Spino-Pelvic Fixation in Unstable Sacral Fracture: A Case Report

A 22-year-old female patient visited the emergency room (ER) after a pedestrian traffic accident in a drunken state. An examination at the ER revealed fractures at the right side of the sacral ala, sacral foramina, left anterior acetabulum, right inferior ramus, and right superior articular process of S1. She underwent spino-pelvic fixation and iliosacral (IS) screw fixation. One year later, bone union was completed and implant removal was performed and the treatment was completed without complications. The authors recommend spino-pelvic fixation and IS screw fixation for unstable sacral fractures as one of the excellent methods for obtaining posterior stability of the pelvis among the various treatments of unstable sacral fractures.

Free Hand Insertion Technique of S2 Sacral Alar-Iliac Screws for Spino-Pelvic Fixation: Technical Note, Acadaveric Study

A rigid spino-pelvic fixation to anchor long constructs is crucial to maintain the stability of long fusion in spinal deformity surgery. Besides obtaining immediate stability and proper biomechanical strength of constructs, the S2 alar-iliac (S2AI) screws have some more advantages. Four Korean fresh-frozen human cadavers were procured. Free hand S2AI screw placement is performed using anatomic landmarks. The starting point of the S2AI screw is located at the midpoint between the S1 and S2 foramen and 2 mm medial to the lateral sacral crest. Gearshift was advanced from the desired starting point toward the sacro-iliac joint directing approximately 20degrees angulation caudally in sagittal plane and 30degrees angulation horizontally in the coronal plane connecting the posterior superior iliac spine (PSIS). We made a S2AI screw trajectory through the cancellous channel using the gearshift. We measured caudal angle in the sagittal plane and horizontal angle in the coronal plane. A total of eight S2AI screws were inserted in four cadavers. All screws inserted into the iliac crest were evaluated by C-arm and naked eye examination by two spine surgeons. Among 8 S2AI screws, all screws were accurately placed (100%). The average caudal angle in the sagittal plane was 17.3+/-5.4degrees. The average horizontal angle in the coronal plane connecting the PSIS was 32.0+/-1.8degrees. The placement of S2AI screws using the free hand technique without any radiographic guidance appears to an acceptable method of insertion without more radiation or time consuming.

Treatment of Unstable Sacral Fractures Related to Spino-Pelvic Dissociations

PURPOSE: To evaluate the outcomes of surgical treatment modality in unstable sacral fractures combined with spinal and pelvic ring injury depending on the presence of spino-pelvic dissociations. MATERIALS AND METHODS: The subjects were 16 patients, with unstable sacral fractures combined with spinal and pelvic ring injuries, were operated from July 2004 to January 2011. The patients were divided into 2 groups depending on the presence of spino-pelvic dissociations: those with dissociations were group 1, and those without dissociations were group 2. Group 1 was treated with spino-pelvic fixations using iliac screw, while group 2 was treated with percutaneous iliosacral screw fixations. The availability of the radiological bony union with its application periods, and clinical results using visual analogue scale (VAS) and oswestry disability index (ODI) were evaluated, retrospectively. RESULTS: Out of 16 patients, 8 patients in group 1 were treated with spino-pelvic fixation using iliac screw, and 8 patients in group 2 were treated with percutaneous iliosacral screw fixation. The mean bony union period was 17.4 weeks in group 1, and 19.6 weeks in group 2. The Mean VAS and ODI scores on the last follow-up were 2.5 points and 15.6 points in group 1, 2 points and 18.8 points in group 2, respectively. Both groups had favorable clinical results at the last follow-up. CONCLUSION: For surgical treatments of unstable sacral fractures, spino-pelvic fixation using iliac screws is advised for cases with combined spino-pelvic dissociation, while percutaneous iliosacral screw fixation is advised for cases without combined dissociation.