Defects In Dogs Research Articles

Anatomic, histopathologic, and echocardiographic features in a dog with an atypical pulmonary valve stenosis with a fibrous band of tissue and a patent ductus arteriosus

BackgroundCongenital pulmonary valve stenosis and patent ductus arteriosus are common congenital heart defects in dogs. However, concurrence of atypical pulmonary valve stenosis and patent ductus arteriosus is uncommon. This report describes the anatomic, histopathologic, and echocardiographic features in a dog with concomitant pulmonary valve stenosis and patent ductus arteriosus with atypical pulmonary valve dysplasia that included a fibrous band of tissue.Case presentationA 1.5-year-old intact female Chihuahua dog weighing 3.3 kg presented with a continuous grade VI cardiac murmur, poor exercise tolerance, and an intermittent cough. Echocardiography indicated pulmonary valve stenosis, a thickened dysplastic valve without annular hypoplasia, and a type IIA patent ductus arteriosus. The pulmonary valve was thick line-shaped in systole and dome-shaped towards the right ventricular outflow tract in diastole. The dog suffered a fatal cardiac arrest during an attempted balloon pulmonary valvuloplasty. Necropsy revealed pulmonary valve dysplasia, commissural fusion, and incomplete opening and closing of the pulmonary valve because of a fibrous band of tissue causing adhesion between the right ventricular outflow tract and the dysplastic intermediate cusp of the valve.ConclusionsA fibrous band of tissue between the right ventricular outflow track and the pulmonary valve should be considered as a cause of pulmonary valve stenosis. Pulmonary valve stenosis and patent ductus arteriosus can have conflicting effects on diastolic and systolic dysfunction, respectively. Therefore, beta-blockers should always be used carefully, particularly in patients with a heart defect where there is concern about left ventricular systolic function.

Osteoprogenitor cells can enhance early bone formation in critical bone defects in dogs

ABSTRACT: The aim of this study was to evaluate the effect of osteoprogenitor cells derived from mesenchymal stem cells from adipose tissue (OC-AD-MSCs), and differentiated into osteoblasts, in the treatment of critical bone defects in dogs. Adipose tissue derived mesenchymal stem cells (AD-MSCs) were subjected to osteogenic differentiation for 21 days and used in the treatment of bone defects in dogs radius. Either three experimental groups were bone defects treated with OC-AD-MSCs (OC), defects filled with autogenous bone (Control- C +), or empty defects (Control- C -). Bone regeneration was assessed by radiology, densitometry, and histomorphometry. The area of new bone formation was higher in the OC group compared to the control group (C-) on postoperative day 15. Defects treated with OC-AD-MSCs showed greater neovascularization than the other two groups at 90 days. We concluded that treatment with OC-AD-MSCs increased the area of new bone formation 15 days after surgery; however, it didn’t complete the bone union in critical bone defects in the radius of dogs at 90 days.

Effects of topically applied heterologous serum on reepithelialization rate of superficial chronic corneal epithelial defects in dogs.

OBJECTIVE To assess the effects of topical application of undiluted heterologous serum on time to corneal reepithelialization in dogs with superficial chronic corneal epithelial defects (SCCEDs). DESIGN Multicenter, randomized, double-masked, controlled clinical trial. ANIMALS 41 client-owned dogs. PROCEDURES After collection of baseline clinical and historical data, dogs were randomly assigned to receive topically applied undiluted heterologous serum (n = 22) or isotonic saline (0.9% NaCl) solution (19) along with tobramycin and atropine. Epithelial debridement (at all visits) and grid keratotomy (at visits 2, 3, and 4) of SCCEDs were performed. Ophthalmic examination including fluorescein application was performed once weekly for 4 weeks or until corneal reepithelialization. Clinicians and owners were masked to treatment group. RESULTS No differences in baseline data were detected between treatment groups. No difficulties with medication administration, noncompliance, or adverse reactions were noted. All SCCEDs in both groups healed by 4 weeks after treatment began. Median time to reepithelialization (2 weeks) was not significantly different between serum-treated and placebo-treated eyes. Irrespective of treatment group, median time to reepithelialization was not significantly different for Boxers versus non-Boxer breeds. Direct correlations were detected between time to reepithelialization and vascularization score at study entry, vascularization score at time of reepithelialization, and ulcer area at study entry in both groups. Time to reepithelialization was not correlated with age, sex, or duration of signs in either group. CONCLUSIONS AND CLINICAL RELEVANCE Topical application of undiluted heterologous serum was well tolerated by dogs with SCCEDs but, as an adjunct to standard treatment, did not reduce time to corneal reepithelialization.

Congenital heart defects in dogs: A retrospective study of 301 dogs

The aim of the study was to assess the frequency of congenital heart defects in a population of dogs in Poland and to determine which breeds were affected by particular defects. A retrospective study of the medical records of cardiologically examined dogs revealed 301 cases of echocardiographically confirmed congenital heart defects. Dogs with congenital heart defects made up 2.7% of the dogs that underwent a cardiologic examination. The age at diagnosis ranged from 2 weeks to 190 months. Mixed breeds (33 dogs, 11%), Bull Terriers (31, 10%), Boxers (28, 9%), German Shepherds (17, 6%), Yorkshire Terriers (17, 6%), and French Bulldogs (16, 5%) were the most frequently affected breeds. Subaortic stenosis (120 cases, 33.9%), pulmonic stenosis (64, 18.1%), patent ductus arteriosus (59, 16.7%), mitral valve dysplasia (56, 15.8%), ventricular septal defect (24, 6.8%) and tricuspid valve dysplasia (17, 4.8%) were the most frequent congenital heart defects recognized in this study. Isolated congenital heart disease occurred in 258 dogs (86%), while multiple heart defects were noted in 43 dogs (14%). Most (60%) congenital heart defects were recognized in dogs older than 1 year. Early recognition of congenital heart defects is important for better patient care. Collecting information on the frequency of congenital heart defects in particular breeds will be useful in educating breeders and thus in improving the overall health of the breed.

Periodontal wound healing following reciprocal autologous root transplantation in class III furcation defects.

PurposeFurcation involvement in the molars is difficult to treat, and has been recognized as a risk factor for tooth loss. Although periodontal regenerative therapies, including guided tissue regeneration and various types of bone grafts, have been applied to furcation defects, the effects of these treatments are limited, especially in large class III furcation defects. The purpose of this pilot study was to investigate the effect of reciprocal autologous root transplantation on periodontal wound healing and regeneration in class III furcation defects in dogs.MethodsFurcation defects (7 mm wide and 6 mm high) were surgically created after root separation of the unilateral third and fourth premolars in 4 dogs. Eight furcation defects were randomized to receive either reciprocal autologous root transplantation (test) or no further treatment (control). In the test group, the mesial and distal roots were transplanted into the distal and mesial extraction sockets, respectively. The animals were sacrificed 10 weeks after surgery for histologic evaluation.ResultsThe healing pattern in the control group was characterized by extensive collapse of the flap and limited periodontal regeneration. New bone formation in the test group (3.56±0.57 mm) was significantly greater than in the control group (0.62±0.21 mm). Dense collagen fibers inserting into the residual cementum on the transplanted root surfaces were observed in the test group. Slight ankylosis was observed in 2 of the 4 specimens in the test group on the mesiodistal sides where the root-planed surfaces faced the existing bone. Root resorption (RR) was detected in both the control and test groups.ConclusionsWithin the limits of this study, it can be concluded that reciprocal autologous root transplantation was effective for bone regeneration in class III furcation defects in dogs. However, further studies are required to standardize the approach in order to prevent unwanted RR prior to clinical application.

Cutaneous Flaps for Closing Skin Defects in Dogs

Cutaneous flaps are used for closing wounds caused by traumatic accidents, oncological surgery (tumor removal), and burns (thermal, chemical, radiations). Skin grafting has the advantages of requiring just only one surgery for closing the defects once the wound bed is adequately prepared.The objective of the study was to describe and asses the eficiency of local cutaneous flaps for closing skin defects in dogs.Seven dogs underwent reconstruction of soft tissue wounds resulted from traumatic lesion or after large tumors removal. Skin defects were located on the trunk and limbs. Cutaneous local flaps(advancement and rotational) were created by surgical preparations and mobilization the full tickness skin fold to enabling closure of adjacent defects. After wound debridment or tumoral removal a very carefull atraumatic and aseptical preparation of the flaps were performed to preserve vascularization for adecquate blood supply.Cutaneous local flaps proved effective for closing large defects in all dogs. Partial marginal necrosis of a portion of the flap occurred in one dog because of procedure and technique errors, but the concurent remanent defects were adequate to primary closure. The wounds ultimately healed , without major complications.The skin local flaps(advancement and rotational) are a versatile technique that could be use in a variety of locations, depending on skin defects shape and localization. The clinical results are comparable with those reported for advanced reconstructive procedure.

Root coverage using porcine collagen matrix with fibroblast growth factor-2: a pilot study in dogs.

The aim of this study was to evaluate the effect of fibroblast growth factor-2 (FGF-2) in combination with porcine collagen matrix (CM) for coverage of gingival recession defects in dogs. In five male mongrel dogs, labial gingival recession defects were surgically created in the lower-third incisors bilaterally. The defects were randomly assigned to the CM/FGF-2 group (experimental) or the CM-only group (control). Standardized clinical photographs and silicone impressions were taken at 4 and 16weeks of healing to calculate the remaining recession area. The dogs were euthanized after 16weeks for histometric analysis. At 4weeks, the recession area of the CM/FGF-2 group was significantly smaller than that of the CM-only group (2.55±0.66 and 4.92±1.05mm2 , respectively, p=0.023), However, no significant difference was observed at 16weeks. Histometrically, the amount of newly formed cementum was larger in the CM/FGF-2 group than in the CM-only group at 16weeks (1.55±0.44 and 0.88±0.51mm, respectively, p=0.024). The combination of CM/FGF-2 may enhance the early wound healing and may promote cementum formation to a higher extent compared to the use of CM alone.

Retraction note: Histopathological features of bone regeneration in a canine segmental ulnar defect model

Today, finding an ideal biomaterial to treat the large bone defects, delayed unions and non-unions remains a challenge for orthopaedic surgeions and researchers. Several studies have been carried out on the subject of bone regeneration, each having its own advantages. The present study has been designed in vivo to evaluate the effects of cellular auto-transplantation of tail vertebrae on healing of experimental critical bone defect in a dog model. Six indigenous breeds of dog with 32 ± 3.6 kg average weight from both sexes (5 males and 1 female) received bilateral critical-sized ulnar segmental defects. After determining the health condition, divided to 2 groups: The Group I were kept as control I (n = 1) while in Group II (experimental group; n = 5) bioactive bone implants were inserted. The defects were implanted with either autogeneic coccygeal bone grafts in dogs with 3-4 cm diaphyseal defects in the ulna. Defects were stabilized with internal plate fixation, and the control defects were not stabilized. Animals were euthanized at 16 weeks and analyzed by histopathology. Histological evaluation of this new bone at sixteen weeks postoperatively revealed primarily lamellar bone, with the formation of new cortices and normal-appearing marrow elements. And also reformation cortical compartment and reconstitution of marrow space were observed at the graft-host interface together with graft resorption and necrosis responses. Finally, our data were consistent with the osteoconducting function of the tail autograft. Our results suggested that the tail vertebrae autograft seemed to be a new source of autogenous cortical bone in order to supporting segmental long bone defects in dogs. Furthermore, cellular autotransplantation was found to be a successful replacement for the tail vertebrae allograft bone at 3-4 cm segmental defects in the canine mid- ulna. Clinical application using graft expanders or bone autotransplantation should be used carefully and requires further investigation. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2028232688119271

Repair of segmental radial defects in dogs using tailor-made titanium mesh cages with plates combined with calcium phosphate granules and basic fibroblast growth factor-binding ion complex gel.

Repair of large segmental defects of long bones are a tremendous challenge that calls for a novel approach to supporting immediate weight bearing and bone regeneration. This study investigated the functional and biological characteristics of a combination of a tailor-made titanium mesh cage with a plate (tTMCP) with tetrapod-shaped alpha tricalcium phosphate granules (TB) and basic fibroblast growth factor (bFGF)-binding ion complex gel (f-IC gel) to repair 20-mm segmental radial defects in dogs. The defects were created surgically in 18 adult beagle dogs and treated by implantation of tTMCPs with TB with (TB-gel group) or without (TB group) f-IC gel. Each tTMCP fitted the defect well, and all dogs could bear weight on the affected limb immediately after surgery. Dogs were euthanized 4, 8 and 24weeks after implantation. Histomorphometry showed greater infiltration of new vessels and higher bone union rate in the TB-gel group than in the TB group. The lamellar bone volume and mineral apposition rate did not differ significantly between the groups, indicating that neovascularization may be the primary effect of f-IC gel on bone regeneration. This combination method which is tTMCP combined with TB and f-IC gel, would be useful for the treatment of segmental long bone defects.

Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog.

Objective:Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs.Methods:Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery.Result:FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed.Conclusion:FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization.

Quantitative Analysis of Interradicular Bone Regeneration after Use of Modified Perforated Collagen Membrane versus Occlusive Membrane in the Management of Grade II Furcation Defects in Dogs

Quantitative Analysis of Interradicular Bone Regeneration after Use of Modified Perforated Collagen Membrane versus Occlusive Membrane in the Management of Grade II Furcation Defects in Dogs

Epidemiology, presentation and population genetics of patent ductus arteriosus (PDA) in the Dutch Stabyhoun dog.

BackgroundPatent ductus arteriosus (PDA) is one of the most common congenital heart defects in dogs and is considered to be a complex, polygenic threshold trait for which a female sex predisposition has been described. Histological studies in dogs suggest that smooth muscle hypoplasia and asymmetry of the ductus tissue is the major cause of PDA. The Stabyhoun population is small and a predisposition for PDA has been suggested. The aims of this study were to describe the incidence, presentation from a clinical and histopathological perspective, and the population genetics of PDA in the Dutch Stabyhoun population.ResultsForty-six cases were identified between 2000 and 2013. Between 2009 and 2012 the birth incidence of PDA in the Stabyhoun breed was 1.05 %. We estimated this to be 7–13 times higher than expected in the general dog population. Twelve of the 46 cases were part of a litter in which more than one sibling was affected. There was no sex predilection in our case cohort. Dogs diagnosed in adulthood showed severe cardiomegaly. The mean inbreeding coefficient of the reference population of Stabyhoun dogs was 31.4 % and the actual and effective numbers of founders were 14 and 6.5, respectively. The heritability of PDA was 0.51 (±0.09) for the reference population and 0.41 (±0.10) for the phenotyped population. Histopathology of sections of the PDA from two dogs showed findings similar to those described in other breeds although the smooth muscle of the ductus adjacent to the pulmonary artery appeared more hypoplastic than that in the ductus adjacent to the aorta.ConclusionsThe Stabyhoun breed shows a strong predisposition for PDA. Apart from the absence of a higher incidence in females, no other significant features distinguish PDA in Stabyhouns from the condition in other dog breeds. Heritability and the mean inbreeding coefficient are both very high making the Dutch Stabyhoun breed particularly suited to the study of inherited risk factors for PDA.

Corneal grafting for the treatment of full-thickness corneal defects in dogs: a review of 50 cases.

To describe corneal grafting for the treatment of full-thickness corneal defects in dogs and to determine its effectiveness in preserving vision. A review of the medical records of dogs that underwent corneal grafting following corneal perforations (≥3 mm) at the VTH-UAB from 2002 to 2012 was carried out. Fifty dogs of different breed, age and gender were included. Brachycephalic breeds were overrepresented (37/50;74%). All cases were unilateral, with euryblepharon being the most common concurrent ocular abnormality (20/50;40%). Full-thickness penetrating keratoplasties (FTPK) were performed in 21/50 eyes (42%) and lamellar keratoplasties (LK) in 29/50 eyes (58%). Frozen grafts (FroG) were used in 43/50 eyes (86%) and fresh homologous grafts (FreHoG) in 7/50 (14%). Of the former group, 26 were homologous (FroHoG:60%) and 17 heterologous (FroHeG:40%). A combination of topical medication (antibiotics, corticosteroids, cycloplegics, and 0.2% cyclosporine A) and systemic mycophenolate mofetil was administered. Median follow-up time was 200 days. Postsurgical complications included wound dehiscence (6/50;12%) and glaucoma (4/50;8%). Clinical signs of graft rejection were diagnosed as follows: FroHoG (13/26;50%), FroHeG (11/17;65%), FreHoG (4/7;57%), FTPK (12/21;57%), and LK (16/29;55%). Medical treatment successfully controlled graft rejection in 11/28 eyes (39%). Good anatomical outcome was achieved in 86% (43/50), of which 95% (41/43) were visual at last examination, with moderate opacification to complete transparency of the graft present in 48.2%. Corneal grafting is an effective surgical treatment for full-thickness corneal defects in dogs. If graft rejection is present, additional medical or surgical therapy may be necessary, achieving a highly satisfactory visual outcome.

Echocardiographic Assessment of Cardiac Function by Conventional and Speckle-Tracking Echocardiography in Dogs with Patent Ductus Arteriosus.

BackgroundPatent ductus arteriosus (PDA) is one of the most common congenital heart defects in dogs. Advanced echocardiographic techniques such as speckle‐tracking echocardiography (STE) have not been extensively used to evaluate cardiac function in affected dogs.HypothesisAdvanced echocardiographic techniques are more sensitive than standard echocardiographic techniques in analyzing systolic function in dogs with PDA.AnimalsForty‐four client‐owned dogs: 34 dogs with PDA (preoperative evaluation) and 10 healthy sex‐ and weight‐matched controls.MethodsProspective study. Dogs were recruited over a 2‐year period. Complete echocardiographic evaluation was performed, including conventional (end‐diastolic volumes indexed to body surface area in B and M‐mode [EDVIB /M], end‐systolic volumes indexed to body surface area in B and M‐mode [ESVIB /M], allometric scaling in diastole and systole [AlloD/S], pulmonary flow to systemic flow [Qp/Qs], ejection fraction [EF] and fractional shortening [FS]) and speckle‐tracking echocardiography ([STE]: global longitudinal, radial and circumferential strain [S] and strain rate [SR]).ResultsDogs with PDA had significantly different EDVIB /M, ESVIB /M, AlloD/S, Qp/Qs and all STE‐derived parameters (global longitudinal S and SR, global circumferential S and SR, global radial S and SR)compared to healthy dogs. No correlation was found between standard techniques (EDVIB /M, ESVIB /M, AlloD/S, Qp/Qs) and STE‐derived parameters (global longitudinal, circumferential and radial S and SR).Conclusion and Clinical ImportanceConventional parameters routinely used to assess systolic function (EF and FS) were not different between the groups; STE‐derived parameters identified subtle changes in cardiac systolic function and contractility between the 2 groups of dogs. Based on these findings, STE may be a more appropriate tool to assess cardiac contractility in dogs with PDA.

Speckle-Tracking Echocardiography in Dogs With Patent Ductus Arteriosus: Effect of Percutaneous Closure on Cardiac Mechanics.

BackgroundPatent ductus arteriosus (PDA) is 1 of the most common congenital heart defects in dogs and percutaneous closure is effective in achieving ductal closure; PDA closure is associated with abrupt hemodynamic changes.HypothesisA marked decrease in standard parameters of systolic function as assessed by M‐ or B‐mode echocardiography after PDA closure was identified in previous studies. Speckle tracking echocardiography can provide further insight into the effect of PDA closure on cardiac mechanics in dogs affected by PDA.AnimalsTwenty‐five client‐owned dogs with PDA.MethodsProspective study. Dogs were recruited over a 2‐year period. Complete echocardiographic evaluation was performed before and 24 hours after PDA closure, including standard (end‐diastolic volumes indexed to body surface area in B‐ and M‐mode [EDVIB /M], end‐systolic volumes indexed to body surface area in B‐ and M‐mode [ESVIB /M], allometric scaling in diastole [AlloD] and systole [AlloS], pulmonary flow to systemic flow [Qs/Qp], ejection fraction [EF], and fractional shortening [FS]), and advanced speckle‐tracking echocardiography (STE): global longitudinal, radial, circumferential and transverse strain (S), and strain rate (SR).ResultsPatent ductus arteriosus closure was associated with statistically significant decreases in EDVIM /B and ESVIM /B, AlloD and AlloS, SI, EF, and FS. A statistically significant decrease in the absolute values of radial, transverse, and circumferential S and SR was observed, whereas longitudinal S and SR did not change significantly.Conclusion and Clinical ImportancePatent ductus arteriosus closure by percutaneous approach is associated with marked decreases of conventional echocardiographic parameters as a result of the changes in loading conditions, but no evidence of systolic dysfunction was identified by means of STE, as none of the S and SR values were below reference ranges. In the short term, contractility is enhanced in the long axis (long S/SR values were not statistically different before and after closure) and decreases to normal values in short axis (circumferential, radial, and transversal S/SR decreased to normal reference range).

Single-staged vs. two-staged implant placement in vertically deficient alveolar ridges using bone ring technique - Part 2: implant osseointegration.

The aim of this study was to evaluate the osseointegration of implants placed in a single-staged compared to two-staged procedure using bone ring technique. In this study were used standardized, vertical alveolar bone defects in dogs. In the test group, dental implants (Straumann BL® , Basel, Switzerland) were inserted simultaneously with bone ring technique. As control group served implants inserted 6months following grafting. Implants of both groups were left for an osseointegration period of 3 and 6months. The peri-implant bone loss and bone-to-implant contact within the bone ring and native bone were analyzed morphometrically. An explorative statistical analysis was performed. The peri-implant bone level remained relatively stable within groups and between groups per given time period. Most of bone apposite on the implant surface in two groups was composed of newly formed bone. A nonparametric analysis of variance (ANOVA) revealed no significant advantage for two-staged implant placement for new and total bone, except for residual bone (P=.0084). Furthermore, two groups of implants performed similarly in bone ring and in native bone throughout the observation period. In terms of osseointegration, both techniques are likely equally efficient in the present defect model. The single-staged implant placement with cortical bone grafts warrants further documentation in clinical studies.

Developmental Structural Tooth Defects in Dogs - Experience From Veterinary Dental Referral Practice and Review of the Literature.

Developmental tooth abnormalities in dogs are uncommon in general veterinary practice but understanding thereof is important for optimal management in order to maintain masticatory function through preservation of the dentition. The purpose of this review is to discuss clinical abnormalities of the enamel and general anatomy of dog teeth encountered in veterinary dental referral practice and described in the literature. More than 900 referral cases are seen annually between the two referral practices. The basis of the pathogenesis, resultant clinical appearance, and the principles of management for each anomaly will be described. Future research should be aimed toward a more detailed analysis of these conditions so rarely described in the literature.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future.

Comparison of Osteogenesis between Adipose-Derived Mesenchymal Stem Cells and Their Sheets on Poly-ε-Caprolactone/β-Tricalcium Phosphate Composite Scaffolds in Canine Bone Defects.

Multipotent mesenchymal stem cells (MSCs) and MSC sheets have effective potentials of bone regeneration. Composite polymer/ceramic scaffolds such as poly-ε-caprolactone (PCL)/β-tricalcium phosphate (β-TCP) are widely used to repair large bone defects. The present study investigated the in vitro osteogenic potential of canine adipose-derived MSCs (Ad-MSCs) and Ad-MSC sheets. Composite PCL/β-TCP scaffolds seeded with Ad-MSCs or wrapped with osteogenic Ad-MSC sheets (OCS) were also fabricated and their osteogenic potential was assessed following transplantation into critical-sized bone defects in dogs. The alkaline phosphatase (ALP) activity of osteogenic Ad-MSCs (O-MSCs) and OCS was significantly higher than that of undifferentiated Ad-MSCs (U-MSCs). The ALP, runt-related transcription factor 2, osteopontin, and bone morphogenetic protein 7 mRNA levels were upregulated in O-MSCs and OCS as compared to U-MSCs. In a segmental bone defect, the amount of newly formed bone was greater in PCL/β-TCP/OCS and PCL/β-TCP/O-MSCs/OCS than in the other groups. The OCS exhibit strong osteogenic capacity, and OCS combined with a PCL/β-TCP composite scaffold stimulated new bone formation in a critical-sized bone defect. These results suggest that the PCL/β-TCP/OCS composite has potential clinical applications in bone regeneration and can be used as an alternative treatment modality in bone tissue engineering.

Indications, outcome and complications with axial pattern skin flaps in dogs and cats: 73 cases.

To determine the indications, frequency of complications and long term outcome associated with axial pattern flaps used to repair wound defects in dogs and cats. Medical records from two independent referral centres for dogs and cats undergoing wound repair with an axial pattern flap were reviewed. Seventy-three animals were included, 49 dogs: 24 cats. Indications for axial pattern flaps were chronic wounds (43/73; 59%) and closure following tumour resection (30/73; 41%). Axial pattern flaps used were: thoracodorsal, caudal superficial epigastric, reverse saphenous conduit, superficial brachial, deep circumflex iliac, superficial cervical, caudal auricular, lateral thoracic, cranial superficial epigastric, genicular and superficial temporal. Postoperative complications occurred in 64 patients (89%) and 8 patients (11%) had no complications. Complications were: dehiscence, swelling of the flap, necrosis, infection, discharge and seroma. Flap outcome was excellent in 16 patients (23%), good in 29 (41%), fair in 21 (30%) and poor in 5 (7%). There is a high complication rate associated with axial pattern flaps but these are usually easily managed and long term outcome is excellent, in either species.