| ObjectiveAs China gradually steps into the aging society,the body's bones and muscles decline by degrees,and more and more people suffer from osteoporotic hip fractures due to falls.Among them,the high risks and high medical expenses brought by femoral neck fractures are particularly prominent.Thus,preventing of femoral neck fractures in the elderly is of strategic importance in reducing the social economic burden and reducing patient mortality.At present,the main effective measures are taking oral drugs which stimulate the bone formation and inhibit bone resorption to enhance bone mineral density in patients with hip fracture prevention.However,the clinical efficacy has not yet reached the desired standard;In addition,there are no relevant reports in the world that protective action response of muscle stress in elderly patients is also an important factor affecting hip fracture.Based on the theory of "spleen governing muscle and kidney governing bone" in traditional Chinese medicine,the gluteus medius muscle in elderly patients with yang deficiency of spleen and kidney as the study object is carried on the related discussion.While the gluteus medius muscle makes the hip joint to abduct,the anterior muscle fiber has an internal rotation and the posterior muscle fiber has an external rotation.Therefore,the purpose of this study is to:1.Analyze the correlative function of contralateral hip abductor muscle group after the elderly women falling between femoral neck fractures and of non-fracture patients by clinical prospective study,find out the relevant rules of the muscles which have the effect on the occurrence of femoral neck fractures at an attempt to provide one new ideal for clinical prevention of aged osteoporotic femoral neck fractures.2.Establish the three-dimensional finite element model of hip joint according to clinical CT data,load the active response of the gluteus medius model,introduce the engineering fracture mechanics principle into the biomechanical finite element analysis of fractures,fine out the effects of the anterior muscle fibers and posterior muscle fibers on the femoral neck fractures respectively after simulating active response of the gluteus medius,make a contribution to adding new energy to the biomechanics of femoral neck fractures in the elderly.Methods 1.Clinical research:Thirty patients are selected from outpatient and emergency department of Orthopedics in the First Affiliated Hospital of Guangzhou University of Chinese Medicine,the age of whom distribution ranged from 65 to 89 years with a mean age of 75.06 ± 5.86 years.Half of them are femoral neck fracture clinic review after operating,and the remaining patients are diagnosed no fractures by orthopedic surgeon after falling with hip pain.After consultation with the patients and their families,the performance of the abductor muscles of them were measured by Biodex isokinetic assessment system.The two indexes,namely,the cycle that achieved the maximum work value for evaluating muscle strength and the average energy of neuromuscular performance,were selected for statistically examined to analyze the correlation of muscles for femoral neck fractures in elderly women.2.Experimental study:(1)Bone model: Bilateral hip CT image data of one elderly patients with femoral neck fracture who meet the research requirements were saved in DICOM format as a CD-ROM copy,and then imported into Mimics19.0 software for threshold segmentation and mask processing Morphological calculation,lacuna filling,editing mask,smooth 3D model and so on to rebuild the contralateral pelvis and proximal femur three-dimensional model.Next,loading the generated STL format model into the reverse engineering software named Geomagic Studio 2013 to generate surface and fit surface for optimization processing.At last,the model is loaded into the Hypermesh14.0 which was used for delimiting the material properties of the osteoporotic bone to the pelvis and proximal femur respectively.(2)Muscle stretching test: Endow the muscle model which provided by State Key Laboratory of Advanced Design and Manufacture of Automobile Body of Hunan University with the muscle material properties,apply 300 N tensile force to the tendon ends of both ends,import it into the LS-DYNA to get calculations,then simulate state of the muscle expansion.(3)Skeleton and Muscle Assemblage :After have a good state of the muscle expansion,load the finite element analysis model of muscles with active response into the Hypermesh14.0,connect the muscle model with a rigidbody form on the basis of the anatomical starting and ending point of the gluteus medius muscle with hip skeletal structure to simulate the contractile function of gluteus medius muscle after the commands of pan and rotate.Then next step,set the model with a fracture mechanics failure parameters on the interface Hypermesh14.0,set the load operation and boundary constraints,generate a K form file(The specific boundary conditions are as follows :before muscle activation,K1 model: apply 500 N load on the model from top to bottom on the basis of the femoral head and sagittal position with an angle of 20 degrees;after muscle activation,K2 model:take the abduction and the external rotation of the hip joint by 5 degrees separately on the basis of the K1 model;K3 model:take the abduction and the internal rotation of the hip joint by 5 degrees separately on the basis of the K1 model),load the three models into the finite element post-processing software LS-DYNA individually for calculation,get the fracture models of the femoral neck fracture before and after the active response of the gluteus medius muscle in view of the stress-strain curve relation,compare and analyze the fracture cracks before and after the fracture of three finite element fracture models.Results(1)The experimental group and the control group of the abductor muscle have statistically significant differences of the three measurement data including the age,the maximal power cycle and the mean energy,indicate that the maximal energy output and neuromuscular performance of the abductor muscles decrease gradually with the increase of age,show a negative correlation,accord with the clinical and human physiology,so we can say that the results have a certain degree of credibility and rationality.In addition,the volunteers of the stronger abduction muscles and the more flexible neuromuscular,have the lower possibility of hip fracture after falling contrast to the experimental group.(2)K2,K3 model comparison of gluteal muscle active response: K3 model have a 5 degrees abduction and internal rotation,there is not a femoral neck fracture of the hip joint,but fracture in the femoral constrained area.K2 model still have a femoral neck fracture after the abduction and internal rotation of the hip joint.(3)Compared with the K1 and K2 models: the two models both have the femoral neck fractures,whose occurrence time are all 22.5ms.According to the degree of fracture displacement,K1 model fracture crack is estimated of GardenII type,but K2 model fracture crack is estimated of GardenIII type,which is more serious than the K1 model shift.Conclusion(1)The finite element model of the muscle has a high degree of simulation,the muscle contractions can provide some reference value for the finite element operation of the clinical human muscles after the active response.(2)After initiative response of the gluteal muscle,which the muscle contraction make changes of the falling postures of the hip joint may be the impact factors of the fractures of the elderly femoral neck fracture.(3)The risk of osteoporotic fractures in spleen-kidney yang deficiency type elderly patients after falling is relatively high.Invigorating the kidney and spleen method may be beneficial to reduce the incidence of femoral neck fractures in the elderly and provide a new type of traditional Chinese medicine for the prevention and treatment of geriatric orthopedic diseases method. |
PDF Full Text Request