A primary imaging study on quantitative measurement of the supra-acetabular screw safe fixation zone
TAN Shan, GAO Shi-chang, ZHANG An-wei, CHEN Jian-fei
Chinese Journal of Clinical Anatomy ›› 2018, Vol. 36 ›› Issue (3) : 259-263.
A primary imaging study on quantitative measurement of the supra-acetabular screw safe fixation zone
Objective To investigate the entry point location and orientation of the supra-acetabular screw as well as its safe corridor size. Methods 100 (male 50, female 50) CT data of pelvis were collected from our hospital. The three-dimensional model of supra-acetabular corridor (oriented from the anterior inferior iliac spine (AIIS) to posterior superior iliac spine (PSIS) was reconstructed by Mimics software. On the horizontal scan, the screw was placed along the two midpoints of the anterior and posterior narrowing in the corridor, and the relevant parameters of safe corridor were measured from inferior to superior at an interval layer thickness of 2.5 mm. On the middle layer, the orientations of the central virtual screws were measured and the position relation between the entry point and the center apex of AIIS was determined. The safe fixation zone was measured by moving the tip of the screw on the horizontal and sagittal planes. Results There were two narrowing in the supra-acetabular corridor. From inferior to superior, the width of the anterior narrowing had the characteristic of narrow-wide-narrow and the posterior narrowing became wider and wider. The width for safe fixation corridor from inferior to superior had the feature of narrow-wide-narrow. The width of the corridor on the middle layer was (10.61±2.10) mm for male and (8.44±2.03) mm for female (t=7.413，P<0.001). On the middle layer, the distances from the entry point to anterior narrowing, greater sciatic notch and posterior narrowing were about 50 mm, 70 mm and 100 mm, respectively. The whole length of the corridor was about 130 mm. The inward inclination angle was (29.50±4.05) degrees for male and (28.00±3.78) degrees for female (t=2.709, P=0.007), and the virtual screw had a safe rang about 5 degrees. The cranial inclination angle was (29.40±5.38) degrees for male and (28.57±6.01) degrees for female (t=1.025, P=0.306), and the safe rang was about 10 degrees. 97% of the entry points were located on the lateral area of the AIIS, and 71% in the lateral-inferior quadrant. Conclusion The entry point of the supra-acetabular screw are located on the lateral area of the AIIS. The inward and cranial inclination angles are both about 30 degrees.
Supra-acetabular fixation; / Pelvic fracture; / Anterior inferior iliac spine; / Imaging study
[1] Tscherne H, Pohlemann T, Gnsslen A, et al. Crush injuries of the pelvis[J]. Eur J Surg, 2000, 166(4): 276-282.
[2] Galois L, Pfeffer F, Mainard D, et al. The value of external fixation for unstable pelvic ring injuries[J]. Acta Orthop Belg, 2003, 69(4): 321-327.
[3] Calafi LA, Routt ML. Anterior pelvic external fixation: is there an optimal placement for the supra-acetabular pin[J]. Am J Orthop (Belle Mead NJ), 2013, 42(12): E125-E127.
[4] Haidukewych GJ, Kumar S, Prpa B. Placement of half-pins for supra-acetabular external fixation: an anatomic study[J]. Clin Orthop Relat Res, 2003, 411(6): 269-273.
[5] Gardner MJ, Kendoff D, Ostermeier S, et al. Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone[J]. J Orthop Trauma, 2007, 21(7): 435-441.
[6] Vigdorchik JM, Esquivel AO, Jin X, et al. Biomechanical stability of a supra-acetabular pedicle screw internal fixation device (INFIX) vs external fixation and plates for vertically unstable pelvic fractures[J]. J Orthop Surg Res, 2012, 7(9): 31-35.
[7] Gardner MJ, Nork SE. Stabilization of unstable pelvic fractures with supraacetabular compression external fixation[J]. J Orthop Trauma, 2007, 21(4): 269-273.
[8] Berry JL, Stahurski T, Asher MA. Morphometry of the supra sciatic notch intrailiac implant anchor passage[J]. Spine (Phila Pa 1976), 2001, 26(7): E143-E148.
[9] Schildhauer TA, McCulloch P, Chapman JR, et al. Anatomic and radiographic considerations for placement of transiliac screws in lumbopelvic fixations[J]. J Spinal Disord Tech, 2002, 15(3): 199-205.
[10]Mitchell PM, Corrigan CM, Patel NA, et al. 13-Year experience in external fixation of the pelvis: complications, reduction and removal[J]. Eur J Trauma Emerg Surg, 2016, 42(1): 91-96.
[11]汪方, 唐昊, 王秋根, 等. 髋臼上方置钉骨盆外固定的应用解剖[J]. 解剖学杂志, 2010, 33(3): 377-380.
[12]Mischkowski RA, Selbach I, Neugebauer J, et al. Lateral femoral cutaneous nerve and iliac crest bone grafts--anatomical and clinical considerations[J]. Int J Oral Maxillofac Surg, 2006, 35(4): 366-372.
[13]Bjurlin MA, Davis KE, Allin EF, et al. Anatomic variations in the lateral femoral cutaneous nerve with respect to pediatric hip surgery[J]. Am J Orthop (Belle Mead NJ), 2007, 36(3): 143-146.
[14]Osterhoff G, Aichner EV, Scherer J, et al. Anterior subcutaneous internal fixation of the pelvis - what rod-to-bone distance is anatomically optimal [J]. Injury, 2017, 48(10): 2162-2168.
/
| 〈 |
|
〉 |
