237. PERTINENCE OF BI-ILIAC POSTERIOR POLYAXIAL SCREW FIXATION FOR UNSTABLE INJURY OF THE PELVIC GIRDLE

Abstract

Purpose of the study: Different posterior osteosynthesis techniques have been described for the treatment of unstable injury of the pelvic girdle. Bi-iliac fixation using threaded rods or plate-screw fixation has been proposed. The purpose of this work was to describe a modification of the posterior osteosynthesis using instrumentation designed for the spinal column.

Material and methods: From January 2006 to October 2008, four patients (three men, one woman, mean age 24 years, range 18–34) underwent surgery in our unit for unstable fractures of the pelvis with a trans-sacral posterior fracture line (AO classification C1.3–4). Two patients presented neurological signs including one by head trauma with hemiplegia. Two patients had an anterior fixation with an external fixator and another an anterior plate fixation. The operation was conducted via a posterior midline incision. After reduction of the fracture, the osteosynthesis was achieved with two poly-axial screws inserted in each of the iliac wings and connected by two rods and one or two cross connectors.

Results: Mean follow-up was 7.5 months (range 5–17). None of the patients developed infectious, neurological or mechanical complications postoperatively. Complete pain-free weight-bearing and walking were achieved in patients at three months. None of the patients had a horizontal or vertical misalignment callus measuring more than 5 mm. Screw analysis showed that three screws penetrated the sacroiliac joint in the first patient of the series with no clinical consequence.

Discussion: This posterior fixation technique for unstable fractures of the pelvis appears to be reliable and reproducible for type C fractures in combination with anterior fixation. It uses standard instrumentation for spinal osteosynthesis. A study with a larger population and longer follow-up is needed.