Dog Tibia Research Articles

Hydroxyapatite/β-tricalcium phosphate composite for guiding bone tissue growth into a titanium tube in 8 mm dog tibia cavity defects

We developed a fixation method and evaluate bone regrowth in the cavities of a ϕ4 mm× 8 mm titanium (Ti) tube through porous hydroxyapatite (HAP)/β-tricalcium phosphate (β-TCP) composite filling (group A), chitosan/calcium phosphate composite filling (group B), and HAP particle modification (group C). After 2 and 5 months of implantation in dog tibia defects, new bone formation in the three groups was studied by histology and histomorphometry. Group A displayed the most bone regenerated area in both 2 and 5 months post-operation. The chitosan/calcium phosphate composite in group B mostly degraded 2 months after implantation, leading to fibrous tissue invasion after 5 months. By contrast, less bone formation was observed in group C. These results indicated that filling the cavities of metal prostheses with a porous HAP/β-TCP composite can be used for stable long-term fixation in clinical settings.

Effects of counter torque and transposition (transfer) of installed implants timing on their integration in dog tibia.

PURPOSEThe purpose of this research was to evaluate the amount of reosseointegration after counter torquing (reverse torque) and transposing the installed implants at different times.MATERIALS AND METHODSThis study was done on ten tibiae of five cross-bred dogs. At the first day one implant was installed in each tibia. After one week half of the implants were randomly counter torqued (1WCT) and the other half were explanted and reimplanted in a new juxtaposition site (transposed)(1WT). At the same time three new implants were installed in each dog, one of them was considered as one week control (1WC) and remaining two as 8 week groups (8WCT&8WT). After eight weeks the 1WCT and 1WT implants were loosened by counter torque and the quantity of needed force for liberation was measured with the digital device (BGI). At the same time one implant was installed in each dog as eight week control (8WC) and the same protocol was repeated for 8 week groups after another 8 weeks.RESULTSAll implants were osseointegrated. Mean quantities of osseointegration in case groups indicated better amounts rather than control groups.CONCLUSIONCounter torque or transposition of the installed implants one week or eight weeks after the implantation did lead to osseointegration.

Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs.

This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time–intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0–3 according to the number of vascular signals. A parabolic shape of time–intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.

An animal model study for bone repair with encapsulated differentiated osteoblasts from adipose-derived stem cells in alginate.

Adipose derived stem cells (ADSCs) can be engineered to express bone specific markers. The aim of this study is to evaluate repairing tibia in animal model with differentiated osteoblasts from autologous ADSCs in alginate scaffold. In this study, 6 canine's ADSCs were encapsulated in alginate and differentiated into osteoblasts. Alkaline phosphatase assay (ALP) and RT-PCR method were applied to confirm the osteogenic induction. Then, encapsulated differentiated cells (group 1) and cell-free alginate (group 2) implanted in defected part of dog's tibia for 4 and 8 weeks. Regenerated tissues and compressive strength of samples were evaluated by histological and Immunohistochemical (IHC) methods and Tensometer Universal Machine. Our results showed that ADSCs were differentiated into osteoblasts in vitro, and type I collagen and osteocalcin genes expression in differentiated osteoblasts was proved by RT-PCR. In group 2, ossification and thickness of trabecula were low compared to group 1, and in both groups woven bone was observed instead of control group's compact bone. Considering time, we found bone trabeculae regression and ossification reduction after 8 weeks compared with 4 weeks in group 2, but in group 1 bone formation was increased in 8 weeks. Presence of differentiated cells caused significantly more compressive strength in comparison with group 2 (P-value ≤0.05). This research showed that engineering bone from differentiated adipose-derived stem cells, encapsulated in alginate can repair tibia defects.

A Histological and Radiological Study of Bone Formation around Porous Resorbable β-Tricalcium Phosphate Used as Bone Defect Filling

The purpose of this study was to analyze the histological, histochemical and radiological findings gained from pre-clinical in vitro and in vivo tests and from implantation of ß-tricalcium phosphate PORESORB®-TCP (P). (P) is a bioactive, resorbable, inorganic, crystalline, non-metallic material with osseoconductive properties intended for replacement of bone tissue. The (P) granules (size 1-2mm) were implanted into the tibia of dogs for 3 and 6 months. The formation of 53% and 72% of new bone was observed after 3 and 6 months respectively.Material (P) sized 0.3-0.6 mm was used to fill in the periodontal defect and also as a carrier of growth proteins. During the study period, no undesired response to the material used was observed. The values of the plaque index showed standard hygienic conditions – the values of PlI were 0.72, 0.65 and 0.62 before treatment and 6 and 12 months after treatment, respectively.A total of 72 two-stage sinus lifts were performed in 54 patients. The autologous bone was harvested from the mandibular ramus and mixed with the (P) material sized 1-2 mm. The materials were used in a proportion ranging between 1: 1 and 1: 3. The residual allograft area was 16.21 ± 8.78 %. The connective tissue was 44.16 ± 5.85 %.This has been a retrospective review of the healing of bone defects, due to benign tumours or tumour-like lesions, using (P) material sized 1.3 mm, 0.7 mm (0.6-2 mm) as bone graft substitutes. 87 patients with bone defects (average volume 15 cm3; interval 0.4 – 144 cm3) were included. Defects with a volume up to 4 cm3 had the same successful rate of healing both for autologous bone grafts and (P). (P) sized 1.3 mm; 0.7 mm (0.6-2 mm) was successfully used in defects with volume up to 4 cm3. However, it is evident that the ratio of the size of the defect and the size of the applied granule must be kept near to 10/1 for successful treatment.

The in vivo effect of P‐15 coating on early osseointegration

The aim of this study was to evaluate mechanically and morphologically the effect of a specific peptide sequence P-15, when incorporated into implant surfaces. Three types of implants were used for the study: Group A: commercially pure titanium implant (blasted and acid etched) + electrochemical thin calcium phosphate deposition, Group B: commercially pure titanium implant (blasted and acid etched) + electrochemical thin calcium phosphate deposition + P-15 incorporation, and as control, Group C: commercially pure titanium implant (blasted and acid etched). After a topographical characterization, transcortical osteotomies were made, and all implant groups (102 implants per group) were randomly placed bilaterally in the tibiae of adult beagle dogs (n = 24). At, 1, 2, and 4 weeks post-surgery, the animals were sacrificed and the samples were retrieved for removal torque tests, for nano indentation, and for histomorphometrical analysis. The results (mean ± 95% CI) showed that Group B (34.4 ± 8.7%) presented statistically higher bone-to-implant contact than the other groups (A = 23.9 ± 7.8%; C = 21.7 ± 8.3%) at 1 week, indicating an enhanced osteogenesis due to the peptide incorporation. The results suggested that the incorporation of P-15 to implant surfaces increased its bioactivity and the effects were notable especially in the early stages of the healing process.

The Production of Nickel-Chromium-Molybdenum Alloy with Open Pore Structure as an Implant and the Investigation of Its Biocompatibility In Vivo

A dental crown material, Nickel-Chrome-Molybdenum alloy, is manufactured using precision casting method from a polyurethane foam model in a regular and open-pore form, as a hard tissue implant for orthopedic applications. The samples produced have 10, 20, and 30 (±3) pores per inch of pore densities and 0.0008, 0.0017, and 0.0027 g/mm3densities, respectively. Samples were implanted in six dogs and observed for a period of two, four, and six months for the histopathological examinations. The dogs were examined radiologically in 15-day intervals and clinically in certain intervals. The implants were taken out with surrounding tissue at the end of these periods. Implants and surrounding tissues were examined histopathologically in terms of biocompatibility. As a result, it is seen that new bone tissue was formed, in pores of the porous implant at the head of the tibia in dogs implanted. Any pathology, inflammation, and reaction in old and new tissues were not observed. It was concluded that a dental alloy (Ni-Cr-Mo alloy) could also be used as a biocompatible hard tissue implant material for orthopedics.

Anatomical Study on the Diaphyseal Nutrient Foramen of the Femur and Tibia of the German Shepherd Dog

To provide anatomical data on the nutrient foramen (NF), the authors observed the number, site and its index (SI), position, diameter and penetrating direction of the nutrient canal (NC) in the femur and tibia of German shepherd dogs. The femur often had more than two NF on the caudal surface with 30.0 to 86.7% of SI. The proximal NF of the femur was regarded to be the major NF, because it was present in most dogs and had the largest diameter. The tibia always had only one NF with 23.2 to 38.3% of SI on the lateral border. Their direction of the NC followed Bérard's rule with the exception of the proximal NF of the femur. These results describe the anatomical condition of the NF and NC in the dog.

Measurement of the patellar tendon-tibial plateau angle and tuberosity advancement in dogs with cranial cruciate ligament rupture

To (i) compare agreement of the common tangent (CT) and tibial plateau angle (TP) methods in terms of measuring the patellar tendon angle (PTA) and required advancement and (ii) determine the intra- and inter-observer reliability of observers who measured PTA and the advancement. Six observers were divided into three groups based on their level of experience. They measured the PTA and the required advancement on 43 radiographic images of the tibiae of dogs affected by cranial cruciate ligament rupture. Each observer repeated the measurements three times with each method. The inter-technique (interT), intra-observer (intraO), and interobserver (interO) reliabilities were evaluated, assessed by calculating the intraclass correlation coefficient (ICC), and represented by Jones plots. The agreement between PTA-CT and PTA-TP was low (the ICC interT values ranged from 0.11 to 0.4). The PTA-CT was associated with moderate intra-observer reliability (ICC intraO, CT = 0.61) and poor interobserver reliability (ICC interO, CT = 0.33). The PTA-TP was associated with good intra-observer reliability (ICC intraO, TP = 0.75) and moderate interobserver reliability (ICC interO, TP = 0.59). Interobserver reliability did not depend on the level of experience. The advancement measurements were associated with reliability results similar to those obtained for PTA. Jones' plots showed that the CT method consistently yielded lower PTA and advancement values than the TP method. Given its poor reliability, the CT method is not recommended.

The use of bovine screws to promote bone formation using a tibia model in dogs

The objective of this study was to evaluate the use of a unique resorbable bovine bone screw to stimulate bone formation. Bovine bone screws were inserted in the tibia of beagle dogs. Each animal received 8 screws, divided into groups A (screws + no membranes), B (screws + titanium reinforced membranes), and C (bone defects treated with autogenous bone grafts). Animals were killed at 2, 4, and 6 months. New bone was measured with a periodontal probe and reported an average of 7.4 mm in vertical bone gain for group B, 3.6 mm for group A, and 1.7 mm for group C. Submission to Kruskal-Wallis test showed statistical differences among groups (P < .05). Histologic examination revealed an intimate contact between the newly formed bone and the resorbing bone screws. We conclude that bovine bone screws provide an environment for new bone formation and thus may provide an alternative therapy for enhancing bone formation vertically, including for regenerative procedures as well as before implant therapy.

&lt;i&gt;In Vivo&lt;/i&gt; Behaviour of the Synthetic Porous Hydroxyapatite Prepared by Low Temperature Microwave Processing and Comparison with Deproteinized Bovine Bone

The aim of this study was to evaluate the osteoconductive properties of synthetic porous hydroxyapatite prepared by low-temperature microwave processing OssaBase® HA (SPHA) in comparison with biological apatite, non-sintered deproteinized bovine bone Bio-Oss® (DBB). The materials were implanted into the bone sockets of the tibia of Beagle dogs for 3 and 6 months. The bone response to granules of the materials of similar sizes was compared. Histological analysis of the specimens with histomorphometry was performed at different times after in vivo implantation. Based on the histological analysis, the level of bone formation in the spaces between the implanted granules and through the interconnected pores of both implanted materials within a cortical region was significantly higher (bone area ingrowth 72–85%) than within a cancellous bone site (bone area ingrowth 16–28%) at three and six months after implantation. According to our study, the bioactive and osteoconductive properties (bone implant contact and bone area ingrown) of the synthetic porous hydroxyapatite are very high and comparable with the biological apatite, non-sintered deproteinized bovine bone. The favourable influence of the high specific surface area and carbonate content of the synthetic, porous hydroxyapatite on bone formation was confirmed.

Radiographic Quantitative Assessment of Caudal Proximal Tibial Angulation in 100 Dogs with Cranial Cruciate Ligament Rupture

To evaluate inter- and intraobserver variability in the measurement of distal tibial axis/proximal tibial axis angle (DPA) from lateral radiographs of canine tibia in dogs with cranial cruciate ligament rupture (CCLR). Retrospective clinical study. Dogs (n=100) with cranial cruciate ligament rupture. Medical records of dogs diagnosed with CCLR were reviewed. In addition to signalment and TPA measurements, measured DPA (mDPA) was calculated for each lateral view of the tibia in each animal, twice, by 3 blinded observers. Subjective scoring of DPA (sDPA) was also recorded, twice, by 3 additional blinded observers from lateral views of the proximal half of the tibia in each dog. Inter- and intraobserver variability was measured by intraclass correlation coefficient (ICC) for each measurement. Correlation between mDPA and sDPA was also determined. Median tibial plateau angle (TPA) of the subject population was 27.9° (range 18.8-41.3°; IQR: 25.5-30.75°). Mean ± SD mDPA was 6.50 ± 2.81° (confidence intervals [CI]: 5.94-7.06°; range 0-13.33°). There was no correlation between age and weight of dogs and the mDPA (P=.58 and .12). There was a moderate correlation between mDPA and TPA (r(2)=0.49, P<.0001). There was a moderate correlation between sDPA and mDPA (r(2)=0.27, P<.0001). Good inter- and intraobserver agreement was found in the measurement of mDPA. mDPA is a reproducible measurement of caudal angulation of proximal tibia. Furthermore, mDPA of dogs with cranial cruciate ligament disease in this report are in concordance with previous reports.

Bone mineral apposition rates at early implantation times around differently prepared titanium surfaces: a study in beagle dogs

This study evaluated the bone mineral apposition rate (MAR) at the bone-implant interface region of alumina-blasted/acid-etched (AB/AE), plasma-sprayed hydroxyapatite (PSHA), and nanometric-scale bioceramic-coated surfaces at early implantation times in a dog tibia model.Implants (n = 12 per group) with three different surfaces-AB/AE, PSHA, and a bioceramic coating in the 300- to 500-nm thickness range-were placed bilaterally along the proximal tibiae of six male beagles. Implants remained for 3 and 5 weeks in vivo. Ten and 2 days prior to euthanization, calcein green and oxytetracycline were administered for bone labeling. Following euthanization, the limbs were retrieved by sharp dissection and the implants and bone were processed nondecalcified into ~30-Μm-thick sections along the implant long axis. MAR was measured by the distance between bone labels over time at the interface region (to 0.5 mm from the implant surface) and at regions > 3 mm from the implant surface (remote site). A generalized linear mixed-effects analysis of variance model was conducted with significance levels set at .05.Irrespective of implant surface, the MAR at the interface region was significantly higher than the MAR at the remote site. Significant MAR differences in the interface region were observed between the different surfaces (PSHA > AB/AE > nano).Bone kinetics during early healing stages were influenced by implant surface modifications.

Scanning electron microscopy observation of the growth of osteoblasts on Ti-24Nb-4Zr-8Sn modified by micro-arc oxidation and alkali-heat treatment and implant-bone interface

To observe the efficacy of micro-arc oxidation and alkali-heat treatment (MAH) on Ti-24Nb-4Zr-8Sn (Ti2448). Disks (diameter of 14.5 mm, thickness of 1 mm) and cylinders (diameter of 3 mm, height of 10 mm) were fabricated from Ti2448 alloy. Samples were divided into three groups: polished (Ti2448), micro-arc oxidation(MAO-Ti2448), micro-arc oxidation and alkali-heat treatment (MAH-Ti2448). MC3T3-E1 osteoblastic cells were cultured on the disks and cell morphology was observed with scanning electron microscopy (SEM) aftre 3 days. The cylinder samples were implanted in the tibia of dogs and implant-bone interface was observed with SEM after 3 months. A rough and porous structure was shown in both MAO and MAH group. The MC3T3-E1 cells on the MAH-Ti2448 discs spread fully in intimate contact with the underlying coarse surface through active cytoskeletal extentions. Osseointegration was formed in the implant-bone interface in MAH samples. MAH treatment can provide a more advantageous Ti2448 surface to osteoblastic cells than MAO treatment does, and the former can improve the implant-bone integration.

Histomorphologic and Bone-to-Implant Contact Evaluation of Dual Acid-Etched and Bioceramic Grit-Blasted Implant Surfaces: An Experimental Study in Dogs

The objective of this study was to histologically evaluate a bioceramic grit-blasted and acid-etched surface (presenting calcium and phosphorous incorporation within the surface and its oxide) versus a dual acid-etched (no calcium and phosphorous, control) moderately rough implant surface in a dog tibia model. Implants 3 x 10 mm were placed bilaterally along the proximal tibia of 6 Doberman dogs and remained for 2 and 4 weeks in vivo. After the dogs were euthanized, the implants were nondecalcified processed to approximately 30-microm-thick plates. Transmitted light optical microscopy was used to evaluate healing patterns and bone-to-implant contact. Statistical analysis was performed by 1-way analysis of variance at the 95% level of significance and by Tukey post hoc tests. At 2 weeks, histologic evaluation showed woven bone formation throughout the perimeter of both implant surfaces. However, replacement of woven bone by lamellar bone was only observed around the test surface at 4 weeks in vivo. No significant differences in bone-to-implant contact were observed for the different groups (P > .27). Despite nonsignificant differences between bone-to-implant contact for the different surfaces and times in vivo, higher degrees of bone organization were observed for the test implants. Biomechanical testing is warranted to verify potential differences in biomechanical fixation effectiveness between surfaces.

Biomechanical and histomorphometric analysis of etched and non-etched resorbable blasting media processed implant surfaces: An experimental study in dogs

This study characterized the interplay between topography/chemistry and early bone response of etched and no-etched resorbable blasted media (RBM) processed surfaces. Screw-root form Ti–6Al–4V implants treated with alumina blasting/acid-etching (AB/AE), RBM alone (RBM), and RBM + acid-etching (RBMa) were evaluated. The surface was characterized by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Implants placed in the tibia of dogs remained 3 and 5 weeks in vivo. Following euthanasia, half of the specimens were torqued to interface failure and the remaining subjected to bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) between threads evaluation. The AB/AE surface was rougher than the RBM and RBMa. Higher levels of calcium and phosphorous were observed for the RBM surface compared to the RBMa. No significant differences were observed in torque, BIC, and BAFO between surfaces. Woven bone formation at 3 weeks and its initial replacement by lamellar bone at 5 weeks were observed around all implants’ surfaces.

Evaluation of Intra- and Interobserver Variability and Repeatability of Tibial Plateau Angle Measurements with Digital Radiography Using a Novel Digital Radiographic Program

To compare the intra- and interobserver variability occurring when observers with differing experience levels measure tibial plateau angles (TPAs) with a novel digital radiographic projection program (tibial plateau leveling osteotomy [TPLO] planning program), the Kodak Picture Archiving and Communications System (PACS), and standard sized printed films (SF). Cross-sectional study. Dogs (n=36) with cranial cruciate ligament (CCL) rupture that had a TPLO. Six observers, divided into 3 equal groups based on experience level, measured TPA on 36 digitally captured radiographic images of tibiae of dogs clinically affected with CCL rupture. Each observer used 3 methods of measuring TPA and repeated the measurements 3 times with each method. The intra- and interobserver variability was compared using the coefficient of variation. Averaged over all replications and images, there was no significant difference (P>.05) in the average variability occurring with each method for all but 1 observer. There was no effect of experience level on measurement variability; however, interobserver variability was significantly less with measurements made with the PACS and TPLO planning program compared with measurements made from SF (P<.05). Repeated measurements of TPA made using digital images and computer-based measurement programs were significantly less variable between observers than those made from images printed on standard radiographic films. Digital radiography and computer-based measurement programs are effective for determining the TPA, allowing less variability in measurements compared with SF. The ability to manipulate the image may allow better identification of anatomic landmarks.

The effect of platelet rich plasma in bone formation on implant installation in the tibia of beagle dogs

Introduction: The purpose of this study is to evaluate the effect of platelet rich plasma in bone formation and osseointegration of implant i nstalled in the bone marrow space. Materials and Methods: Five beagle dogs were used as experimental animals. Two implants were installed on each tibia in the dogs. Implants of the control group were installed with no additional graft. Those of the experimental group 1 were installed with autogenous bon e graft from the ilium autogenous bone. Platelet rich plasma (PRP) alone was used in experimental group 2 and the mixture of PRP and autogenous bone w as used in experimental group 3. The animals were sacrificed at 8 weeks after implantation. The parts of tibia containing implant were harvested and radiographs were taken for radiographic examination. The specimens were prepared for histological examination and histomorphometric analysis of implant-bone contact ratios. Results: 1. All implants showed sufficient osseointegration in the cortical bone radiographically and histologically, but osseointergrat ion in the marrow space was not satisfactory. 2. Histomorphometrically, the implant-bone contact ratios in the bone marrow was sequentially high in the experimental group 3 (autogenous bone + PRP group), group 1 (autogenous bone group), group 2 (PRP group), and control group (non-additive). 3. It was verified that there was statistical significance between two experimental groups (group 1 and 3) and the other groups (group 2 and control group). ( P<0.005) 4. However, there was no statistical significance between group 3 and group 1, also group 2 and control group respectively. Conclusion: These results suggest that platelet rich plasma is effective to osseointegration in the implant installation but there is no st atistical significance.

Mechanical testing of a modified stabilisation method for tibial tuberosity advancement

This in vitro study evaluated three modified techniques of tibial tuberosity advancement (TTA). Loads to failure were calculated for each technique. A 9 mm TTA procedure was performed in the tibiae of dogs weighing between 32 and 38 kg. In group 1 (n = 12), the distal part of the tibial crest was left attached to the tibia by the cranial cortex, and a figure-of-eight wire was added for stabilisation. In group 2 (n = 12), the tibial crest was left attached but no additional device was used for stabilisation. In group 3 (n = 12), the tibial crest was completely separated from the tibia and fixed by a figure-of-eight wire so that, in this group, only the wire opposed avulsion of the tibial crest. Unidirectional axial force was applied via the patella to determine the maximal load to failure of the model. There was no significant difference between group 1 and group 2. These two groups both had a significantly stronger construct than that of group 3. We described modifications to the TTA procedure without plate fixation that warrant clinical investigation. When the crest is broken during its advancement, the tension sustained by the repair is significantly weaker from a biomechanical point of view and the use of such a repair clinically is not recommended by the authors.

1014 イヌ脛骨巨大離断欠損部再生における水酸アパタイト/コラーゲン骨類似ナノ複合体の気孔率の影響(OS13-(4)オーガナイズドセッション《生体医工学及びバイオマテリアル》)

Bone is a typical nanocomposite composed of hydroxyapatite nanocrystals and type-I collagen molecules. That nanostructure realizes biochemical and biomechanical properties of bone. The authors had been reported synthesis of bone-like hydroxyapatite/collagen nanocomposite (HAp/Col) and incorporation of HAp/Col into bone remodeling metabolism. In this paper, the authors report influence of porosity of HAp/Col on regeneration of critical tibia defect of bone. High (H) and low (L) porosity unidirectional porous HAp/Col and core-shell type (C) HAp/Col were prepared from the HAp/Col membrane. Three kinds of HAp/Col were implanted into dog tibia segmental defect of 20 mm in length. After 12 weeks, 90%, 109% and 121% of defect were filled with new bone by H, L and C HAp/Col, respectively. The C-type HAp/Col is expected to be high performance artificial bone to regenerate large bone defect without cells.