Design,Manufacture And Preclinical Study Of Personalized Implants Based On Three-Dimensional Measurement Of Hip Joint

OBJECTIVE Total hip arthroplasty is the best choice for the treatment of end-stage hip disease.In order to improve the therapeutic effect,especially the 3D printing technology,it puts forward new requirements for the surgical planning and prosthesis Design.In this paper,1)a novel method is proposed for the segmentation of acetabular femoral images;2)Three dimensional automatic algorithm for measuring the shape of pelvis,acetabulum and femur was designed and its accuracy and reliability quantified;3)In standard pelvic coordinate system,three-dimensional acetabular orientation of 100 Chinese were measured,and relevant characteristics were reported;4)Based on the morphological characteristics of the proximal femur,short stem prosthesis was designed and manufactured with additive manufacturing technology to explore its biomechanical and histological performance.MATERIALS AND METHODS1.Segmente acetabulum and femoral modeling by spherical mask,obtain the APP by Tangent point correction algorithm,obtain MSP by Iterative Closest Point algorithm,establish standardized PCS and verify its accuracy and reliability;2.Based on standard PCS,fit the acetabular circle and verify its accuracy and reliability,obtain CT data of 100 Chinese subjects and 3D acetabular orientation was investigated;3.Femoral measurement algorithm was used to automatically model the entire medullary cavity of the femur and key anatomical parameters of the proximal femoral medulla were measured in 30 healthy patients.According to the proximal femoral medullary cavity,personalized short stem was designed and made by means of AM.RESULTS1.The establishment of the pelvis model and standard PCS have excellent accuracy(1-3mm)and reliability(ICC > 0.90).2.Significant differences were detected between males and females the three kinds of definitions of anteversion,and there were significant differences in anatomical abduction angle.3.The measurement of the femur has excellent accuracy and repeatability(> 0.87),and based on the proximal anatomical morphology of the femoral medullary cavity,personalized femoral short stem can be designed and made by AM.CONCLUSIONS1.A novel algorithm tailored to segmentation of the hip joint was used to construct3 D pelvic models and e A surface-based method was developed to establish a reliable 3D PCS,and the PCS has excellent accuracy and reliability.It can fully meet the clinical needs.2.significant differences were detected between male and female.Intrapatient acetabular orientations were symmetrical,but interpatient acetabular orientations ranged widely.3.On the basis of three-dimensional anatomical characteristics of proximal femoral medullary cavity,combined with the concept of "priority areas" and priority zone in the design of femorl stem proposed by Kerong Dai,personalized short femoral stem was designed.With AM,personalized short femoral stems were manufactured in order to study the biomechanical and histological properties.