Treatment for mallet finger is extension splinting of the
DIP only for about 6 weeks or more is the usually treatment. Acute injuries
with minimal displacement and no joint subluxation are treated with extension
splinting of the DIP joint for 6-8 weeks. You will need to keep the splint on
for 24 hours daily. The splinting can be volar splinting or dorsal splinting.
Allow the PIP joint to move freely in flexion and extension. After 6 weeks of
splinting, night splinting may be needed for longer periods. It appears that
supplemental night splinting after full time splinting treatment is
controversial and may not really improve the outcome. Wearing the splint may
not be liked by professionals such as doctors, hair dressers, or dentists, and
they may desire the surgery of percutaneous pin fixation. Conservative
treatment can be tried even if the treatment is delayed up to four weeks with
low, long term complication rates. There is an increased complication rate with
surgical treatment. The goal of surgery is to keep the DIP extended until the
bone or the tendon heals. K-wire utilization is a very common technique.
Indications for surgery include volar subluxation of the distal phalanx,
avulsion fracture with a large joint fragment more than 50%, and some
physicians think that 30% of articular involvement is an indication for
surgery. Some orthopaedic surgeons will continue to treat this injury by closed
means (splint), even if there is a volar subluxation of the joint. The
rationale is that a stiff finger that is treated by closed means is better than
a stiff finger that is treated by surgery. A closed injury with or without a
small avulsion fracture is different than a closed injury that involves a large
fragment (more than 50% of the joint) or an injury that causes subluxation of
the DIP joint. Mallet finger with subluxation of the DIP joint is clearly an
indication for surgery. It may require open or closed reduction and pinning of
the fracture or the joint. A single pin is usually sufficient for the treatment
of a purely tendon injury. When pinning a purely tendon injury, make sure you
mark the affected finger on the dorsal aspect as well as the volar aspect of
the finger preoperatively. Make the finger, because the x-ray will not show any
evidence of injury, and this will help you to avoid pinning the wrong finger.
The finger position will change if the finger is pinned with palm down or with
the palm up. For extension block pinning technique, flex the DIP and insert the
k-wire from distal to proximal direction. The k-wire is passed dorsal to the
bony fragment and through the extensor tendon into the middle phalanx. Then
extend the DIP and the k-wire will help in buttressing and reducing the
fracture with extension of the DIP. After the surgery, the patient may
experience an extensor lag, but without functional deficit. Complications of
mallet finger include residual deformity that usually does not affect the function
and swan neck deformity. Care must be taken during treatment to avoid this
deformity. The PIP should be moving freely in extension and flexion to avoid
this deformity.
