Classic history and presentation: The patient typically presents after a fall with pain and limited range of motion (ROM) of the elbow, particularly supination and pronation. Point tenderness and pain over the lateral elbow with passive rotation, and an elbow effusion, will be present.
Prevalence: Radial head and neck fractures account for about one-third of all elbow fractures in adults. Radial neck fractures account for 5% of pediatric elbow fractures.
- Age – If a fracture of the proximal radius occurs, the radial head is more vulnerable in adults while the radial neck is more vulnerable in children. This diagnosis is most common in middle adulthood or in the pediatric population, at age 8-10 years.
- Sex / gender – There is a slightly higher incidence in females.
Pathophysiology: Function and stability of the elbow depends on 3 separate articulations: the ulnohumeral, radiocapitellar, and proximal radioulnar joints. The radial head articulates with the proximal ulna and capitellum and is an important stabilizer for valgus, axial, and posterolateral rotational forces.
There is an increased incidence of associated injuries with increasing severity of radial head or neck fractures: 20% in nondisplaced fractures and up to 80% in comminuted radial head fractures.
Grade / classification system:
Mason classification of radial head fractures
- Type 1 – Undisplaced segmental / marginal fracture; intra-articular displacement less than 2 mm.
- Type 2 – Displaced segmental fracture; intra-articular displacement more than 2 mm or angulated.
- Type 3 – Comminuted fracture.
- Type 4 – Fracture associated with posterior dislocation.
- Type I – less than 30 degrees of angulation
- Type II – 30-60 degrees of angulation
- Type III – more than 60 degrees of angulation
