Pp. Lin et al., PLACEMENT OF SCREWS IN THE SUSTENTACULUM-TALI - A CALCANEAL FRACTURE MODEL, Clinical orthopaedics and related research, (352), 1998, pp. 194-201
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.