Screw fixation of pelvic fractures: the applied anatomy and clinical significance

Abstract

Objective To understand the thickness of each section of the pelvic loop and the positions of the peripheral large vessels and nerves,so as to provide evidence for the screw fixation of pelvic fractures. Methods A total of 74 normal osseous specimens of the pelvis(male 40 cases,female 34 cases) were selected for the present study.Pelvic center was taken as the dot,and the thickness of the pelvic bone along the pelvis line were measured in the clockwise direction.Thirty 30 CT images of normal pelvis were used to measure the bone thickness of the pelvic loop in the same manner.Moreover,cadaver specimens were also dissected and the position line of the peripheral large vessels and nerves of the pelvic loop were observed in the clockwise direction. Results(1) The thicknesses(mm) of the pelvic bone along the pelvis line(from 0:00 to 6:00) were 25.36±3.03(female 24.48±2.16),32.59±7.21(female 22.88±2.13),24.06±2.89(female 20.40±2.07),44.12±3.97(female 37.55±3.60),27.88±2.36(female 22.68±2.26),13.80±2.14(female 10.22±2.05),and 15.04±2.31(female 13.53±2.22),respectively;and the results of CT measurement were 25.44±2.95,30.45±7.14,24.49±2.74,44.35±4.21,27.66±2.12,14.06±1.86 and 15.85±2.15,respectively.(2)Based on the clockwise scale,the positions of the main vessels and nerves around the pelvic loop were as follows: the positions of the femoral nerves and the femoral arteries and veins were between 4:00 and 4:30 on the left and between 7:00 and 7:30 on the right;the positions of obturator nerve vessels were between 4:30 and 5:00 on the left and between 7:00 and 7:30 on the right.Conclusion When pelvic center is taken as the dot,it is simple and practical to determine the position of each point of the pelvis and the large vessels and nerves in the clockwise direction.The thickness of each part of the pelvic loop is important to guide screw internal fixation of the pelvic fracture.