Traction apophysitis of the fifth metatarsal base with an avulsion fracture
Presentation
Pain over the lateral border of the foot for a few months. Exacerbated by a recent twisting injury during a football game.
Patient Data
A bony fragment lateral to the base of the fifth metatarsal oriented longitudinally; with a widening of chondro-osseous junction, fragmentation: traction apophysitis of the fifth metatarsal base.
Transverse lucency at the base of the fifth metatarsal: avulsion fracture.
Blue: Iselin disease
Red: Avulsion fracture
Case Discussion
Iselin's disease is a traction apophysitis of the tuberosity of the fifth metatarsal. It occurs in physically active boys and girls between the ages of 9 and 14. It is caused by repetitive traction of peroneus brevis tendon at the site of its attachment. Clinically, there is a lateral midfoot pain aggravated by sports activities.
Differential diagnosis includes:
- Normal apophysis: painless longitudinally oriented apophysis without fragmentation or widening of chondro-osseous junction.
- Os vesalianum.
- The base of 5th metatarsal fractures: A fracture tends to be oriented transversally; whereas a growth plate has always a longitudinal orientation.
In this case, Iselin disease and an avulsion fracture are present simultaneously.