Design and application of a drilling guide for iliosacral screw insertion in internal fixation of sacroiliac join

Abstract

Objective To design a drilling guide which can improve the success rate and quality of insertion of S1 pedicle iliosacral cannulated screw in internal fixation of the sacroiliac joint.Methods We designed a drilling guide. It consisted of a scale which could make measurement of length, a dial regulator which could adjust the transverse iliosacral screw angle (TSA), sagital iliosacral screw angle (SSA) and the distance from the iliosacral screw entrance point to the backbone (DIS) for the internal fixation of the sacroiliac joint. The device was used in clinic for 15 patients with unstable fracture of the pelvis involving the sacroiliac ligaments (3 cases), sacral zone Ⅰ (5 cases), sacral zone Ⅱ (5 cases), sacral zone Ⅲ (2 cases). They were 6 men and 9 women, aged from 19 to 60 years (mean, 45.6 years) . Altogether 18 cannulated S1 pedicle iliosacral screws were inserted through the guide using the data of TSA, SSA and DIS measured on the preoperative CT and X-ray films of the patients.Results The postoperative CT and X-ray examinations revealed that all the S1 pedicle iliosacral screws were accurately inserted with the same or similar TSA and SSA. Conclusions The drilling guide is reasonable in design and convenient in use. Moreover, it can improve the accuracy and quality of insertion of S1 pedicle iliosacral screws and reduce X-ray exposure to the operation staff. Key words: Pelvic bones; Fractures; Fracture fixation, internal; Bone nails; Sacroiliac joint