Thigh and Knee Pain in an Obese 10-Year Old
Radiology Cases in Pediatric Emergency Medicine
Volume 2, Case 10
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
This is a large 10-year old male who presents to the
acute care clinic with a two week history of right thigh
and knee pain. He states that the pain is mainly in his
thigh (points to his upper thigh) but radiates down to his
knee. He was playing basketball when he collided with
another player and fell. He noted severe pain in his
thigh and had to limp home, mostly on his left leg.
Since then, he has been complaining of pain in his right
thigh when bearing weight. However, the pain would
subside when lying in bed. He did not appear to
improve much and he was finally brought to an acute
care clinic. He had no history of fever, rash, chest
discomfort, or pains in other joints.
Exam VS T37.0 (oral), P66, R20, BP 112/65, weight
69.3 kg (>>95th percentile), height 152 cm (>95th
percentile). Alert, cooperative, in no distress while lying
down. Obese and large for age. HEENT
unremarkable. Neck normal range of motion. Heart
regular without murmurs. Lungs clear. Abdomen round
contour, soft, non-tender, bowel sounds active.
Right lower extremity: Moderate tenderness in the
upper anterior thigh. Severely tender in the hip. Pubic
symphysis non tender. Mid thigh and knee non-tender.
Tibia/fibula and foot non-tender. No joint swelling
noted. Range of motion about the hip is not done.
Range of motion of the right knee is good.
Left lower extremity: Mild tenderness of the hip on
palpation. Mild tenderness on range of motion testing.
Good range of motion. Otherwise unremarkable.
Although his chief complaint is thigh pain, his exam
indicates that his injury is in his hip. He probably
perceives this hip pain as pain in his upper thigh and
this is how he expressed his pain to others.
Radiographs of the hips are ordered.
View hip radiographs.
A common pitfall is to focus on the patient's chief
complaint. In this case, focusing on the thigh may lead
one to focus on the mid thigh and ignore the hip. His
exam clearly points to his hip as the source of his pain.
Whenever a patient complains of thigh pain, always
examine the hip since this is frequently the source of
the thigh pain. Hip injuries may also present with knee
pain. Whenever a patient complains of knee pain,
always examine the hip since this is occasionally the
source of the knee pain.
The history of his collision and fall suggests an acute
injury such as a non-displaced fracture. An obese child
with hip pain in this age group should always raise the
possibility of slipped capital femoral epiphysis. His hip
radiographs show a slipped capital femoral epiphysis on
the right. His left hip appears to be normal. However, it
is difficult to rule out an early slip on the left as well. He
is very heavy and he has been putting most of his
weight on his left hip for two weeks because of the pain
in his right hip. He now has mild tenderness in his left
He is hospitalized and put at bedrest. After a few
hours of bedrest, his left hip is no longer tender. His left
hip exam is completely normal. He is taken to the
operating room for internal fixation of his right femoral
The radiographic diagnosis of slipped capital femoral
epiphysis (SCFE) can be subtle. In this case, the
physis appears to be wider and more lucent in the
patient's right hip compared to his left. This is probably
due to SCFE, however, this sign cannot be relied upon
alone. The position of the femoral head epiphysis
should resemble a cap over the physis. Subtle cases
may just show a slight malpositioning of the epiphysis.
Examine the diagram of our patient's hips.
The lines drawn along the superior border of the
proximal femur metaphysis (the Klein line) should
intersect part of the proximal femoral epiphysis. The
patient's right hip (left on the screen) shows the line just
touching the lateral margin of the epiphysis. This is
abnormal, indicating that the femoral capital epiphysis
has slipped inferiorly and medially. The patient's
normal left hip (right on the screen) shows the line
intersecting the lateral part of the femoral epiphysis.
This is normal.
Some cases of SCFE are very obvious.
View obvious case.
You don't need to draw the lines here to appreciate
that the patient's left hip (right on the screen) is
abnormal. This is a severe left slipped capital femoral
epiphysis. However, the slipped capital femoral
epiphysis on the right may not be as obvious, especially
if the left hip distracted your attention. This patient has
bilateral SCFE, severe on the left, and moderately
severe on the right.
Slipped capital femoral epiphysis is a diagnosis that
will occasionally present to an emergency department
with acute, subacute, or chronic pain in the hip, thigh, or
knee. The diagnosis of SCFE is not difficult if it is
considered. However, patients may have vague
symptoms that don't precisely point to the hip. Their
degree of pain may range from severe to non-existent.
Their ambulatory ability may range from non-weight
bearing to a normal gait. The pitfall of misdiagnosing
SCFE as a pulled muscle, a hip bruise, a hip sprain, a
Charlie horse, or a knee sprain should be avoided by
carefully examining the hip in any patient presenting
with hip, thigh, or knee pain.
Most SCFE patients prefer to keep their hip
externally rotated. A major clinical finding in SCFE is
their inability to fully internally rotate their hip.
SCFE can be detected radiographically in most
instances. In obvious cases, the epiphysis is obviously
displaced. In subtle cases, the epiphyseal plate
(physis) may be widened or irregular compared to the
normal side. A line drawn along the superior border of
the metaphysis (the Klein line) may intersect less of the
epiphysis compared to the normal side (As noted in the
In other subtle cases, the physis may appear to be
thinner than the normal side. This can occur if the slip
occurs posteriorly. Early slips can be difficult to
demonstrate radiographically. AP views of the hips can
only detect inferior and medial slips. Early slips tend to
slip only in the posterior direction. Posterior slips are
best seen on lateral views of the hips, but these are
difficult to obtain. CT scanning can be helpful for
orthopedic surgeons, but this is not usually needed in
the emergency department. MRI scanning is not useful
Treatment is largely the responsibility of the
orthopedic surgeon. However, one of the major goals
of treatment is to prevent further slipping. Further
slipping cannot be prevented unless the diagnosis of
SCFE is made on the initial presentation. Avoid the
pitfall of missing this diagnosis since sending the
patient home with the wrong diagnosis will likely worsen
the slip. These patients should be put at bedrest.
Simple traction is reasonable, however, it is best to
discuss this with an orthopedic surgeon.
Morrissy RT. Slipped Capital Femoral Epiphysis
(Chapter 24). In: Morrissy RT (ed). Lovell and
Winter's Pediatric Orthopedics, third edition.
Philadelphia, JB Lippincott Co., 1990, pp. 885-902.
Return to Radiology Cases In Ped Emerg Med Case Selection Page
Return to Univ. Hawaii Dept. Pediatrics Home Page