Sonographic imaging of mallet finger

Mallet finger is a flexion deformity of the distal interphalangeal joint (DIPJ) caused by a disruption of the extensor mechanism. The deformity can b e caused by active trauma, minor trauma or other conditions like rheumatoid arthritis or osteoarthritis.

To describe the sonographic findings in mallet finger.

We performed sonographic examination on thirty patients with traumatic mallet finger, on thirty control patients where we examined the same finger in the opposite hand (,) and thirty patients with rheumatoid arthritis or osteoarthritis and flexion deformity.

We found four criteria for traumatic mallet finger which included: discontinuity of the extensor tendon with partial or complete tear, avulsion fracture, no real time movements of the extensor tendon, and fluid in the region of insertion of the extensor tendon.

Sonographic examination of patients with traumatic mallet finger is an important diagnostic tool and can differentiate between traumatic mallet finger and flexion deformity of rheumatoid arthritis or osteoarthritis.