OBJECTIVE: To study the treatment efficacy of vascularized periosteum graft and bone filling material for long bone defect. METHODS: Forty young and forty adult rabbits were divided into four groups respectively according to the bone filling materials. A 3 cm long segment was removed from the middle part of the rabbit radius to make a bone defect model. The periosteum was reserved and restored to set up a vascularized tubulate periosteum graft. On the left side, autogenous bone graft, decalcified allograft, tricalcium phosphate, and hydroxyapatite were used to fill in the bone defect respectively; on the right side, no bone filling material was used as controls. The repairing effect of bone defect was evaluated by roentogenography, biomechanical, and histological methods. RESULTS: In young rabbits, bone defects on both sides healed in the 6th week after operation. The bending strength of radius in the tricalcium phosphate group and in the hydroxyapatite group were lower in the 12th week and there was significant difference when compared with autogenous bone graft group, decalcified allograft group and control group (P lt; 0.05). The repairing mechanism included intramembranous and endochondral ossification, and intramembranous ossification was prevalent. In the adult rabbits, the repairing rates of bone defect were 50% in the autogenous bone graft group, 40% in the decalcified allograft group, 30% in the tricalcium phosphate group and in the hydroxyapatite group and 42.5% in the control group, respectively. CONCLUSION: In young rabbits, large bone defect can be repaired with vascularized tubulate periosteum graft with or without the combining use of bone filling materials. The bone filling material which will be substituted slowly is disadvantageous to the recovery of bone strength. In adult rabbits, vascularized tubulate periosteum graft combined with bone filling materials can not repair the large bone defect effectively.
Objective To investigate the advance in the management of skeletal trauma of the extremities. Methods The literature at home and abroad was reviewed, and the research findings withclinical experience in the therapeutic methods for fracture of the extremities were summarized.Results The concept on fracture management was renewed, the minimally invasive surgery (MIS) was developed and popularized, the implantation was improved, the navigation technique with computerassisted surgery was applied, and the tissue engineering was developed. The fracture mana gement was changed from the anatomical reduction with absolutely rigid fixation to the biological osteosynthesis with protection of the fracture environment. The minimally invasive surgical techniques included the minimally invasive plate osteosynthesis, intramedullary nailing, external fixation, arthroscopic surgery,and computer-assisted surgery. In concordance with the MIS principles, the newimplants, such as the locking compression plate, and the less invasive stabilization system were well designed and put into clinical practice so as to provide effective therapeutic results in treating osteoporotic fractures and complicated articular and/or metaphyseal fractures. In treatment of the delayed union or nonunion offractures, more effective techniques were employed, including the application of bone substitutes, which are degradable and have properties of bone conduction and induction. In the repair of segmental defects of the long tubular bone, the bonetransport and the vascularized bone grafts could work well. The investigation of the bone engineering revealed its great potentiality.Conclusion Fracture of the extremities is a common problem and its management should emphasize the recovery of the extremity function of the patient in addition to emphasis on the replacement and fixation of the biological structures. The combination of bone engineering and microsurgery represents the development tendency inthis field.
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.
Objective To explore the effects of exogenous basic fibroblast growth factor (bFGF) on insheathed tendon healing and adhesion formation. Methods Ninety Leghorn chickens were randomly divided into 3 groups (groups A, B and C), 30 animals for each group, and the right third digitorum longus tendon of the chicken was transected to make defect models. In group A, the tendon was sutured in situ after transection. In group B, the tendon was sutured after 0.6 μl fibrin sealant (FS) was applied at repair site. In group C, the tendon was sutured after 0.6 μl FS mixed with 500 ng bFGF was appliedat repair site. At 1, 2, 4 and 8 weeks after operation, the tendons of 6 chickens in each group were harvested for morphological and histological evaluation. Six specimens of each group was obtained for biomechanical test at 8 weeks. Results The gross observation showed that the differences of grading of tendon adhesion were not significant between groups A, B, and C 8 weeks after operation(Pgt;0.05). Histological evaluation showedthat there were no significant differences in fibroblast counting and the content of collagen fibers between groups A and B(P＞0.05). The angiogenesis, fibroblast proliferation and collagen production in the sheath, epitendon and parenchyma at repair site in group C occurred earlier and were more than those in groups A and B, showing significant differences (Plt;0.05). The biomechanical tests showed that the gliding excursionof the tendon in group A, B and C were 3.44±0.43、3.51±0.56 and 2.84±0.42 mm respectively; the work of flexion were 14.87±1.72、14.08±1.85 and 20.62±3.52 Nmm respectively; the ultimate tensile strength of the tendon was10.34±1.45，11.26±1.83 and 15.02±2.20 N respectively; showing no significant differences between groups A and B(Pgt;0.05), but showing significant differences between group C and groups A, B(Plt;0.05). Conclusion The exogenous bFGF at tendon repair site can facilitate insheathed tendon healing, but also increase the tendon adhesion formation.
【Abstract】 Objective To measure the changes of bone mineral density and bone micro-architecture of thefemoral head that harvested from the three-foot bearing ethanol destroyed canine model for osteonecrosis of femoral head, and discuss the influences of local injection of ethanol and biomechanical loading to the structural properties of the femoral head. Methods Twenty-four Beagles were divided randomly into four-foot bearing canines and three-foot bearing canines. One fore-l imb was fixed randomly in three-foot bearing canines. Osteonecrosis was induced in all experimental animals by local injection of 5 mL pure ethanol into one side of the femoral head. The hind l imbs injected with NS were acted as control group, that of three-foot canines injected with ethanol were acted as three-foot canine group, and that of four-foot canines injected with ethanol were acted as four-foot canine group. The contralateral femoral head was injected into equal amount of NS. Animals were sacrificed at the time intervals of 1, 3, 6, and 12 weeks after the injection of ethanol. Quantitative microcomputedtomography was used to characterize changes in bone micro-architecture and bone mineral density of femoralhead. Results The clear three-dimensional model of trabecular bone of necrotic femoral head were obtained. There were no significant differences among 3 groups according to the time l ine by 1 week after ethanol injection(P gt; 0.05). At 3 weeks after injection of ethanol, in three-foot canine group and four-foot canine group, the volume of BMC, BMD, BVF, and BS/BV increased gradually as the distance to the drill ing canal increased. There were significant differences between 3 regions (P lt; 0.05). At 6 weeks, in three-foot canine group and four-foot canine group, the volume of BMC, BMD,BVF, and Tb.N of region I and II decreased significantly compared with region III (P lt; 0.05). At 12 weeks, there are no differences among 3 groups (P gt; 0.05). There were significant decreases in BMD values, BVF, BS/BV, Tb.N, Tb.Sp and Tb.Th after the injection of pure ethanol. And, the changes were more and more obvious by the time l ine. These changes were differentiable at 3 weeks after injection of ethanol, and became obvious at 6 weeks. These changes were more obvious at the part that near the injection canal. The changes in threefoot canine group were more obvious than that in four-foot canine group. Conclusion Resorption of necrotic compact bone trabecular may weaken the structural properties of the femoral head. Moreover, remodel ing and repairing process of necrotic bone trabecular may be hampered by constant biomechanical loading that presented in three-foot bearing canines, and thereby further weaken the structural properties of the femoral head. Biomechanical loading may be one of the critical reasons that lead to the collapse of femoral head.
Objective To compare the cl inical results of two plating osteosynthesis techniques, open reduction and plating ostosynthesis (ORPO) and minimal invasive plating osteosynthesis (MIPO), in surgical treatment of mid-distal humeralshaft fractures. Methods From March 2004 to October 2006, 40 cases of closed unilateral mid-distal humeral shaft fractures were surgically treated with MIPO or ORPO. In the MIPO treated group (n=19), there were 14 males and 5 females, with a mean age of 39.05 years. Fractures involved in middle humeral shaft in 10 cases and distal fragment in 9 cases. According to OTA classification, there were 3 cases of type A, 13 cases of type B and 3 cases of type C. Four cases compl icated by radial nerve palsies. In the ORPO treated group (n=21), there were 13 males and 8 females with a mean age of 39.05 years, including 14 cases of type A and 7 cases of type B fractures according to OTA classification. The fractures involved in middle humeral shaft in 13 cases and distal fragment in 8 cases. Five cases compl icated by radial nerve palsies. The time from injury to operation in both groups were 2 to 14 days. For patients in the MIPO group, fractures were closely reduced and fixated with an anterior placed plate inserted through two small incisions made at the anterior side of arm, away from fracture sites. The radial nerves were not exposed. For patients in the ORPO group, fractures were exposed, reduced, and fixated with an anterolateral or a posterior positioned plate after careful dissection and protection of radial nerve through an anterolateral or a posterior approach. The operation time, the occurrence of iatrogenic radial nerve palsy and the bone heal ing time were recorded. The functions of the affected shouldersand elbows were evaluated with UCLA end-result score and Mayo elbow perform index (MEPI), respectively. Results All the wounds in both groups healed primarily. There was no iatrogenic radial nerve palsies in the MIPO group after surgery; however, 5 cases of transient iatrogenic radial nerve palsies were identified in the ORPO group after surgery, and the function of radial nerve recovered in these cases at the last follow-up. Eighteen cases were followed up 14-44 months (mean 25.44 months) in MIPO group, and 19 cases were followed up 13-48 months (mean 32.11 months) in ORPO group. The mean bone heal ing time was 17.06 (12-32) weeks in MIPO group and 16.11 (8-58) weeks in ORPO group, showing no significant difference between two groups (P gt; 0.05). There was no nonunion and hardware failure in both groups. The mean forward flexion of the shoulder was 166.94° (150-170°) in MIPO group and 164.74° (130-170°) in ORPO group. The mean UCLA shoulder score was 34.78 (33-35) points in MIPO group and 34.42 (30-35) points in ORPO group. The mean range of motion of the elbow in MIPO and ORPO groups was 133.33° (120-140°) and 136.7° (120-140°), respectively. The MEPI in these two groups was 99.44 (90-100) and 99.74 (95-100) points, respectively. There was no statistically significant difference between two groups in all indexes mentioned above. Conclusion The good results could be obtained when ORPO and MIPO technique are appl ied to treat mid-distal humeral shaft fractures. MIPO technique has advantages to not expose the radial nerve and to decrease the occurrence of iatrogenic radial nerve palsies.
【Abstract】 Objective To establ ish a stable animal model for glucocorticoid-induced avascular necrosis of femoral head in rabbits. Methods Thirty-six adult New Zealand rabbits were randomly divided into four groups:ten were injected twice with l i popolysaccharide (group A), ten were treated with a combination of l i popolysaccharideand methylprednisolone (group B), ten were injected three times with methylprednisolone (group C), and six wereinjected normal sal ine as a control (group D). MR imaging was performed in the rabbits before the first injection ofl i popolysaccharide or methylprednisolone, and at 2, 4, and 6 weeks after the last injection of l i popolysaccharide ormethylprednisolone. Histopathological changes in the femoral heads were observed by l ight microscope and transmission electron microscope at the end of six weeks after the injection. Vascular infusion with Chinese ink was made to evaluate the morphological changes of blood vessels in the femoral head. The percentage of trabecular bone area and empty lacunae and microvascular density were measured. According to the histological and MR imaging appearance of the femoral heads in all groups, the incidence of osteonecrosis of every group was calculated. Results Listlessness, blepharal hyperemia,less activity and reduced diet were found in the rabbits of groups A and B after injected with l ipopolysaccharide. At 3 weeks after the final injection, the body weight of groups B and C was decreased. At 4 weeks after the final injection, the body weight of groups A and D was increased. No abnormal signal could be detected on MR images in rabbits of all groupsbefore injection and at 2 weeks after the injection. At 4 weeks and 6 weeks after the last injection, irregular low signal on T1-weighted images and irregular low or high signal on T2-weighted images could be detected on MR images in rabbits of groups B and C, no abnormal signal could be detected on MR images in rabbits of groups A and D. At 6 weeks after the last injection,the trabecular bone of group B became thin and sparse, some were broken. The percentages of empty lacunae were 11.8% ± 4.7%, 34.4% ± 6.2%, 20.0% ± 4.7% and 9.3% ± 4.6%; the percentages of trabecular bone area were 59.2% ± 6.8%, 40.1% ± 6.0%, 51.5% ± 5.6% and 63.2% ± 8.3%; and the microvascular densities were 14.3% ± 2.7%, 4.5% ± 2.1%, 10.2% ± 3.1% and 15.4% ± 4.1% in groups A, B, C and D respectively. There were statistically significant differences between group B and groups A, C, D (P lt;0.01). The fatty tamponade accumulated in the medullary cavity and intramedullary vascular sinusoids were pressed by the l ipocytes and became narrow. Limposomes were found in osteocytes and vascular endothel ia of group B and group C. Osteocytes of group B crimpled and pyknosis or karyolysis of chromatin were observed in these osteocytes, nuclearmembrane of the osteocytes was discontinous. Vascular endothel ia became swollen and the cell junctions widened or were destroyed in groups A and B. The incidence of osteonecrosis in group B (88.9%) was higher than that in group C (22.2%, P lt; 0.05). There was no osteonecrosis occurred in groups A and D . Conclusion Methylprednisolone combined with l ipopolysaccharide can induce typical rabbit model for early avascular necrosis of femoral head.