Midshaft clavicle fractures associated with atlantoaxial rotatory displacement: a report of two cases.

Two cases of clavicle fractures associated with atlantoaxial rotatory displacement as well as 11 additional cases from the literature are presented. Most cases occur in girls 6 to 10 years old. The head is most often laterally bent toward and rotated away from the fractured clavicle. There is often a delay in making the diagnosis, which is best demonstrated by dynamic CT. Treatment of the clavicle fracture is straightforward, but failure to recognize and treat the C1-2 rotatory displacement promptly can lead to fixed C1-2 deformity. Displacement recognized within the first 3 weeks of injury can be successfully treated nonoperatively. A delay of 6 weeks or greater in the diagnosis leads to fixed deformity at C1-2 that can be addressed with a limited cervical fusion.