Terminal Extensor Tendon · DIP Joint
Mallet
Finger
Mallet fingers often occur when the end of the finger is “jammed” against an object. The terminal extensor tendon tears and leaves the tip of the finger in a flexed (bent towards the palm) position.
Call our office · (623) 264-3300What Actually Tears
The terminal extensor tendon is the structure that straightens the very last joint of the finger.
The Tendon Attaches at the Tip
It anchors to the bone just past the last joint, directly beneath the fingernail
A Jam Tears It
The fingertip is forced into flexion while the tendon is under tension
Nothing Straightens the Tip
With the tendon torn, the fingertip stays bent — you cannot actively straighten it
Sometimes Bone Comes With It
The tendon may pull a small fragment of bone away, which affects healing and later arthritis risk
Overview
What Is a Mallet Finger?
Mallet fingers often occur when the end of the finger is “jammed” against an object. The terminal extensor tendon tears and leaves the tip of the finger in a flexed (bent towards the palm) position.
The result is a fingertip that droops and cannot be actively straightened, even though it can usually still be pushed straight passively with the other hand. That difference — passive correction but no active straightening — is the hallmark of the injury.
The decision regarding nonoperative versus operative treatment is complex and should be discussed with your treating physician.
Why the Joint Must Stay Straight
A torn tendon heals by forming a bridge of scar tissue between the two ends. That bridge can only form if the two ends stay close together. Every time the fingertip is allowed to bend during the healing period, the ends separate again and the process restarts — which is why splinting is full-time at first, not as-needed.
Common Causes
- A ball striking the extended fingertip
- Jamming the finger against a door, drawer or wall
- Catching the finger while making a bed or tucking in sheets
- Any impact that forces the tip into a bent position
Tendon or Bone?
When only the tendon tears, it is a soft-tissue injury. When the tendon pulls a fragment of bone off with it, the injury involves bone as well — and arthritis may occur when there is bone involvement. X-rays help tell the two apart, because the treatment and the long-term outlook differ.
Treatment
Splinting Is the Mainstay
Nearly all mallet fingers are treated without surgery. What matters most is keeping the joint straight, continuously, for as long as the tendon needs to heal.
Full-Time Splinting
Initial treatment involves full-time splinting of the affected distal interphalangeal joint (joint directly adjacent to the fingernail) in a neutral position. Splinting aims to correct the flexed posture.
Monitoring the Skin
The skin should be monitored to ensure that splinting does not create excess pressure that may lead to sores. Splints are checked and adjusted as needed.
Weaning Off
Eventually, under the guidance of a physician, splinting transitions to night-time only, followed by eventual discontinuation.
Non-Operative Treatment
Splinting the DIP joint in a neutral position, with a gradual transition to night-time wear and eventual discontinuation.
- Full-time splinting of the DIP joint in a neutral position
- Regular skin checks to prevent pressure sores
- Transition to night-time only, then discontinuation
- Repeat splinting if a significant recurrent lag occurs
Non-operative treatment also carries risks and benefits which should be discussed with your treating physician.
Operative Treatment
Occasionally for very specific individuals/circumstances, surgery involving the placement of a temporary buried wire to maintain the joint in a neutral position may be performed.
- A temporary buried wire holds the joint straight while the tendon heals
- The wire is typically removed once healing is confirmed
- Reserved for select individuals and circumstances
Outcomes after surgery vary and risks and benefits should be discussed in detail with your treating physician.
What to Expect
After Treatment
A mallet finger usually does well, but some changes at the joint can persist. These are expected — not signs of failure.
Dorsal Prominence
After treatment, dorsal prominence of the joint may occur — the back of the joint can look more prominent than before.
Residual Lag
A small remaining bend in the fingertip may persist. Residual lag of the finger is a recognized outcome.
Recurrent Lag
If a significant recurrent lag occurs immediately after splinting has been discontinued, the process of splinting is often repeated.
Arthritis
Arthritis may occur when there is bone involvement, which is why X-rays matter at the outset.
Why You Shouldn't Test It
It is natural to want to check whether the finger is better by straightening it. During the splinting period, that single movement can pull the healing tendon ends apart and reset the clock. If the splint needs to come off — for cleaning or any other reason — keep the fingertip supported in a straight position the whole time, and confirm the plan with your physician first.
Related Reading
Other Finger Conditions
A mallet finger affects the tendon at the last joint of the finger. Other finger conditions involve different structures — the pulleys, the joints, or the bone — and are treated differently.
Common Questions
Mallet Finger FAQs
What is a mallet finger?
Mallet fingers often occur when the end of the finger is “jammed” against an object. The terminal extensor tendon tears and leaves the tip of the finger in a flexed (bent towards the palm) position.
How is a mallet finger treated initially?
Initial treatment involves full-time splinting of the affected distal interphalangeal joint (joint directly adjacent to the fingernail) in a neutral position. Splinting aims to correct the flexed posture.
Why does the skin need to be monitored during splinting?
The skin should be monitored to ensure that splinting does not create excess pressure that may lead to sores.
How long is splinting needed?
Eventually, under the guidance of a physician, splinting transitions to night-time only, followed by eventual discontinuation.
What happens after treatment?
After treatment, dorsal prominence of the joint and residual lag of the finger may occur. Arthritis may occur when there is bone involvement.
What if the finger droops again after splinting ends?
If a significant recurrent lag occurs immediately after splinting has been discontinued, the process of splinting is often repeated.
When is surgery considered?
Occasionally for very specific individuals/circumstances, surgery involving the placement of a temporary buried wire to maintain the joint in a neutral position may be performed.
Precision Hand and Orthopedic Surgery
A Fingertip That Won't Straighten
If the tip of your finger droops after a jam or impact, an evaluation can confirm the diagnosis, check for bone involvement, and get you into the right splint early — which is when this injury responds best.
(623) 264-3300 · Now accepting new patients
Disclaimer: This information is not intended to convey, substitute or supplant any medical advice. In order to establish a treating relationship, please schedule and complete your visits with a licensed physician.
Copyright 12/9/2021 Tanay Amin, MD. Do not copy, distribute, or publish this article. Please contact Precision Hand and Orthopedic Surgery PLLC with regards to any inquiries or corrections.