Study On The Relationship Between The Selection Of The Collum Femoris Preserving Prosthesis Type And The Parameters Of The Proximal Femoral Medullary Cavity

Objective:To determine the factors affecting the morphological parameters of the proximal femoral medullary cavity and the regularity of the type selection of the Collum Femoris Preserving(CFP)prosthesis.Preparation of a suitable prosthesis before surgery could reduce the operation time,improve the accuracy of prosthesis fixation and increase the safety of operation.Method: The patients who underwent CFP total hip arthroplasty in The Third Hospital of Hebei Medical University from August 2015 to March 2016 were selected as the research objects.We measured 200 hips of 157 patients,which include 123 hips of 99 males aged 48.2±11.9(ranging from 22 to 76)and 77 hips of 58 females aged 53.3±12(ranging from 28 to 74).The left hips account for 43.5% and the others are right hips.Application of PACS software was used to measure the femoral parameters that included the medullary cavity diameter at the level of lesser trochanter center(T0),the medullary cavity diameter at the level of 20 mm above the lesser trochanter center(T+20),the medullary cavity diameter at the level of 20 mm below the lesser trochanter center(T-20),the medullary cavity diameter at the level of the stem tip,the isthmus width,the extracortical width at isthmus level,the location of the isthmus,the residual neck,the femoral canal flare index(CFI),the metaphyseal canal flare index(MCFI),the distal canal flare index(DCFI),cortical index(CI),Noble type.The sex,age,height,weight and the body mass index(BMI)was recorded.The parameters were all processed statistically represented by mean ± standard deviation and compared with T test,variance analysis and correlation analysis.Results:1 T+20 is 43.81±4.28 mm,T-20 is 26.48±3.42 mm,T0 is 18.78±2.63 mm,T tip is 12.62±2.04 mm,the internal diameter of the isthmus is 11.06±2.09 mm,the external diameter of the isthmus is 7.08±2.79 mm,the location of the isthmus is 105.99±11.98 mm,the reside neck is 18.38±3.67 mm,the offset is 42.50±6.19 mm,CFI is 4.18±0.82,MCFI is 2.42±0.31,DCFI is 1.73±0.24,CI is 0.57±0.08,the cortical thickness is 7.51±1.39.2 Compared with other domestic groups,the parameters of our group have no statistical significance.Compared with Noble and Massin,T+20?T0?T-20?the internal diameter of the isthmus and the location of the isthmus are all significantly smaller.3 There was no significant difference in the proximal femur parameters between the left and right sides,and there was also no significant difference between the left and right side of prosthesis types.4 There was statistical significance in T+20?T0?T-20?the internal diameter of the isthmus during genders.The proximal femoral medullary cavity of the male was larger than that of the female,and the majority prosthesis types of male patients were actually M,while the female patients were mainly S.5 There was a positive correlation between the height and the parameters of the proximal femoral medullary cavity,which was positively correlated with the femoral prosthesis type.There is a positive correlation of body weight,body mass index and isthmus diameter,cortical thickness.6 T+20,T0,T-20,the internal diameter of the isthmus and the location of the isthmus of the DDH group is smaller than other groups,the difference is statistically significant,while there is no significant difference between the groups of other diseases.The femoral stem model of DDH patients is mainly XS and S.7 T0 and T-20 in the different types of femoral stem has statistically significant difference,T+20 has no statistically significant difference,CFP femoral stem type selection was not significantly correlated with T+20,and was positively correlated with T0 and T-20.8 The internal diameter of the medullary cavity in the isthmus level has a strong positive correlation with that in the prosthesis tip level,and there is a strong positive correlation with stem type selection.9 There is a strong correlation between CFI,MCFI,Noble typing and the selection of femoral stem,and there is a weak correlation between DCFI and femoral stem type selection.Conclusion: 1 Compared with the European and American people,the proximal femoral medullary cavity diameter of the Chinese is relatively smaller,and the proportion of champagne bottle type cacity is significantly larger.The actully used prosthesis type is focused on XS-M type and bias to smaller types.So the CFP prosthesis based on the west is larger to the Chinese.2 There was a positive correlation between height and the parameters of proximal femoral medullary cavity and CFP femoral stem type.The diameter of the femoral medullary cavity became larger with the increase of height,and the type of CFP prosthesis became larger,too.3 Comparison of different disease groups,the proximal femoral medullary cavity diameter of the hip diaplasia patients became smaller and a smaller type of prosthesis is needed to be prepared before surgery or we need prepare a relatively thin distal prosthesis.4 CFP prosthesis type is closely related to the internal medullary cavity diameter at the level of the lesser trochanter center?below 20 mm of the lesser trochanter center and the isthmus.5 CFI,MCFI can be a very good response to the medullary cavity morphology of the proximal femur and the greater trochanter and highly correlated to CFP prosthesis type.The smaller of the CFI and MCFI,the larger of the CFP prosthesis type is used in operation.