Mallet Finger

Upper Limb

Overview

Mallet finger is a deformity caused by disruption of the extensor digitorum tendon at its insertion on the distal phalanx, resulting in loss of active extension at the distal interphalangeal (DIP) joint. This injury typically results from blunt trauma to the fingertip, such as a ball strike during sports, and presents with a characteristic drooping posture of the distal phalanx. Early appropriate management with prolonged immobilization can achieve excellent functional outcomes without surgical intervention in most cases.

Pathophysiology

The extensor digitorum tendon inserts on the dorsal base of the distal phalanx and is responsible for DIP joint extension. Blunt force trauma causes either rupture of the tendon directly (Type 1) or avulsion of the bone insertion with tendon attachment (Type 2). In some cases, a large bony fragment may be avulsed with the tendon (Type 3). The resultant loss of active extension at the DIP joint leads to characteristic mallet posturing, with the distal phalanx adopting a flexed position. Secondary dorsal skin tightness and PIP hyperextension compensation can develop if not properly managed during the healing phase (typically 6-12 weeks).

Patient Education

Consistent immobilization of your fingertip joint in full extension for 6-12 weeks is critical for healing; even brief periods without immobilization can significantly delay recovery or result in permanent deformity.

Typical Presentation

Site

Distal interphalangeal (DIP) joint of the affected finger; most common in index through ring fingers, particularly the dominant hand

Quality

Sharp or aching pain at the time of injury; subsequently characterized by functional loss rather than pain

Intensity

Acute pain at injury (often mild), followed by variable discomfort dependent on immobilization tolerance and secondary joint stiffness

Aggravating

Attempts to actively extend the DIP joint; removal of immobilization; activities requiring precision grip; trauma to the digit

Relieving

Immobilization of the DIP joint in full extension; rest; ice application in acute phase; pain relief medications

Associated

Loss of active DIP extension with preserved passive range (early stages); visible drooping of fingertip; swelling and bruising over dorsal DIP joint; potential PIP joint hyperextension compensation; secondary stiffness if immobilization is inadequate

Orthopaedic Tests

Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.

Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).

No accuracy study

Mallet Finger Test (Loss of DIP Extension)

Procedure

Hold the middle phalanx so the PIP joint stays straight and ask the patient to straighten the fingertip.

Positive Finding

The fingertip droops and cannot be actively straightened, although it can usually be straightened passively.

Interpretation

The key sign of a mallet injury: disruption of the terminal extensor tendon at the base of the distal phalanx, with or without a bony fragment. Arrange an X-ray to check for a fracture or joint subluxation, and splint the DIP joint in extension without delay.

Sources

No accuracy study

Passive DIP Extension (Correctability) Check

Procedure

Gently extend the DIP joint passively to neutral. Do not force it into hyperextension.

Positive Finding

The DIP joint cannot be passively straightened to neutral.

Interpretation

In an acute mallet injury the DIP should straighten passively. A joint that will not straighten suggests a chronic injury, joint subluxation or a fracture, and needs an X-ray and hand surgery advice.

Sources

No accuracy study

Tenodesis Test

Procedure

Let the hand relax, then passively flex the patient's wrist and watch all the fingers.

Positive Finding

In the injured finger, the fingertip does not straighten with the others as the wrist flexes.

Interpretation

Supports loss of continuity of the terminal extensor tendon. Useful when pain limits active testing.

Further reading

No accuracy study

Radiographic Assessment (DIP Joint Alignment & Fracture)

Procedure

A true lateral X-ray of the affected finger, plus a PA view.

Positive Finding

A fragment from the dorsal base of the distal phalanx and/or palmar subluxation of the distal phalanx (bony mallet), or a flexed DIP with no fracture (tendinous mallet).

Interpretation

Separates tendinous from bony mallet injuries and shows joint subluxation, which changes management. Large fragments or any subluxation need a hand surgery opinion.

Sources

⚠ Red Flags

  • •Large bony avulsion (>30% of articular surface) on imaging without specialist review
  • •Signs of infection (increasing pain, erythema, purulent drainage after 48 hours)
  • •Vascular compromise (pale, cold, mottled fingertip; absent capillary refill)
  • •Nerve injury indicated by sensory loss in fingertip distribution
  • •Inability to achieve full passive extension at DIP joint (suggests advanced contracture or missed diagnosis)

⚡ Yellow Flags

  • •Previous poor compliance with immobilization-based treatment
  • •Work or occupational demands incompatible with required immobilization period
  • •Anxiety regarding permanent deformity leading to avoidance behaviors
  • •Secondary depressive symptoms from functional hand impairment
  • •Catastrophizing about injury severity or prognosis

Osteopathic Techniques

Most mallet finger injuries, tendon or small bony, are treated without surgery: the DIP joint is splinted straight, full-time, for 6–8 weeks (some protocols up to 12). Only the DIP needs splinting; the PIP can move. No trials of osteopathic techniques were found.

Safety: The DIP must not bend at all while it is splinted: any flexion means restarting the 6–8 weeks. Keep techniques off the DIP. X-ray to check for a bony mallet with DIP subluxation, which falls outside non-operative care.

Region

PIP joint (the DIP stays in its splint)

Technique

Articulation, wrist and handNo trials found

Rationale

Gentle glides of the wrist, carpal and hand joints to restore movement.

How it's done, cautions & evidence

How it's done

Passive, rhythmic, low-velocity glides of the radiocarpal, midcarpal and intercarpal joints, the distal radioulnar joint, the thumb carpometacarpal (CMC) joint and the finger joints, within or up to the end of the available range. In thumb-base osteoarthritis trials this was Maitland-style passive accessory gliding of the CMC joint.

Cautions

After a fall on the hand, rule out a fracture first: scaphoid fractures are often missed on the first X-ray, so snuffbox pain needs a splint and repeat imaging. Do not move a joint that is splinted for a tendon injury: the DIP in mallet finger, the PIP in a central slip (boutonnière) injury.

Evidence in Mallet Finger

Searched 26 Oct 2026: no trials of PIP mobilisation in mallet finger.

Region

Dorsal forearm extensor compartment

Technique

Soft tissue, elbow and forearmNo trials found

Rationale

Soft tissue to the forearm flexor and extensor muscles that move the wrist and fingers.

How it's done, cautions & evidence

How it's done

Hands-on kneading, stroking and sustained pressure to the forearm extensor and flexor muscles, their tendon origins at the epicondyles, the supinator, the pronators and the triceps. Deep transverse friction across the tendon origin is part of the Cyriax method for lateral elbow pain.

Cautions

Avoid direct pressure on an olecranon bursitis. A red, warm, tender bursa, especially with fever, may be septic and needs medical review.

Evidence in Mallet Finger

Searched 26 Oct 2026: no trials of forearm soft tissue in mallet finger.

Region

Wrist and forearm muscles

Technique

Muscle energy, elbow and forearmNo trials found

Rationale

Muscle energy technique to ease tight forearm muscles that act on the wrist (wrist extensors or flexors, pronators or supinators).

How it's done, cautions & evidence

How it's done

The wrist or forearm is taken to the barrier of the tight muscle group (wrist extensors or flexors, pronators or supinators). The patient pushes gently back, at about 10–20% effort, against resistance for 5–10 seconds, relaxes for 3–5 seconds, and the new barrier is taken up.

Cautions

Not used with an acute fracture, a joint infection or a bone malignancy; take care with severe osteoporosis or after surgery that limits muscle contraction. Use the least force needed: too much can tear a muscle or pull off a tendon, especially in older patients.

Evidence in Mallet Finger

Searched 26 Oct 2026: no trials of forearm muscle energy technique in mallet finger.

Rehabilitation Exercises

Passive DIP Joint Extension (Early Phase)

Range of MotionBeginner

PIP Joint Flexion and Extension Mobilization

Range of MotionBeginner

Dorsal Hand and Forearm Extensor Stretch (Wrist Flexion with Fingers Extended)

StretchingBeginner

Intrinsic Hand Muscle Stretch (Finger Abduction Against Resistance)

StretchingIntermediate

Isolated DIP Extension Against Gravity (Post-Immobilization)

StrengtheningIntermediate

Finger Extensor Strengthening with Resistance Band (Late Phase)

StrengtheningIntermediate

Grip Strengthening Progression (Therapy Putty or Stress Ball)

StrengtheningIntermediate

Fine Motor Dexterity: Coin Manipulation and Transfer

BalanceBeginner

Pinch Grip Coordination (Tripod Pinch with Progressive Resistance)

BalanceIntermediate

Wrist and Finger Neutral Posture Awareness (Functional Positioning)

PosturalBeginner

Upper Limb Ergonomic Positioning and Activity Modification

PosturalBeginner

Whole-Body Cardiovascular Conditioning (Non-Impact Modalities)

CardiovascularBeginner

Referral Criteria

  • •Large bony avulsion fragments (>30% of articular surface) requiring surgical consultation
  • •Failure to achieve or maintain full passive DIP extension suggesting advanced soft tissue contracture
  • •Signs of compartment syndrome or vascular compromise
  • •Evidence of infection that does not resolve within 48-72 hours of conservative management
  • •Persistent loss of DIP extension after 12 weeks of appropriate immobilization despite compliance
  • •Secondary PIP joint hyperextension contracture that limits functional grip and cannot be managed conservatively
  • •Significant swelling or stiffness unresponsive to conservative care after 4-6 weeks
  • •Occupational or functional demands requiring earlier return to activity that may compromise healing