To The Editor:
I read with interest the article "Custom Patellofemoral Arthroplasty
of the Knee" (2006;88:1475-80), by Sisto and Sarin. It is not uncommon
for young patients with isolated patellofemoral arthritis to have a dysplastic
trochlea. Instead of being concave, the trochlea is flat or even convex. In
such a setting, I have always worried that a custom implant that duplicates
the articulating anatomy of the patient's patella (convex) will lead to an
unstable construct. The authors do not appear to have encountered this
problem. Would they comment on this?
As an aside, I think that their patellofemoral replacement (or any other)
would be equally indicated in frail and elderly patients who are unlikely to
have deterioration of the other compartments in their lifetime.