Biomedical Engineering Reference
In-Depth Information
13.21
The appropriate geometry has been restored thanks to an
external fixator, connected with screws to the bone segments.
More recently, locked nails have been proposed as systems able to control
torsional stresses better at the fracture site. When they are locked only at
one end, the dynamic mechanism of the synthesis is preserved; but when
both ends are locked, the nail behaves more or less as an internal plate.
13.4.2 Devices for joint replacement
Joint prostheses are experiencing an ever increasing number of applications.
Nearly every joint in the body has seen the development of an artificial substitute
for its replacement. However, not everything has been successful.
The paradigm for artificial joint replacement is the hip joint. This is a heavy
weight-bearing joint which, when affected by a degenerative process, has
very little response to any conservative treatment. in fact, both in congenital
and in acquired conditions, load bearing worsens the progress of the disease.
