Case 1– A 15-year-old female admitted with a two-year
history of bilateral knee pain and swelling that had been
prominent in the right side for the last year. She had
also complained of locking in the knee joint. Her past
medical history was negative for tuberculosis, chronic
fever, trauma, psoriasis, inflammatory bowel disease,
uveitis, or back pain. She reported mild pain relief with
nonsteroidal anti-inflammatory drugs (NSAIDs).
On physical examination, tender swellings that
were more prominent at the suprapatellar level of both
knees were detected. A patellar shock test was positive
on the right side. No redness or localized heat increase
was reported. There was no limitation in the range of
movements in either knee; however, the right knee was
painful during examination. The McMurray test, the
Apley test (meniscal rotator test), and stability tests
were negative.
Laboratory findings, including erythrocyte
sedimentation rate (ESR), C-reactive protein (CRP),
immunoglobulin M (IgM) rheumatoid factor (RF),
full blood count, complements, Ig levels, and routine
biochemistry tests, were within normal limits. Antinuclear
antibodies (ANA), anti-double-stranded
deoxyribonucleic acid (anti-dsDNA), Brucellar
agglutination, and human immunodeficiency virus
(HIV) tests were negative. Protein electrophoresis was
also normal, but the urine and throat cultures were
negative.
Synovial fluid aspiration was obtained from
the right knee. The fluid was yellow in color and
nonpurulent in nature. In a mucin coagulation test,
there was strong mucin positivity. A microscopic
evaluation demonstrated 200 leukocyte/mm3, 20
erytrocyte/mm3. Aspirated synovial fluid culture
samples for common pathogens and tuberculosis were
negative.
X-rays of the knees were normal except for mild
degenerative changes. Sonographic examinations of the knees were performed by the Logiq 9 ultrasound
imager (GE Medical Systems, Milwaukee, Wis) with
a high frequency linear array probe. These revealed
globular and villous hyperechoic structures projecting
into the suprapatellar effusion in the right knee. There
were focal areas of hyperechogenicity suggesting fatty
deposition (Figure 1). Magnetic resonance imaging
was performed using a 1.5-T MR unit (Symphony
Vision, Siemens Medical Systems) with an extremity
coil for knee studies. The sequence included T1- and
T2-weighted spin echo, T1-weighted gradient echo,
and T2-weighted fat-suppressed spin echo in the axial,
coronal, and sagittal planes.
Click Here to Zoom |
Figure 1: Globular and villous hyperechoic structures
projecting into the suprapatellar effusion of the right knee in
ultrasonografi examination. |
Magnetic resonance imaging revealed a large
effusion and numerous frond-like projections which
were prominent in the suprapatellar compartment
of right knee. The intensity of these frond-like
synovial projections, which were suppressed in fatsaturated
sequences, was similar to the intensity of
fat (Figures 2a, b). An effusion and a mass-like lesion
were also detected in the popliteal bursa of the right
knee. (Figures 3a, b) In addition, mild osteochondral
changes occurred in both knees which were more
pronouced on the right side (Figure 2a). Suprapatellar
effusion was also detected in the left knee. No meniscal
or ligament pathology was detected in either knee.
Click Here to Zoom |
Figure 2: (a) Mild osteochondral changes (short arrows) and numerous frond-like projections (long arrow) in the
suprapatellar compartment of the right knee in T1-weighted spin echo in the sagittal plane. (b) Suppression of intensity of
frond-like synovial projections (arrow) in the right knee in T2-weighted fat suppressed spin echo in the sagittal plane. |
Click Here to Zoom |
Figure 3: (a) The mass-like lesion (arrow) in the popliteal bursa of the right knee in T1-weighted spin echo in the sagittal
plane. (b) Suppression of intensity of the mass-like lesion (arrow) in T2-weighted fat suppressed spin echo in the sagittal
plane in the right knee. |
The presence of the large effusion and the numerous
frond-like synovial projections in conjunction with the
mass-like lesion, the intensity of which was suppressed
in fat- saturated sequences in the right knee, led us to
the diagnosis of LA. Since the MRI of the left knee
did not meet the criteria for the LA diagnosis, the
patient was referred to the orthopedics department for a surgical synovectomy of the right knee and for
diagnosis of the problem in the left knee. During
preoperative evaluation, echocardiography revealed
atrial septal defect and the patient was referred to
pediatric cardiology department for further evaluation.
Case 2– A nine-year-old female presented with
bilateral knee pain and swelling which had persisted for one year. The pain and swelling were more
prominent in her right knee, and she described recent
aggravation of the pain. Her past medical history was
unremarkable.
On physical examination, there were tender
swellings and local heat increases in both knees. A
patellar shock test was positive on the right side. There was no limitation in the range of movement in either
knee; however, the right knee was painful during the
examination. The McMurray test, the Apley test, and
stability tests were negative.
Laboratory findings were within normal limits,
and the patient’s urine and throat cultures were
negative. Synovial fluid aspiration was obtained from
the right knee. The fluid was yellow in color and noninflammatory
in nature. A microscopic evaluation
demonstrated 500 leukocyte/mm3. Aspirated synovial
fluid culture samples for common pathogens and
tuberculosis were negative.
X-rays of the knees revealed minimal degenerative
changes. Sonographic examination of both knees was
performed by the EUB 6000 (Hitachi Medical Systems,
Japan) with a high frequency linear array probe, and
this revealed villous hyperechoic structures projecting
into the suprapatellar effusion and a hyperechoic
pseudo-mass lesion in the suprapatellar bursa in the
right knee (Figure 4). Magnetic resonance imaging
was performed using a 1.5 Tesla MR unit (Intera,
Philips Medical Systems, the Netherlands) with
an extremity coil for knee studies. The sequence
included T1- and T2-weighted turbo spin echo (TSE)
images in the fat-suppressed Short Tau Inversion
Recovery (STIR) sequence in the axial, coronal, and
sagittal planes. Magnetic resonance imaging revealed
a large effusion (Figure 5), a hyperintense masslike
lesion, and numerous frond-like projections in
the suprapatellar compartment of the right knee (Figure 6a). The intensity of these frond-like synovial
projections and the mass-like lesion, which were
suppressed in the fat-saturated STIR sequences, was
similar to the intensity of fat (Figure 6b). Chemical
shift artifact was also detected (Figure 5). The signal
intensities of these lobules were isointense with fat on
the T1- and T2-weighted TSE images. These findings
confirmed the fatty nature of the lesion and led us to
the diagnosis of LA in the right knee. There were also
mild osteochondral changes in both knees prominent
in the right side. No meniscal or ligament pathology
was detected in either knee.
Click Here to Zoom |
Figure 4: Villous hyperechoic structures (short arrows)
and the hyperechoic pseudo-mass lesion (long arrow)
projecting into the suprapatellar effusion in the right knee in
ultrasonografi examination. |
Click Here to Zoom |
Figure 5: The large effusion with the hyperintense masslike
lesion (long arrow) and chemical shift artifact (short
arrow) in the suprapatellar compartment of the right knee in
T2-weighted turbo spin echo in the sagittal plane. |
Click Here to Zoom |
Figure 6: (a) The hyperintense mass-like lesion (long arrow) and numerous frondlike
projections (short arrow) in the suprapatellar compartment of the right knee in
T1-weighted turbo spin echo in the axial plane. (b) Suppression of intensity of frondlike
synovial projections and the mass-like lesion in fat-saturated (STIR) sequence in
the axial plane in the right knee. |
A synovectomy is accepted as the treatment of choice
for LA. Post-surgical recurrences are uncommon.1 We
referred our patients to the orthopedics department,
but the family did not agree to the surgical
synovectomy. Nonsteroidal anti-inflammatory drugs
(NSAIDs) provided significant relief in the symptoms
in both cases. We advised avoidance of weight-bearing
activities and trauma to both knees and also suggested
follow-up appointments every three months at one of
our outpatient clinics.
)
)
)
)
)
)
