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 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.
To investigate the operative technique of treating Freiberg’s disease with dorsal wedge osteotomy and absorbable pin fixation, and to evaluate the cl inical outcome. Methods From June 2005 to June 2007, 8 patients with Freiberg’s disease were treated, including 2 males and 6 females aged 16-66 years old (average 36 years old). X-ray films revealed osteosclerosis, collapse of the metatarsal head and ischemic necrosis of the second metatarsal head. According toSmill ie classification system, there were 4 cases of stage II, 3 of stage III and 1 of stage IV. The duration of symptoms was 6-36 months (average 19 months). After dorsal wedge osteotomy, the metatarsal heads were rotated to reconstrust the joint surface, then 3-4 pieces of absorbable pin 1.5 mm in length were implanted for fixation. Results All wounds healed by first intention, and no early postoperative compl ications occurred. Five patients were followed for 11-35 months (average 14 months) and had significant pain rel ief. At 3 months after operation, the dorsal-flexion of metatarsophalangeal joint was improved by 0-50° (average 21°), and the plantar-flexion was increased by 0-10° (average 5°). X-ray films showed that solid union of the osteotomy was achieved in all patients at 8-13 weeks after operation (average 10 weeks). Average shortening of metatarsal was 1.7 mm (range 1.3-2.0 mm). All patients returned to sports and recreational activities at 4 months after operation, except one case of stage IV who had constant swelling and stiffness in the joint and was improved at 12 months after operation. Conclusion Dorsal wedge osteotomy in complex with absorbable pin fixation is an effective procedure for stage II and III Freiberg’s disease, because it is capable of reconstructing the metatarsophalangeal joint effectively, allowing early joint motion and avoiding a second operation.
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.
Objective To investigate the expression of transforminggrowth factor β1(TGF-β1) and insulin-like growth factorⅠ(IGF-Ⅰ)in new bone after low frequency micromovement. Methods Fifteen female sheep from Shandong province were involved in the study and their bilateral tibias transversely osteotomized in the middle shafts with a defect of 2 mm.The hind limbs were fixed with unilateral external fixators connected to a controlled micromovement device. Ten days after osteotomy, one hind limb of each sheep randomlywas selected to perform micromovement at an amplitude of 0.25 mm and a frequency of 1 Hertz, 30 min a day for 4 weeks ( micromovement group). The other hindlimb served as the control group. Five sheep were sacrificed at 3,4 and 6 weeks after osteotomy, respectively, and specimens were harvested for detecting the expression of TGF-β1 and IGF-Ⅰby immunohistochemistry and RT-PCR. Results Immunohistochemistry: In the third postoperative week in the micromovement group, the expression of TGF-β1 was detected in different areas of new chondrocytes at the margin of callus, mainly in proliferating area, and IGF-Ⅰexpressed in osteoblasts at the margin of endochondral ossification area, calcified and mature chondrocytes and osteocytes. There was seldom expression ofIGF-Ⅰ and little expression of TGF-β1 in the corresponding area in the control one. In the 4th postoperative week in the micromovement group, theexpression of TGF-β1 diminished gradually with the mature of new bone and be located in extracellular matrix and osteoblasts around ossified areas; The expression ofIGF-Ⅰ reached the peak and be located mainly in osteoblasts of new bone surface, maturing osteocytes and calcifing osteoid. But there was little expression of them in the control group. In the sixth postoperative week in the micromovement group, there was a little expression of IGF-Ⅰ expression but little expression of TGF-β1; there was nearly no expression of them in the control group. In the micromovement group, the absorbance values of TGF-β1 at 3 and 4 weeksand of IGF-Ⅰat 3, 4 and 6 weeks were significantlyhigher than those in control group（P＜0.05）. RTPCR: In the third and fourth postoperative weeks in the micromovement group, there was higher expression of mRNA of TGF-β1 and TGF-I than those in control group; in the sixth postoperative week, the expression diminished gradually, but was higher than that in control group. The absorbance values of TGF-β1 at 3 and 4 weeks and IGF-Ⅰat 3, 4 and 6weeks were significantly higher than those of control group（P＜0.05）. Conclusion Low frequency and controlled micromovement in the early stage of the fracture healing can promote the expression of TGF-β1 and IGF-Ⅰ.They worked together to regulate the process of the endochondral ossification, while in the late stage the differentiation of osteocytes and mineralization of osteoid were regulated mainly by IGF-Ⅰ, which played an important role in regulating the cell biological behavior during micromovement.
Objective To investigate the possibility of constructing eukaryotic expression vector for human glial derived neurotrophic factor （hGDNF）, transfecting it to spinal cord tissue of rats so as to treat acute spinal cord injury. Methods The eukaryotic expression vector pcDNA3-hGDNF was constructed by recombinant DNA technique, transfected into glial cell and neuron of spinal cord by liposome DOTAP as experimental group. In control group, mixture of empty vector and liposome was injected. The mRNA and protein expressions of hGNDF were detected by RT-PCR and Western blot. Results After the recombinant eukaryotic expression vector for hGDNF was digested with Hind III and XbaⅠ, electrophoresis revealed 400 bp fragment for hGDNF gene and 5 400 bp fragment for pcDNA3 vector. In the transfected spinal cord tissue, the mRNA and protein expressions of hGDNF gene were detected with RT-PCR and Western blot. Conclusion The constructed eukaryotic expression vector pcDNA3hGDNF could be expressed in the transfected spinal cord tissue of rat, so it provide basis for gene therapy of acute spinal cord injury.
【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 study the proliferation change of tunica intima and smooth muscle in artery after hydrolic dilation for potential clinical use. METHODS: Sixten adult New Zealand rabbits were randomly divided into 4 groups, named group A, B, C and D. Right carotid arteries of rabbits of those 4 groups were dilated by hydrolic dilation with different pressures with 0 kPa, 40 kPa, 80 kPa, and 120 kPa respectively. The arterial calibers, thickness of tunica intima and smooth muscle were analyzed by automatic medical photograph analyzer immediately, 1 week and 2 weeks later respectively. RESULTS: The arterial calibers in the experimental group were larger than those in control group after immediate hydrolic dilation and 1 week later (P lt; 0.01). At 2 weeks, the arterial calibers in group B and D has no significant difference compared to group A (P gt; 0.05), and those in group C were larger than that of group A (P lt; 0.01). There were no significant difference in thickness of tunica intima and smooth muscle between the experimental group and control group (P gt; 0.05) after immediate hydrolic dilation. At 1 and 2 weeks after dilation, there were no significant difference between group A and group B (Pgt; 0.05), and those in group C and D were all larger than those in group A (P lt; 0.01). No obvious proliferation of tunica intima were observed in group B at 2 weeks after hydrolic dialation, but the proliferation of tunica intima could be observed in group C and D, especially in group D. CONCLUSION: Caliber of artery can be expanded by hydrolic dilation with higher pressure, but the proliferation of tunica intima and smooth muscle may be occurred in hydrolic dilation with higher pressure over 80 kPa, therefore it is safe to use hydrolic dilation with pressure no more than 40 kPa.