A mallet finger is a fingertip that droops at the last joint, the DIP joint, and cannot be straightened actively. It results from disruption of the terminal extensor tendon, the tendon that straightens the very tip of the finger, where it attaches at the base of the fingertip bone. Sometimes a small piece of bone is pulled off with the tendon, called a bony mallet.
The classic cause is a ball striking the end of an extended finger, which is why it is sometimes called baseball finger. The injury forcibly bends the fingertip while the tendon is trying to keep it straight, and the tendon either tears or avulses a fragment of bone. The good news is that most mallet fingers heal well with splinting alone, provided the splint is worn correctly and continuously.
What happens in the finger
The terminal extensor tendon is what straightens the fingertip. When it is disrupted, the tip can no longer be held straight and droops downward, while the pull of the flexor tendon on the palm side goes unopposed. The aim of treatment is to hold the fingertip straight continuously so the tendon, or the bony fragment, can heal in the correct position.
How it is diagnosed
The diagnosis is usually clear on examination: the fingertip droops and cannot be actively straightened. An X-ray is important to determine whether the injury is purely tendinous or whether a fragment of bone was avulsed, and if so, how large the fragment is and whether the joint has shifted out of position (subluxation). These findings guide whether splinting alone is sufficient or whether surgery should be considered.
Splinting is the foundation
For the great majority of mallet fingers, continuous splinting of the fingertip in a straight position for six to eight weeks allows the tendon to heal. The single most important factor in success is keeping the fingertip straight at all times during this period, including when changing or cleaning the splint. Letting the tip droop even briefly can reset the healing clock.
Dr. Lee treats the great majority of mallet fingers nonoperatively. The fingertip is held straight in a splint continuously for six to eight weeks, followed by a period of nighttime splinting as the tendon matures. The emphasis throughout is on splint technique and compliance, because the tendon heals reliably only if the fingertip is never allowed to droop during the healing period.
Surgery is reserved for specific situations: a large bony fragment with the joint shifting out of position (subluxation), an open injury, or selected cases that do not heal with splinting. When surgery is needed, the goal is to restore the alignment of the joint and the attachment of the tendon. For most patients, however, a well-managed splinting program is all that is required.
Non-surgical treatment
Most mallet fingers are treated successfully without surgery:
- Continuous DIP extension splinting for six to eight weeks, keeping the fingertip straight at all times
- A period of nighttime splinting afterward as the tendon matures
- Careful splint hygiene, keeping the tip straight even during splint changes
- Hand therapy guidance on technique and a graded return to motion
When surgery is considered
Surgery is reserved for a large bony fragment with the joint shifting out of position (subluxation), open injuries, and selected cases that do not heal with splinting. The goal is to restore the joint alignment and the tendon attachment. Most patients never need an operation.
Recovery timeline
Recovery follows the healing of the tendon:
- Weeks 0 to 8Continuous splinting holds the fingertip straight so the tendon heals. The tip must not be allowed to droop, even during splint changes.
- Weeks 8 to 12Splinting is gradually reduced, often continued at night, and gentle motion of the fingertip begins under guidance.
- Beyond 12 weeksReturn to full use. A small residual droop or a slight bump at the joint is common and usually does not affect function.
What patients commonly misunderstand
A few points worth clearing up:
- It is not just a jammed finger. A drooping fingertip that cannot be straightened is a tendon injury, not a simple sprain. It needs splinting, and an X-ray to check for a bone fragment.
- Splint compliance is everything. The fingertip must stay straight continuously for six to eight weeks. Letting it droop, even briefly during a splint change, can restart the healing process.
- Most do not need surgery. The great majority of mallet fingers heal well with splinting. Surgery is reserved for large bony fragments with joint subluxation or open injuries.
This page is general educational content authored by Dr. Lee. It is not a substitute for individual medical advice. Every patient's case is different, book a consultation to discuss yours.