Definition
Radial head subluxation
Incidence
Average 2 - 3 years
- rare > 7
- annular ligament has better attachment after 5
- common, but exact incidence unknown
MOI
Axial traction with extended elbow
- annular ligament subluxes off radial head
- more common with ligament laxity
History
History axial traction
Snap sometimes heard
Examination
Limb in extension & pronation
- pain on supination
Pseudoparalysis
Tender over radial head
X-Ray
Usually normal
- mild increase radio-capitellar line > 3mm
US
May show increase radio-capitellar distance between elbows
- > 3 mm difference suggestive of subluxation
Management
Concept
Pronation tends to sublux both DRUJ & PRUJ
Hence stabilise in Supination
Technique
Supination + Flexion
Mild analgesia
- warn parents
- painful cry then relief
Feel for snap
- classically immediate pain relief
- child will use arm immediately
If subluxed for > 12/24 often 2° synovitis has developed
- pain relief not dramatic
- may not have snap
- place in sling & review next day
- will often self reduce
Complications
1. Unreduced subluxations
No series reports any long-term sequelae in which the subluxation is not recognized & reduced
Almost all the subluxations reduce spontaneously
2. Recurrent subluxations
5% to 39%
- usually respond to the same MUA as the initial injury
- ceases after 5 years of age
3. Irreducible subluxations
Open reduction is rarely necessary
- delineate from radial head dislocation which need reduction
- MRI if unreduced after 2/52