The patient will have jammed his finger, causing a
hyperextension injury that forces the middle phalanx
dorsally and proximally out of articulation with the distal
end of the proximal phalanx. An obvious deformity will be
seen unless the patient or a bystander has reduced the
dislocation on his own. There should be no sensory or
What to do:
Unless a shaft fracture is suspected, x rays may be
deferred and joint reduction can be carried out first.
If there has been significant delay in seeking help or the
patient is suffering considerable discomfort, a digital
block over the proximal phalanx will allow for a more
To reduce the joint, do not pull on the fingertip; instead,
push the base of the middle phalanx distally, using your
thumb until it slides smoothly into its natural anatomical
Now test the finger for collateral ligament instability and
avulsion of the central extensor tendon slip. The patient
should be able to extend his finger at the proximal
interphalangeal (PIP) joint. Testing for avulsion of the
volar carpal plate, you will be able to hyperextend the PIP
joint more than that of the same finger on the uninjured
hand. If any of these associated injuries exist, orthopedic
consultation should be sought and prolonged splinting and
rehabilitation will be required.
Post-reduction x-rays should be taken. "Chip fractures" may
represent tendon or ligament avulsions.
Splint in extension for 3-4 days and provide followup for
actiive range of motion exercises to restore normal joint
Inform the patient that joint swelling and stiffness may
persist for months after the initial injury.
Remind the patient to keep the injured finger elevated.
Recommend ice application for the next 24 hours and aspirin
If there is any doubt as to the competence of the central
extensor slip or the volar carpal plate, the joint must be
splinted in full extension for 3 weeks.