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Timothy Bhattacharyya, MD et al ABSTRACT For patients with OA of the knee,
conservative measures such as steroid injection, physical therapy, NSAID
therapy, and braces are often used to restore function and reduce pain.
When these fail, surgery is often considered, and MRI is often
ordered to further assess the knee. Often,
the MRI reveals a torn meniscus, and the patient undergoes removal of the
torn lesion. Torn medial meniscus is the primary diagnosis in 29.3% of
patients who undergo an arthroscopic treatment of an arthritic knee.
However, there is no data on the incidence rate of meniscal tears
in the osteoarthritic knee, and this study sought to find out the baseline
prevalence rate of meniscal tears, and do their arthritic symptoms worsen
when there is a meniscal tear. A total of 154 subjects with
symptomatic OA of the knees, consisting of males over the age of 45 and
females over the age of 50, were compared to a control group of age and
sex matched individuals numbering 49 subjects having asymptomatic OA.
Those with OA had confirmation via radiographs that revealed
degenerative changes and osteophyte formation, and all subjects were
issued the WOMAC (Western Ontario and McMaster University Osteoarthritis
Index) questionnaire and filled out a 100mm visual analog pain scale.
MRI was performed to determine the prevalence of meniscal tears in
the subjects. Meniscal tears were found to be
common in both groups, with m medial tears in 86% of the patients with
symptomatic OA, but also at 67% of the group with asymptomatic OA.
A tear of the posterior horn of the medial meniscus was in 76% of
symptomatic patients yet 53% of the asymptomatic patients.
Lateral meniscal tears were found in 60% versus 39%, and a medial
or lateral tear was found in 91% versus 76%.
Meniscal tears were more common in men than women, at 91% versus
76%. Patients with no
evidence on radiographs of meniscal tears still had a 70% prevalence rate,
while those with severe OA had a 100% rate.
80% of the 91 subjects with
symptomatic OA and mild changes on the radiograph were men, with an
average age of 67, and WOMAC score range of 0-96 points, and pain range
from 10-95mm. Mean WOMAC
scores did not differ significantly between those with meniscal tears and
those without, nor did the visual analog scores.
It appears that older patients with
radiographic evidence of OA also have a high prevalence of meniscal tears,
and may have surgery on these tears based only on MRI findings.
It may be prudent to assess more on functional complaint and
general complaints than strictly on the imaging results.
The OA knees will present more with stiffness and pain, while the
meniscal patients will complain more of join line tenderness, mechanical
symptoms, and possibility of trauma. MRI may be useful in patients with
loose bodies, osteonecrosis, tumor, osteochondral defects, of ligamentous
injury. It may not be
beneficial in discovering unstable meniscal tears, and the clinical exam
may be more beneficial in determining the patient’s problem and
preventing an unnecessary or unsuccessful surgery. COMMENTS This study reminds us all to always
treat what we see clinically, with a preponderance of the evidence, as
opposed to treating simply what an imaging exam says. If a patient has a positive MRI for a disc HNP but presents
with signs and symptoms of mechanical LBP, we should treat accordingly,
especially in light of the studies that have shown a high percentage of
HNP in normal populations. The
same appears to be true for the knee.
If the patient presents with subpatellar pain, pain on stairs,
stiffness when sitting and in the morning, tenderness at the patellar
facet, yet has a torn meniscus on MRI with no positive meniscal test
findings, why would we treat it as a meniscus tear?
Treat what you see and keep in the back of your mind the other
“problem”, avoiding any exercise or activity that could still
exacerbate that problem. While
the patient may have an HNP that is not symptomatic, it may become
symptomatic and add to their existing problem if the wrong exercises are
performed, or the wrong treatment is performed. An example in this study would be the person who has a fairly
large meniscal tear yet presents with typical OA complaints.
I usually perform quad stretches, which could easily increase the
injury to the meniscus, as the lateral meniscus can move up to 11mm during
full flexion from extension. Make sure you tell the patient they should only feel the
stretch in the thigh, and no pain in the knee. The same will apply for other exercises.
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