Digital Anatomic Study For Entry Point Of Percutaneous Cannulated Screw Fixation For The Pubic Symphysis Diastasis

Objective: By measuring the pelvic CT scan image in pubis symphysis of the normal adult male and female,establishing the appropriate entry point,angle and screw length in the image of percutaneous cannulated screw fixation for the treatment of pubic symphysis diastasis,so as to guide the clinical practical application.Methods:1 Materials: Select the inpatients and outpatients who were tested by the pelvic CT scan and three-dimensional reconstruction in The First Hospital of Qinhuangdao from June 2014 to 2015 June,excluding the patients who were dysplasia,epiphyses patent,pubic symphysis diastasis,pubic branch fracture,symphysis pubic tumor and poorly CT scanning angle.A total of 91 adult male and female patients with normal development were randomly selected,including 49 male patients and 42 female patients.Instruments: American GE company LightSpeed 64 row spiral CT,PACS medical image browsing software.2 Measuring Content: On CT section image,select the junctions of between the pubic tubercle and the superior branch of pubic bone,between the pubic tubercle and the lower part of the pubic symphysis respectively for the screw entry points.Measure the maximum distance from the point of entry to the other side of the bone,the angle of the nail and the thickness of the bone.Named the horizontal distance between the junctions of pubic tubercle and pubic branch for A1,the maximum distance of the left to right in the bone for A2 left,the relative angle for?_Aleft,the thinnest bone in the path of A2 left for A_{thick right},the maximum distance on the right side to the left in the bone for A2 right,the relative angle of for ?_Aright and the thinnest bone in the path of A2 right for A_{thick left}.Similarly,taking the junctions of between the pubic tubercle and the lower part of the pubic symphysis as the screw entry point,named the measurement indexes for B1,B2 left,B2_right,?B_left,?B_right,Bthick left and Bthick right.All measurements were measured for three times.Take the average values of three times of the results as the final measurement results,and record the results to retain two decimal places.3 Data Analysis: Data were analyzed by SPSS17.0 software.The results were described by mean±standard deviation??±s?.Test the normality of the content data respectively.If the data accords with normal distribution,then take two independent samples t-test,if the data does not conform to the normal distribution,then take the non-parametric test.Analysis the statistical difference of distance,angle and thickness between the left and right sides in the same sex and the same measuring pionts between the sexes.If P<0.05,the difference would be statistically significant.Results:1 In males,the length of A1 is 5.88±0.58cm;the length of A2 left is 8.16±0.83cm;the length of A2 right is 8.22±0.88 cm.There is no statistical difference about contrast?P>0.05?.The ?_Aleft is 17.21±2.10°;?_Aright is 17.42±2.21°.There is no statistical difference about contrast?P>0.05?.The A_{thick left} is 1.51±0.23cm;the A_{thick right} is 1.48±0.27cm;There is no statistical difference about contrast?P>0.05?.The length of B1 is 5.19±0.67cm;the length of B2 left is 6.45±0.36cm;the length of B2 right is 6.50±0.40 cm.There is no statistical difference about contrast?P>0.05?.The ?B_left is 26.42±1.34°;?B_right is 26.33±1.17°;There is no statistical difference about contrast?P>0.05?.2 In females,the length of A1 is 6.08±0.25cm;the length of A2 left is 7.08±0.38cm;the length of A2 right is 7.05±0.32 cm.There is no statistical difference about contrast?P>0.05?.The ?_Aleft is 16.34±2.02°;?_Aright is 16.55±1.76°;There is no statistical difference about contrast?P>0.05?.The A_{thick left} is 1.39±0.13cm;the A_{thick right} is 1.48±0.47 cm.There is no statistical difference about contrast?P>0.05?.The length of B1 is 4.62±0.69cm;the length of B2 left is 6.04±0.45cm;the length of B2 right is 6.03±0.47 cm.There is no statistical difference about contrast?P>0.05?.The ?B_left is 26.17±2.69°;?B_right is 25.77±3.09°.There is no statistical difference about contrast?P>0.05?.3 In contrast in males and females,there are significant differences among A1?A2_left?A2_right,?_Aleft,?_Aright,A_{thick left},A_{thick right},B1,B2 left,B2_right,Bleft thick,Bthick right,?P < 0.05?.There is no statistical difference between ?B_left and ?B_right?P > 0.05?.Conclusion:1 It is feasible that taking the junction of between the pubic tubercle and the superior branch of pubic bone as the screw entry point when horizontal nailing or inward rear angulated nailing.It has statistical difference?P < 0.05?between the sexes in the screw length and the angle.The females' length of horizontal screw is larger than the males' and the males' is larger than the females' in other indicators.2 It is feasible that taking the junction of between the pubic tubercle and the lower part of the pubic symphysis as the screw entry point when horizontal nailing or inward rear angulated nailing.It has statistical difference?P < 0.05?between the sexes in the screw length and the males' is larger than the females'.However,it has no statistical difference?P < 0.05?between the sexes in the screw angle?P >0.05?.3 In men and women,in the same position,the screw can get through the thinnest sclerotin and reached on the bone cortex in a certain angle.Moreover,the length is greater than the horizontal screw.So,the screw can have extensive contact with pubic symphysis,and can provide more powerful fixation for pubic symphysis diastasis.