Radial Head Subluxation and Associated Complications

1. Radial Head Subluxation and Associated Complications Aimee Disharoon December 14, 2005

2. Radial Head Subluxation • AKA “Nursemaids’ Elbow” • Common injury that is seen most often in children between the ages of 1-6 years • Occurs when longitudinal traction is placed on the hand while the elbow is extended and the forearm pronated. • Usually occurs when child falls and continues to be held by the hand, or when small children are swung by their arms.

3. Anatomy • The annular ligament normally passes around the proximal radius just below the radial head. With traction on the extended arm, the annular ligament slides over the head of the radius into the joint space and becomes entrapped • Common early childhood injury because at an early age, the radial head is spherical and is composed mainly of cartilage

4. Clinical Presentation • history of arm being pulled • injured elbow pronated, partially flexed and held by side, child will not use • there is anterolateral tenderness over the radial head • no swelling, redness, warmth, abrasions, or ecchymosis • have been reports of infants < 6 months old with a history of not using arm after rolling over and their arms getting caught

5. Radiographs • Diagnosis is by history and physical examination. Radiograph examination is usually not necessary and are normal in most instances. • If x-rays are taken, often the subluxation is reduced when the technician positions the arm on the plate. • Radiographs become necessary if pain continues post-reduction.

6. Reduction • Cup affected elbow with opposite hand • Apply pressure over radial head • Thumb in antecubital fossa • Apply slight longitudinal traction by grasping wrist • Supinate (palm up) and flex (to 90 degrees) forearm • Palpable click felt with reduction

7. Post-reduction Management • Child should be pain-free and use arm within 0-15 minutes. Immobilization optional (Sling for 1-2 days) • If child fails to use arm after 15 minutes, obtain elbow views to rule out concomitant fracture • If x-rays normal but child still not using arm, use a posterior splint and sling and re-evaluate in 24 hours • If child has 3 recurrent episodes of subluxation, then apply hard cast for 3 weeks

8. Views: AP Oblique Lateral Technique: Elbow in 90 degree flexion Compare with opposite elbow Evaluation: The radial head should always point at the capitellum in all views. A line drawn down the long axis of the radius (radial head) should intersect the capitellum in all views (if the line doesn’t intersect, this is a sign of dislocation) Elbow X-ray

9. Complications • If pain does not subside post-reduction, then suspect fracture (x-rays required) • Supracondylar Fracture /Salter-Harris Fracture • Monteggia Fracture • Green Stick Fracture Fractures can be seen as lines tranversing the bone, displace-ment of one end of bone relative to the other end, and as joint effusions or “fat pads”

10. Supracondylar Fracture • True supracondylar fractures typically occur just above the humeral epicondyles • Salter-Harris fractures occur in the epiphysis of the humerus, are subtle and often hard to differentiate from dislocations (line drawn through the radius intersects with capitellum)

11. Monteggia Fracture • Fracture of the proximal third of ulna with radial head dislocation

12. Green Stick Fracture • Incomplete fracture of the radius or ulna which causes “bowing” of the bone

13. References • Choung, Walter, and Heinrich,Stephen. Acute Annunlar Ligament Interposition into the Radiocapitellar Joint in Children (Nursemaid's Elbow). Journal of Pediatric Orthopedics. Vol. 15, No.4 1995 • Waander, Hellerstein, and Ballock. Nursemaid's Elbow, Pulling out the Diagnosis. Contemporary Pediatrics. June 2000 • Nursemaid’s Elbow, Familypracticenotebook.com • Riego de Dios, Ricardo, and Norris, Burl. Elbow Fractures and Dislocations. eMedicine. July 2004