| Chance fracture | |
| Synonyms: | Chance fracture of the spine, flexion distraction fracture, lap seat belt fracture |
| Symptoms: | Abdominal bruising, paralysis of the legs |
| Complications: | Splenic rupture, small bowel injury, mesenteric tear |
| Risks: | Head-on motor vehicle collision in which a person is only wearing a lap belt |
| Diagnosis: | Medical imaging (X-ray, CT scan) |
| Differential: | Compression fracture, burst fracture |
| Treatment: | Bracing, surgery |
| Frequency: | Rare |
A Chance fracture is a type of vertebral fracture that results from excessive flexion of the spine.[1] [2] Symptoms may include abdominal bruising (seat belt sign), or less commonly paralysis of the legs.[3] [4] In around half of cases there is an associated abdominal injury such as a splenic rupture, small bowel injury, pancreatic injury, or mesenteric tear.[5] Injury to the bowel may not be apparent on the first day.[6]
The cause is classically a head-on motor vehicle collision in which the affected person is wearing only a lap belt.[7] Being hit in the abdomen with an object like a tree or a fall may also result in this fracture pattern.[8] [4] It often involves disruption of all three columns of the vertebral body (anterior, middle, and posterior).[9] The most common area affected is the lower thoracic and upper lumbar spine.[10] A CT scan is recommended as part of the diagnostic work-up to detect any potential abdominal injuries. The fracture is often unstable.[11]
Treatment may be conservative with the use of a brace or via surgery.[11] The fracture is currently rare.[9] It was first described by G. Q. Chance, a radiologist from Manchester, UK, in 1948.[5] [12] The fracture was more common in the 1950s and 1960s before shoulder harnesses became common.[5] [13]
In some Chance fractures there is a transverse break through the bony spinous process while in others there is a tear of the supraspinous ligament, ligamentum flavum, interspinous ligament, and posterior longitudinal ligament.[4]
On plain X-ray, a Chance fracture may be suspected if two spinous processes are excessively far apart.[4]
A CT scan of the chest, abdomen, and pelvis is recommended as part of the diagnostic work-up to detect any potential abdominal injuries.[13] [4] MRI may also be useful.[4] The fracture is often unstable.[11]
It was first described by G. Q. Chance, an Irish radiologist in Manchester, UK, in 1948.[5] [12] The fracture was more common in the 1950s and 1960s before shoulder harnesses became common.[5] [13]