Hip Pain in a Hefty 13-Year Old
Radiology Cases in Pediatric Emergency Medicine
Volume 2, Case 12
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
A 13 year old male was brought to the emergency
department after injuring his right hip at a soccer game.
He was running down the field when he heard and felt a
crack in his right hip. He was not struck by another
player. He did not twist his hip. He was not kicking at
the time. He clearly felt the crack before he fell to the
ground. He was unable to get up and since then, he
has not been able to bear weight on his right leg. He
denied any pain in his thigh or knee. He denied any
tingling, numbness, or weakness distally. He had been
complaining of pain in his right hip for the past two
weeks, but he did not seek medical attention for this.
Exam: T37.0 (tympanic), P100, R20, BP 114/53,
weight (by history) 105 kg (230 pounds). He was very
large for his age of 13 years. He was moderately
obese and husky. He was comfortable lying down.
Head without signs of trauma. Neck full range of
motion. Heart regular without murmurs. Lungs clear.
Chest wall without signs of injury. Abdomen benign.
His right hip was very tender on palpation externally.
Range of motion testing was not performed because
the patient indicated that this would be very painful.
There were no visible deformities or bruises. His thigh
and knee were not tender. His neuromuscular function
below the thigh was normal. Radiographs of his hips
were obtained.
View Hip Radiographs.
His history did not indicate the presence of a
sudden impact severe enough to cause a fracture
unless this was a pathological fracture. His obesity and
age made the diagnosis of slipped capital femoral
epiphysis a high likelihood. In examining his
radiographs, his femoral physis is nearly fused. There
is no difference in the appearance of the right and left
femoral growth plates. It does not appear that his
radiographs are consistent with a slipped capital
femoral epiphysis. This was very confusing at the time
since the clinician was almost certain that the
radiographs would confirm the diagnosis of slipped
capital femoral epiphysis.
An orthopedic consultation was obtained since an
occult slip of the capital femoral epiphysis was still
suspected. The radiographs were interpreted as
showing an avulsion fracture of the lateral aspect of the
right acetabulum. This is visible as a very faint and
indistinct bony fragment (there may actually be two
fragments) just above the hip joint lateral and superior
to the superior margin of the acetabulum. This is so
faint, you may need to turn down the room lights, adjust
the contrast on your monitor, and step back to
appreciate it.
The following radiograph, points it out.
The black arrows point to the two fracture
fragments. If you can't see the black arrows, then you
need to adjust the contrast on your monitor.
This fracture probably occurred because of the
extreme forces borne by the acetabulum. It is likely
that his history of hip pain for the previous two weeks
was the result of weakening of the acetabulum which
finally resulted in a fracture.
Since this patient's history and clinical appearance
was a classic description of a patient with a slipped
capital femoral epiphysis, this expectation clouded the
physician's ability to consider an alternative diagnosis.
The radiographic characteristics of slipped capital
femoral epiphysis are described in Case 10.
This case presents a good opportunity to review the
anatomy of the bony pelvis. This knowledge is
important when describing the location of abnormalities
over the phone when discussing a patient with an
orthopedic surgeon who is relying on your verbal
description of the patient's radiographs.
Identify the labeled structures in the radiograph of
the pelvis.
View Pelvic Radiograph.
A. Iliac crest
B. Sacroiliac joint
C. Femur head
D. Acetabulum
E. Femoral capital physis
F. Obturator foramen
G. Pubic symphysis
H. Lumbosacral junction
I. Iliac fossa
J. Pubic ramus
K. Ischial tuberosity
L. Femur neck
M. Greater trochanter
N. Anterior superior iliac spine
Return to Radiology Cases In Ped Emerg Med Case Selection Page
Return to Univ. Hawaii Dept. Pediatrics Home Page