yogabook / pathology / radiuskopfsubluxation

Definition

Radial head subluxation is a common injury in children, which can occur up to around the age of 4 if the child’s pronated arm is pulled suddenly and without warning. From the age of 5, the ligamentum anulare radii, which guides the head of the radius, is thought to be too stable to allow subluxation to occur. Three typical triggering situations are:

1. lift the crying child off the floor by the hand, despite his resistance
2. to pull a child away by the arm whilst they are clinging on somewhere
3. Hold the child by both hands and spin them round quickly in a circle, using centrifugal force (‘playing at being an angel’).

This injury also occurs in judo; other causes are rare. The triggering event is very painful; subsequently, there remains pain on movement and only moderate pain at rest, which causes the child to keep the elbow slightly bent whilst the forearm is pronated. The assumed pathomechanism is that the head of the radius subluxates distally out of the ligamentum anulare radii, and as the tension subsides, the ligamentum anulare radii becomes pinched between the head of the radius and the capitulum humeri, which explains the pain on movement. This condition must not be confused with congenital radial head dislocation, which occurs at an incidence of 2–4 per 1,000 due to a flattened
capitulum humeri.

Cause

1. a forceful or jerky pull on the arm whilst it is largely extended, particularly in the pronated position

Predisposing

1. Age before the 5th Lj.

Diagnosis

1. based on medical history and clinical presentation
2. If symptoms persist following successful repositioning, an X-ray may be required to rule out fractures
3. if necessary. I am

Symptoms

1. Posture: slightly bent elbow joint with pronated forearm
2. painful restriction of movement towards flexion of the elbow joint
3. sudden pain at the onset of the triggering event, followed by pain on movement and only moderate pain at rest
4. Absence of signs of inflammation
5. localised tenderness, if present

Therapy

1. Repositioning (various techniques) can be carried out without anaesthesia and, if performed promptly, repositioning provides immediate relief
2. in the event of frequent relapses, a plaster cast on the upper arm for 3–6 weeks

Complications

1. Reluxation following delayed repositioning
2. chronic instability following true dislocation (not subluxation)
3. rare: damage to blood vessels or the ulnar nerve