Pulled elbow and hypermobility of joints.

Pulled elbow and hypermobility of joints are frequently seen in young children, the latter occurring in 5% of the general population. A group of 100 children with pulled elbows, composed of 64 girls and 36 boys with a mean age of 25.5 months, and their parents were checked for joint hypermobility in a prospective study over a period of two years. Results were compared with a normal (non-pulled elbow) control group of 30 children. The prevalence of hypermobility among children with pulled elbow was 73%, which is 23% higher than in normal children of similar age. The main differences in hypermobility between the groups were noted in elbows and knees. There was no significant difference between girls and boys. In 48% of the cases of children with pulled elbows, at least one of the parents had hypermobility, whereas only in 10% of the control group were parents hypermobile. The association between pulled elbow and hypermobility indicates that pulled elbow can be considered one of the effects of this condition. Since not all patients with pulled elbows were hypermobile nor did they have parents with hypermobility, other factors may be relevant, such as variations in the anatomy of the radial head and surrounding structures in combination with the degree of violence involved.