Johns Hopkins Gazette: April 10, 1995

Strict Guides Could Reduce Knee Surgery Medical Costs

By John Cramer

     Health care costs associated with knee replacement surgery
amount to about $2 billion annually nationwide. But a recent
Hopkins study has found that these expenses could be reduced by
one-fourth if stricter guidelines are used to determine which
patients should have one or both knees replaced at the same time.

     The study results, reported recently at the American Academy
of Orthopedic Surgeons' annual meeting in Orlando, Fla., found
that savings would amount to 100 percent of the cost of the
unnecessary second-knee replacements and up to 50 percent of the
cost of separate knee replacements that would be performed
instead in one procedure.

     Certain patients with mild X-ray findings and symptoms of
arthritis who are having one knee replaced should not have both
knees replaced at the same time because they are unlikely ever to
need the other replacement, said Michael Mont, the study's lead
author and assistant professor of orthopedic surgery, and David
Hungerford, the study's senior author and professor of orthopedic
surgery, both at the School of Medicine.

     Certain patients with moderate X-ray findings and symptoms
probably also should not have the second knee replaced
simultaneously, they concluded.

     Patients with severe X-ray findings and severe symptoms
probably should have both knees replaced at the same time because
the other knee is likely to need replacing within about two

     "This finding will be somewhat controversial and warrants
further research," Dr. Mont said, "because mortality and
morbidity rates for patients receiving two replacements at the
same time vary greatly in many studies." 

     Using stricter clinical and radiographic guidelines would
reduce by 40 percent the total number of knee replacements. The
reduction would include a 20 percent cut in the number of
unnecessary second-knee replacements and a 20 percent cut in the
number of separate operations on patients who should have both
knees replaced at the same time.

     The study followed 185 patients who had a knee replacement
between January 1980 and November 1983. The subjects were
evaluated on average 10 years after their replacement. The study
found that 93 percent of the subjects with moderate or severe
symptoms and severe X-ray findings needed the other knee
replaced, but that only 20 percent with moderate symptoms and
X-rays and 9 percent with mild symptoms and X-rays needed the
other knee replaced.  

     "I've always believed there should be stricter guidelines
adhered to concerning the need or lack of need for second knee
replacements," Dr. Mont said.

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