scapula (shoulder blade) is here with me, a 3-D representation levitating
on the computer screen in front of me. Just a few years ago, Stanley’s case
would have been unmanageable by any shoulder surgeon in the world, so
significant is his bone loss and deformity, but now his case has become
almost routine.
I first met Stanley four months ago in clinic, a man at the end of his
rope. He had undergone total shoulder arthroplasty eight years before in
the Midwest, and while the initial results were excellent, over the last few
years his shoulder slowly became more painful. I reviewed his original X-
rays and told him I would have been pleased had the implant placement
been my own; however, in the intervening years the metal and plastic parts
had started loosening. At the time of implantation, orthopedic prosthetic
parts have to be extremely stable and secure. Any slight wobble in the
bone dooms the replacement to eventual failure, but even ideal time-zero
positioning is no guarantee for success.
Sandy-haired with a ready, gap-toothed smile and smoker’s cough,
Stanley had been evaluated by several surgeons prior to seeing me, and
had been assured that his X-rays weren’t worrisome. After performing a
physical examination and scrutinizing the new X-rays I told Stanley that I
thought his total shoulder replacement was loose, and possibly infected,
which caught him by surprise. As a sixty-one-year-old male, he confided
that he needed to work for several more years before retirement, and the
realization that his replacement had failed was distressing. I
recommended that we operate, remove the loosened implants, test for
infection, and assess the degree of bone loss. In these types of cases, an
unsteady glenoid component (shoulder socket implant made of
polyethylene, resembling white candle wax) inflicts slow-motion
destruction to the socket-portion of the shoulder blade. As the cobalt-
chrome metal head of the replaced humeral head revolves over the glenoid
prosthesis, the pegs of the polymer component can start to unseat, working
away from the host bone like a rickety wooden post wobbles and fails to
support a garden gate. Ignored for too long, the bone of the scapula
impalpably fades away, leaving an eggshell of bone encasing tapioca-like
fibrous tissue and an unmoored polymer implant.
In my first operation with Stanley a month ago, I found what I had
feared: massive bone loss, and implants that were swimming in sloppy
bone. After opening the deepest part of his shoulder, I found a combination
marcin
(Marcin)
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