Failure of metal-backed cementless patellar components frequently has been
observed clinically. To determine the effect of component design on clinica
l outcome, the authors reviewed the results of total knee arthroplasty with
metal-backed patellar components of two different designs. The results of
168 total knee arthroplasties (Miller-Galante) with dome-shaped metal-backe
d patellar components and 93 total knee arthroplasties Miller-Galante II wi
th modified dome-shaped metal-backed patellar components were reviewed. Kap
lan-Meier survivorship was determined for both groups. Revision for patella
r wear or failure was done or recommended in 36 Miller-Galante total knee a
rthroplasties. The cumulative survival rates at 3, 5, 7, and 9 years postop
eratively were 99%, 92%, 81%, and 73%, respectively for this group. In cont
rast, only three of 93 Miller-Galante II patellar components required revis
ion. Catastrophic patellar component failure, typically seen with the Mille
r-Galante metal-backed patellar components, was not observed with the Mille
r-Galante II components. Cumulative survival of the Miller-Galante II patel
la at 3, 5, 7. and 9 years postoperatively was 100%, 100%, 98.7%, and 93.2%
respectively. The results of the current study show a dramatic reduction i
n metal-backed component failure by design changes incorporated into the mo
dified dome-shaped Miller-Galante II patellar component and highlights the
importance of design on the survival of cementless metal-backed patellar co
mponents.