HAC spacer showed better bonding stiffness to the bone.

scholarly journals Analysis of microscopic bone properties in an osteoporotic sheep model: a combined biomechanics, FE and ToF-SIMS study

2019 ◽  
Vol 16 (151) ◽  
pp. 20180793 ◽  
Author(s):  
R. Müller ◽  
A. Henss ◽  
M. Kampschulte ◽  
M. Rohnke ◽  
A. C. Langheinrich ◽  
...  
Keyword(s):  
Biomechanical Testing ◽  
Tissue Level ◽  
Osteoporotic Bone ◽  
Compression Tests ◽  
Micro Computed Tomography ◽  
Deficient Diet ◽  
Element Analysis ◽  
Sheep Model ◽  
Tissue Properties ◽  
Bone Properties

The present study deals with the characterization of bone quality in a sheep model of postmenopausal osteoporosis. Sheep were sham operated ( n = 7), ovariectomized ( n = 6), ovariectomized and treated with deficient diet ( n = 8) or ovariectomized, treated with deficient diet and glucocorticoid injections ( n = 7). The focus of the study is on the microscopic properties at tissue level. Microscopic mechanical properties of osteoporotic bone were evaluated by a combination of biomechanical testing and mathematical modelling. Sample stiffness and strength were determined by compression tests and finite-element analysis of stress states was conducted. From this, an averaged microscopic Young’s modulus at tissue level was determined. Trabecular structure as well as mineral and collagen distribution in samples of sheep vertebrae were analysed by micro-computed tomography and time-of-flight secondary ion mass spectrometry. In the osteoporotic sheep model, a disturbed fibril structure in the triple treated group was observed, but bone loss only occurred in form of reduced trabecular number and thickness and cortical decline, while quality of the residual bone was preserved. The preserved bone tissue properties in the osteoporotic sheep model allowed for an estimation of bone strength which behaves similar to the human case.

P7. Relationship between porous geometry and bone ingrowth at the surface of hydroxyapatite ceramic spacer for anterior spinal reconstruction

2004 ◽  
Vol 4 (5) ◽  
pp. S83-S84
Author(s):  
Manabu Ito ◽  
Yoshihisa Kotani ◽  
Norihiro Hojo ◽  
Kuniyoshi Abumi ◽  
Ken Kadoya ◽  
...  
Keyword(s):  
Bone Ingrowth ◽  
Hydroxyapatite Ceramic ◽  
Spinal Reconstruction

scholarly journals Local and systemic inflammation after implantation of a novel iron based porous degradable bone replacement material in sheep model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernd Wegener ◽  
Maik Behnke ◽  
Stefan Milz ◽  
Volkmar Jansson ◽  
Christian Redlich ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Bone Substitutes ◽  
Histological Evaluation ◽  
Control Group ◽  
Blood Levels ◽  
Porous Iron ◽  
Sheep Model ◽  
Bone Replacement ◽  
Alloy Particles ◽  
Iron Based

AbstractDespite the high potential of healthy bone to regenerate, the reconstruction of large bone defects remains a challenge. Due to the lack of mechanical stability of existing bone substitutes, recently developed degradable metallic alloys are an interesting alternative providing higher load-bearing capabilities. Degradable iron-based alloys therefore might be an attractive innovation. To test the suitability of a newly-designed iron-based alloy for such applications, an animal experiment was performed. Porous iron-based degradable implants with two different densities and a control group were tested. The implants were positioned in the proximal tibia of Merino sheep. Over a period of 6 and 12 months, blood and histological parameters were monitored for signs of inflammation and degradation. In the histological evaluation of the implants` environment we found degraded alloy particles, but no inflammatory reaction. Iron particles were also found within the popliteal lymph nodes on both sides. The serum blood levels of phosphorus, iron and ferritin in the long term groups were elevated. Other parameters did not show any changes. Iron-based degradable porous bone replacement implants showed a good biocompatibility in this experiment. For a clinical application, however, the rate of degradation would have to be significantly increased. Biocompatibility would then have to be re-evaluated.

Influence of a titanium mesh on the management of segmental long bone defects

2015 ◽  
Vol 28 (06) ◽  
pp. 417-424 ◽  
Author(s):  
S. A. Papadimitriou ◽  
A. D. Galatos ◽  
N. N. Prassinos ◽  
D. Psalla ◽  
M. Dalstra ◽  
...  
Keyword(s):  
Critical Size ◽  
Experimental Studies ◽  
Long Bone ◽  
Histological Evaluation ◽  
Autogenous Bone ◽  
Bone Block ◽  
Titanium Mesh ◽  
Micro Computed Tomography ◽  
Critical Size Defect ◽  
Group B

SummaryObjectives: To evaluate the influence of titanium mesh on guided bone regeneration when used, either alone or in combination with autogenous bone block graft, in a canine ulnar model.Methods: Thirty-two, purpose bred, adult, castrated male Beagles were used, divided into four equal-size groups. A unilateral middiaphyseal ulnar critical-size defect was created in each dog. The ulnar segments were stabilized with a stainless-steel plate and screws. Each defect was managed by: no further treatment (Group A) or by placement of a bone block graft taken from the ipsilateral iliac crest (Group B), or titanium mesh wrapped around the ulna (Group C), or a bone block graft and titanium mesh (Group D). After six months, bone block biopsies were performed and the samples were scanned using micro-computed tomography. Qualitative histological evaluation was performed on two non-decalcified longitudinal sections from each block.Results: No significant differences in terms of mineralized bone volume were detected between the grafted sites (Groups B and D) or between the non-grafted ones (Groups A and C). The histological evaluation indicated good integration of the bone blocks irrespective of the use of titanium mesh.Clinical significance: The use of titanium mesh does not influence the amount of bone formation. The canine ulnar critical-size defect model seems to be a reliable model to use in experimental studies.

scholarly journals A redescription of the Late Jurassic (Tithonian) turtle Uluops uluops and a new phylogenetic hypothesis of Paracryptodira

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Yann Rollot ◽  
Serjoscha W. Evers ◽  
Walter G. Joyce
Keyword(s):  
Computed Tomography ◽  
Phylogenetic Analysis ◽  
Late Jurassic ◽  
Internal Carotid ◽  
Circulation System ◽  
Phylogenetic Hypothesis ◽  
Micro Computed Tomography ◽  
Future Studies ◽  
Computed Tomography Scans ◽  
Palatine Artery

AbstractWe study the Late Jurassic (Tithonian) turtle Uluops uluops using micro-computed tomography scans to investigate the cranial anatomy of paracryptodires, and provide new insights into the evolution of the internal carotid artery and facial nerve systems, as well as the phylogenetic relationships of this group. We demonstrate the presence of a canalis caroticus lateralis in Uluops uluops, the only pleurosternid for which a palatine artery canal can be confidently identified. Our phylogenetic analysis retrieves Uluops uluops as the earliest branching pleurosternid, Helochelydridae within Pleurosternidae, and Compsemydidae including Kallokibotion bajazidi within Baenidae, which suggests at least two independent losses of the palatine artery within paracryptodires. We expect future studies will provide additional insights into the evolution of the circulation system of paracryptodires, as well as clarifying relationships along the turtle stem.

A Biomechanical Comparison of Three Miniature Locking Plate Systems in a Rabbit Radial and Ulnar Fracture Model

2019 ◽  
Vol 32 (04) ◽  
pp. 297-304 ◽  
Author(s):  
Harue Takizawa ◽  
Muneki Honnami ◽  
Takamasa Sakai ◽  
Akari Sasaki ◽  
Ayumi Sakamoto ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Locking Plate ◽  
Healing Process ◽  
Biomechanical Testing ◽  
Histological Evaluation ◽  
Fracture Stabilization ◽  
Significant Difference ◽  
Ulnar Fracture ◽  
Fracture Models

Objective The aim of this study was to evaluate the biomechanical properties of three different miniature locking plate systems used to fixate radial and ulnar fractures in toy breed dogs. Implant size, shape, material and locking systems differ, and their influence on the fracture healing process is unknown. In the present study, we aimed to investigate this matter in vivo using rabbit radial and ulnar fracture models. Study Design Eighteen rabbits were randomly divided into three groups, and the left radius and ulna were osteotomized to create fracture models. The osteotomies were then fixated using either the TITAN LOCK 1.5, Fixin micro or LCP 1.5 system. Radiographs were obtained 2, 3 and 4 weeks after surgery. Four weeks after surgery, the radiuses were collected and used for biomechanical testing or histological examinations. Results During the 4 weeks of observation, no adverse effects due to the implants occurred. The radiographic scores in each group did not differ significantly at any time point. The maximum load in the LCP group was significantly higher than that in the TITAN and Fixin groups. There was no significant difference in bending stiffness or work to failure among the groups. Initial fracture healing via woven bone was evident at histological evaluation. Conclusions All three miniature locking plate systems provided adequate fracture stabilization 4 weeks after surgery, despite their differences, in rabbit models.

Small Subchondral Drill Holes Improve Marrow Stimulation of Rotator Cuff Repair in a Rabbit Model of Chronic Rotator Cuff Tear

2020 ◽  
Vol 48 (3) ◽  
pp. 706-714 ◽  
Author(s):  
Yucheng Sun ◽  
Jae-Man Kwak ◽  
Erica Kholinne ◽  
Youlang Zhou ◽  
Jun Tan ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Rotator Cuff Repair ◽  
Large Diameter ◽  
Biomechanical Testing ◽  
Rabbit Model ◽  
Small Diameter ◽  
Histological Evaluation ◽  
Control Group ◽  
Greater Tuberosity ◽  
Cuff Repair

Background: Microfracture of the greater tuberosity has been proved effective for enhancing tendon-to-bone healing after rotator cuff repair. However, no standard diameter for the microfracture has been established. Purpose/Hypothesis: This study aimed to assess treatment with large- and small-diameter microfractures to enhance healing during rotator cuff repair surgery in a rabbit model of chronic rotator cuff tear. It was hypothesized that a small-diameter microfracture had advantages in terms of tendon-to-bone integration, bone-tendon interface maturity, microfracture healing, and biomechanical properties compared with a large-diameter microfracture. Study Design: Controlled laboratory study. Methods: Bilateral supraspinatus tenotomy from the greater tuberosity was performed on 21 New Zealand White rabbits. Bilateral supraspinatus repair was performed 6 weeks later. Small-diameter (0.5 mm) microfracture and large-diameter microfracture (1 mm) were performed on the left side and right side, respectively, in 14 rabbits as a study group, and simple repair without microfracture was performed in 7 rabbits as a control group. At 12 weeks later, 7 of 14 rabbits in the study group were sacrificed for micro–computed tomography evaluation and biomechanical testing. Another 6 rabbits were sacrificed for histological evaluation. In the control group, 3 of the 7 rabbits were sacrificed for histological evaluation and the remaining rabbits were sacrificed for biomechanical testing. Results: Significantly better bone-to-tendon integration was observed in the small-diameter microfracture group. Better histological formation and maturity of the bone-tendon interface corresponding to better biomechanical results (maximum load to failure and stiffness) were obtained on the small-diameter microfracture side compared with the large-diameter side and the control group. The large-diameter microfracture showed worse radiographic and histological properties for healing of the microfracture holes on the greater tuberosity. Additionally, the large-diameter microfracture showed inferior biomechanical properties but similar histological results compared with the control group. Conclusion: Small-diameter microfracture showed advantages with enhanced rotator cuff healing for biomechanical, histological, and radiographic outcomes compared with large-diameter microfracture, and large-diameter microfracture may worsen the rotator cuff healing. Clinical Relevance: This animal study suggested that a smaller diameter microfracture may be a better choice to enhance healing in clinical rotator cuff repair surgery in humans.

scholarly journals Impact of DBBM Fragments on the Porosity of the Calvarial Bone: A Pilot Study on Mice

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4748
Author(s):  
Ulrike Kuchler ◽  
Patrick Heimel ◽  
Alexandra Stähli ◽  
Franz Josef Strauss ◽  
Bernadette Luza ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Histological Evaluation ◽  
Random Allocation ◽  
Bovine Bone ◽  
Distribution Analysis ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Calvarial Bone ◽  
Ct Analysis ◽  
Bovine Bone Mineral

Deproteinized bovine bone mineral (DBBM) is brittle and can break into fragments. Here, we examined whether DBBM fragments have an impact on mice calvarial bone during bone augmentation. DBBM was either randomly crushed (DBBM fragments) or left undisturbed (DBBM granules). Then, DBBM fragments or original DBBM granules were placed onto calvarial bone in 20 BALB/c mice. Following random allocation, ten mice received DBBM fragments and ten mice received original DBBM granules. After fourteen days of healing, micro computed tomography (micro-CT) and histological analysis of the augmented sites were performed. The primary outcome was the porosity of the calvarial bone. The micro-CT analysis revealed that DBBM fragments failed to significantly change the porosity of the calvarial bone as compared with original DBBM granules, despite the slightly higher bone resorption in the DBBM fragment group, 10.3% (CI 6.3–11.6) versus 6.1% (CI 4.1–7.8, p = 0.355), respectively. The cortical bone volume was not altered by DBBM fragments as compared with original DBBM granules, i.e., 79.0% (CI 78.9–81.2) versus 81.5% (CI 80.1–83.3, p = 0.357), respectively. The DBBM fragment group revealed similar bone thickness values as compared with the DBBM granules group, i.e., 0.26 mm (CI 0.23–0.29) versus 0.25 mm (CI 0.22–0.27, p = 0.641), respectively. The histological evaluation supported the micro-CT observations, displaying minor signs of porosity and resorption. The particle-size distribution analysis confirmed a shift towards smaller particle sizes in the DBBM fragment group. These findings suggest that DBBM fragments behave similarly to original DBBM granules in terms of bone morphological changes at augmented sites.

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