97. MINIMALLY INVASIVE TREATMENT OF UNSTABLE PELVIC RING INJURIES WITH AN INTERNAL ANTERIOR FIXATOR (INFIX) AND POSTERIOR ILIOSACRAL SCREWS

Abstract

Purpose: The purpose of this paper is to present a novel technique of anterior fixation of unstable pelvic fractures which is minimally invasive, biomechanically suitable, easy to apply, and uses readily available spinal implants.

Method: Eighteen consecutive patients with unstable pelvic fractures (AO type A-12 patients and type B-6 patients) underwent stabilization using the novel technique of fixation and were included in the study. Two trauma trained orthopedic surgeons performed all the procedures. All patients were evaluated clinically and with imaging studies that included antero-posterior, inlet and outlet radiographs and a CT scan. At surgery the posterior instability was addressed first with iliosacral screw fixation following reduction of the fracture in a standard fashion. A 2–3cm longitudinal incision was then made over the anterior inferior iliac spine bilaterally to obtain a starting point in the supra acetabular region. Pedicle screws of size 7mm or 8mm x 80mm (Synthes Spine Paoli, USA) were then placed in the supra-acetabular position under fluoroscopic guidance. A pre-contoured 6mm titanium rod with a bow was then tunneled subcutaneously to connect the screws. Care was taken to place the rod just below the lower abdominal crease to prevent pressure on the bowel or vascular structures. The implants were compressed using standard compressors and C-rings. Patients were followed until the pelvis fracture healed as documented on X-rays and clinical exam.

Results: Patients were followed for a minimum 6 months (range 6–12 mo). All patients healed by 3 months (similar to our prior experience using other methods). Complications included: 2 deaths in poly trauma patients unrelated to the pelvic procedure; 2 patients with transient lateral femoral cutaneous nerve palsy (one on each side), and one early implant failure due to a surgical technical error that was re-operated the next day.

Conclusion: Disruptions of the pelvic ring are complex injuries and should be managed on a case specific basis. By employing the established principles of supra-acetabular fixation, this technique allows for minimally invasive, definitive internal anterior fixation. The potential complications of pin tract infection and a cumbersome external appliance associated with external fixation are avoided with this technique and better patient acceptance is achieved.