Biomedical Engineering Reference
In-Depth Information
Figure 14.14
Compressive stress
distributions in the Cambridge
and MITCH
-PCR Cups. The
upper images represent sections
taken through the cup and the
pelvis in the plane parallel to the
support fins of the MITCH-PCR
Cup. The lower images represent
views into the acetabulum, with
anterior directed to the left of
figure. Similar stress distributions
are seen with both implants.
These FE analyses provide an understanding of the
effects of acetabular reconstruction on supporting
bony structures using a flexible, horseshoe-shaped
implant fabricated from CFR-PEEK. We found that
the stresses in the CFR-PEEK bearing and the fixa-
tion fins were below the yield strength of the mate-
rial, suggesting that failure of the implant is unlikely
under the conditions considered in this study. Addi-
tionally, our analyses suggest that the MITCH
performed in several international centers. Early
clinical observations are consistent with the biome-
chanical response predicted by the current study
(
Fig. 14.17
). Long-term clinical monitoring, DEXA
analysis, and postmortem retrieval will be required to
fully validate the computational predictions and to
fully understand the clinical performance of a PEEK
acetabular component.
-
PCR Cup has comparable biomechanics to the
Cambridge Cup and that geometrically flexible
acetabular cup designs may be a viable alternative to
conventional hemispherical cups in the future.
In light of the encouraging biomechanical find-
ings, as well as extensive preclinical fatigue and wear
testing conducted by the manufacturer
[93]
,
14.8 Outlook for PEEK in
Orthopedic Implants
PEEK biomaterials in orthopedics are currently in
a period of consideration and conservative adoption.
The traditional metal, ceramic, and polymer implants
currently used for total hip and knee replacement are
perceived by many surgeons
the
MITCH
-PCR Cup has received CE mark approval
and a postmarket surveillance study of the cup was
and patients
as
