Fixation technique influences osteogenesis of comminuted fractures

Comminuted fractures most often are associated with compromised soft tissue conditions and diminished vascularization leading to a reduced osteogenesi s, In contrast to stable fixation by compression plating with lag screws, t he less stable but also less invasive techniques of external fixation, unre amed nailing, or bridging plates have become increasingly popular. The aim of this study was to compare the bone healing and osteogenesis of these fix ation techniques. A triple wedge osteotomy of the sheep tibia was used as a bone healing model. Internal compression plate fixation of all fragments w ith lag screws was used in one group. In the other three groups, only the m ain proximal and distal fragments were fixed by external fixation, unreamed interlocking nail, or bridging plate. The sheep with compression plate fix ation and lag screws showed the worst results after 12 weeks. The periostea l and endosteal osteogenesis and the apparent density of the newly formed b one in the fracture gaps were significantly lower than those seen in the sh eep in the other three technique groups. The best results were found for th e bridging plate and external fixator, From these results, it can be conclu ded that compression plate fi:nation should be avoided for treatment of com minuted fractures.