Clinical Result And Finite Element Analysis Of Deactived Autograft-prosthesis Composite After Resection Of Bone Giant Cell Tumor In Distal Femur

The giant cell tumors(GCT) is one of the most ordinary primary bone tumor.The incidence rate is 10%-15%in bone tumor in china.In Occident,the rate is 5%-8%.There is a higher incidence rate in China compare with in Occident. GCT general occurred in the metaphyseal bone,and the tissue source is not clear, generally believed that began in the bone marrow mesenchymal. The GCT has a tendency potential with local invasion,recurrence and metastatic.As GCT has a uncertainty biological behavior and a higher local recurrence rate.The diagnosis, treatment selection and prognosis often face many difficulties.At present, the purpose of GCT's treatment is removal of lesions, reduction the opportunities of local recurrence and retention the function of joint. Surgery is a mainly treatment for GCT. There are two surgical methods, One is intralesional excision, the other is en-bloc resection.Because of it's high recurrence rate and malignant or metastatic potential.There is a argument now on how to chosen a satisfactory surgy.The surgical treatment of GCT with Campanacciâ…¢level or recurrence with pathological fracture or the articular surface of the bone invasion is en-bloc resection.Recently the research focus on which surgical treatment can minimize the rate of tumor recurrence and maintain a certain degree of joint function.As the surgical treatment of GCT which has reached Campanacciâ…¢level is controversial, combine with Clinical,we found that deactived autograft-prosthesis composite for the treatment of GCT in the distal femur has some advantages. First:the choice of en-bloc resection can significantly reduce the risk of recurrence. Second:Since the use of deactived autograft-prosthesis composite, joint function in patients with a certain reservation, And the bone healing can be achieved in long term between inactivated bone and host bone.In long term can significantly improve the life of the prosthesis and reduce the chance of renovation.To verify the deactived autograft-prosthesis composite efficacy and biological stability, We designed this experimental. First:By 5 cases GCT with Campanacci III level surgical treatment with deactived autograft-prosthesis composite,use of MSTS functional scoring system and ISOLS image score system to evaluation the function after surgical treatment.Second:Create three-dimensional finite element model for 40% defect of distal femur and reconstruction by deactived autograft-prosthesis composite to simulate surgy, Use finite element method analysis the biomechanical of deactived autograft-prosthesis composite. On the one hand can reduce costs, save time and eliminate the individual differences between samples. On the other hand the experimental can be controlled by change it's conditions. Accurately simulate the mechanical conditions in vivo.Our experiment bear with the following two parts:Part one:Clinical result of deactived autograft-prosthesis composite after resection of bone giant cell tumor in distal femur.Part two:Instant and Long Term Finite Element Analysis of deactived autograft-prosthesis composite in Distal Femur Reconstruction Objective:This study was to evaluate the clinical outcome and application feasibility of alcohol-deactived autograft-prosthesis composite after resection of bone giant cell tumor in distal femur.Methods:The clinical results of 5 patients treated from January 2007 to October 2008 were evaluated according to MSTS limb function score system and ISOLS composite graft evaluation method. The 5 patients were 3 males and 2 females, with the average age 29.6 years (22 to 46 years) at surgery. Four patients were located in right distal femur and 1 in left. Three patients were diagnosed as postoperative recurrence and 2 as with pathological fracture Three-dimensional finite element models were established based on CT images.Results:The 5 patients were diagnosed as Grade III of Campanacci classification. With the mean follow-up of 37 months (28 to 49 months), there was no infection, recurrence, loosening and limb length inequality. The bony healing time was 6 to 11 months in 5 patients. The mean MSTS function score was 25.7 (85.7%) (range 25-27). The mean ISOLS graft score was 31.4 (87.2%) (range 28-35).Conclusion:These results suggest that the alcohol-deactived autograft-prosthesis composite after resection of bone giant cell tumor in distal femur can decrease the tumor recurrence rate, and improve the short-term functiona.Objective:To create three-dimensional finite element model for 40%defect of distal femur and reconstruction by deactived autograft-prosthesis composite, analyze the influence on the stress distribution of femur-cement after the intramedullary implantation in instant and long term.Methods:Three-dimensional finite element models were established based on CT images. Three times of body mass load corresponding to the normal walking gait cycle (3km/h) was applied. The influence on stress distribution of femur-cement and prosthesis stem was analyzed in instant and long term.Result:For the early-term model the maximum stress on the bone recorded in the medial proximal femur is 145.82Mpa. The maximum stress on bone cement recorded in the 1/4 proximal cement is 40.90 Mpa. The maximum stress on prosthesis-stem record in the proximal stem is 389.24Mpa. The maximum stress was not exceeding of the three materials. For the long-term model, with the fracture healing.The maximum stress is reduced on both of the three materials.The Stress shelter is reduced on femurConclusion:The biomechanical stability of Tumor-type Prosthesis in Distal Femur Reconstruction is Stable in instant term. With the fracture healing,it can effectively reduce the loosening of prosthesis probability.