An MRI can diagnose a tear in the disc of cartilage cushioning the knee, but it does not reliably predict which tears can be repaired with surgery, a new study finds.
An MRI can diagnose a tear in the disc of cartilage cushioning the
knee, but it does not reliably predict which tears can be repaired with
surgery, a new study finds. It's estimated that more than 850,000
Americans undergo surgery each year for injuries to the menisci, two
wedges of shock-absorbing cartilage in the knee joint. That surgery can
involve either suturing the tear back together or removing the damaged
portion of the meniscal tissue altogether. At present, surgeons cannot
tell whether the tear will be reparable until the surgery is underway.
Knowing ahead of time would be helpful for both surgeons and patients,
according to Dr. Nicholas M. Bernthal, the lead researcher on the new
study. For patients, it matters because repaired meniscus tears have a
more involved recovery compared with surgical removal of the tissue.
When the injured tissue is simply trimmed off, "people can
basically get up and walk home," said Bernthal, an orthopedic
surgeon at the University of California, Los Angeles. They'll have
some pain, he noted, but there are few restrictions on what they can do,
and most can fully return to their usual physical activities within
about two weeks.
People who have the meniscal tear repaired, on the other hand, need
about four to six weeks of recovery, often with physical therapy. So it
would be nice, Bernthal said, to be able to tell patients ahead of time
which surgery they are going to get. "This is one of the few
instances in surgery where we can't tell people what to
expect," Bernthal said. MRI scans are widely used to diagnose
meniscus tears, and they are accurate up to 99% of the time, Bernthal
noted. But that same MRI information has traditionally been considered a
poor predictor of whether or not the tear can be repaired. While the
imaging can show doctors that a tear exists in the meniscus, it is not
good with the details--where the tear begins and ends, or how complex it
is. Bernthal and his colleagues report the findings in the American
Journal of Sports Medicine.