Finger Dislocations

High Yield Overview

FINGER DISLOCATIONS

PIP and DIP Joint Injuries | Management Algorithms | Exam Pearls

PIPJMost common joint

DorsalMost common direction

6 WeeksVolar splint duration

40%Surgical threshold

DISLOCATION TYPES

Dorsal

PatternMiddle phalanx dorsal to proximal

TreatmentEarly motion (Buddy tape)

Volar

PatternMiddle phalanx volar to proximal

TreatmentStatic extension splint (6 wks)

Lateral

PatternCollateral ligament disruption

TreatmentBuddy tape 4-6 weeks

Fracture-Fx

PatternVolar lip avulsion fragment

TreatmentSurgical if greater than 40% articular surface

Critical Must-Knows

Dorsal PIPJ is most common; treated with early motion and buddy taping.
Volar PIPJ is rare but critical - central slip injury requires 6 weeks extension splint.
V-sign on lateral X-ray indicates dorsal subluxation and joint instability.
Digital blocks are required for reduction and comprehensive stability assessment.
Complications include permanent fusiform thickening and chronic stiffness.

Examiner's Pearls

"
Early motion for dorsal; strict extension for volar. Mismanaging volar causes Boutonnière.
"
Assess collateral stability in 30° of flexion after successful reduction.
"
Irreducible dislocations usually implicate volar plate or FDP tendon entrapment.
"
Check for 'Volar Plate Sign' - small avulsion fragment from middle phalanx base.

Clinical Imaging

Imaging Gallery

PA hand radiograph showing dorsal PIPJ dislocation of ring finger — Dorsal PIPJ Dislocation - PA View. PA radiograph of hand showing dorsal dislocation of ring finger PIPJ. The middle phalanx is displaced dorsally relative to the proximal phalanx. Note the associated soft tissue swelling.Credit: PMC Open Access, CC BY 4.0

Lateral radiographs showing dorsal PIPJ dislocation before and after reduction — Dorsal PIPJ Dislocation - Pre and Post Reduction. (A) Pre-reduction lateral showing dorsal displacement of middle phalanx with joint incongruity. (B) Post-reduction lateral demonstrating anatomic joint alignment. True lateral views are essential for assessing reduction quality and detecting the V-sign of instability.Credit: PMC Open Access, CC BY 4.0

Critical Exam Points: PIPJ Dislocations

Dorsal vs Volar Distinction

Crucial Distinction:

Dorsal: Volar plate avulsion. Treat with early motion (buddy tape) to prevent stiffness.
Volar: Central slip rupture. Treat with static extension splint (6 weeks) to prevent Boutonnière deformity.

The 'V-Sign' Instability

On lateral X-ray, dorsal subluxation creates a V-shaped joint space. This indicates instability and often requires extension block splinting or surgical intervention.

Stiffness and Swelling

Fusiform swelling and stiffness persist for months. Early mobilization is key for stable (dorsal) dislocations. Always warn patients about permanent finger thickening.

At a Glance

Finger Fracture-Dislocation Patterns

Pattern	Mechanism	Stability	Treatment
Simple Dorsal	Hyperextension	Stable	Buddy tape / Early motion
Volar Dislocation	Rotational / Volar force	Unstable (Central Slip)	Extension splint 6 weeks
Complex Fracture	Articular greater than 40%	Unstable	Surgical Fixation
Lateral	Collateral stress	Stable	Buddy tape 4 weeks

Mnemonics

Mnemonic

DORALDorsal vs Volar Distinction

Dorsal

Most common direction

Open

Often associated with skin tears (DIPJ)

Reduction

Traction and flexion

Active

Early active motion is key

Lithgow

Lithgow criteria for stability

Memory Hook:Dorsal dislocations are the 'Typical' type - keep 'em moving!

Mnemonic

VOLARVolar Dislocation Management

Volar

Middle phalanx volar to proximal

Obligatory

Central slip injury is mandatory

Look

Check for boutonniere (delayed)

Avoid

Avoid flexion for 6 weeks

Rigid

Rigid extension splinting

Memory Hook:Volar = Volatile behavior of the central slip. Splint it!

Mnemonic

VSIGNThe V-Sign of Instability

V-shaped

Gap on lateral X-ray

Subluxation

Dorsal subluxation of joint

Incongruent

Joint surfaces are not parallel

Grip

Unstable grip on the phalanx

Next step: Extension block splinting

Memory Hook:See the V? Think instability!

Overview and Epidemiology

Finger dislocations are among the most common hand injuries seen in both primary care and emergency departments. The Proximal Interphalangeal (PIPJ) joint is the most frequently affected, earning its reputation as the "workhorse" joint of the finger.

Mechanism of Injury

Hyperextension: Most common mechanism for dorsal PIPJ dislocations.
Axial Loading: Often seen in "jammed finger" sports injuries.
Rotational Stress: Results in lateral dislocations and collateral ligament disruption.
Volar Displacement: Occurs with a palm-directed force on a flexed finger, rupturing the central slip.

Anatomy

Joint Stabilisers

Box Structure:

Volar: Volar Plate (Fibrocartilage). Prevents hyperextension.
Lateral: Collateral Ligaments (Proper and Accessory).
Dorsal: Extensor mechanism (Central slip).

Volar Plate:

Thick distal attachment to middle phalanx base.
Thin membranous proximal attachment (Check-rein ligaments).
In Dorsal dislocation, it usually avulses from the base of the middle phalanx (+/- bone fragment).

Mnemonics

Pathology:

Middle phalanx dorsal to proximal.
Volar plate rupture.

Treatment:

Reduction: Traction + Flexion.
Stability Check: Active flexion/extension. Stress collaterals.
Simple: Dorsal blocking splint (prevent last 30° extension) for 1-2 weeks or Buddy taping. Early Motion essential.
Complex (Fracture-Dislocation):
- If articular fragment over 40% or unstable.
- Extension Block Splinting (Ishiguro).
- ORIF or Volar Plate Arthroplasty.

Volar PIPJ Dislocation

Pathology:

Middle phalanx volar to proximal.
Central Slip Rupture is frequent.

Treatment:

Reduction: Traction + Extension.
Splinting: Static Extension Splint for 6 weeks (treat as Acute Boutonnière).
Rehab: Maintain DIPJ flexion exercises (pulls lateral bands).

DIPJ Dislocation

Usually Dorsal.
Often open (skin tears).
Reduction: Digital block → Pull and flex.
Repair: Irreducible? Interposition of FDP or Volar plate.
Splint: 2 weeks.

Extension Block Splinting

Hamer DW, et al. • J Hand Surg Br (1994)

Key Findings:

For unstable dorsal fracture-dislocations
Splint allows full flexion but blocks extension beyond stable point (e.g., -30 degrees)
Weekly X-rays to increase extension by 10 degrees
Good functional results compared to surgery for fragments under 50%

Clinical Implication: Conservative management with extension blocking is effective for most fracture-dislocations.

Eaton and Littler Technique

Eaton RG, et al. • J Hand Surg Am (1980)

Key Findings:

Volar plate arthroplasty remains the gold standard for chronic PIPJ fracture-dislocations.
Provides a stable gliding surface for the proximal phalanx condyle.
Satisfactory results in fragments involving greater than 40% of the articular surface.

Clinical Implication: Consider volar plate arthroplasty for complex, comminuted volar lip fractures.

The Elson Test

Elson RA • J Bone Joint Surg Br (1986)

Key Findings:

A clinical test for early diagnosis of central slip rupture.
Specifically differentiates between central slip and lateral band function.
High sensitivity for detecting early Boutonnière risk.

Clinical Implication: Perform Elson's test in all volar PIPJ dislocations to confirm central slip integrity.

PIPJ Stability Criteria

Kiefhaber TR, et al. • J Hand Surg Am (1986)

Key Findings:

Fractures involving less than 30% articular surface are consistently stable.
Fractures involving greater than 50% articular surface are consistently unstable.
30-50% is the 'gray zone' requiring stress testing under fluoroscopy.

Clinical Implication: Use the 30/50 rule for deciding between conservative and surgical management.

Ishiguro Technique Outcomes

Ishiguro T, et al. • J Hand Surg Am (1997)

Key Findings:

Percutaneous K-wire extension block pinning for mallet and PIPJ injuries.
Minimally invasive alternative to ORIF.
Excellent functional results with minimal soft tissue disruption.

Clinical Implication: Extension block pinning is an effective minimally invasive option for unstable dorsal injuries.

At a Glance

Finger dislocations most commonly involve the PIPJ and are classified by direction: dorsal (common—volar plate rupture), volar (rare—central slip rupture), or lateral. Dorsal PIPJ dislocations are reduced with traction/flexion and treated with early mobilisation (buddy taping or dorsal blocking splint) to prevent stiffness. Volar PIPJ dislocations require 6 weeks static extension splinting (like acute boutonnière) due to obligatory central slip injury—early mobilisation causes boutonnière deformity. The "V-sign" on lateral X-ray indicates dorsal subluxation and instability. Unstable fracture-dislocations (over 40% articular involvement) may need extension block splinting (Ishiguro) or ORIF/volar plate arthroplasty. Expect prolonged fusiform swelling.

Overview

Finger Dislocation Overview

Epidemiology:

Very common sports injury ("jammed finger")
PIPJ dislocations most common
DIPJ and MCP dislocations less frequent

Classification by Direction:

Dorsal: Most common - volar plate injury
Volar: Less common - central slip rupture
Lateral: Collateral ligament injury

Dislocation Types

Type	Structure Injured	Key Treatment
Dorsal PIPJ	Volar plate	Early motion (buddy tape)
Volar PIPJ	Central slip	Extension splint 6 weeks
Lateral PIPJ	Collateral ligament	Buddy tape 4-6 weeks

Anatomy

PIPJ Stabilising Structures

Box Structure:

Volar: Volar plate (fibrocartilage)
Dorsal: Central slip of extensor tendon
Lateral: Proper and accessory collateral ligaments

Volar Plate:

Thick distal attachment to middle phalanx base
Thin proximal attachment (check-rein ligaments)
Prevents hyperextension
Avulses in dorsal dislocation

PIPJ Stabilisers

Structure	Location	Injury Consequence
Volar plate	Volar	Dorsal dislocation
Central slip	Dorsal	Boutonnière risk (volar dislocation)
Collaterals	Lateral	Lateral instability

Classification

Classification by Direction

PIPJ Dislocations:

Dorsal: Middle phalanx dorsal to proximal (most common)
Volar: Middle phalanx volar to proximal (rare, central slip injury)
Lateral: Collateral ligament disruption (rotatory component)

By Joint Involvement:

Simple dislocation (soft tissue only)
Fracture-dislocation (bony avulsion)

Classification Summary

Type	Injured Structure	Stability
Dorsal simple	Volar plate	Usually stable post-reduction
Dorsal fracture-dislocation	Volar plate + bone	Depends on fragment size
Volar	Central slip	Requires extension splinting
Lateral	Collateral ligament	May have rotatory instability

Clinical Assessment

History

Mechanism:

Hyperextension injury (dorsal dislocation)
Rotational force (lateral or volar)
Ball sports most common (basketball, football, cricket)

Key Questions:

Time since injury
Previous reduction attempts
Hand dominance and occupation

Examination

Inspection:

Obvious deformity (dorsally or volarly displaced)
Swelling and bruising
Skin integrity (open injuries common in DIPJ)

Palpation and Assessment:

Point tenderness
Neurovascular status (capillary refill, sensation)
Active ROM after reduction

Clinical Signs by Dislocation Type

Type	Appearance	Key Finding
Dorsal PIPJ	Finger shortened, hyperextended posture	Volar plate avulsion on X-ray
Volar PIPJ	PIPJ flexed, DIP extended	Cannot actively extend PIPJ
Lateral	Ulnar/radial deviation	Rotational malalignment

Investigations

Radiographic Assessment

Standard Views:

AP, lateral, and oblique of affected finger
TRUE lateral is essential for classification

Pre-Reduction X-ray:

Confirm dislocation direction
Identify associated fractures
Assess joint congruity

Post-Reduction X-ray:

Confirm concentric reduction
Check for V-sign (dorsal subluxation)
Assess fracture fragment position

X-ray Findings

Finding	Significance	Action
Volar plate avulsion	Small fragment common in dorsal dislocation	Usually conservative if stable
V-sign	Dorsal subluxation indicating instability	Extension block splinting or surgery
Parallel articular surfaces	Volar plate interposition	Open reduction required

Management Algorithm

Management

Treatment by Dislocation Type

Dorsal PIPJ (Most Common):

Digital block anaesthesia
Reduction: Longitudinal traction + flexion
Assess stability through ROM
If stable: Buddy taping, early motion
If unstable: Extension block splinting

Volar PIPJ (Central Slip at Risk):

Reduction: Traction + extension
Test active PIPJ extension
Static extension splint for 6 weeks
Active DIP flexion exercises during immobilisation

DIPJ Dislocation:

Usually dorsal, often open injury
Digital block, irrigate if open
Reduce and splint for 2-3 weeks

Treatment Algorithm

Type	Stable	Unstable
Dorsal PIPJ	Buddy tape + early motion	Extension block splint
Volar PIPJ	Extension splint 6 weeks	Open repair if needed
Fracture-dislocation	Extension block if less than 30%	Surgery if greater than 40%

Surgical Technique

Open Reduction Techniques

Indications for Surgery:

Irreducible dislocation
Fracture-dislocation greater than 40% articular surface
Chronic dislocation
Failed closed treatment

Surgical Approaches:

Volar (Bruner) - preferred for volar plate extraction
Dorsal - for central slip repair
Lateral - for collateral ligament repair

Volar Approach Steps:

Bruner zigzag incision over PIPJ
Identify and protect neurovascular bundles
Retract flexor tendons
Identify interposed volar plate
Extract and reduce joint
Repair volar plate to bone (suture anchors)

Surgical Options

Procedure	Indication	Key Points
ORIF	Large fragment fracture-dislocation	Screws, plate, or K-wires
Volar plate arthroplasty	Comminuted volar lip	Advance volar plate into defect
Hemihamate graft	Chronic defect greater than 50%	Autograft from hamate

Complications

Common Complications

Stiffness (Most Common):

Fusiform swelling persists for months
Warn patients about permanent finger thickening
Prevention: Early protected motion in dorsal dislocations

Boutonnière Deformity:

PIPJ flexion with DIPJ hyperextension
Results from untreated central slip injury
Common after incorrectly mobilised volar dislocation

Swan Neck Deformity:

PIPJ hyperextension with DIPJ flexion
Results from volar plate laxity
May follow chronic dorsal subluxation

Complication Summary

Complication	Cause	Prevention
Stiffness	Prolonged immobilisation	Early motion (dorsal type)
Boutonnière	Central slip rupture	Extension splint 6 weeks (volar)
Swan neck	Volar plate laxity	Proper treatment of volar plate injury
Chronic instability	Inadequate healing	Appropriate splinting duration

Postoperative Care

Rehabilitation Protocol

Dorsal Dislocation (Stable):

Buddy taping to adjacent finger
Immediate active motion exercises
Full ROM expected by 4-6 weeks
Protect during sports for 6-8 weeks

Volar Dislocation:

Static extension splint (PIPJ in full extension)
Allow DIP flexion exercises
Maintain for 6 weeks minimum
Progressive PIPJ flexion after 6 weeks

Post-Surgical:

Extension block splinting 2-3 weeks
Hand therapy referral essential
Progressive extension by 10°/week
Full motion by 6-8 weeks

Rehabilitation Timeline

Phase	Dorsal (Stable)	Volar	Post-Surgery
Week 1-2	Buddy tape, active ROM	Extension splint only	Extension block splint
Week 3-4	Full motion, buddy tape sports	Extension splint, DIP exercises	Progressive extension
Week 5-6	Return to sport	Begin gentle PIPJ flexion	Full ROM goals

Outcomes

Expected Outcomes

Simple Dorsal Dislocation:

Excellent prognosis with early motion
Greater than 90% achieve functional ROM
Residual stiffness common but usually mild
Return to sport within 4-6 weeks

Volar Dislocation:

Good outcomes if splinted correctly
Higher complication rate than dorsal
Boutonnière risk with improper treatment
Full recovery may take 3-6 months

Fracture-Dislocation:

Outcomes depend on articular involvement
Less than 30% fragment: good prognosis
Greater than 50% fragment: guarded prognosis
Post-traumatic arthritis risk increases with severity

Outcome Summary

Type	Good Result Rate	Main Risk
Dorsal simple	Greater than 90%	Stiffness
Volar	80-85%	Boutonnière deformity
Fracture-dislocation	60-80%	Arthritis, stiffness

Evidence Base

Key Studies

Eaton and Littler (1969):

Volar plate arthroplasty technique
For chronic dorsal fracture-dislocations
Remains gold standard for comminuted injuries

Kiefhaber and Stern (1986):

Classic PIPJ fracture-dislocation review
Established 40% rule for surgical intervention
Foundation for current treatment algorithms

Hamer and Quinton (1992):

Extension block splinting technique
Conservative management for stable fracture-dislocations
Good outcomes for fragments less than 50%

Landmark Studies

Study	Year	Contribution
Eaton & Littler	1969	Volar plate arthroplasty technique
Kiefhaber & Stern	1986	40% rule for surgery
Williams et al	2003	Hemihamate arthroplasty

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Scenario 1: Dorsal PIPJ Dislocation

EXAMINER

"A goalkeeper presents with a swollen middle finger. Lateral X-ray shows a dorsal dislocation of the PIPJ with a small avulsion fracture at the base of the middle phalanx. Reduction was easy. How do you treat him?"

EXCEPTIONAL ANSWER

This is a **Dorsal PIPJ Dislocation** with a volar plate avulsion fracture. **Assessment:** - **Stability:** After reduction, I must assess stability. Does it subluxate dorsally on active extension? - **Fracture size:** Is the fragment over 40% of the joint surface? (Small fragment usually stable). **Management:** 1. **Stable (Most common):** - The joint remains reduced through a functional arc of motion. - **Buddy Taping** to the Index finger (radial side stabilizes better) allows immediate motion. - **Dorsal Block Splint** (preventing full extension) for 1-2 weeks if slightly apprehension in extension. - **Early Motion:** Crucial to prevent stiffness. 2. **Unstable (V-sign on X-ray):** - **Extension Block Splinting:** Splint at 30° flexion (or angle of stability). Allow full flexion. Reduce flexion by 10° per week. **Counseling:** - He will have a swollen ("fat") finger for 6-12 months, possibly permanently. - Stiffness is the main risk.

KEY POINTS TO SCORE

Distinguish Dorsal (Early motion) from Volar (Splint extension)

Assess active stability post-reduction

Swelling persists for months

Buddy strapping is definitive treatment for simple stable dislocations

COMMON TRAPS

✗Splinting a dorsal dislocation in full extension for weeks (Stiffness)

✗Missing a Volar dislocation and treating it with early motion (Boutonnière)

✗Ignoring rotatory instability

LIKELY FOLLOW-UPS

"What is the V-sign on lateral X-ray?"

"How do you treat an irreducible dislocation?"

"Describe the anatomy of the volar plate."

VIVA SCENARIOChallenging

Scenario 2: Volar PIPJ Dislocation - Central Slip Injury

EXAMINER

"A 28-year-old basketball player presents to the emergency department 2 hours after jamming his index finger. Examination shows the PIPJ held in slight flexion with the fingertip pointing volarly. Lateral X-ray confirms volar dislocation of the middle phalanx relative to the proximal phalanx. The ED resident asks you about the best treatment approach. What do you tell them?"

EXCEPTIONAL ANSWER

This is a volar PIPJ dislocation which is much less common than dorsal dislocation but significantly more problematic. The critical point is that volar PIPJ dislocation is almost always associated with central slip rupture or significant attenuation, which places the patient at high risk for developing a boutonnière deformity if not treated correctly. My immediate management would be closed reduction under digital block - gentle longitudinal traction with extension force to reduce the middle phalanx. After reduction, I would carefully examine for central slip integrity. I would test active PIPJ extension against resistance with the finger held in the examiner's hand - if the patient cannot fully extend the PIPJ or there is an extensor lag, this confirms central slip disruption. The crucial management point I would emphasize to the ED resident is that unlike dorsal dislocations which require early mobilization, volar dislocations must be splinted in full PIPJ extension for 6 weeks to allow central slip healing - exactly like treating an acute boutonnière injury. During this period, the patient should perform active DIP flexion exercises to pull the lateral bands dorsally and prevent contracture. After 6 weeks, I would start gentle progressive PIPJ flexion exercises. If they mobilize this early like a dorsal dislocation, the patient will develop a boutonnière deformity (PIPJ flexion, DIP hyperextension) which is very difficult to treat once established. This is the most common error in managing these injuries.

KEY POINTS TO SCORE

Volar PIPJ dislocation = central slip rupture until proven otherwise

Must splint in full PIPJ extension for 6 weeks (NOT early motion)

Active DIP flexion during immobilization prevents lateral band contracture

Early mobilization causes boutonnière deformity (most common error)

Test active PIPJ extension post-reduction to confirm central slip integrity

COMMON TRAPS

✗Treating volar dislocation like dorsal dislocation with early motion

✗Splinting in flexion instead of extension

✗Not recognizing association with central slip injury

✗Forgetting DIP flexion exercises during PIPJ immobilization

LIKELY FOLLOW-UPS

"What is the anatomy of the central slip and why does volar dislocation disrupt it?"

"How would you manage a boutonnière deformity that develops despite proper treatment?"

"Can you have a volar PIPJ dislocation without central slip injury?"

VIVA SCENARIOCritical

Scenario 3: Irreducible PIPJ Dislocation

EXAMINER

"A 35-year-old presents with a dorsal PIPJ dislocation of his ring finger sustained 4 hours ago. Multiple attempts at closed reduction in the emergency department have failed. X-rays show the middle phalanx remains dorsally dislocated with the PIPJ joint surfaces parallel to each other rather than overlapping. There is no fracture. What is your assessment and management?"

EXCEPTIONAL ANSWER

This is an irreducible dorsal PIPJ dislocation and the X-ray appearance of parallel articular surfaces is pathognomonic for volar plate interposition. In a normal dislocation, the joint surfaces overlap, but when the volar plate becomes trapped within the joint, the surfaces sit parallel. Repeated forceful attempts at closed reduction are contraindicated as they will not succeed and may cause further soft tissue damage or fracture. The volar plate has flipped proximally and become trapped between the articular surfaces, creating a mechanical block to reduction. My management is open reduction in the operating theatre under regional or general anesthesia. I would use a volar zigzag approach to the PIPJ. After carefully identifying and protecting the neurovascular bundles, I would identify the displaced volar plate which will be sitting within the joint. I would extract the volar plate from the joint, reduce the dislocation, and then assess the volar plate - if the tissue quality is good, I would repair it back to the base of the middle phalanx with suture anchors; if it is too damaged or attenuated, I may accept the injury and rely on healing by scar. Post-operatively, I would use a dorsal blocking splint allowing full flexion but limiting extension to 30 degrees for 2-3 weeks, then progressive extension. Alternative causes of irreducibility include FDP tendon entrapment (the tendon wraps around the condyle) or lateral band interposition, but volar plate interposition is by far the most common. The key learning point is recognizing the parallel articular surfaces on X-ray which should prompt immediate planning for open reduction rather than continued closed reduction attempts.

KEY POINTS TO SCORE

Parallel articular surfaces on X-ray = volar plate interposition

Irreducible dislocation requires open reduction, never force

Volar approach allows extraction of trapped volar plate

Volar plate may be repaired if good tissue quality

Post-op dorsal blocking splint, progressive extension over 2-3 weeks

COMMON TRAPS

✗Repeated forceful closed reduction attempts causing iatrogenic injury

✗Not recognizing parallel surfaces as sign of interposition

✗Attempting dorsal approach (volar approach gives better exposure)

✗Immobilizing in full extension post-reduction (causes stiffness)

LIKELY FOLLOW-UPS

"What other structures can cause irreducibility besides volar plate?"

"How would your approach differ for FDP tendon entrapment?"

"What is complex MCP dislocation and how does it differ from this?"

MCQ Practice Points

Exam Pearl

Q: What is the mechanism and treatment of dorsal PIP dislocation?

A: Mechanism: Hyperextension injury with axial load, disrupting the volar plate. Most common finger dislocation. Proximal phalanx displaces dorsally relative to middle phalanx. Reduction: Digital block, longitudinal traction with gentle flexion. Post-reduction: Assess stability through ROM; If stable to 30° flexion: Buddy taping with early mobilization. If unstable: Extension block splinting (blocking last 20-30° of extension) for 2-3 weeks, progressive extension.

Exam Pearl

Q: What is a volar PIP dislocation and why is it more concerning than dorsal?

A: Volar PIP dislocation: Middle phalanx displaces volarly; Less common but higher complication rate. Mechanism: Rotatory force or direct blow to extended finger. Central slip disruption is common (risk of boutonniere deformity). Reduction often more difficult (may require open reduction). Post-reduction: Splint PIP in full extension for 6 weeks to protect central slip (opposite of dorsal dislocation protocol). Earlier mobilization risks boutonniere deformity.

Exam Pearl

Q: What is an irreducible PIP dislocation and what causes it?

A: Irreducible dislocation: Cannot achieve closed reduction due to interposed tissue. Causes: Volar plate interposition (flips proximally, blocks reduction); FDP entrapment (tendon wraps around condyle); Lateral band interposition; Button-holing of condyle through volar plate. Clinical clue: Failed gentle reduction attempts, palpable block to reduction. Treatment: Open reduction through volar or dorsal approach, extraction of interposed tissue, volar plate repair.

Exam Pearl

Q: How do you assess and manage PIP fracture-dislocations?

A: Assess stability: Lateral X-ray - measure percentage of volar articular surface (middle phalanx) fractured. Less than 30%: Usually stable after reduction - extension block splinting. 30-50%: Borderline stable - may require surgical fixation (hemihamate arthroplasty, volar plate arthroplasty, dynamic external fixator). Greater than 50%: Unstable, high subluxation risk - requires surgical stabilization. V-sign (incongruent joint on lateral view) indicates instability requiring intervention.

Exam Pearl

Q: What is the treatment for MCP joint dislocation and what makes it complex?

A: Dorsal MCP dislocation: Proximal phalanx dorsal to metacarpal head. Simple: Reducible closed with wrist flexion, MCP hyperextension then flexion. Complex (irreducible): Volar plate interposition, often with metacarpal head button-holed through flexor tendons/lumbricals. Clinical sign: Skin puckering over MCP. Complex dislocation contraindication: Repeated forceful reduction attempts (can further tighten noose). Requires open reduction (dorsal or volar approach).

Australian Context

In the Australian healthcare setting, finger dislocations are frequently managed in Emergency Departments. Simple, stable dorsal dislocations are redirected to primary care (GPs) for follow-up and basic hand therapy. However, suspected volar dislocations or unstable fracture-dislocations are usually referred to specialist Hand Surgery clinics (often within public hospital networks) for definitive management.

Medicare and MBS Integration: Clinicians should be familiar with relevant Medicare Benefit Schedule (MBS) items for closed reduction and open reduction of finger dislocations. Hand therapy is a critical component of Australian recovery protocols, often accessible through allied health Medicare referrals or private insurance.

Sport-Specific Considerations: Given Australia's high participation in community sports like AFL, Cricket, and Basketball, finger injuries are a significant burden. Elite and community clubs often utilize functional bracing or buddy strapping to facilitate early return to sport where safe.

Clinical Guidelines: The therapeutic guidelines (eTG) recommend digital nerve blocks using 1% lignocaine (without adrenaline) for reduction. Post-reduction neurovascular assessment and radiographic confirmation remain the mandatory standard of care in all Australian jurisdictions.

Finger Dislocation Quick Reference

High-Yield Exam Summary

Direction

•Dorsal: Volar plate injury → Early Motion
•Volar: Central Slip injury → Splint Extension (6w)

Irreducible?

•Volar Plate interposition
•FDP tendon entrapment (rare)
•Condyle buttonholing

References

Eaton RG, et al. Joint injuries of the fingers. Bull N Y Acad Med. 1967.
Kiefhaber TR, et al. Dislocation and fracture-dislocation of the proximal interphalangeal joint. J Hand Surg Am. 1986.

Finger Dislocations

High Yield Overview