RESORBABLE RODS AND SCREWS FOR THE FIXATION OF ANKLE FRACTURES - A PROSPECTIVE RANDOMIZED CLINICAL-TRIAL

A prospective randomized clinical trial was performed to evaluate the use of self-reinforced absorbable composites (Biofix) in the fixation of ankle fractures. The aim of this study was to demonstrate that fixa tion with Biofix rods and screws is as good as the standard A. O. fixa tion. The benefits of Biofix rods and screws are: a reduction in costs since no secondary operation is needed, prevention of stress-shieldin g and thereby diminishing the risk of bone porosity. Patients aged bet ween 16 and 75 years old with closed, non-comminuted fractures of the lateral and/or medial malleolus and dislocation of the fracture fragme nts greater thean 2 mm were included in the study. 22 patients were tr eated with Biofix rods and screws and the control group of 19 patients with a standard technique. After 3, 6 and 12 months, rontgenograms we re taken. At the same time functional results were evaluated following the criteria of Olerud and Molander. Two patients were withdrawn from the trial for non-medical reasons. 22 patients (12 from the Biofix gr oup, 10 from the AO group) operated two or more years ago were contact ed to see if any complications had occured since they were last seen. In 4 cases a Biofix screw broke down just beneath the head during inse rtion. This did not result in an insufficient fixation of the fracture . There were no early post-operative complications. The functional and rontgenological results in both groups were equal. In three cases a s terile sinus developed at the site of screw insertion. Biofix rods and screws, made of polylactic acid, are a good alternative for the fixat ion of fractures of the ankle. The use of resorbable fracture fixation material has the advantage that a second operation to remove osteosyn thesis material is not necessary. The long term results are good. Ther e is, however, a possibility of development of tissue reaction to the resorbable material.