Although many designs of total hip replacement have high success rates at f
ollowup times of 10 years and more, new designs continue to be introduced.
Some of these designs are similar to what is available already, but may off
er advantages such as additional sizes or improved materials, In such cases
, a key question is whether the new implant will produce the best possible
results for routine use. Rather than simply relying on long-term followup d
ata, which would eliminate the widespread use of a new device for a long ti
me, it is suggested that the vast experience and knowledge of the orthopaed
ic community should be used. The proposal is that an authoritative group of
individuals formulate a specification of the design features of total hip
replacement which produce successful results. A second key question is how
to be reasonably certain that a device with significantly new features, mat
erials or techniques, is better and whether and when it should be used, eit
her routinely or for specific indications. The proposal is that federal fun
ding should be available to the research community for the specification an
d development of extensively researched and validated test methods. A point
which is applicable to all innovations is that rather than relying on only
one test or on a limited number of tests to validate the device, the Desig
n Method must be used. This method involves the formulation of a methodical
series of tests, preclinical and clinical, covering all combinations of us
e of the device. There are no simple answers to validating a design, but th
ere are positive signs that new innovations are being introduced more caref
ully than in the past, and that many of these innovations will lead to impr
oved long-term results.