There is a history of a sudden resisted flexion of the
distal interphalangeal (DIP) joint, such as when the finger
tip is jammed or struck by a ball, resulting in pain and
tender ecchymotic discoloration over the dorsum of the base
of the distal phalanx. When the finger is held in extension
the injured DIP joint remains in slight flexion.
What to do:
Obtain an x ray. It may or may not demonstrate an avulsion
fracture. Apply a finger splint that will hold the DIP joint
in neutral position or slight hyperextension, and firmly
tape it in place.
Instruct the patient to keep the splint in place
continuously and seek orthopedic followup care within one
week.
Prescrlbe an analgesic as needed.
What not to do:
Do not assume there is no significant injury just because
the x ray is negative. With or without a fracture the tendon
avulsion requires splinting.
Do not forcefully hyperextend the joint. This can result in
ischemia and skin breakdown over the joint.
Discussion
Adequate splinting usually restores full range and
strength to DIP joint extension, but the patient will
require 6 weeks of immobilization, and should be informed
that healing might be inadequate, requiring surgical repair.
A wide variety of splints are commercially available for
splinting this injury (e.g. Stack, "frog") but, in a pinch,
a tape-covered paper clip will do. A dorsal splint allows
more use of the finger, but requires more padding and may
contribute to ischemia of the skin overlying the DIP joint.