ABSTRACT
<p><b>OBJECTIVE</b>To explore a new approach to determining the location of S1 screw for percutaneous screw fixation of the sacroiliac joint using a targeting device.</p><p><b>METHODS</b>Virtual three-dimensional pelvic models were reconstructed using the computed tomography (CT) scan data obtained from 100 adult subjects without any bony abnormalities. Mimics software was used to determine the ideal operating plane for S1 sacroiliac screw fixation based on the osseous marks. The parameters for screw fixation on the plane were measured, including the entry point, the needle angle (γ) and the safety range, and the accuracy of these parameters was verified using the digital models.</p><p><b>RESULTS</b>The ideal operating plane could be determined by the osseous prominences of ASIS (A) and PSIS (B) and the midpoint of S1 vertebral spines. The point at the posterior 1/3 of the line connecting points A and B could be defined as the entry point on the plane. The range of the needle angle γ was 101.4-117.2° for male and 109.5-120.78° for female patients, showing a significant sexual difference. Simulation results based on these parameters resulted in a total success rate of 91.25% (92.5% in male and 90% in female).</p><p><b>CONCLUSION</b>These parameters of the S1 screw can ensure a high success rate for percutaneous screw fixation of the sacroiliac joint and provide anatomical evidence for the development of a targeting device for the procedure.</p>
Subject(s)
Adult , Female , Humans , Male , Bone Screws , Fracture Fixation, Internal , Sacroiliac Joint , SoftwareABSTRACT
BACKGROUND:During open reduction and plate fixation for acetabular anterior column fracture, screw penetrating the articular surface often occurred. To prevent this complication, quantitative anatomical measurement is very important for safe pedicle screw in acetabular area using anterior column plate technology. OBJECTIVE:To provide anatomical basis for screwing placement safely in acetabular anterior column plate. METHODS:Mimics Software was used to perform three-dimensional reconstruction of the 40 cases of male pelvic and 40 cases of female pelvic CT scan data. The cutting tool was used to make serial cross-sections of the acetabular anterior column and the measuring tool was used to determine the safe length and direction of screw entry on al entry points of each cross-section. Al data were uploaded into SPSS 13.0 software for statistics process. RESULTS AND CONCLUSION: The distance from anterior acetabular margin to posterior acetabular margin and iliopubic eminence was as folows: in males: (56.63±2.05) mm, (12.30±1.51) mm, and in females: (49.07±5.07) mm, (16.93±1.74) mm, respectively. The distance from posterior acetabular margin to iliopubic eminence was as folows: in males: (45.46±3.44) mm, and in females: (33.72±6.85) mm. The safe entry angle of screws to iliac plate in the sagittal plane was (72.17±0.93)° in males, and (81.05±0.92)° in females. On each section of B, C and D, the maximum of the safe entry angle of screws to iliac plate in the oblique coronal plane was (53.88±3.01)°, (43.22±1.86)°, (54.60±2.97)° in males; and (49.54±1.81)°, (39.10±1.22)°, (47.91±2.23)° in females, respectively. Results indicated that three-dimensional model can be used to measure anatomic characteristics of acetabular anterior column plate and has important instruction significance for avoiding screwing into joint in acetabular anterior column plate technique.