Volume 4, Case 20
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
This is a 15-year old male who presents with left hip pain for one hour. He was sprinting during a track and field meet. He experienced a sudden pain in his left hip while running through a turn to the left. He noted cramping in his left leg as well. He denies falling onto his hip. His pain is now somewhat better, and he is able to stand. He reports a one week history of suffering from a left hip strain. He has been doing stretching exercises and applying ice to his hip. His past history is unremarkable.
Exam VS: T37.3 (oral), P90, R18, BP 128/69. Weight 59 kg. He is of slim build and normal stature. He is not obese. He is alert and in no distress. He is able to stand. There are no signs of external trauma such as abrasions or bruises. He has some tenderness to palpation of his left hip. His internal and external rotation about the hip are normal, and there is minimal pain. Most of pain is elicited with flexion of his hip. His flexion is limited to approximately 45 degrees. There is no warmth about the hip noted. There are no deformities or tender areas along the long bones. Neurovascular testing distally is normal.
Radiographs of his hips are obtained.
View hip radiographs.
What would we expect to see on his radiographs?
His history indicates that his injury was not caused by an impact. A prolonged stress history is present, which may have been exacerbated by an acute stress precipitating the injury. Such a history may be seen with small avulsion fractures (refer to Case 12 in Volume 2, Hip Pain in a Hefty 13-Year Old), a slipped capital femoral epiphysis (refer to Case 10 in Volume 2, Thigh and Knee Pain in an Obese 10-Year Old), or a pathological fracture among other things.
This hip radiograph shows a bony fragment superior and lateral to the left hip joint. This is an avulsion fracture of the left superior iliac spine. Such avulsion fractures of the pelvis commonly occur during athletic competition. These occur at the sites of muscle insertion into the pelvis. Extreme muscle contraction forces pull at the insertion site. This may cause microfractures, resulting in pain and weakening such as in Osgood-Schlatter's disease of the tibial tuberosity. Our patient exhibited symptoms of this type of preceding injury with his hip strain for one week preceding the avulsion fracture. The three common sites of avulsion fractures of the pelvis are the anterior inferior iliac spine (insertion of rectus femoris), anterior superior iliac spine (insertion of sartorius), and the ischial tuberosity (insertion of multiple hamstrings).
Of the common types of pelvic fractures (pelvic ring fractures, acetabular fractures, iliac wing fractures, etc.), avulsion fractures are the most benign. These can usually be treated on an outpatient basis with crutches, analgesics, and modified activity. Spontaneous recovery usually occurs within 4 to 6 weeks. Occasionally, surgical intervention is required to remove painful fragments or to regain anatomic fixation.
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