What Your Doctor May Not
Tell You About Joint Replacement
ANSWERS TO COMMON QUESTIONS
by Ronald P. Grelsamer, M.D.
How do I know when I need a joint replacement?
When your pain becomes intractable despite all reasonable
nonoperative approaches. You don’t need a joint replacement
just because the X-ray “looks bad.”
Where do I find a surgeon who can put in a hip replacement
through a mini-incision?
You are asking the wrong question. You want a surgeon
who can give you a painfree hip for a long time to come.
How long should my joint replacement last?
Ten years. At least that’s the party line. Many implants
will last over twenty years. After that either the implant loosens
or the bearing wears out, especially if you are still young or
active at that point.
Where is the hip joint?
Not where you think it is! The hip joint is closer to
the front of your thigh than to your butt. A hip problem will,
therefore, tend to cause pain in the groin area, at the crease
between your upper thigh and belly. Pain in the area of your butt
is much more likely to come from a pinched nerve in your back
than from a hip problem.
Is arthritis always painful?
No! This is true of arthritis anywhere in the body. You
can have arthritis for years without even knowing it. Don’t
let yourself get talked into a joint replacement on the basis
of a “bad looking” X-ray. (“Mrs. Jones, this
X-ray looks terrible. Why don’t we replace your knee at
the beginning of next month?”)
Are some implants glued in?
No. There is no glue in joint replacement surgery. Many
implants are cemented in place, but the cement isn’t sticky.
No more so than the cement between two bricks.
Is the whole knee removed in a total knee replacement?
No. Only slivers at the ends of the bone are removed.
What is a hip dislocation?
The hip joint consists of a ball and a socket. When the
ball slips out of the socket, the hip is said to have dislocated.
This is a painful situation. The process of putting it back in
is called the reduction, and once the process is complete, the
hip is said to be reduced.
Are there warning signs before a hip dislocates?
Alas, no. Heed the precautions taught to you by your surgeon,
nurse, and therapist, and don’t count on any warning signs.
If your hip pops out, it will do so in a fraction of a second.
Is a hip dislocation a lifelong risk? Do I have to watch
what I do the rest of my life?
Yes. After a while the precautions become second nature.
What’s the big deal about a “revision”
(redo) joint replacement?
Redoing a hip replacement is much more difficult and
much riskier than a first-time replacement. This is true anywhere
in the body, and it is the result of the tissues being much less
soft and pliable. Also, dense scar will have wrapped itself around
everything, and this will have to be slowly and methodically peeled
away by the surgeon before he can do anything to your hip or knee.
Why the reluctance on the surgeon’s part to place
a joint replacement in a young person?
The implant will loosen or wear out in the person’s
lifetime, thus subjecting them to a revision.
I am eighty-two years old. Am I too old for a joint replacement?
It’s a question of health and motivation, not age.
In fact, there’s no advantage to waiting. The implant will
last your lifetime. If you meet all the criteria for a joint replacement,
have the procedure while your doctor still allows it.
Why won’t my doctor let me play tennis after a
He might let you play some easy doubles, but he’ll
discourage you from any vigorous running and twisting. Unless,
of course, he doesn’t plan on being around when you’ve
worn out the bearing of your joint replacement and it needs to
Can I get an MRI if I’ve had a joint replacement?
Yes. Your implant is metallic but nonmagnetic. The pictures
produced by an MRI will be blurry in the immediate vicinity of
the implant, but it is not dangerous to undergo an MRI. Pictures
taken of areas away from the joint replacement will be perfectly
Why do I need to see my surgeon on a regular basis even
if I’m feeling well?
You won’t feel the plastic wearing out in your
joint replacement. If this should happen to any significant degree,
the microscopic debris may cause the surrounding bone to gradually
disappear. And you won’t feel that either until a massive
amount of bone is gone! Better to discover this early.
It’s been three months and I’m still having
pain after my joint replacement. Is this normal?
Not if the pain is severe. Some achiness is normal, but
no more than that—especially in the hip. The knee can be
sore from the bending and straightening exercises. In the first
three months, pain can be attributed to the surgery itself, but
after three months, the surgeon will start to look for other sources
I need a joint replacement and I’ve just read about
a new type of implant. I should make sure my surgeon uses this
model. Right or wrong?
Wrong. Your implant should last you ten, twenty, or thirty
years, if not longer. If it hasn’t been around that long,
how do you know it will? Because of the manufacturer’s assurances?
Note that no manufacturer will ever make that assurance on a new
implant. And most implants introduced since the inception of joint
replacement surgery have not stood the test of time.
Joint replacement is big-time surgery and the surgeon
is making big-time bucks. Right or Wrong?
Wrong. Although a surgeon may occasionally be well reimbursed,
the average hip or knee replacement earns a surgeon between $1,600
and $1,800—and that includes three months of follow-up care
no matter how stormy your postoperative course is. An orthopedic
surgeon pays upwards of $75,000 a year in malpractice insurance.
You do the math.
Will my implant set off the alarms at the airport?
It used to be unlikely, but since 9/11, the possibility
of setting off an alarm has increased.
A special joint replacement ID card will allow me to
breeze through airport security, no?
No. Anybody in the terror business can make an ID purporting
to show that the bearer has had a joint replacement. No halfway
competent airport security guard is going to wave you on just
because you have an ID card.
In performing a hip replacement, is it not harmful to
remove the marrow from the thighbone?
No. The marrow found in the upper femur (thighbone) doesn’t
produce blood cells in any significant quantity.
What is a “press-fit” implant?
An implant needs to be fixed to the underlying bone.
If it is pressed/jammed/impacted into the bone rather than being
cemented, it is said to be press-fit.
Should I have both hips/knees replaced on the same day?
Maybe. It’s a lot of surgery. You have to be physically
and mentally up to it. I usually recommend operating on one hip
or knee at a time unless the other one is so bad that rehabilitation
will be impossible. Your family doctor will have a say in this.
What’s the difference between the true and apparent
length of my leg, and why does it matter?
The apparent leg length is what you feel. The true leg length
is the actual measurement of your legs as measured, for example,
on an X-ray. The two don’t always match. For example, one
leg might be short, but if your pelvis and back have adapted,
you might not notice because your apparent leg lengths might be
Who is going to be unhappier with a difference in leg
length after surgery: Sally, who’s had a hip fracture, or
Gordon, who’s been suffering from arthritis?
In fact, Sally in general is going to be less happy. Sally had
absolutely no pain before her fracture. She wants to be good as
new after the surgery. Anything less will leave her unhappy. Gordon
has suffered for years. Any significant improvement should please
him. So given the same result, Gordon will be more grateful.
The day before surgery why can’t I eat or drink
anything after midnight?
Because anesthesia relaxes the muscles around your stomach
and esophagus, stomach contents can go back up toward your throat
and back down into your lungs. This leads to a very serious type
of pneumonia because stomach contents are very acidic and can
burn through lung tissue.
If the doctor thinks I have an infection, why does he
not simply prescribe antibiotics?
Antibiotics alone are often ineffective because scar tissue prevents
them from reaching the infection.
What can I do to prevent an infection?
Alert the doctor to the presence of drainage (liquid coming from
the wound) even if the liquid appears to be no more than water.
Eat well. You want a healthy mix of foods. If your appetite isn’t
great, consider milk shake–like products that your doctor
or pharmacist can point you to.
How long should my hip or knee hurt after joint replacement
There is no specific answer to that question, because patients
exhibit very different levels of pain tolerance. By and large,
most of the hip pain should have resolved within a month and knee
pain should be very tolerable by the end of the third month. This
is a rough guideline. Patients with noncemented (“cementless”)
implants may take a little longer.
Why did Sally need crutches for six weeks while Harry
needed them for only four?
The two variables here are the magnitude of the surgery and the
surgeon’s preference. Bone is a living tissue that adapts
to its surroundings. A joint replacement radically alters the
forces around a hip or knee, and it will take time for the bones
in those areas to adjust to this new set of forces. Excessive
pressure applied to bones that are remodeling may or may not cause
pain. The surgeon will combine his experience and understanding
of the orthopedic literature with his knowledge of your particular
operation to judge how long you should use crutches.
My hip still hurts, and my surgeon is blaming it on
my back. Is he full of malarkey?
Not necessarily. It is true that hip pain can be coming from the
back, even in the absence of back pain. One should be particularly
suspicious of this when the hip X-rays don’t suggest much
Do I need anti-rejection medications after a joint replacement?
Excerpted from What Your Doctor May Not Tell You About
Hip and Knee Replacement Surgery by Ronald P. Grelsamer,
M.D. Copyright © 2004 Ronald Grelsamer, M.D. Excerpted by
arrangement with Warner Books, Inc., New York, NY. All rights
reserved. $14.95. Available in local bookstores or click