- Discussion:
- subluxation of the head of radius from its encirclement by annular ligament is a common elbow injury among young children; (nurse maid)
- most common prior to age 6 yrs because prior to this age, the radial head is spherical and is composed mainly of cartilage;
- mechanism:
- subluxation of the radial head generally results from a sudden pull on the upper limb, such as that exerted by an adult to prevent the child from falling;
- radial head is traumatically subluxated w/ forceful traction on the hand w/ the elbow extended and the forearm pronated;
- annular ligament either tears or slips over the radial head, allowing subluxation of radial head;
- w/ release of traction, the ligament remains interposed between the radial head and capitellum;
- diff dx:
- need distinguish nurse maid from congenital dislocation of radial head:
- Monteggia frx:
- occurance of radial head dislocation along w/ a subtle plastic deformation of the ulnar shaft;
- note that posterior border of ulnar shaft should appear perfectly straight on the lateral radiograph, and any bowing indicates an associated green stick frx;

- Clinical Presentation:
- child presents w/ injured elbow pronated, partially flexed and held by side;
- forearm is pronated and the elbow is partially flexed;
- there is anterolateral tenderness over the radial head;
- usually occurs in children under age 4 and rare after age > 5;
- the child presents with a flexed and pronated forearm supported closely to the trunk of the body;
- the patient complains of pain around the radial head;

- Radiographs:
- radiographs to r/o associated fractures;
- lateral radiograph of a nurse maid's elbow does not show dirsuption of colinear relationship between capitulum & central axis of the radius;
- relationship of radius & ulna that indicates pronated posture of the forearm;

- Reduction of nurse maid elbow:
- interposed annular ligament can be repositioned in its normal site by simple supination of forearrm w/ the elbow in slight flexion;
- elbow is gently flexed to 90 deg by gripping childs forearm above wrist w/ one hand while, w/ other hand, lower end of humerus and elbow are held to prevent rotation at shoulder;
- thumb is placed in region of of the radial head for palpation & application of posteriorly directed pressure on the head of the radius, while firmly, supinating and extending the forearm;
- childs forearm is firmly rotated into full supination;
- immediately following reduction, a click may be heard, & child should note the sudden relief of pain;
- these manipulations screw the radial head into the annular lig;

- Post Reduction Treatment:
- immobilization is not necessary for the first episode of subluxation;
- if treatment of subluxation is delayed for > 12 hrs following reduction, upper limb is immobilized for 10 days in long arm posterior splint w/ elbow in 90 deg of flexion & forearm in full supination;
- if pt has 3 recurrent episodes of subluxation, then apply cast for 3 weeks

- References:

Absence of radiographic abnormalities in nursemaid's elbows.

Investigation on 2331 cases of pulled elbow over the last 10 years.

Recurrent radial head subluxation treated with annular ligament reconstruction. A case report and follow-up study.

Chronic posterior subluxation and dislocation of the radial head.

Acute annular ligament interposition into the radiocapitellar joint in children (nursemaid's elbow).

Tee shirt management of nursemaid's elbow.

"Nursemaid's elbow" in infants six months and under.

Treatment of chronic post-traumatic dislocation of the radial head in children.

The Usefulness of MRI in Atypical Pulled/Nursemaid’s Elbow: A Case Report