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J.Orthopaedics 2007;4(4)e7
index.htm
Introduction:
The knee is one of most frequently injured joint because of its
anatomical structure, its exposure to external forces and the
functional demands placed on it.1 With increase in vehicular
trauma, competitive and recreational athletic activities acute
traumatic lesions of the knee are becoming increasingly common.
Accurate diagnosis of these traumatic lesions is of
paramount importance to facilitate appropriate management,
prevention of long term disability and improve clinical
outcome.1 Clinical suspicion provokes the clinician to request
other diagnostic modalities to rule out any fallacy in the
clinical judgment. A no of non invasive and invasive diagnostic
aids are currently available to confirm the intraarticular
pathologies. Despite this rapid progress in diagnostic imaging,
clinical evaluation still remains the basic step in management
of these injuries. Accurate clinical diagnosis can decrease the
incidence of unnecessary costly investigation.
The
purpose of this study was to compare the findings on clinical
evaluation, with those on arthroscopy to determine the accuracy
of clinical methods for specific type of knee lessons.
Material and Methods :
This was a retrospective study of one hundred and forty cases
with knee pain in whom a clinical evaluation was followed by
arthroscopic examination by the senior author (M.F).There were
ninety eight male and forty two female patients. The patient age
ranged from sixteen to fifty seven years (mean forty two years)
Right knee was involved in eighty nine and left in fifty one
cases. Duration of symptoms avenged six months (range four month
to thirteen months). Patients wee referred to senior author from
out patient department, general practitioners and orthopedics
surgeon with the clinical suspicions of a knee lesion. Patients
were evaluated by the senior author and the co-authors.
Examination involved detailed clinical examination
of the involved joint apart from an entire general examination.
Specific tests were performed to diagnose the cause of pain.2.
These included. -McMurry’s test for meniscal tears, Appley’s
grinding test, Squat test 1, Anterior and posterior
drawer test for cruciate ligament integrity, valgus and varus
tests for collateral ligament stability
A clinical diagnosis was made and recorded in the patients’
record sheet. Patients were required to get their affected knee
radiographed, followed by magnetic resonance imaging [MRI].Patients
were provisionally dated for an arthroscopic examination of the
knee.
Arthroscopic examination in all cases was done by the senior
author [MF]. A Storz arthroscope was used for examination.
Procedure was performed under spinal, epidural or general
anesthesia. Tourniquet was applied before the procedure was
begun.
An inflow cannula was inserted in the suprapetellar
pouch and joint distended with normal saline. An anterolateral
portal was chosen, located approximately one cm above the
lateral joint line and approximately, one cm lateral to the
margin of the patellar tendon. If required an anteromedial
portal one cm above the medial joint line and one cm inferior to
the tip of the patella and one cm medial to the edge of the
patellar tendon was used. A 30-degree oblique fore lense
arthroscope was used for most diagnostic procedures. The
examination of the joint was routinely done in the following
compartments, supra patellar pouch, patelo- femoral joint,,
medial and lateral gutter, medial and lateral compartment, intra
condylar notch and posteromedial and posterolateral compartment.
The findings of knee examination were recorded in
the case sheet. Specific procedure was carried out in the same
or addressed subsequently.
The data was analyzed to calculate the sensitivity
and specificity and the predictive value of the clinical
examination, with arthroscopy as the gold standard for
comparison.
Results :
The results of clinical examination were compared with those of
arthroscopy. Clinical examination of medial meniscal tear
yielded seventy four true positive, thirty two true negatives
nineteen false positives and fifteen false- negative results.
The sensitivity was 83.14% and the specificity 62.74%. the
positive predictive value i.e. percentage of patients who were
diagnosed as having a medial meniscal tear on clinical
examination were subsequently found to have tear on arthroscopy,
was 79.56%. The negative predictive value i.e. the percentage of
patients who were diagnosed as having no tear on clinical
examination and were subsequently found to have no tear on
arthroscopy was 68.08%
Clinical examination of anterior cruciate ligament
tear yielded twelve true positive, seven false negatives, eight
false positives and one hundred thirteen true negative results.
The sensitivity in this case was 63.15% and specificity of
93.38%. The positive prediction value of clinical examination
was 60% and negative predictive value of 94.16%
Common condition which was mostly
misdiagnosed as medial meniscal tear included medial compartment
osteoarthritis.
Discussion:
Knee pain is present in up to 20% of the adult general
population 3, 4 and is associated with clinically
significant disability 3, 4, 5. Meniscal and
ligament injuries are amongst the common cause of this ailment.
Approximately two thirds of all derangements of the knee joint
are due to lesions or degenerative changes of the menisci
2, 6.
The diagnosis of internal derangement of the knee
caused by meniscal tear can be difficult even for experienced
orthopaedic surgeon. History and clinical examination
supplemented by standard radiographs, imaging techniques and
arthroscopy minimizes the errors in diagnosing meniscal tears to
less than 5% 1. On the other hand with a careful
history and examination, an acute injury to a knee ligament
usually can be localized, classified and graded according to its
severity. Though the advances in technology in medicine have
resulted in a de-emphasis on the rudimentary history and
clinical examination 2 the significance of a
meticulous clinical evaluation in diagnosing a knee problem
cannot be under estimated.
An early study demonstrated that
physical examination had a clinical accuracy of 75 percent in
patients who had symptoms suggestive of internal derangement of
the knee; the clinical findings were compared with the
arthroscopy 7. Jackson et al 8 while
evaluating the knee pain in the primary care reported that
physical examination was reasonably sensitive in detecting
meniscal injuries, anterior cruciate ligament, and posterior
cruciate ligament tears (74% to 81%) but less sensitive for
detecting other cartilaginous lesions. For all lesions, except
medial meniscal lesions, specificity was high (92% to 96%)
suggesting that physical examination is usually normal in
patients without damage to these structures. Our findings are in
agreement with the above observation in that specificity of
clinical examination in diagnosing medial meniscal lesions was
only 62.24% whereas the same for anterior cruciate ligament was
93.38%.
Another study 9 on correlation of arthroscopic and
clinical examination with magnetic resonance imaging findings of
injury knees in children and adolescents reported a highly
positive correlation (78.5%) between clinical and arthroscopic
finding for meniscal, anterior cruciate ligament and articular
surface injuries. In this series, accuracy, positive prediction
value, negative predictive value, sensitivity, and specificity
data were much more favorable for clinical examination than from
magnetic resonance imaging.
The findings of the present study show that clinical examination
had a high specificity (P<0.05) for diagnosing anterior cruciate
ligament injuries, the sensitivity though was less. On the
contrary specificity for diagnosing a tear of medial meniscal
was statistically insignificant (P>0.05) Most common conditions
that were erroneously diagnosed as medial meniscal tear were
medial compartment osteoarthritis loose bodies and chondromlacia
patellae.
Gilles et.al 10 in 1979 which comparing clinical
evaluation, arthrography and arthroscopy reported that a
clinical evaluation was the most accurate diagnostic procedure
in diagnosing meniscal lesions. The rapid progress in
arthroscopic surgery during the past decade may prove this
statement wrong, but the fact is that the importance of a
clinical examination can never be overlooked. Supported by the
current findings and reports in literature, we reiterate the
importance of a robust clinical diagnosis, sparing patients from
expensive & unnecessary diagnosis tests.
Conclusion:
Knee pain is a common presentation in orthopaedics and
traumatology, and clinicians choose several imaging modalities
to come to a diagnosis. A careful physical examination is
especially importance in initial evaluation with remarkably good
diagnostic accuracy in the hands of a trained examiner. This
would avoid unnecessarily non invasive requisitions, and
referral for invasive diagnostic modalities apart from the
potential cost saving benefits.
Reference :
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Cannale (Ed) St. Louis Mosby. 1998.
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