The Research On Percutaneous Internal Fixation Using Sacroiliac Screw In Dorsal Position For Treatment Of Pelvic Posterior Ring Injuries

Objective: Pelvic posterior ring, which locotes posterior part of the pelvic ring, is the hinge of the function transferring through our body and the core of pelvic function. The integrity and succession of the pelvic anatomic structure are the foundation of its vitodynamics stability and also are the premise of completing its function. Complicated pelvic fracture including sacrum bone fracture mostly displays pelvic posterior ring injuries. Internal fixation using sacroiliac screw is a fine surgery method in curing pelvic posterior ring injuries. But at present, internal fixation using sacroiliac screw is performed in prone position, making some patients who can't in prone position not to be cured effectively. The experiment measures the S₁ correlated parameter by pelvic X-ray plain film and MRI three dimensional picture, and provides theoretical basis for percutaneous internal fixation using sacroiliac screw in dorsal position for treatment of pelvic posterior ring injuries. Through the internal fixation using sacroiliac screw operation of the corpse in dornal and prone position, approach the feasibility of percutaneous internal fixation using sacroiliac screw in dorsal position for treatment of pelvic posterior ring injuries, and compare it with internal fixation using sacroiliac screw in prone position. Using this method in clinic and learn the curative effect of percutaneous internal fixation using sacroiliac screw in dorsal position for treatment of pelvic posterior ring injuries .Methods: 1.Choose 101 examples common adult pelvic A-P position X-raypolished section, tagging with metal stud at the apogee of the anterior superior iliac spine, and measure the vertical dimension between S₁ upper lamina terminalis and the line which is from double anterior superior iliac spine to the apogee of the iliac crest. 2.Measure S₁ correlated parameters in MRI three dimensional picture, including centrum height, transverse diameter A-P diameter, angle of ambi-side cacroiliac joint and effective length of double-side pedical of vertebral arch; measure the orbit of the screw whose diameter is 7.2mm in the pedicle of vertebral arch through traverse and coronal position pictures, and the screw whose width is 7.2mm and length exceeds the effective length of the pedicle of vertebral arch should be designed to rect heliostele. 3.Choose 10 common adult hygro-corpses , and decide the entering screw 's point , the entering screw's angle and direction of internal fixation using sacroiliac screw through the vertical dimension which is from S₁ upper lamina terminalis to the link of double-side anterior superior iliac spines and S₁ correlated parameters in MRI three dimensional picture. Under the clairvoyance of the C-type brachium, one hollow screw should be inserted by percutaneous sacroiliac in dorsal position on the left of the 10 corpses and another hollow screw should be tackled at the same way on the right of the 10 corpses. After the operation, screen the X-ray polished section of pelvic A-P position, lateral projection of the lumbar vertabrae and scan pelvic posterior ring by CT, watching the screw entering position and make statistic analysis of the results in that two ways. 4.Choose 7 examples of clinical pelvic fracture patients, who all have pelvic posterior ring injuries which should be dealt with. Insert a 7.2mm hollow titanium screw per cutem sacroiliac in dorsal position by the clairvoyance of C-type brachium, make ambi-side one pou , and insert 8 screws in all, also treat other bone joint damages at the same time. After the operation, screen the X-ray polished section of the pelvic A-P position and the lumbar vertabrae lateral position, and scan pelvic posterior ring by CT, watch the screw entering position and make statistic analysis.Results: The vertical dimension from S₁ pervious lamine terminals toambi-anterior superior iliac spine is 39.886±11.156 mm in X-ray of pelvic anteroposterior position. And the vertical dimension from S₁ pervious lamine terminals to apogee of iliac crest is 40.497±10.588mm. There is nonsignificant difference between them. In MRI three dimensional picture, the S₁ correlated parameter measure: for adult male, height of S₁ vertebral body is 24.393±3.232mm, transverse diameter is 51.049±5.611mm, sagittal diameter is 34.951±3.862mm; In S₁ pedicle of vertebral arch effective length: left is 74.262±6.324mm and right is 73.049±6.448mm, its diameter: left is 14.721±2.339mm and right is 14.459±2.453mm; angle of ambi- cacroiliac joint: left is 26.918±8.572°and right is 28.410±9.458°.For adult female, height of S₁ vertebral body is 23.232mm±2.115mm, transverse diameter is 51.429±4.238mm, sagittal diameter is 33.946±3.640mm; In S₁ pedicle of vertebral arch effective length: left is 74.357±4.354mm and right is 74.375±4.685mm mm, diameter: left isl4.804±2.268mm and right is 13.625±2.137mm; angle of ambi- cacroiliac joint: left is 30.196±9.170°and right is 30.429±9.314°.In adult MRI picture coronal, height of ambi-S₁ pedicle of vertebral arch: left is 21. 857±2. 859mm and right is 21. 906±2. 684mm; Left angle is 20. 950±4. 674°and right is 21. 620±4. 524°; In ambi- pedicle of vertebral arch the largest movement extent of 7.2mm screw: left is 1. 241±7. 827°- 30. 440±3.815°and right is 0. 912±7. 354°- 32.403±3.793°.10 examples of cadaver were inserted 10 screws in dorsal and prone position separately per cutem sacroilio, according to the link -distance parameter which is from S₁ upper lamine terminalis to ambi-side anterior superior iliac. spine measured by pelvisc A-P position X-ray polished section and the S₁ correlated parameter measured by MRI three dimensional picture. By comparison of operation method, operation time, perspective time and site of screw, site of screw has three stage: well, good and difference. Both of two methods has one screw in vertebral canal and there is nonsignificant difference in statistics. In clinic, seven patients has been treated by method of putting screw in cadaver. There is eight screws in total and one cadaver have two sides. Besides seven screws have good site,one screw break S1 vertebral body posterior contex into vertebral canal and there are no complications. Analysis of statistics displays significant difference.Conclusions: For pelvic fracture patient, doctor must pay attention to diagnosis and treatment of pelvic posterior ring. According to pelvis A-P position X-ray distance from S1 previous lamina to ambi-anterior superior iliac spine and MRI three dimensional picture S1 correlated parameter measurement, intersection of 2-3cm above anterior superior iliac spine and posterior axillary line ahead 20°- 30°.Per cutem insertion sacrum-ilium screw in supine position, needling inclining 5°- 15°toward foot is the best pathway. Through operate in corpse and application in clinic, per cutem insertion sacrum-iliurn hollow screw in perspective and supine position is safe and feasible. There is a new pathway for treatment of pelvic fracture pelvic posterior ring injuries and it is to be worth to spread and application in clinic. Operation doctor should be familiar with pelvic anatomy and earnest with location at X-ray perspective in operation. You cannot blind burr hole to insert screw to avoid operation complication.