Femoro-acetabular impingement - Video

X-ray of the day

History: Six-year-old girl with pain after falling.

Diagnosis: Lateral condyle fracture

Findings: There is a left lateral condylar fracture, with anterior fat pad sign. Fragment is less than 2 mm displaced. Radial head is in place.

The lateral condyle typically ossifies at the age of ten years. At age six, as with this case, a lateral condylar fragment that looks like an ossification center (articulating with the radial head) cannot be an ossification center.

This type of fracture is considered a Salter-Harris type IV fracture.

Here are the follow-up x-rays both 3 and 6 weeks later



Followup imaging reveals bony bridging compatible with healing.

Key points about lateral condyle fracture:

• Second most common pediatric elbow fracture (15%).
• Seen most often from age 4 to 10, peak incidence at age 6.
• Usually related fall on an outstretched hand with the elbow extended and the forearm abducted.
• Considered to be a Salter-Harris 4 injury.
• Stage or type 1 fractures with less than 2 mm displacement can be treated with immobilization.
• Open reduction recommended for all type 2 or 3 fractures.
• Easily missed if thought to represent a normal ossification center. The lateral condyle does NOT ossify until age 10.

X-ray of te day: Osteopetrosis

Findings: There is diffuse sclerosis throughout the bones. Additionally, there is a bone within bone appearance involving multiple bones, as well as metaphyseal banding, with alternating bands of lucency and sclerosis.

Differential diagnosis for diffuse bony sclerosis:

• Osteopetrosis
• Sickle cell disease with bone infarcts
• Metastatic blastic disease
• Mastocytosis
• Fluorosis
• Metabolic diseases such as renal osteodystrophy

Diagnosis: Osteopetrosis.

• Failure of bony resorption by osteoclasts.
• Numerous possible genetic causes. May present as adult onset or infantile onset.
• Infantile onset typically leads to death in childhood secondary to anemia, bleeding or infection.
• Adult onset can be relatively asymptomatic.
• Typically, bones appear markedly sclerotic.
• Bones may have a "bone within bone" appearance (aka "endobone" appearance).
• Alternating sclerotic and lucent bands may be seen at the ends of long bones. This is known as metaphyseal banding.
• Vertebrae may be diffusely sclerotic, or show alternating bands (rugger jersey spine); this sign can also be seen in hyperparathyroidism.
• Fracture risk is high.