FIXATION STRENGTH OF A BIODEGRADABLE SCREW IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

We compared the strength of fixation of a biodegradable screw with tha t of two metal screws in a bone-patellar-tendon-bone (BPTB) graft in t he bovine knee. We used 33 fresh BPTB specimens with a circular tibial bone plug of 9 mm in diameter which were anchored in a tibial metaphy seal bone tunnel with either an interference screw (n = 11), an AO can cellous screw (n = 11) or a fibrillated, self-reinforced biodegradable poly-L-lactide screw (n = 11) The mean force to failure (+/-SD) in th e three groups was 1358 +/- 348 N, 1081 +/- 331 N and 1211 +/- 362 N, respectively. There was no significant difference in the groups with r egard to the linear load or the elastic moduli of the fixation. We con clude that the biodegradable screw is as good as either of the two met al screws in the fixation of a BPTB graft in the bovine knee and can b e recommended for ACL reconstruction using this type of graft.