Testing and introduction of new materials - Orthopaedic Biomaterials in Research and Practice - page 388

organs and body parts. Living cells can be layered onto a gel medium
and slowly built up to form 3D biological structures. There is also poten-
tial for the use of 3D printing to produce customized devices, such as
“patient-specific” joint replacement components. However, this has yet
to be explored on a commercial basis. Any such device would have to
comply with standard regulatory requirements prior to implantation.

Clinical trials

Initial studies The most exhaustive engineering and biologic tests of a new biomate-

rial can do no more than to remove the risk of gross adverse biologic
response in clinical application. Qualification of a new material for rou-
tine clinical use in specific device types requires careful, controlled pro-
spective clinical trials.
Ethical considerations prevent the isolated testing of new materials in
patients as can be done in animals. Often, such clinical trials become an
examination of the performance of a new material in a new or modified
device for treatment of a particular clinical condition. As a result, “quali-
fication” of implant biomaterials is not really possible: other applications
may raise new questions and require additional preclinical and clinical
testing. Appropriately, animal studies serve as surrogates in evaluations
of new materials.
Therefore, initiation of clinical trials will require the production of
some quantity of a device incorporating the new material. In the early
stages of such evaluation, the devices may be made, one at a time, at the
direct instruction of a physician with the intention that they be used on
a specific patient. Such devices are said to be “custom devices” and are
controlled by only two regulatory requirements:

1. They must be manufactured in a registered facility that meets the
FDA's GMP regulations (21 USC 351, 352; 21 CFR Part 820).

2. Their use must be approved by the Institutional Review Board
(IRB), which ordinarily controls experimental procedures on
patients in the given institution.

These are relatively modest requirements that will permit the ini-
tial group of academic and clinical investigators to finalize aspects of
design, fabrication, and clinical use of the material in question, with
implantations in perhaps 5-15 patients, before embarking on a full-scale
clinical trial.

Clinical protocol

Design of clinical protocols has become an art in itself and is the subject
of many articles and topics. Many institutions now employ specialists
to aid in this, and similar services are available from a wide range of
qualified consultants.