The extensor tendons of the finger are held in place during flexion extension by a fibrous connective complex called the dorsal hood.
The dorsal hood is attached to the underlying metacarpal head by a medial and lateral sagittal band.
It functions as the insertion by proxy of the extensor mechanism to the proximal phalanx
The sagittal bands may become injured particularly as a consequence of fist impaction.
Disruption of the sagittal band allows the extensor tendon to sublux during flexion.
This is usually palpable and an imaging diagnosis is generally not warranted.
In cases where there is clinical difficulty or difficulty in examining large or chubby hands, ultrasound can readily demonstrate the abnormal tendon movement.
As the patient flexes the fingers, the extensor tendon is seen to deviate over the metacarpal head
Injuries are divided into:
• Soft tisue avulsion
• Avulsion fracture
Simple avulsion
Split no joint depression
Split with joint depression
