Objective To investigate the clinical application of self-settingcalcium phosphate cement (CPC) in bone defect repair of extremities. Methods From May 1998 to January 2000, 32 cases of bone defect, in 36 sites, were repairedand reviewed, aged from 4 to 59 years old (24.7 years old on average), with bone defect 2 to 125 cm2 in size (13.1 cm2 on average). The causes of the bone defect werefracture, bone cyst, iliac bone harvesting, fibrous dysplasia, enchondroma and bone tuberculosis, which involved femur, iliac, tibia, humerus, phalanx, fibula, calcaneus, talus and acetabulum. All of the cases were followed up for 1 to 23 months, 15.3 months on average, before radiographic examination. Results All operations were successful and no general response was observed in all of the cases. X-ray examination showed an integrity interface between CPC and bone. And CT showed no gap existed. There was no increase of serum calcium and phosphate levels. Conclusion CPC is applicable in the low- or non-weight-bearing site of the extremities.
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.
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.
Objective To study in vitro sustained release behaviour of the recombinant human bone morphogenetic protein 2(rhBMP-2) from the sample which porous calcium phosphate cement (PCPC) was combined with rhBMP-2, and to evaluate the effect of PCPC/rhBMP-2 composite on repairing bone defect in the animalstudy.Methods rhBMP-2 was absorbed into PCPC by vacuum-adsorption and freeze-dried at -40℃, the PCPC/rhBMP-2 enwrapped with chitosan as the experimental group, the pure PCPC/rhBMP-2 as the control group, then the sustained release ofrhBMP-2 from PCPC was determined in simulated body fluid (SBF) by UV-VIS spectrophotometer. At same time, the PCPC/rhBMP-2 composites with chitosan were implanted into the (4.2 mm×5.0 mm femora defects of rabbits, which were considered as the experimental group, whereas in the control group only PCPC was implanted. The effect of repairingbone defect was evaluated in the 4th and 8th week postoperatively by radiograph and histomorphology.Results The PCPC have a high absorption efficiency to rhBMP-2, and the release of rhBMP-2 was sustained release system. The release of rhBMP-2 from PCPC in the experimental group (99% after 350 hours) was slowerthan that in the control group (100% after 150 hours). In the experimental group, the radiological and histomorphological evaluations showed that theinterfaces between the materials and host bones became blurred both at 4th and 8th week. The implanted materials were partially absorbed, and the implanted areas exhibited the formation of new bone. In the control group, a little amount of new bones was observed. Conclusion The PCPC shows great clinical potential as a carrier for rhBMP-2. The PCPC/rhBMP-2 composite possesses much potentialities of osteoinductivity and the ability of repairing bone defect, so it can be used as a novel bone substitute clinically.
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.
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.
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 evluate the clinical outcome of autograftsof ilium and interbody fusion cage or bone morphogenetic protein(BMP)／artificial bone material／ cage in treating lumbar spondylolisthesis. Methods From January 1997 to January 2004，114 patients with lumbar spondylolisthesis were treated with posterior lumbar interbody fusion and pedicle screw fixation． There were 45 males and 69 females with an average age of 43 years ranging from 32 to 61 years. Of 114patients, 85 cases were classified as degree Ⅰ, 24 cases as degree Ⅱ and 5 cases as degree Ⅲ. The patients were divided into three groups accordingto the material used for interbody fusion: autografts of ilium (group A, n=42), interbody fusion cages(group B, n=36), and BMP／artificial bone material／ cage (group C, n=36)．The clinical and radiographic results of the patients were compared among three groups． Results All patients were followed from 13 to 30 months with an average of 15 months． There were no statistically significant differences in surgical time, blood loss, and disc space height of preoperation(P＞0.05) among three groups. No severe complication occurred in the three groups(P＞0.05). The excellent and good rates in groups A，B and C were 81.0％, 80.6％, and 83.3％ respectively, showing no statisticallysignificant difference(P＞0.05)．The fusion rate of group C(97.0%) was significantly higher than those of group A(81.0%) and group B(83.3%) (P＜0.05) after 1 year of operation．And the average loss of disc space height in groups B and C was significantly lower than that in group A(P＜0.05). Conclusion Higher fusion rate and lower loss of disc space height can beobtained in treating lumbar spondylolisthesis with BMP／artificial bone materiel.It is an effective method in the treatment of spondylolisthesis.