This study aims to biomechanically assess whether there is an increased strength to failure with a fibula pro-tibia construct when compared with standard locking plate fixation for ankle fractures in an ankle fracture saw bone model. The lateral malleolus appears therefore to be the key to the anatomical reduction of displaced bi-malleolar fractures, and restoring the integrity of the lateral malleolus restores the integrity of the ankle.īeing able to maintain the integrity of the lateral malleolar fixation in osteoporotic bone in therefore important. When external immobilization is discontinued, the lateral ligaments remain in a stretched position and slight to moderate talar instability, which predisposes to development of late degenerative arthritis, may be the result.
Repositioning of the talus can be achieved by forcibly internally rotating the ankle in such cases, but this stretches the fibular collateral ligament. Reducing the medial malleolus alone may prevent anatomical repositioning of the talus, as in some cases the lateral malleolus cannot be accurately reduced when it impinges on the proximal fibular fragment. In unstable bi-malleolar ankle fractures, the talus remains attached to the lateral malleous. This technique adds little operative time, is inexpensive, and is a technically straightforward method to increase the stability of the construct. In comparison to the same construct without additional screws, fibula pro-tibia fixation has demonstrated a 9% increase in torque to failure, 24% increase ability to withstand external rotation, and a 34% increase in energy before failure of the construct. One such example of the latter is the use of tri- or tetra-cortical fixation with fibula pro-tibia (syndesmotic) screws. The ways to try to obviate these risks include the use of locking, posterior plating, or non-locking constructs with adjunct fixation. In osteoporotic bone, there is unsatisfactory fixation strength with uni-cortical cancellous fixation for distal fibula fractures, which can lead to loss of fixation as well as delayed or non-union.
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