| BackgroundAlthough the effect of treatment for nonunion has been improved markedly with the advancement in orthopedic theory and technique, some cases of nonunion are still troublesome to treat and a great challenge for orthopedists.Ilizarov technique is a useful method based on distraction osteogenesis which can lead bone natural reconstruction and be golden standard for nonunion or bone defects. The major reconstruction techniques used are isolated shortening, compression followed by distraction, shortening associated with lengthening after corticotomy and segmental bone transport. There is a complication to this technique:faulty union or nonunion at docking site which may caused by poor local soft tissue condition or instability at docking site.Is there a method that can enhance both the ability of union and the stability at the docking site? We introduce a new technique that using intramedullary fibular transplantation combined with Ilizarov method to treat complicated nonunion. In this research, we will study the vitality and the capability of osteogenesis and revascularization by animal experiments and evaluate the results and outcomes of clinic cases useing this technique.Objective1To study the vitality of fibular bone graft after intramedullary transplantation.2To study the capability of osteogenesis and revascularization of fibular bone graft after intramedullary transplantation.3To investigate a new technique for atrophic nonunion:excision of the atrophic segment and intramedullary fibular transplantation combined with bone lengthening and evaluate its effect.4To compare of the effect of intramedullary fibular transplantation associated with shortening-lengthening method and segmental bone transport to treat posttraumatic nonunion.5To study and evaluate the result of the treatment of tibial infected nonunion using intramedullary fibular transplantation associated with Ilizarov methodMethods1Laboratory animals were20New Zealand rabbits. Intramedullary fibular transplantation were performed in the rabbits’right hindlimbs, nonvascularized and vascularized fibular transplantation were performed in their left hindlimbs. At1week,2weeks,4weeks and8weeks after operation,5rabbilts were put to death and the fibular grafts were acquired.Then single cell solution from the grafts was prepared for cell vitality test using trypan blue rejection experiment.2Laboratory animals were20New Zealand rabbits. Intramedullary fibular transplantation were performed in the rabbits’right hindlimbs, nonvascularized and vascularized fibular transplantation were performed in their left hindlimbs. At1week,2weeks,4weeks and8weeks after operation,5rabbilts were put to death and the fibular grafts were acquired for routine tissue slices. Then HE and ALP pigmentation were processed. Immunohist-ochemical method was used to determine the expression of CD31. The value of rate of positive area and beckgroud area (PA/BA) and microvessel density (MVD) was calculated and analyzed.3A series of operations were performed using the technique of excision of the atrophic segment and intramedullary fibular transplantation combined with bone lengthening in21patients suffered atrophic nonunion who had undergone several surgical procedures. The main pionts of this technique include excision of the atrophic segment, intramedullary fibular grafts, close contact of tibial stumps and bone lengthening using Ilizarov method.4A retrospective study was done by collecting cases who were diagnosed as posttraumatic nonunion since2008in our department. The patients were divided into two groups according to different operations:intramedullary fibular transplantation associated with shortening-lengthening method in group A and bone transport in group B.Time of operation, time of healing and ASAMI classification of the results were analyzed and compared between the two groups. 5Operations were performed using the technique of intramedullary fibular transplantation combined with Ilizarov method in15patients suffered infected nonunion.The effect of this method was evaluated by long term follow-up.Results1The rate of viable cell was29.36%in intramedullary fibular grafts(IFG),10.87%in nonvascularized fibular grafts(NFG) and57.76%in vascularized fibular grafts(VFG) at1week postoperatively. The variance among three groups was significant, and the variance between every two groups was also significant. The rate of viable cell was43.49%in IFG,15.58%in NFG and62.02%in VFG at2weeks postoperatively. The variance among three groups was significant, and the variance between every two groups was also significant. The rate of viable cell was59.67%in IFG,25.42%in NFG and68.24%in VFG at4weeks postoperatively. The variance among three groups was significant, and the variance between every two groups was also significant. The rate of viable cell was73.53%in IFG,38.44%in NFG and75.73%in VFG at8weeks postoperatively. The variance among three groups was significant. The variance between IFG and NFG was significant, but the variance between IFG and VFG was not significant.2The value of PA/BA in IFG was higher than it in NFG but lower than it in VFG at1week postoperatively. The variance was significant. The value of PA/BA in IFG was higher than it in NFG but lower than it in VFG at2weeks postoperatively. The variance between IFG and NFG was significant but that between IFG and VFG was not. The value of PA/BA in IFG was higher than in NFG and VFG at4weeks and8weeks postoperatively. The variance was significant. The value of MVD in IFG was higher than it in NFG but lower than it in VFG at1week,2weeks and4weeks postoperatively. The variance was significant. The value of MVD in IFG was higher than it in NFG but lower than it in VFG at8weeks postoperatively. The variance between IFG and NFG was significant but that between IFG and VFG was not.3All21patients were followed up for12to36months(mean19.4+5.8months). The average time to union was4.83±0.62months(ranged4to6months). Bone results for ASAMI classification were rated as excellent in all cases. The functional results were rated as excellent in11, good in9, fair in1. Complications were recorded as infection at pin tract in7, ankle joint stiffness in1.4The average time of operation was2.58±0.35hours in groupA and2.06±0.37hours in groupB. The average time to union was4.8±0.6months in groupA and5.6±1.1months in groupB. Bone results for ASAMI classification were rated as excellent in all cases in groupA, excellent in13, good in3, fair in1and poor in1in groupB. The functional results were rated as excellent in12, good in10, fair in1in groupA, while exellent in5, good in9, fair in2, poor in2in groupB. The variance of time of operation, time to union and ASAMI classification between the two groups were all significant.5All15patients were followed from12to36months, the mean healing time was24.6weeks (ranged18to54weeks). According to ASAMI score, they were all excellent for bone union except1fair case, and excellent in7cases, good in6cases, fair in2cases for functional rehabilitation.Concludes1The vitality of fibular bone graft after intramedullary transplantation is good and enhance quickly, which is almost equal to vascularized fibular grafts at8weeks postoperatively.2The capability of osteogenesis and revascularization of fibular bone graft after intramedullary transplantation is better than nonvascularized bone grafts.3It is effective for treating atrophic nonunion by using the technique of excision of the atrophic segment and intramedullary fibular transplantation combined with bone lengthening.4Compared with bone transport, intramedullary fibular transplantation associated with shortening-lengthening method need shorter time for union and lead to better outcome, but can not replace the role of bone transport.5It is an effective way to treat tibial infected nonunion and defects with using intramedullary fibular transplantation associated with Ilizarov method. |
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