Objective To study the effect of vascular endothelial cell growth factor (VEGF) on repair of bone defect with cortical bone allograft. Methods Forty five New Zealand white rabbits, weighted 2.5-3.0 kg, were made bone defect model of 1.5 cm in length in the bilateral radii and then were randomly divided into 3groups. The defect was repaired with only cortical bone allograft in the control group, with the cortical bone allograft and local injection of human recombinantVEGF in the experimental group, and with the cortical bone allograft and abdominal injection of VEGF PAb3 in the antagonist group. Roentgenography, immunohistochemical staining and tetracycline labelling were carried out to evaluate the reparative results 1, 3, 5, 8 and 16 weeks after operation. Results Immunohistochemical staining results showed that a great deal of blood vessels formed in the experimental group, and the number of blood vessels increased gradually with the time and reached the highest value at the 8th week. Tetracyclinelabelling showed the same result.The best results in callus formation, ossification rate and count of microvascular density were shown in the experimental group, while those in the control group were significantly better than those in the antagonist group (Plt;0.05),but there was no significant difference between the experimental group and the control group at the 8th week and the 16th week (Pgt;0.05). Conclusion VEGF can accelerates the bone formation and angiogenesis in the bone allografts, thus it can promote the repair of bone defects.
Seven cases with bone tumor in upper limb were reported. Five cases were treated by using free vascularized fibular graft, 2 cases by using fusion between humorus and clavicle. A follow-up study of six patients showed that the graft bone was united within 3 months in 5 cases, in 6 months in one case. Partial function of upper limb in 6 patients have been restored.
Six cases of old fracture of the tibia with large sear, bony defect, and shortening deformity of the limb were treated by elongation osteotomy at epiphysis and compression fixation of the fracture with external semilunar fixation frame. The bony defect ranged from 3cm to 6cm. Bony healing developed in all patients 4-7 months after operation. Early postoperative movement was suggested. The results revealed that there was an obvious improvement of the joint function and the shortened legs were corrected. The advantages of this method are that there is no need of bone grafting and operative treatment of the scar prior to treatment of the bone.
Objective To investigate the cl inical efficacy of the cancellous granule-type calcium phosphate cement in repair bone defect. Methods Between July 2008 and July 2009, 35 patients (42 l imbs) with fractures, nonunion, and benign bone tumor were treated with cancellous granule-type calcium phosphate cement. There were 32 males and 3 females,with an age range from 9 to 73 years (median, 41 years), including 24 l imb fractures (19 cases), 4 osteotomy for deformity of ulna and radius (2 cases), 2 femur intertrochanteric bony cysts (2 cases), 3 enchondroma (3 cases), 5 bone defect at donor il ium (5 cases), 3 nonunion (3 cases), and 1 lumbar spinal stenosis (1 case). The size of bone defect was 1-5 cm. Bone defect was repaired with cancellous granule-type calcium phosphate cement (1-5 g). Results All cases were followed up 8-23 months (13.7 months on average). Thirty-nine incisions (32 cases) healed by first intention and the suture was removed after 10-14 days. Incision dehiscence occurred in 2 cases, and wounds healed after second debridement and removal of artificial bone. Exudation of incision occurred in 1 case, and wound healed after symptomatic treatment. No local red swell ing, higher temperature, maculopapule, and ulceration of skin occurred at implantation site. X-ray films showed that bone graft fusion was achieved and bone defect was radically repaired at 6 months after operation and artificial bone was absorbed completely at 12 months. Conclusion Cancellous granule-type calcium phosphate cement can be used as a new graft bone material, which is suitable for defect fill ing after traumatic fracture, benign bone tumors, and il iac bone donor.
OBJECTIVE To manufacture adriamycin-porous tricalcium phosphate (A-PTCP) ceramic drug delivery system (DDS) as a possible method for bone defect treatment after bone tumor operation. METHODS A-PTCP DDS was made from putting adriamycin into PTCP. Thirty rabbits were divided randomly into group A(24 rabbits) and group B(6 rabbits). A-PTCP was implanted in the greater trochanter of the right femur in group A. Adriamycin were injected into veins in group B. Muscle around A-PTCP and plasma were taken out at different period. Adriamycin concentrations in muscle and plasma were measured by high performance liquid chromatography (HPLC). RESULTS A-PTCP could gradually release adriamycin over 10 weeks. Adriamycin concentrations in the muscle were higher than that in plasma. CONCLUSION A-PTCP may be a new method for repairing bone defects after bone tumor operation.
OBJECTIVE To present a simple and reliable method for the reconstruction of metacarpophalangeal joint by the cartilage transplantation of metatarsophalangeal joint. METHODS From 1990, nine cases (11 sides) with traumatic metacarpophalangeal joint defect were treated by the autogenous cartilage transplantation of metatarsophalangeal joint followed by modified treatment. Appropriate biological mechanics was provided by internal fixation and collateral ligament repair. RESULTS Followed up 6 months to 7 years, the range of joint motion was increased 35.1 degrees. The fusion of donor phalanges was fine, and the range of joint motion was decreased, even ankylosis after plastic operation, but no pain and no effect on walk. CONCLUSION The key to successful operation is better matching of cartilage, reliable internal fixation, ligament reconstruction, thin cartilage and little bone of the donor, appropriate biological mechanical surroundings.
Objective To evaluate the effect of WO-1 on repair of the bone defect in the New Zealand rabbit radius by an oral or local administration. Methods Bone defects were surgically created in the bilateral radii of 36 Zealand rabbits (1.6-2.0 kg), which were randomly divided into3 groups. In Group A, the defective areas were given WO-1 0.1 ml (50 mg/ml) by the local injections; in Group B, the rabbits were given WO-1 5 mg each day by the oral administration. Group C was used as a control group. Among each of the 3 groups, 4 rabbits were randomly selected and were sacrificed at 20, 30 and 60 days after operation, respectively. Then, the serological, X-ray and histological examinations were performed. Results The serum alkaline phosphatase and bone glaprotein levels were significantly higher at 20 and 30 days after operation in Groups A and B than in Group C, but significantly lower at 60 days after operation in Groups A and B than in Group C（Plt;0.01）. The X-ray and histological examinations at 20, 30 and 60 days after operation revealed that the callus formation and remodeling were earlier in Groups A and B thanin Group C, and the remodeling was earlier and better in Group A than in Group B. Conclusion WO-1 can promote the repair of the radial defect in a rabbit; however, further studies on the doseeffect relationship, administration time, and administration route are still needed.
Objective To investigate the effect of “two-phase” tissue engineered cartilage constructed by autologous marrow mesenchymal stem cells(MSCs) and allogeneic bone matrix gelatin(BMG) in repairing articular cartilage defects. Methods Thirty-twoNew Zealand white rabbits were involved in the experiment. “Two-phase” allogeneic BMG scaffold (one side of porous cancellous bone and the other side of cortical bone; 3 mm both in diameter and in thickness) was prepared from iliac bone and limb bone of 5 rabbits by sequentially chemical method. The MSCs wereseparated from 18 New Zealand white rabbits and induced to express chondrocyticphenotype. The chondrocyte precursor cells were seeded onto “two-phase” allogeneic BMG to construct tissue engineering cartilage. Masson’s trichrome staining, PAS staining and scanning electronic microscopic observation were carried out at 1, 3 and 5 weeks. The defects of full thickness articular cartilage(3 mm both in diameter and in depth) were made at both sides of femoral medial condyles in 27 rabbits(including 18 of separated MSCs and the remaining 9). The defects were repaired with the tissue engineered cartilage at the right side (group A, n=18), with BMG at the left side(group B, n=18), and without any implant at both sides in the remaining 9 rabbits as a control( group C, n=18). After 1, 3 and6 months, the 6 specimens of femoral condyles were harvested in 3 groups, respectively. Gross observation, Masson’s trichrome and Alcian blue staining, modified Wakitani scoring and in situ hybridization of collagen type Ⅱ were carried out to assess the repair efficacy of tissue engineered cartilage. Results The “two-phase” BMG consisted of the dense cortical part and the loose cancellous part. In cancellous part, the pore size ranged 100-800 μm, in which the chondrocyte precursor cells being induced from MSCs proliferated and formed the cell-rich cartilaginous part of tissue engineered cartilage. In cortical part, the pore size ranged 10-40 μm, on which the cells arranged in a layer and formed the hard part of subchondral bone. After 1 month of transplantation, the cartilage and subchondral bone were regenerated in group A; during observation, the regenerated cartilage graduallythinned, but defect was repaired and the structure of the articular surface ansubchondral bone was in integrity. In groups B and C, defects were not repaired, the surrounding cartilage of defect was abrased. According to the modified Wakitani scoring, the indexes in group A were significantly higher than those in group B and C(Plt;0.01) except the thickness of cartilage at 6 months. The positive cell rate of in situ hybridization for collagen type Ⅱ in group A was also higher than those in groups B and C(Plt;0.01). Conclusion “Two-phase” allogeneic BMG is a prospective scaffold for tissue engineered cartilage,which combines with autologous chondrocyte precursor cells induced from MSCs toconstruct the tissue engineering cartilage. The tissue engineered cartilage can repair defects of articular cartilage and subchondral bone.
Objective To study efficiency of vascularized bone graft combining with reconstituted bone xenograft (RBX) in repairing bone defect and the expression of the vascular endothelial growth factor (VEGF) in serum. Methods From January 1998 to December 2002, 27 cases of bones defects were treated and randomly divided into 3 groups according to different repair materials: group A (the vascularized bone graft-RBX group, n=9), group B (the vascularized bone graft group, n=10)and group C(the RBX group, n=8). The bone defect repair, the bone healing time and the bone graft resorption were observed by radiograph after 3 months, 6 months and 12 months of operation, and the expression of VEGF in serum was assayed with lumino-enzyme immunoassay before operation and after operative 2 weeks, 4 weeks, 6 weeks and 8 weeks respectively. Results The X-ray films showed that the bonehealing was achieved in 8 cases of group A, in 6 cases of group B and in 3 cases of group C after 3 months; in 1 case of group A, respectively in 3 cases of both group B and group C after 6 months. The bone graft resorption was observed in1 case of group B and in 2 cases of group C after 12 months. The serum VEGF values after operative 2 weeks and 4 weeks were higher than those before operation in all of 3 groups(Plt;0.05), and the VEGF values of groups A and B were higher than that group C(Plt;0.05) after 4 weeks. There were no significant differences (Pgt;0.05) in serum VEGF level between postoperative 6, 8 weeks and preoperation in 3 groups. Conclusion The expression of serum VEGF obviously increase in the early period of bone transplanting, it is value of clinical evaluation of reparative efficiency of bone defect.