Coral is an osteoconductive material used as a bone graft extender and human platelet rich plasma has been used as a source of osteoinductive factor. A combination of human platelet rich plasma and coral is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of human platelet rich plasma and coral on osteogenesis in vivo using rabbit model of bone healing. A critical size defect of 10 mm elongation was created in the radial diaphysis of 36 rabbit and either supplied with coral-human PRP, or coral alone or left empty (control group). The platelets in the PRP were about 10.1 fold compared to normal blood. Radiographs of each forelimb was taken postoperatively on 1st day and then at the 2nd, 4th, 6th and 8th weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses were removed on 56th postoperative day and were grossly and histopathologically evaluated. In addition, biomechanical test was conducted on the operated and normal forearms of the rabbits. This study demonstrated that coral-human PRP (hPRP), could promote bone regeneration in critical size defects with a high regenerative capacity. The results of the present study demonstrated that coral-hPRP could be an attractive alternative for reconstruction of the major diaphyseal defects of the long bones in animal models.

Hydroxyapatite is an osteoconductive material used as a bone graft extender and exhibits excellent biocompatibility with soft tissues such as skin, muscle and gums, making it an ideal candidate for orthopedic and dental implants or components of implants. Synthetic hydroxyapatite has been widely used in repair of hard tissues, and common uses include bone repair, bone augmentation, as well as coating of implants or acting as fillers in bone or teeth. On the other hand, human platelet rich plasma (hPRP) has been used as a source of osteoinductive factor. A combination of hPRP and hydroxyapatite is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of hydroxyapatite and hPRP on osteogenesis in vivo, using rabbit model bone healing. A critical size defect of 10 mm long was created in the radial diaphysis of 36 rabbit and either supplied with hydroxyapatite-human PRP or hydroxyapatite or was left empty (control group). Radiographs of each forelimb were taken postoperatively on 1st day and then at the 2nd, 4th, 6th and 8th weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses of half of the animals in each group were removed on 56th postoperative day and were grossly and histopathologically evaluated. In addition, biomechanical test was conducted on the operated and normal forearms of the other half of the animals of each group. This study demonstrated that hydroxyapatite-humanPRP, could promote bone regeneration in critical size defects with a high regenerative capacity. The results of the present study demonstrated that hydroxyapatite-hPRP could be an attractive alternative for reconstruction of the major diaphyseal defects of the long bones in animal models.

BackgroundBone grafting is used to enhance healing in osteotomies, arthrodesis, and multifragmentary fractures and to replace bony loss resulting from neoplasia or cysts. They are source of osteoprogenitor cells and induce bone formation and provide mechanical support for vascular and bone ingrowth. Autografts are used commonly but quantity of harvested bone is limited. The aim of this study is to evaluate autograft and new xenogenic bovine demineralized bone matrix (DBM) effects on bone healing process.Materials and methodsTwenty male White New Zealand rabbits were used in this study. In group I (n = 10) the defect was filled by xenogenic DBM and in autograft group the defect was filled by fresh autogenous cortical graft and fixed by cercelage wire. Radiological, histopathological and biomechanical evaluations were performed blindly and results scored and analyzed statistically.ResultsStatistical tests did not reveal any significant differences between two groups on the 14th postoperative day radiographically (P > 0.05). There was a significant difference for union on 28th and 42nd postoperative days and for remodeling at on the 56th postoperative day radiologically (P < 0.05). Statistical tests did not support any significant differences between two groups for radiological bone formation (P > 0.05). Histopathological and biomechanical evaluation revealed no significant differences between two groups.ConclusionsThe results of this study indicate that satisfactory healing occurred in rabbit radius defect filled with xenogenic bovine DBM. Complications were not identified and healing was faster, same as in cortical autogenous grafting.

Bone grafting is used to enhance healing in osteotomies, arthrodesis, and multifragmentary fractures and to replace bony loss resulting from neoplasia or cysts. They are source of osteoprogenitor cells and induce bone formation and provide mechanical support for vascular and bone ingrowth. Autografts are used commonly but quantity of harvested bone is limit. This study was designed to evaluate fresh cortical autograft and allograft effects on bone healing process. Twenty male White New Zealand rabbits were used in this study. In autograft group the defect was filled by fresh autogenous cortical graft, in allograft group the defect was filled by a segment of fresh allogenous cortical bone which was harvested at the time of surgery during the creation of radius bone defect. Then all surface soft tissue, such as muscle attachments, were removed from the harvested bone and changed between rabbits as a fresh allogenous cortical bone graft and was fixed by cercelage wire. Radiological, histopathological and biomechanical evaluations were performed blindly and results scored and analyzed statistically. Statistical tests did not support significant differences between two groups at the 14th and 56th postoperative day radiographically (P > 0.05). There was a significant difference radiologically for the 28th and the 42nd postoperative (P < 0.05). Autograft was superior to allograft at the 28th and 42nd postoperative day in radiological evaluation (P < 0.03). Histopathological and biomechanical evaluation revealed no significant differences between two groups.

Caudal epidural anesthesia is commonly utilized in veterinary medicine to allow diagnostic, obstetrical, and surgical intervention, in the perineal region of large animal. The aim of this study is to directly compare the time of onset and duration of analgesia produced by a tramadol and lidocaine-tramadol combination with that produced by lidocaine administration in the epidural space of Cattle. Five healthy adult Holstein dairy cows were selected to this study. Epidural anesthesia was produced in all cows by lidocaine, with 2 weeks intervals repeated by a combination of lidocaine-tramadol and tramadol. Time to onset and duration of analgesia were recorded. Heart rate, respiratory rate and body temperature were recorded at 0 min and at 5, 10, 15, 30, 60, and 75 min after the epidural administrations of each treatments. The tramadol produced a significant (P < 0.05) longer duration of analgesia (306.8 ± 8.58 min) than lidocaine (69.40 ± 8.96 min) alone and lidocaine-tramadol combination (174 ± 4.84 min). Also, lidocaine-tramadol combination produced a significant (P < 0.05) longer duration of analgesia than lidocaine alone. Complete analgesia began at 14.10 ± 1.57 min in the tramadol treatment, being more delayed than in the treatments with lidocaine-tramadol (4.84 ± 0.68 min) and lidocaine (3.90 ± 0.89 min). Body temperatures, heart rates, and respiratory rates were not significantly different in comparison with baseline values throughout the study in the all treatments. The combination of lidocaine-tramadol produced anesthesia of longer duration than lidocaine and the onset time was approximately same as for the lidocaine group. Utilizing this combination, long duration of anesthesia could commence relatively soon after epidural injection and might be used without re-administration of anesthetic agent in long-duration obstetrical and surgical procedures.