Treatment of unstable pelvic ring injuries with an internal anterior fixator: initial clinical series

Objective: To investigate the clinical effectiveness of minimally invasive subcutaneous pedicle screw and rod system in treatment of anterior pelvic ring injury. Methods: Altogether, 28 patients (17 men, 11 women; average age 39.8 years, range 19-68 years) with pelvic ring fractures were treated using a subcutaneous internal anterior fixation device composed of supra-acetabular spinal pedicle screws and a subcutaneous connecting rod (INFIX). Causes of injuries were traffic accidents (n=15), falling from a height (n=7), and crushing (n=6). The injuries were rated according to Young-Burgess and AO/OTA classifications: APCII or 61-B1 (n=3), LCI or 61-B2.1 (n=8), LCII or 61-B2.2/61-B2.3 (n=11), VS or 61-C1/61-C2 (n=6). Two pedicle screws were inserted bilaterally at the mid-ilium between the anterosuperior and anteroinferior iliac spine. The precontoured rod was tunnelled subcutaneously from one screw to the other. The caps of the pedicle screws were then tightened. For stable posterior ring fractures, only the anterior pelvic ring was stabilized with the device. For unstable posterior ring fractures, posterior injuries were addressed first, followed by anterior injuries. Results: Follow-up was 6-12 months (average 8.7 months). All patients tolerated the device well. All fractures healed within 3 months, without loss of reduction. There were no surgical-site infections and no loosening of the internal fixation. Femoral cutaneous nerve injuries were bilateral in seven patients and unilateral in five. All recovered within 3 months postoperatively. Conclusions: Advantages of this technique include its minimally invasive nature, stable fixation, and acceptable complications. It is an ideal method for stabilizing anterior pelvic ring fractures.