OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
The primary results of five patients in whomthe block hydroxyapatite artificial bone (BHAB)used in maxillofacial plastic repair were reported. All incisions healed up with no evidence ofinfection. None of the implants was rejected norhad resorption changes. Satisfactory estheticaleffects were maintained. The results demonst-rated BHAB had a good biocampatibility andcould be used as a bone graft substitute inmaxillofacial plastic repair. This kind of material could be carved and contoured ...
Objective
To evaluate the biomechanical stability of a newly-designed Y type pedicle screw (YPS) in osteoporotic synthetic bone.
Methods
The osteoporotic synthetic bone were randomly divided into 3 groups (n=20). A pilot hole, 3.0 mm in diameter and 30.0 mm in deep, was prepared in these bones with the same method. The YPS, expansive pedicle screw (EPS), and bone cement-injectable cannulated pedicle screw (CICPS) were inserted into these synthetic bone through the pilot hole prepared. X-ray film examination was performed after 12 hours; the biomechanical stability of YPS, EPS, and CICPS groups was tested by the universal testing machine (E10000). The test items included the maximum axial pullout force, the maximum running torque, and the maximum periodical anti-bending.
Results
X-ray examination showed that in YPS group, the main screw and the core pin were wrapped around the polyurethane material, the core pin was formed from the lower 1/3 of the main screw and formed an angle of 15° with the main screw, and the lowest point of the inserted middle core pin was positioned at the same level with the main screw; in EPS group, the tip of EPS expanded markedly and formed a claw-like structure; in CICPS group, the bone cement was mainly distributed in the front of the screw and was dispersed in the trabecular bone to form a stable screw-bone cement-trabecular complex. The maximum axial pullout force of YPS, EPS, and CICPS groups was (98.43±8.26), (77.41±11.41), and (186.43±23.23) N, respectively; the maximum running torque was (1.42±0.33), (0.96±0.37), and (2.27±0.39) N/m, respectively; and the maximum periodical anti-bending was (67.49±3.02), (66.03±2.88), and (143.48±4.73) N, respectively. The above indexes in CICPS group were significantly higher than those in YPS group and EPS group (P<0.05); the maximum axial pullout force and the maximum running torque in YPS group were significantly higher than those in EPS group (P<0.05), but there was no significant difference in the maximum periodical anti-bending between YPS group and EPS group (P>0.05).
Conclusion
Compared with EPS, YPS can effectively enhance the maximum axial pullout force and maximum rotation force in the module, which provides a new idea for the design of screws and the choice of different fixation methods under the condition of osteoporosis.
Artificial bone replacement has made an important contribution to safeguard human health and improve the quality of life. The application requirements of rapid prototyping technology based on reverse engineering in individualized artificial bone with individual differences are particularly urgent. This paper reviewed the current research and applications of rapid prototyping and reverse engineering in artificial bone. The research developments and the outlook of bone kinematics and dynamics simulation are also introduced.
OBJECTIVE To improve the osteoinduction of coral and provide a perfect bone graft substitute for clinical bone defects. METHODS By combining coral with collagen and recombinant human bone morphogenetic protein-2(rhBMP-2), coral/collagen/rhBMP-2 composite was obtained. The composite was implanted into the back muscle pouches of mice, and coral/collagen or coral/rhBMP-2 were implanted as control. The osteoinduction of the composite was assessed by histology and image analysis system. RESULTS The chondrocyte differentiation and matrix formation were observed in local sites after one week, lamellar bone with bone marrow were formed after 4 weeks, and coral were absorbed partially. The quantity of osteoinduction was time-related and rhBMP-2 dose-related(P lt; 0.01). Coral/collagen and coral/rhBMP-2 implants did not show any bone or cartilage formation. CONCLUSION The coral/collagen/rhBMP-2 composite possesses a superior osteoinduction and will be a new type of bone substitute to be used in orthopedic and maxillofacial surgery.
ObjectiveTo investigate the mechanism of early vascularization of the tissue engineered bone in the treatment of rabbit radial bone defect by local injection of angiopoietin 2 (Ang-2).MethodsForty-eight New Zealand white rabbits were established unilateral 1.5 cm long radius defect models. After implantation of hydroxyapatite/collagen scaffolds in bone defects, the rabbits were randomly divided into 2 groups: control group (group A) and Ang-2 group (group B) were daily injected with 1 mL normal saline and 1 mL saline-soluble 400 ng/mL Ang-2 at the bone defect within 2 weeks after operation, respectively. Western blot was used to detect the expressions of autophagy related protein [microtubule associated protein 1 light chain 3 (LC3), Beclin-1], angiogenesis related protein [vascular endothelial growth factor (VEGF)], and autophagy degradable substrate protein (SQSTMl/p62) in callus. X-ray films examination and Lane-Sandhu X-ray scoring were performed to evaluate the bone defect repair at 4, 8, and 12 weeks after operation. The rabbits were sacrificed at 12 weeks after operation for gross observation, and the angiogenesis of bone defect area was observed by HE staining.ResultsWestern blot assay showed that the relative expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1, and VEGF in group B were significantly higher than those in group A, and the relative expression of SQSTMl/p62 was significantly lower than that in group A (P<0.05). Radiographic and gross observation of specimens showed that only a few callus were formed in group A, the bone defect was not repaired; more callus were formed and complete repair of bone defect was observed in group B. The Lane-Sandhu scores in group B were significantly higher than those in group A at 4, 8, and 12 weeks after operation (P<0.05). HE staining showed that the Harvard tubes in group B were well arranged and the number of new vessels was significantly higher than that in group A (t=–11.879, P=0.000).ConclusionLocal injection of appropriate concentration of Ang-2 may promote early vascularization and bone defect repair of tissue engineered bone in rabbits by enhancing autophagy.
To evaluate the initial cl inical effect of the autologous bone marrow integrating artificial bone and il ium periosteum transplantation in treatment of problematic nonunion. Methods From January 2004 to July 2006, 12 patients (13 l imbs)with problematic nonunion were treated with autologous bone marrow integrating artificial bone and il iumperiosteum. There were 8 males and 4 females, aged 17-58 years old. The position of nonunion were the tibia in 7 l imbs, the femur in 3 l imbs, the humerus in 2 l imbs. The operated number was 1-4, mean 2.5. The time from injury to therapy was 13 months to 9 years, mean 47.6 months. The bone defect distance was 6-30 mm (mean 15 mm) through 1 ∶ 1 X-rays before operation. Eleven l imbs were treated by internal fixation (10 l imbs by the bone nail and 1 l imb by the l imited contact-dynamic compression plate), 2 l imbs were treated by the external fixation. The X-ray films were taken at 1 day, 1, 3, 6, 9, 12 months after operation to observe fracture union. Results All patients were followed up for 12-26 months (mean 17.5 months) and achieved union within 4-7 months (mean 6 months). No deformity of rotation, angulation and crispation occurred in 13 l imbs, but functional impairment occurred in 6 l imbs after union of fracture. Conclusion Autologous bone marrow integrating artificial bone and il ium periosteum transplantation for treatment of problematic nonunion has the satisfactory result.
There is a great hope to treat long bone defects with bioactive artificial bone constructed by osteoblasts and biomaterials, in which the key point is to provide an optimum environment for the normal function of osteoblasts. The cellular sociological characteristics of osteoblasts were summarized and it was suggested that the ideal bioactive artificial bone should be composed of inorganic and organic materials together with cellular components such as osteoblasts and vascular endothelial cells, and combined with control release of growth factors, following its implantation it could be vascularized very soon and merged with the host bone by bony consolidation.
The hydroxyapatite particles were used to repair 23 cases of depressed deformities of face. The patients were follwed up for 3 to 8 months and the short termresults were satisfactory. The operative procedure was briefly introduced. The advantages and attentions relevant to the operation were discussed.
Objective To study the effect and complication of repairing depressed fracture of frontal part with hydroxylapatite particulate artificial bone. Methods From January 1994 to December 2002, 13 patients were all diagnosed as having depressed fracture of frontal part with clinical and X-ray examinations. Thesmall incision before the hair-edge or local small incision was made. After opening the incision, we performed creeping decollement. Then the hydroxylapatite particulate artificial bone was implanted into the sites of the depressed fracture. The effect and complication were observed with clinical and X-rayexaminations in all patients 1 week, 1 month, 3 months after operation.Results The quantity of hydroxylapatite implanted was 10-30g. Primary healing was obtained in all cases without any complication. All cases were followed up for 3 months. The contours of the frontal part were restored well. Conclusion It is a good method to repair depressed fracture of frontal part with hydroxylapatite particulate artificial bone.
