Finger

 Incidence

 

1 / 1000 per year female

1.5 / 1000 per year male

 

Phalangeal fractures

- represent more than half of all hand fractures

 

Goals of Treatment

 

Restore normal function of the finger

 

1.  Restoration of bony anatomy

 

2.  Early motion

- inherent fracture stability

- splinting

- adequate internal fixation

- dynamic external fixation

 

Examination

 

Obvious swelling / bruising / deformity

 

Compound injuries

 

Rotational alignment

1.  With active flexion, all fingers point towards scaphoid tuberosity

2.  Evidence digital overlap (see below)

3.  Plane of nail beds all in same plane

- LF often slightly different rotation

 

 

Tendon avulsion

 

X-rays

 

3 planes centred on MCPJ  middle finger

- AP

- lateral

- oblique

 

Care to look for subtle evidence joint subluxation

 

Principles Closed Treatment

 

POSI (Position of Safe Immobilisation)

- 20^o wrist extension

- flexion of MCPJ to 60 - 70^o

- IP joints in extension

- thumb in abduction

 

Acceptable alignment

 

Pun etal JBJS Am 1989

- 10^o angulation in both planes

- no rotation

- 50% overlay

 

Surgical approaches

 

A.  Midaxial

- dorsal to NV bundle

- make dots on flexion creases with finger flexed

- this marks incision

- approach P1 by excision of one sagittal band

- less tendon disruption

- more difficult visualisation / access

 

B.  Midlateral

- volar to NV bundle

 

C.  Dorsal approach

- direct doral incision

- divide extensor hood over P1

- between lateral bands P2

- repair extensor mechanism at end

- risks scarring down of extensor tendon to implant

 

Types of injuries

 

1.  Extra-articular fractures

 

A.  Distal phalanx tuft fractures

B.  Shaft fractures of the distal, middle and proximal phalanges

 

2.  Joint injuries

 

DIPJ   

- dislocations

- mallet

- Pilon fractures

- Flexor tendon avulsion           

 

PIPJ    

- dorsal dislocations

- dorsal fracture dislocations

- volar dislocations

- Pilon fractures

- Condylar fractures

 

MCPJ dislocations

 

Tuft fractures

 

Most common hand injury

- usually crush mechanism

 

Management

- trephination of subungal haematoma (relieves pain)

- repair nail bed disruption

- irrigation and washout of open injuries

 

Distal phalangeal shaft fractures

 

 

Non displaced fractures

– splint DIPJ for 2-3 weeks

 

Displaced

- higher energy fractures

- washout open wounds

- repair nail bed

- bony reduction with percutaneous K wire

- distal phalanx just under nail bed

 

Shaft fractures middle / proximal phalanges

 

Undisplaced

- usually stable

- buddy strap 3-4 weeks

 

 

Displaced

 

 

Unstable fractures

- oblique, spiral, comminuted fractures

 

Transverse fractures P1 / characteristic deformity

- insertion of intrinsics at base PP flex fragment

- insertion of central slip to MP extend fragment

 

 

Fractures of P2 distal to insertion FDS / characteristic deformity

- FDS will flex fragment

- extensor tendon will extend fragment

 

Closed reduction

- relaxation of intrinsics

- axial traction

- reduction of deformity / POSI

 

ORIF

 

A.  Transverse fractures

- cross K wire

- Lister’s intra-osseous wire fixation

- plating

 

 

B.  Long oblique / spiral fractures

 

Definition

- fracture must be at lease 2 x diameter bone

- can treat with 2 x lag screws

- one perpedicular to fracture to lag

- one perpendicular to shaft to resist shear

 

Options

- percutaneous K wires / screw fixation / plating

 

 

DIPJ Dislocations

 

Dorsal

- most common

- closed reduction with dorsal traction

- failed closed reduction – volar plate, FDP

- 60% injuries open

- splint joint in flexion 2- 3/52 weeks

- ROM at 1/52

 

Volar

- rare

- failed closed reduction – extensor tendon

- DIPJ extension splint 6-8/52

 

Mallet fractures

 

 

Mechanism

- axial load

- extensor tendon attached to bony fragment

 

Closed treatment

- mallet splint (Stack)

- expect 10^o extensor lag with mild loss ROM

- good results with non – op management

 

 

ORIF

 

Indication

- volar subluxation of distal phalanx

- fragment > 50% joint surface

- chronic > 12 weeks old

 

Open treatment

- high incidence of complications

- percutaneous K wire recommended

 

Technique

1.  Reduce and axial K wire

2.  Dorsal blocking K wire / axial K wire

 

Wehbe and Schneider JBJS Am 1984

- 21 patients with intra-articular fractures

- 15 treated non operatively

- 6 treated operatively

- nil improvement in outcome

- worsened surgical morbidity

 

Pilon fractures base distal phalanx

 

Impaction injuries

 

Management

- ORIF very difficult

- all attempts at closed reduction +/- percutaneous pinning should be made

- fallback of arthrodesis / arthroplasty

 

FDP avulsions

 

Leddy and Packer classification

I   Vinculae are ruptured, tendon retracts to palm

II  Vinculae intact, tendon remains at PIPJ

III Large bony fragment, ensnared beyond A4 pulley

 

Type 1

- must be operated within 10 days to avoid contractures

- otherwise 2 stage reconstruction

 

Type 2 / 3

- can operate within 6 weeks

- ORIF large fragments

 

Condylar fractures of head of P1 / P2

 

Mechanism

- torsional and valgus impaction

 

London classification

Type 1  Unicondylar, undisplaced

Type 2  Unicondylar, displaced

Type 3  Bicondylar

 

Displaced unicondylar

- percutaneous K wire

- ORIF with screw

 

 

Open reduction

- P1 – between central slip and lateral band

- P2 – lateral to terminal extensor tendon

- must preserve collateral ligament which supplies blood

 

Type III bicondylar fractures

- difficult fractures

- 90 degree condylar plate

- lag screw and plate

- high risk of joint stiffness

 

MCPJ Destruction

 

Cause

- infection

- trauma

 

Options

- joint replacement

- fusion