Dear Marion,

As a postscript to our somewhat hectic hip surgery exchange
of last night, let me assure you that this morning I'm walking
up and down two flights of stairs without discomfort, albeit slowly.

The medical issue is whether hip replacement surgery should be
done prophylactically, i.e. in anticipation and prevention of
possible deterioration. Prophylactic operations are an issue in
all branches of surgery, and often confront the honest surgeon
with decisions of the greatest difficulty. In ophthalmology: when
should peripheral iridotomy be performed to prevent angle closure
glaucoma, when should filtering surgery be done to forestall 
progressive glaucomatous field loss, when should pan retinal
photocoagulation be performed to prevent proliferative retinopathy?

In the case of hip surgery, the question that should be asked is,
how much less likely is surgical success, if the operation is
postponed until the patient is incapacitated. Aside from risks
of complications related to surgery, antibiotics, immobilization,
or mere hospitalization (which has recently been shown to impair
even post-discharge mental functioning), risks which are substantial
even though the profession denies them, there is the unavoidable
disruption of the patient's activities which deprives him of weeks
if not months of the limited remaining opportunities for creative
work.

I recite my thoughts as a mark of my respect and appreciation for
your solicitude. So long as I am functioning, it seems unlikely that
a detached, unsentimental, rational cost-benefit analysis, untinged
with pessimism or optimism, would favor hip replacement sooner rather
than later. But I'm always ready to learn. I'm prepared to delve as
deeply into analyses of these issues as you wish.

Your suggestion that a gas fired burner might be installed under
our existing hot water boiler is almost certainly correct.
It's good that you alerted me to my error.

Thank you, and thank you again.

Jochen