fractures of the forearm and carpus

ORTHOPAEDICS III: UPPER LIMB

Fractures of the forearm andcarpusNeil Segaren

Tim Cresswell

AbstractFractures of the radius and ulna should be treated as a single unit due to

their intricate relationship. In fractures of the distal radius restoration of

volar tilt, radial inclination and length should be achieved and maintained

during healing by appropriate methods. Carpal fractures are common

injuries that can be difficult to diagnose. Treatment of fractures of the

forearm and carpus aims to restore anatomy and achieve stability allow-

ing early mobilization and good function.

Keywords Carpus; distal radius; fracture of forearm; scaphoid

Forearm fractures

Anatomical considerations

The radius and ulna articulate with each other at the proximal and

distal radioulnar joints. They are linked, however, throughout

their length by the interosseous membrane; a complex and fibrous

sheet which is a major contributor to the stability of the forearm.1

The ulna is a straight bone around which the radius pronates and

supinates. The three-dimensional curvature of the radius is

complex and if altered may result in restrictions of pronation and

supination.2 The intricate skeletal anatomy of the forearm has

prompted some surgeons to treat fractures of the radius and ulna

as intraarticular injuries requiring anatomical reduction, absolute

stability and early movement.2

Fracture classification

Forearm fractures are classified anatomically. The need for

awareness of associated joint subluxations of the proximal and

distal radioulnar joints cannot be overemphasized.

Treatment of forearm fractures

Cast immobilization: is widely used in fractures with little or no

displacement. Manipulation and cast stabilization is the

preferred management in children. Patients must be monitored

for displacement of the fracture fragments.

Internal fixation modalities

� Intramedullary nailing: maintains the advantages of

closed fracture treatment preserving the fracture

Neil Segaren MRCS is a CT3 in Orthopaedics at the Royal National

Orthopaedic Hospital, Stanmore, UK. Conflicts of interest: none.

Tim Cresswell BM FRCS Ed (Tr & Orth) Dip Orth Eng is a Consultant Upper Limb

and Hand Surgeon at the Pulvertaft Hand Centre, Royal Derby Hospital,

Derby, UK. Conflicts of interest: none.

SURGERY 31:4 155

haematoma with insertion of the nails away from the

injury zone. It gives enough stability to allow healing with

callus formation. A variety of intramedullary fixation

devices are available. Elastic titanium nails are used

commonly in children.

� Plating: this is the preferred method in adults, allowing

accurate reduction of the fracture, maintaining the bow of

the radius whilst achieving rigid stability allowing early

forearm mobilization.

Associated injuries

Proximal radioulnar joint subluxation (Monteggia fracture)3:

this is a fracture of the ulna with associated subluxation of the

proximal radioulnar joint (Figure 1).

Classification of Monteggia injuries

Type I: fracture of the ulnar diaphysis at any level with anterior

angulation at the fracture site and an associated anterior dislo-

cation of the radial head.

Type II: fracture of the ulnar diaphysis with posterior angulation

at the fracture site and a posterolateral dislocation of the radial

head.

Type III: fracture of the ulnar metaphysis with a lateral or

anterolateral dislocation of the radial head.

Type IV: fracture of the proximal third of the radius and ulna

at the same level with an anterior dislocation of the radial

head.

Treatment

Good outcomes following Monteggia fractures necessitate early

diagnosis, accurate reduction of the radial head, rigid fixation of

the ulna and postoperative immobilization to allow ligamentous

healing about the dislocated radial head. Rigid fixation of the

ulna is achieved by plating to maintain its length allowing the

reduction of the radial head. Rarely stabilization of the relocated

radial head is required.

Distal radioulnar joint injuries (Galleazzi fractures)

This injury consists of a solitary fracture of the radius at the

junction of the middle and distal third with subluxation of the

distal radioulnar joint (DRUJ).

The insertion of the pronator quadratus on the palmar surface

of the distal fragment, the brachioradialis attachment to the

styloid of the distal radius and the abductors and extensors of the

thumb cause significant deforming forces to the distal fragment

and the DRUJ. These make it very difficult to maintain a reduced

position in cast. These fractures require accurate reduction of the

fracture and DRUJ along with stabilization of the radius

fracture.4

Treatment

Fractures at the junction of the middle and distal thirds of the

radius are best managed with plate fixation, ensuring accurate

reduction of the fracture and the DRUJ (Figure 2). Very rarely

proximal radioulnar joint subluxation can be associated with

fracture of the radial shaft.5

� 2013 Published by Elsevier Ltd.

http://dx.doi.org/10.1016/j.mpsur.2013.01.013

Monteggia fracture (with proximal radioulnar dislocation).

Figure 1


Fractures of the distal radius


The distal radius is the most common site of fracture in the

forearm and three articular surfaces in the wrist need consider-

ation; the radiocarpal articulation is split into the scaphoid fossa

and lunate fossa and the DRUJ where the sigmoid notch of the

Comminuted Galleazzi fracture treated with open redu

Figure 2

SURGERY 31:4 156

radius accepts the head of the ulna. The ulna side of the wrist

joint is supported by the triangular fibro-cartilage complex

(TFCC). Fractures extending into any of these areas are consid-

ered intraarticular. The distal articular surface of the radius is

aligned to its longitudinal axis with 11� of volar tilt and 22� of

ulna inclination. Both intraarticular and extraarticular fractures

ction and internal fixation.




of the distal radius can affect the biomechanical properties of the

wrist joint by altering the volar tilt, ulna inclination and relative

lengths of radius and ulna.

Mechanism of injury

Fractures of thedistal radiusmost commonly arise due to a fall on an

outstretched hand, resulting in axial loading of a dorsiflexed wrist.

The palmar surface of the distal radial metaphysis fractures first in

tension. This fracture line propagates dorsally where bending

moments lead to compression stresseson the dorsal side resulting in

a comminuted fracture in this areawith crushing of cancellous bone

and shortening of the distal radius relative to the ulna.

Classification (Table 1)

Eponymous descriptions of distal radius fractures have tradi-

tionally been good indicators of the type of injury and treatment.

Universal classification system:11 classifies fractures into

intraarticular or extraarticular injuries and accounts for

displacement, reducibility and instability.

Fernandez classification:12 classification system based on the

mechanism of injury. This is advantageous because associated

ligamentous lesions, subluxations, fractures of neighbouring

carpal bones and soft tissue injuries are related directly to the

magnitude of force involved. It also helps in reduction of these

fractures by reversing the mechanism.

Type I e bending fractures of the metaphysis; one cortex fails

to tensile stresses and the opposite one undergoes a certain

degree of comminution. These are extraarticular fractures

(Colles’ and Smith’s fractures).

Type II e shearing fractures. These are intraarticular fractures

(Barton’s, reversed Barton’s, and radial styloid fractures).

Type III e compression fractures. These are intraarticular

comminuted fractures, complex articular fractures, and pilon

radial fractures. These are associated with impaction of the

subchondral and metaphyseal cancellous bone.

Classification of distal radius fractures

Eponymous name Description

Colles’ fracture6 Extraarticular distal radius fracture with dorsal

comminution, angulation, displacement, radial

shortening and supination

Smith’s fracture7 Distal radius fracture with volar displacement

Barton’s fracture8 Displaced, unstable articular fracture-

subluxation of the distal radius with

displacement of the carpus along with the

articular fracture fragment. These may be

either dorsal or volar

Chauffeur’s

fracture9Fracture of the radial styloid. May be

associated with displacement of the carpus

and may be the only bony component of

perilunate injury

Die-punch

fracture10Intraarticular fracture with depression of the

dorsal aspect of the lunate fossa

Table 1

SURGERY 31:4 157

Type IV e avulsion fractures of ligament attachments,

includes ulnar and radial styloid fractures associated with radi-

ocarpal fracture-dislocations.

Type V e high-velocity injuries that involve combinations of

bending, compression, shearing, and avulsion mechanisms or

bone loss.

Clinical features

The dorsal aspect of the hand and wrist are usually quite

swollen, and ecchymosis may be present. The wrist should be

examined for tenderness, not only about the radial fracture site,

but also at the distal ulna, elbow and shoulder. Median nerve

function and flexor and extensor tendon action should be

tested.

Investigations

Standard posteroanterior (PA) and lateral radiographs are ob-

tained to assess displacement, shortening, and communition.

A computed tomography (CT) scan may be useful in assessing

intraarticular extension and other associated fractures or

injuries.

Treatment

The principles of treatment are to achieve and maintain fracture

reduction until bony union is achieved, with rehabilitation to

avoid the consequences of immobilization to the wrist and

adjacent joints. Intraarticular fractures require anatomical

reduction, absolute stability and early mobilization to reduce the

risk of secondary osteoarthritis.

Reduction may be achieved using open or closed means.

Closed reduction is achieved by longitudinal traction through the

fingers to disimpact the fragments and manipulation to correct

deformity. In cases requiring open reduction an indirect method

is preferable where the bony fragments are reduced onto the

template of the carpus.

Maintenance of reduction can be achieved by various

methods

Moulded plaster of Paris cast: is the most commonly used

method (Figure 3). It is non-invasive and avoids the risks of

surgery, however reduction may be imprecise. A proper tech-

nique with three-point moulding is essential to apply a tensional

force on the concave side of the angulation. Extremes of palmar

flexion and ulna deviation are to be avoided to prevent

compression of the median nerve.

Intraosseous Kirschner (K) wire fixation: in this method the

distal fragment is fixed onto the proximal shaft fragment using K

wires. Care must be taken when inserting the wires to avoid

injury to cutaneous nerves and tendons. The fixation does not

provide sufficient stability for early mobilization and supple-

mental orthotic support is required.

External fixation: this method relies on indirect reduction by

ligamentotaxis and supplemental K wire stabilization may be

used to stabilize individual fragments. External fixators are

useful in cases where severe comminution prevents internal

fixation, however treatment is often complicated by pin site

infection.



Sequential radiographs showing displacement in a plaster cast after good reduction was obtained in theatre. Three-point moulding of the cast isof paramount importance.

Figure 3


Internal fixation: a variety of modalities are available and are

broadly categorized on their site of application to the distal

radius into: volar devices, dorsal devices or fragment-specific

fixation devices. The locking plate has threads on the heads of

the screws or smooth pegs. This allows the screw head to be

fixed onto the plate preventing instability at the screweplate

interface allowing its function as a fixed angled device. These

pegs or screws can be placed in such a manner that they act as

Radiographs illustrate restoration of length and articular congruity a with limpression of articular penetration with distal pegs.

Figure 4

SURGERY 31:4 158

a buttress to the articular surface at the subchondral bone

(Figure 4). Locking plate systems generally provide excellent

stability allowing early mobilization and rehabilitation after

injury.

Guide to decision-making

Undisplaced fractures: these are generally stable and unlikely to

displace. They are placed in a below-elbow cast that allows

ocked plate. Note the lateral view is not articular and hence gives the




mobilization of the fingers. Sound plaster technique and good

three-point moulding is vital. Radiographic review is performed

at the end of the first week to assess for displacement at the

fracture site and cast loosening secondary to reduction of

swelling. Internal fixation allows early mobilization and its

benefits need to be weighed against the risk of surgery.

Displaced extraarticular fractures: initially closed reduction

under local anaesthetic block is performed. Radiographic indicators

of instability are: shortening over 5 mm, angulation more than 20�

in the dorsal or volar direction and displacement. If present then

early open reduction and internal fixation is indicated. If fractures

are radiographically acceptable after reduction, that is, less than 5

mm shortening and 0e10� of volar tilt, operative intervention is

instituted only if the fracture re-displaces in the cast.

Displaced intraarticular fractures: early open reduction and

internal fixation is offered in the case of significant intraarticular

step (>2 mm) or gap.

Complications of distal radius fractures

There is a reported 30% complication rate in fractures of the

distal radius.13

Median nerve injury: if satisfactory reduction is obtained

compression symptoms often improve. However if there is no

improvement over the first 48 hours then open reduction,

internal fixation and carpal tunnel release should be performed.

Carpal ligament injuries: 30% of cases have a concomitant

scapholunate ligament tear and 15% a lunotriquetral tear. Open

repair of the lesion is recommended after reduction and fixation

of the distal radius fracture.

Non-union: non-unions of distal radius fractures (Figure 5) are

extremely rare. However non-unions of an ulna styloid process

fracture in conjunction with a distal radius fracture are relatively

common, but these are rarely symptomatic.

Malunion: malunions may result in midcarpal instability, wrist

pain or restricted range of motion. If symptomatic post-traumatic

Figure 5 Non-union after distal radius fractures.

SURGERY 31:4 159

wrist deformity can be corrected with either extraarticular or

intraarticular osteotomies or both.

Carpal fractures


The carpus is made up of two rows of four bones. They articulate

proximally at the radiocarpal joint, distally with the bases of the

metacarpals and with each other at the midcarpal joint. The

proximal rows from lateral to medial are the scaphoid, lunate,

triquetrum, pisiform and the distal row is made up of the

trapezium, trapezoid, capitate and hamate. Fractures of the

scaphoid account for 79% of carpal fractures14 followed by

fractures of the triquetrum (14%) and the trapezium (2%).

Scaphoid fractures


The scaphoid lies in an intermediate position between the two rows

of carpal bones and has a pivotal role in the transfer of mechanical

forces between the hand and wrist. About 82% of scaphoid frac-

tures occur in men,15 with the largest group aged 20e30 years old.

Diagnosis

Scaphoid fractures usually result from a fall onto an outstretched

and dorsiflexed hand. There is radial sided wrist pain over the

‘anatomical snuffbox’ associated with swelling and tenderness

over this area or the scaphoid tubercle.

Routine PA and lateral plain film radiographs are essential

and should be complemented by formal scaphoid views. It is

important to be aware that in the acute setting the incidence of

false-negative radiographs is between 2 and 25%,16 hence if they

are negative and a strong clinical suspicion remains then CT or

MRI should be considered. CT is the most accurate at deter-

mining bony displacement.

Complications of scaphoid fractures

The major arterial supply to the scaphoid (superficial palmar and

dorsal carpal branches of the radial artery) enters its distal,

dorsal surface perfusing in a retrograde manner from distal to

proximal. Very proximal fracture fragments can hence be iso-

lated from the circulation resulting in avascular necrosis or non-

union. Subsequent secondary arthritic changes can lead to pain

and significant reduction in wrist and grip function.

Classification of scaphoid fractures

Anatomical classification of scaphoid fractures helps to decide

fracture stability, optimal management and the risk of subse-

quent complications.

Tubercle fractures: this area has an excellent blood supply and

low mechanical demand, hence these fractures heal well with

minimal immobilization.

Waist fractures: this region has the highest mechanical demand

and is hence is most frequently injured. Waist fractures generally

heal well with 85e90% adequately treated conservatively.

Russe17 classified fracture line orientation to determine stability

which in descending order is: horizontal oblique, transverse and

vertical oblique fractures.




Proximal pole fractures: the absence of a dedicated blood

supply to this area results in the highest incidence of non-union.

As the size of the proximal pole fragment decreases the difficulty

of surgical fixation and the risk of non-union increases.

Guide to management

Fracture configuration dictates stability and hence management.

Unstable fractures have a high risk of associated complication

and need operative intervention.

Tubercule fractures: stable injuries with a low risk of compli-

cation. Treated with cast immobilization for 6 weeks. Symp-

tomatic non-union is rare and treated with excision of small

fragments or bone grafting of larger ones.

Waist fractures

� Undisplaced: scaphoid cast for 8 weeks, followed by clin-

ical and radiographic examination. If union is seen at the

fracture site then mobilization in a wrist splint may begin.

If no bony union, continue with cast immobilization for

four further weeks with repeated examination. If radio-

graphs are inconclusive at this point a CT scan is indicated.

If non-union does occur then surgical fixation is required.

� Displaced: these unstable fractures have a high incidence

of non-union and are treated operatively. Closed reduction

with percutaneous screw fixation is the method of choice

(Figure 6).

Proximal pole fractures

The unstable configuration, tenuous vascularity and intra-

articular location of these fractures mean they have the highest

risk of non-union and complications. They may take 4e5 months

to unite in plaster and are therefore treated with percutaneous or

open internal fixation.

Figure 6 A fracture of a right scaphoid at the waist tr

SURGERY 31:4 160

Uncertain fractures

Failure to treat a stable scaphoid fracture within 4 weeks

increases the risk of non-union, however up to 25%16 of

scaphoid fractures may not be visible on initial radiographs.

Early CT scanning or cast treatment followed by repeat radio-

graphs at 2 weeks can confirm the diagnosis. If doubt persists

isotope bone scans or MRI may be helpful.

Non-union of the scaphoid

Factors that increase the risk of non-union are: proximal pole

fracture, unstable/displaced waist fracture, delays in diagnosis of 3

weeks or greater, poor immobilization or fixation and smoking.

About 10e15% of conservatively treated waist fractures and 30e

40% of proximal pole fractures will lead to non-union. Treatment

options include percutaneous bone grafting with compression

fixation or open fixation and bone grafting.

Fractures of other carpal bones

Carpal bone fractures are usually a result of a fall onto an

outstretched hand or a direct blow. There is usually associated

swelling and bony tenderness and careful radiographical

examination is required. There is a wide spectrum of injuries

and generally undisplaced fractures are treated conservatively

with cast immobilization. Displacement of more than 1 mm is

usually an indication for open or closed reduction and fixation.

There are a number of important fractures that need special

consideration.

Triquetrum fractures

Common injuries sustained in forced hyperextension of the wrist

or from a direct blow. Radiographs are usually diagnostic with

four recognized patterns:

� dorsal ligament avulsion

eated with percutaneous lag screw.




� dorsal impaction fractures, from forced hyperextension

against the ulna styloid

� body fractures

� palmar fractures associated with perilunate dislocation.

Trapezium fractures

These uncommon fractures are difficult to identify radiologically

as routine radiographs superimpose the trapezium with the

surrounding carpal bones. Hence early CT has a role in cases of

high clinical suspicion.

Hamate fractures

Hamate fractures can be associated with other hand injuries such

as: dislocation of the carpo-metacarpal joints and fracture-

dislocations of other carpal bone, metacarpals or phalanxes.

Associated soft tissue injuries can include ulna nerve palsy, flexor

tendon rupture and ulna artery thrombosis. Treatment of hamate

fractures includes swift reduction of any concomitant disloca-

tions. Undisplaced body fractures can be treated conservatively.

Hook of hamate fractures close to the base can be treated with

below-elbow cast immobilization, but surgical intervention is

dependent upon fragment size. Symptomatic non-union of hook

fractures is a well-known risk treated by fragment excision.

Capitate fractures

These rare fractures are usually of the proximal pole as a result of

hyperextension or direct trauma. They are generally associated

with the scaphocapitate syndrome where wrist hyperextension

results in fractures of the neck of the capitate and waist of the

scaphoid. Isolated, undisplaced capitate fractures are treated

conservatively, but when part of the scaphocapitate syndrome or

displaced open reduction and internal fixation is required. A

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