© 2019 Archives of Trauma Research | Published by Wolters Kluwer - Medknow 41 Case Report INTRODUCTION Bilateral sacroiliac joint dislocation is a very unusual and potentially life-threatening injury secondary to high-energy trauma. Given its low incidence and the limited number of cases reported, [1-3] guidelines are not available to treat this condition. It has been hypothesized that the mechanism of injury involves posterior-anterior compression force [4-7] with the lower extremities in a hyperflexed position. [8] This injury corresponds to 61C3.1 according to the AO Classification. Although this lesion constitutes a lost connection between the axial skeleton and pelvis, the term spondylo-pelvic dissociation is not exact and should be reserved for transverse sacral fractures (U, H, or Y types). [9,10] CASE REPORT The patient was a 15-year-old woman involved in a motor vehicle accident. She exhibited signs of peripheral hypoperfusion, including being cold, pale, and clammy (Glasgow Coma Scale 12/15). Vital signs were: Blood pressure, 90/50 mmHg; heart rate, 120 bpm; respiratory rate, 16 bpm; and O2 Sat, 99%. She complained of back and left lower-extremity pain. Hematuria was not observed in the Foley catheter. She exhibited mild lower abdominal stiffness and pain on palpation, ecchymosis in the posterior right thigh and mild internal rotation of her left lower extremity. She was able to mobilize both lower extremities with pain. A blood test revealed the following: Hb, 7.5 g/dL; Ht, 20.7%; and platelets, 100,000. Values compatible with consumption coagulopathy were noted. Abstract Sacroiliac joint dislocation is an uncommon and potentially life-threatening injury secondary to high-energy trauma. Given that bilateral sacroiliac joint dislocation has rarely been reported, its management constitutes a clinical challenge. The aim of this study was to review the literature available about sacroiliac joint dislocation management and to show an effective and reliable method to treat this kind of injury. Case report. We present a 15-year-old female patient who suffered a complete bilateral sacroiliac joint dislocation. The definitive treatment consisted of bilateral L4-iliac assembly plus right sacroiliac screw assisted by an O-arm navigation system. Surgical instrumentation allowed mobilization and full-weight-bearing a few days after surgery. At the 2-year follow-up, the patient remained asymptomatic. The triangle fixation technique stabilizes the sacroiliac joint and binds the lumbar spine to the pelvis. This method could represent a good option that allows early mobilization and weight-bearing. Keywords: Iliac posterior instrumentation, O-arm navigation, sacroiliac joint dislocation, unstable pelvic fractures Access this article online Quick Response Code: Website: www.archtrauma.com DOI: 10.4103/atr.atr_90_18 Address for correspondence: Dr. Fernando Moreno Mateo, Avda Ramón y Cajal 3, 5º Planta Este, Secretaría de Traumatología 47003, Valladolid, Spain. E‑mail: fmorenomateo@gmail.com This is an open access journal, and arcles are distributed under the terms of the Creave Commons Aribuon‑NonCommercial‑ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as appropriate credit is given and the new creaons are licensed under the idencal terms. For reprints contact: reprints@medknow.com How to cite this article: Mateo FM, Ramajo RH, Trigueros Larrea JM, Maniega SS, Aragón FA, González DC. Bilateral sacroiliac joint dislocation treated by posterior instrumentation case report and literature review. Arch Trauma Res 2019;8:41-4. Received: 17-11-2018, Accepted: 30-04-2019. Bilateral Sacroiliac Joint Dislocation Treated by Posterior Instrumentation Case Report and Literature Review Fernando Moreno Mateo, Rubén Hernández Ramajo, José María Trigueros Larrea, Silvia Santiago Maniega, Francisco Ardura Aragón, David César Noriega González Department of Traumatology and Orthopaedic Surgery, Universitary Hospital of Valladolid, Valladolid, Spain ORCID: Fernando Moreno Mateo: 0000‑0002‑8111‑6173 Rubén Hernández Ramajo: 0000‑0001‑9775‑9758 José María Trigueros Larrea: 0000‑0001‑9775‑9758 Silvia Santiago Maniega: 0000‑0002‑8111‑6173 Francisco Ardura Aragón: 0000‑0002‑9348‑5646 David César Noriega González: 0000‑0002‑5909‑1555