Three-dimensional Finite Element Analysis Of The Force Change Of Bone Cement Combined With Plate Internal Fixation In The Treatment Of Benign Proximal Femoral Lesions

Bone tumors and benign bone lesions commonly occur in areas with active bone growth in humans,such as epiphyseal.The incidence of tumors is distal to the femur,proximal to the tibia,and distal to the humerus.The incidence of proximal femur is relatively low.For the patients with benign osteopathy,the patients usually get a good life cycle after surgical treatment.Through continuous improvement of the operation mode,the stress of the proximal femur after the operation of benign osteopathy is studied by using the finite element analysis.The risk of pathological fracture and secondary fracture is predicted and reduced.To explore the best operation and prognosis is of great significance for prolonging and improving the quality of life of patients.The first part:Finite element analysis of the window part of the proximal femoral lesionObjective:Three-dimensional finite element technique was used to analyze the different surgical models of benign proximal femoral lesions.The differences of different surgical models were compared and the rationality and effectiveness of internal fixation were verified.The reliability of the finite element model was verified in the follow-up of patients after operation.Methods:Preoperative CT examination was conducted in 10 patients with benign proximal femoral lesions who met the inclusion criteria.Three models of limbs scraping(group A),cavity internal nail re-infusion bone cement(group B)and intracavitary bone cement joint plate screw(group C)were established by MIMICS.The maximum stress values of the left and right side windows of the cortical model of group A,B and C were measured under simulated conditions,and the stress values of the three groups were compared.All patients signed the informed consent.This study was approved by the Hospital Ethics Committee.Results:The comparison of the maximum stress values of the anterior and posterior sides of the cortical fenestration in the three groups of models was group A > group B > group C(p < 0.05).10 subjects underwent the treatment in group C.The prognosis was good and there were no secondary fractures.The Musculoskeletal Tumor Society score was(27.12±1.93)points 1 year after surgery.The model stress is prone to increase the local stress after opening the window.After adding bone cement and steel plate,the stress value of the model window is significantly reduced.Conclusion:The risk of fracture was high in group A,and the risk of fracture in group B was large.The stress in group C was controlled within a reasonable range,and the risk of fracture was low.After the benign lesions of the proximal femur are scraped,the stress of the fenestration can be effectively reduced by placing the bone cement and the steel plate,and the fracture probability at the surgical site is significantly reduced.Steel plate placement is reasonable.The second part:Finite element analysis of the femoral neck after curettage of proximal femoral lesionsObjective:To analyze the femoral neck force after different surgical methods using finite element technique in the analysis of benign proximal femoral lesions,and to assess the stability of the femoral neck and the risk of fracture after different surgical procedures for cases with a wide range of lesions.Methods:According to preoperative CT data of lesion sites in 10 subjects with benign tumor of proximal femur,three-dimensional model of internal fixation with bone cement and steel plate after focal curettage(group A)and three-dimensional model of treating with bone cement after focal curettage(group B)were set in this study.Finite element technique was used to simulate the maximum force of the femoral neck when walking.The stress peaks of the femoral neck were compared after surgery between the two groups.The risk of fracture at this location was assessed.Patients signed the informed consent.Results:The stress was significantly lower in the group A than in the group B(p=0.007).The local stress of the model was reasonable in the group A.Ten patients were operated with the protocol of the group A.An additional 17 patients with proximal femur benign lesions who met the requirements but refused to enter the finite element experiment were treated with the surgical program of the group A.The patients were followed up for 14-42 months.During the follow-up,no new fracture was found in the operation area,and the internal fixation device was firm without fracture.At 12 months postoperatively,the mean Musculoskeletal Tumor Society score of all patients was(26.12 ± 2.28).Conclusion:The finite element technology for simulating the stress evaluation and postoperative follow-up verified that the treatment of proximal femur benign tumor with bone cement and steel plate internal fixation after curettage is more reasonable and effective.The scheme can effectively reduce the risk of secondary fracture and enhance the stability in the surgical area.