Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Trauma - Ankle / Foot
Abstract number: 25864
A CADAVERIC STUDY COMPARING TWO-HOLE LOCKING PLATE TO
QUADRICORTICAL SCREW FIXATION IN MAISONNEUVE FRACTURE
Taher YOUSRI 1 , Gardner RICHARD 1 , Clark DAMIAN 1 , Holmes FIONA 2 , Phillip
POLLINITINE 2 , Tim HOLSGROVE 2 , Miles TONY 2 , Jackson MARK 1
1 University Hospitals Bristol NHS Trust, Bristol (UNITED KINGDOM), 2 University of
Bath, Bath (UNITED KINGDOM)
Introduction: Treatment of syndesmotic injuries is a subject of ongoing controversy.
Locking plates are fixed angle device that have been shown to provide both angular
and axial stability by eliminating the risk of the screw toggling in the plate. The aim of
this study is to determine whether a two-hole locking plate has biomechanical
advantages over conventional screw stabilisation of the syndesmosis in this pattern
of injury. Methods: We have used 6 pairs of fresh-frozen human cadaver lower legs.
The syndesmotic ligaments, interosseous membrane and the deltoid ligament were
sectioned to simulate an unstable Maisonneuve fracture. The limbs were then
mounted on a servo-hydraulic testing rig and axially loaded with 800N for 14000
cycles. Each limb was compared with its pair; one receiving stabilisation of the
syndesmosis with two 4.5mm quadricortical cortical screw, the other a two-hole -
3.5mm locking plate with locking screws (Smith and Nephew). Failure was defined as
fracture of bone or metalwork, syndesmotic widening or axial migration>2mm.
Results: All ankles showed failure of the metal work with fracture of the lateral
malleolus at the level of the syndesmosis following axial loading and the application
of an external rotation force at an average of 14000 cycles. In 4 of the 6 pairs, using
a locking plate, the torque required to produce failure was at least double the force
required when using syndesmotic screws. Conclusion: Locking plate are more stable
constructs in resisting shear stress, as well as controlling tensile forces across the
syndesmosis.
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