Prospects for bone fixation - development of new cerclage fixation techniques

The principles for the fixation and treatment of bone fractures have been w ell established based on the multidisciplinary studies performed by the Arb eitsgemeinschaft fur Osteosynthesefragen/Association for the Study of Inter nal Fixation (AO/ASIF group). As the basis for modem internal fixation of f ractures, these principles are presently supported by the majority of ortho pedic surgeons. However, with recent advances in bioengineering and biomate rials, it has become necessary to reconsider these principles. We focused o ur attention on cerclage fixation, which is not considered so important by the AO group, and developed two new cerclage materials. One is a nylon strap that is in wide industrial use. In the field of orthop edics, Partridge first employed the nylon strap for internal fixation and d emonstrated its efficacy in 1976. However, its use was thereafter discontin ued because of various complications. We developed a nylon strap for temporary fracture fixation and demonstrated its efficacy in clinical studies. We also developed a bioabsorbable thread for the tight tying of bones. Bone fixation with a thread is sometimes use d clinically, but adequate fixation often cannot be obtained because of loo sening of the knot. Therefore, we prepared a blended thread by mixing poly- L-lactic acid (PLLA) and epsilon -polycaprolactone (PCL) fiber, so that it could be fixed tightly by melting. The fatigue strength of this thread was higher than that of a stainless-steel wire with the same cross-sectional ar ea. We are aiming to establish more effective and convenient methods of treatme nt by developing new bone fixation materials and examining their efficacy. In the future treatment of fractures, it will be important to develop new i nstruments and bone fixation materials for the purpose of standardizing the procedures used by surgeons. (C) 2001 Elsevier Science B.V. All rights res erved.