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.
In order to evaluate coral as a bone graft substitute in repair of bone defect, particulates of coral were implanted into skull bone defect of rabbit, 1.5 cm in diameter. Hydroxyapatite and blank were taken as controls. The rabbits were sacrificed at the second, fourth, eighth and twelveth weeks after the operation. The specimens were taken and performed histological examination and histomorphometry observation. Results were as follows: at the second week many multinucleus giant cells infiltrated. As time elapsed, the coral were progressively degenerated and new bone was formed to fill the defect. Up to the twelveth week, the coral degenerated completely and new bone formed in the center of the defect. Percentage of new bone was in defect was 36.9%. Compared with the controls, there were significant differences (P lt; 0.01). It was suggested that coral had good osteoconductility. Howevel, coral underwent rapid degeneration, it might result in inconplete repair of bone defect.
Abstract To investigate the ectopic new bone formation following implantation of bovine hydroxyapatite Bio-oss together with free periosteum, 12 chabb: ch rabbits were selected. In 10 rabbits, Bio-oss block together with free periosteum was implanted in the gastrocnemius muscle of one leg randomly, and Bio-oss block alone was implanted in the same muscle of the other leg. In the other 2 rabbits, the periosteum was implanted into the gastrocnemius musle of both legs. Histologic examination and quantitative analysis of newbone formation were performed at 3 and 6 weeks postoperatively. The results showed that in the legs implanted bovine hydroxyapatite Bio-oss together with freeperiosteum, new bone formation began at 5th day after implantation. The area ofnew bone composed of 19.0% of the specimens at 3 weeks postoperatively. No boneformation through out the experimental period in Bio-oss block alone implantedlegs and also periosteum implanted legs. We concluded that bovine hydroxyapatite Bio-oss has a good capacity of osteoconduction. New bone can be formed after the implantation of hydroxyapatite combined with free periosteum.
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.
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.
Objective To investigate aesthetic outcomes and postoperative complications of hydroxyapatite particulate artificial bone for repairing sunken deformation of frontal bone following removal of dermoid cyst. Methods From February 2000 to May 2005, hydroxyapatite particulate artificial bone was used to repair the sunken deformation of frontal bone in 13 cases (9 males and 4 females), and the age of the patients was from 17 to 41 years. The dermoid cysts were all found during infant period, and the length and width of the cysts ranged from 6 cm×4 cm to 10 cm×8 cm. Anincision along the hairedge or tumor margin was made to excise the dermoid cyst in the forehead. After complete removal of dermoid cyst, the sunken frontal bone was examined and repaired with hydroxyapatite particulate artificial bone. The clinical checkup and Xray examination were utilized to determine aesthetic outcomes and postoperative complications at 1 week, 1 month and 6 months after operation. Results The primary wound healing was obtained in allpatients postoperatively, and no complications such as hematoma, infection, recurrence of dermoidcysts or displacement of hydroxyapatite particulate artificial bone were observed. With a followup from 1 to 20 months, all sunken deformations were completely repaired with satisfactorily aesthetic outcomes. Through clinical checkup and X-ray examination, the implants were found to integrate with the frontal bones without any gaps and displacement. Conclusion It is a simple and viable method torepair sunken deformation of frontal bone with hydroxyapatite particulate artificial bone.
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.
OBJECTIVE: To study the effect of self-setting calcium phosphate cement (CPC) on the repair of local bone defects after resection of cyst in children. METHODS: From December 1998 to May 2002, 22 patients with bone defects were repaired with CPC. Their ages ranged from 4 to 10 years with an average of 8.3 years. There were 11 cases of non-ossifying fibroma, 7 cases of osteoid osteoma, 2 cases of bone cyst and 2 cases of fibrous dysplasia. The bone defects are located as the following: femur in 14 cases, tibia in 6 cases and humerus in 2 cases. CPC spongiosa granules were filled in 11 cases, injectable CPC were filled in 2 bone cyst cases. The patients were followed up for 5-48 months, averaged 23.5 months. RESULTS: Bone matrix grew well and no recurrence was found. CONCLUSION: The method with simple CPC in repairing bone defects is safe, non-toxic, economic and convenient in children.
Objective To study the mechanism of ectopic osteogenesis of nacre/Polylactic acid (N/P) artificial bone combined with allogenic osteoblasts, and to explore the possibility as a scaffold material of bone tissue engineering. Methods The allogenic- osteoblasts seeded onto N/P artificial bone were co-cultured in vivo 1 week.The N/P artificial bone with allogenic osteoblasts were implanted subcutaneously into the left back sites of the New Zealand white rabbits in the experimental group and the simple N/P artificial bone into the right ones in the control group. The complexes were harvested and examined by gross observation, histologic analysis and immunohistochemical investigation 2, 4 and 8 weeks after implantation respectively.Results In experimental group, the osteoid formed after 4 weeks, and the mature bone tissue withbone medullary cavities formed after 8 weeks; but in control group there was nonew bone formation instead of abundant fibrous tissue after 4 weeks, and more fibrous tissue after 8 weeks.Conclusion N/P artificial bone can be used as an optical scaffold material of bone tissue engineering.