INTERFRAGMENTARY LAG SCREWS AND EXTERNAL FIXATION FOR SEVERE OPEN TIBIAL FRACTURES - A BIOMECHANICAL AND CLINICAL-STUDY

The stability offered by the interfragmentary lag screw with a unilate ral external fixator frame was studied in both experimental and prospe ctive clinical studies. The in-vitro stability of the fixation with an d without the interfragmentary lag screw was tested by a universal tes ting machine in compression, four-point bending, and torsion in 18 hum an tibiae. The in-vivo study was conducted prospectively in 18 patient s with 19 severe open tibial fractures. All patients were treated with one definite surgical procedure on admission. The interfragmentary la g screw increased the system stiffness 47.4 times in compression, 9.9 times in bending, and 3.2 times in torsion. The immediate one-stage ca re of severe open fractures with a simple external fixation system in combination with the interfragmentary lag screw shortens hospitalizati on and may enhance healing.