PLACEMENT OF SCREWS IN THE SUSTENTACULUM-TALI - A CALCANEAL FRACTURE MODEL

Current methods of treating calcaneus fractures vary greatly, and many techniques of internal fixation have been described. The study of the se fractures has been limited in part by the lack of a suitable labora tory model, In this study, a new cadaveric model of calcaneus fracture s was developed, using a combination of osteotomies and impaction, The model allows a pattern of intraarticular :injury to be reproduced con sistently. The model was used to examine one aspect of internal fixati on, It was hypothesized that fixation would be more stable if the scre ws supporting the posterior facet were incorporated into the lateral p late, as opposed to being separate from the plate. Six pairs of anatom ic specimen legs were used, and each pair was divided randomly between two experimental groups. In Group A (screws out), the posterior facet screws were outside the plate, and in Group B (screws in), the screws were incorporated into the plate. The strength of the reconstructed c alcanei were evaluated by axial loading of the limb through the tibia, Stiffness and energy to failure were significantly greater and Bohler 's angle significantly less compromised in Group B, It was concluded t hat the position of the articular fragment of comminuted calcaneal fra ctures will be maintained at higher loads when the screws in the poste rior facet are incorporated into the lateral plate. The model of calca neal fractures described in this study may be suitable for examining o ther aspects of fixation.