Abstract
Background
Internal fixation is one of the main options for treating displaced intracapsular
hip fractures. However, controversy remains over which osteosynthesis is the best
choice. Using a simulated displaced intracapsular hip fracture model, we compared
the mechanical stability of three types of osteosynthesis: the sliding hip screw (SHS),
three cannulated screws and the Targon® FN. We also assessed whether bone mineral density (BMD) influenced the stability
of the fixation.
Methods
Unstable/displaced intracapsular hip fractures were induced in a total of 12 pairs
of fresh-frozen cadaver femora. Each fracture was fixed at random on the left or right
side with an SHS or three cannulated screws (six bone pairs; study 1), or with an
SHS or the Targon® FN implant (six bone pairs; study 2). All femoral heads were exposed to cyclic combined
axial and torque loads until failure. The failure mechanism, the maximal load-to-failure
and the dual-energy X-ray absorptiometry (DEXA) values of the femoral heads were determined
and their relationships were analysed.
Results
There was no significant difference in the maximal load-to-failure between the SHS
and the three cannulated screws. The load-to-failure was significantly higher for
the Targon® FN than for the SHS. There was a high correlation between the bone mineral densities
(BMDs) of the femoral heads and maximal load-to-failure in the Targon® FN group only.
Interpretation
Basing the implant choice on preimplantation BMD measurements does not ensure the
best biomechanical outcome. We found that the combination of a fixed-angle device
and multiple sliding neck screws (Targon® FN) enhances the mechanical strength of reconstructions in unstable/displaced intracapsular
hip fractures.
Keywords
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Article info
Publication history
Accepted:
August 18,
2010
Identification
Copyright
© 2010 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
