Nursemaid Elbow

Nursemaid Elbow Overview

Nursemaid elbow is a common injury among preschool-aged children. It refers to a condition (medically called a radial head subluxation) in which a child's elbow bones get partially pulled out of joint and do not line up normally. The injury can occur innocently from swinging a young child by the arms or pulling a child's arm while in a hurry.

A temporary condition without permanent effects, it can be quite frightening to parents who find their child lacking the ability to use his or her upper arm.
Specifically, a portion of soft tissue, whose function is to hold bones together, is pulled between 2 areas of the bones that make up the elbow joint. The involved bony areas are the radial neck and head of the radius bone in the forearm and the capitellum portion of the humerus, or upper arm bone. Movement of the elbow in this condition results in pain and keeps the child from using the upper arm.
Typically, this type of injury occurs in children aged 1-4 years but has occurred in infants aged 6-12 months as well. As children grow, their bones become larger and more defined. So this injury is rarely seen in children older than 6 years.

Nursemaid Elbow Causes

Nursemaid elbow occurs after a sudden pulling force is applied to the extended upper arm of the child while the arm is slightly twisted. The force may not seem strong, and you may not even realize it has happened.

Some examples of typical situations that can produce the mechanism of force required to cause this injury are these:
- In lifting the child by the hand
- Swinging the child while holding the child by the hands
- Pulling arms through the sleeves of jackets
- Catching a child by the hand to prevent a fall
- Pulling a child along when in a hurry
The young child is prone to this type of injury largely because of the anatomical features of their bones and ligaments. Understanding the mechanism of this injury is helpful in explaining the cause.
- The end of the radius bone that connects to the elbow joint is known as the radial head. This will eventually become shaped like the end of a dowel rod. In the young child, however, it does not yet have a well-defined lip at its end. As such, the radial neck and radial head portions of the radius are similar in size in the toddler.
- The annular ligament holds the radius alongside the ulna, which is the other bone in the forearm, and allows for the radius to twist. At this point in childhood development, it is still relatively loosely attached to the bone and can experience a small tear in some of its fibers.
- The combination of these 2 things allows the loose portions of the ligament to slide over the radial head as a pulling force is applied to the elbow when the forearm is slightly twisted inward (pronation). When this happens, this tissue can become trapped between the 2 bones, resulting in the subluxation of the radial head, or nursemaid elbow.