FRACTURE OF THE DISTAL RADIUS

PRESENTER-Dr.SUNIL C P.G IN ORTHOPAEDICS

MODERATOR-Dr.GUNNAIAH

INTRODUCTION

Distal radius fracture represent approximately one sixth of all fractures

There are three main peaks of fracture distribution,children aged 5-14 years,male aged under 50 years and females over the age of 40 years

Distal radius fractures occur through the distal metaphysisof the radius

May involve articular surface

frequently involving the ulnar styloid

predominantly male population who sustain athletic and high-energy injuries and a second peak in the elderly, predominantly female population characterized by lower-energy or “fragility” fractures

Distal radius fractures tend to cluster in recognizable patterns, and it is important that the treating physician be familiar with the multiple fracture variants to recognize a fracture's “personality,” that is, its behavioral characteristics, energy of injury, relative stability, associated soft tissue injuries, radioulnar involvement, and prognosis

ANATOMY OF DISTAL RADIUS• The epiphysis of the distal radius usually appears at one year

of age,it grows more in lateral than medial direction and forms the radial styloid process,five facets and three articularfossae(scaphoid,lunate,and sigmoid notch) distal radius fuses with diaphysis at 17 years of age in females and 19 years in male

• Five facets are named after their position:distal,volar,dorsal,medial and lateral

• The distal articular facet is triangular in shape and covered completely by hyaline cartilage and has 2 specific areas,thescaphoid and lunate fossae,which articulate with proximal carpal row by scaphoid and lunate bones respectively.

The metaphysis is flared distally in both the AP and the lateral planes with thinner cortical bone lying dorsally and radially . The significance of the thinness of these cortices is that the fractures typically collapse dorsoradially. In addition, the bone with the greatest trabecular density lies in the palmar ulnar cortex

In the anteroposterior plane the strongest bone is found under the lunate facet of the radius. The line of force passes down the long finger axis through the capitolunate articulation and contacts the radius at this location. The “palmar ulnar corner” is often referred to as the keystone of the radius. It serves as the attachment for the palmar distal radioulnar ligaments and also for the stout radiolunate ligament. Displacement of this fragment is associated with palmar displacement of the carpusand also with loss of forearm rotation

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• The anterior aspect of distal radius is smooth and concave except at the insertion of the pronatorquadratus

• The posterior aspect of the distal radius is narrower than the anterior aspect,the most prominent ‘V’ shaped crest is called lister’s tubercle.

• The medial aspect of distal radius is triangular and presents an articular facet at its distal end which is concave and is called sigmoid notch,it articulates with the convex head of the distal ulna.The origin of TFCC attaches to the distal border of sigmoid fossa.

Cross-sectional anatomy of the radial metaphysis. Note that the dorsal surface is much more irregular than the palmar surface. The V-shape dorsally caused by Lister's tubercle (arrow) makes it difficult to contour a plate to fit the dorsum of the radius.

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The lateral aspect of the distal radius is separated from posterior by lister’s tubercle.A vertical groove forms where APL and EPB excursion can be seen clearly

Ligamentous anatomy

• The extrinsic ligaments of the wrist play a major role in the use of indirect reduction techniques. The palmarextrinsic ligaments are attached to the distal radius, and it is these ligaments that are relied on to reduce the components of a fracture using closed methods. There are two factors about these ligaments that make them significant for reduction: First the orientation of the extrinsic ligaments from the radial styloid is oblique relative to the more vertical orientation of the ligaments

attached to the lunate facet.

CONTINUE• The second significance of the ligamentous anatomy

is because of the relative strengths of the thicker palmar ligaments when compared to the thinner dorsal ligaments. In addition, the dorsal ligaments are oriented in a relative “z” orientation, which allows them to lengthen with less force than the more vertically oriented palmar ligaments. The significance is that distraction will result in the palmar ligaments becoming taut before the dorsal ligaments. Thus the palmar cortex is brought out to length before the dorsal cortex. It is for this reason that it is difficult to achieve reduction of the normal 12 degrees of palmar tilt using distraction alone

Applied anatomy

• Jakob and his co-authors interpreted the wrist as consisting of three distinct columns, each of which is subjected to different forces and thus must be addressed as discrete elements

The radial column, or lateral column

The radial column consists of the scaphoidfossa and the radial styloid. Because of the radial inclination of 22 degreees, impaction of the scaphoid on the articularsurface results in a shear moment on the radial styloid causing failure laterally at the radial cortex. The radial column, therefore, is best stabilized by buttressing the lateral cortex

The intermediate column

The intermediate column consists of the lunate fossa and the sigmoid notch of the radius. The intermediate column may be considered the cornerstone of the radius because it is critical for both articularcongruity and distal radioulnar function. Failure of the intermediate column occurs as a result of impaction of the lunate on the articular surface with dorsal comminution. The column is stabilized by a direct buttress of the dorsal ulnar aspect of the radius

The medial column

The ulnar column consists of the ulna styloid but also should include the TFCC and the ulnocarpal ligaments

Role of TFCC• TFCC consists of articular disc,meniscus

homologue,dorsal and volar radioulnarligament,ulnocarpal ligament and ECU sheath

• TFCC is the main stabiliser of distal radioulnar joint in addition to contributing to ulnocarpal stability

• TFCC normally not only stabilises the ulnar head in sigmoid notch of radius but also acts as a buttress to support proximal carpal row

• During axial loading the radius carries the majority of load(82%),and the ulna a smaller load(18%)

• Increasing the ulnar variance to a positive 2.5mm increases the load transmission across the TFCC to 42%

• The TFCC excised the radial load increases to 94%

Pathomechanism of distal radius fracture

• The theory of compression impaction by dupuytrenin 1834

• The avulsion theory in 1852

• The incurvation theory by mayer in 1940

• 1983 Vidal et al conducted a cadaveric study to determine whether ligamentotaxis restore radio palmar tilt in 1A fracture of distal radius..

Pathomechanism of posteriorlydisplaced fracture

• The usual cause is fall on the hyperextended wrist

• A)The theory of compression impaction when is hyperextended proximal carpal bones come and impact dorsal aspect of radius and body weight is transmitted through long axis of radius to distal end and compression occur at dorsal aspect of distal radius leading to fracture

• B)The avulsion theory-The indirect force presented by the body weight are transmitted through humerus,ulna,radiusand then a volar wrist ligaments.Then fracture occured by avulsion mechanism applied by the tensile forces transmitted by the volar wrist ligaments.

CONTINUE....• The Incurvation theory-depends on position of the hand,the

extent of the area of impact,the magnitude of the applied force

Pathomechanism of anteriorlydisplaced fracture• A)Axial stress on the radius with a backward fall on

the palm of the hand.Wrist in extension and without displacement of the body over the hand.The radius incurved sustains compression force on the volarcortex and tensile forces on the dorsum

• B)Forced flexion where direct compression stress on volar cortex combined with traction exerted by the dorsal ligament

Classification

• A)classification based on different fracture types

• 1)Colles fracture/pouteau’s fracture

• 2)Smith’s farcture/reverse colles fracture

• 3)Barton’s fracture

• 4)Chauffer’s fracture

• 5)Lunate load or die punch fracture

CONTINUE• B)Universal classification

1)Extraarticular

2)Intraarticular

C)Other types

Colles fracture• It is an extraarticular fracture occurs at corticocancellous

junction of distal end of radius within 2cm from the articularsurface

• It may extend into DRUJ with six displacements

1. Impaction

2. Lateral displacement

3. Lateral rotation (angulation)

4. Dorsal displacement

5. Dorsal rotation (angulation)

6. Supination.

It may often accompany fracture of the ulnar styloid which signify avulsion of the TFCC and ulnar collateral ligaments

Smith’s fracture/Reverse collesfracture

Occurs at the same level on the distal radius as a colles' fracture.

Distal fragment displaced in palmar (volar) direction with a "garden

spade" deformity.

• Modified Thomas Classification of Smith's Fracture:

• Type I: Extraarticular

• Type II:Crosses into the dorsal articular surface

• Type III:Enters the radiocarpal joint(equivalent to volar

barton fracture dislocation)

Smith's fracture (reverse colle's or volarBarton's)typical deformity: garden-spade deformity

1. Dorsal prominence of the distal end of the proximal fragment

2. Fullness of the wrist on the volar side due to the displaced distal fragment

3. Deviation of the hand toward the radial side

Barton’s fracture• It is an intrarticular fracture dislocation or

subluxation in which the rim of the distal radius dorsally or volarly is displaced with the hand and carpus

• There are 2 types

Dorsal barton

volar barton

• . Dorsal Barton:

• Dorsal rim fracture of distal radius

• Mechanism:

• Fall with dorsiflexion and pronation of the distal forearm on a flexed wrist.

2. Volar Barton:

Palmar rim fracture of distal radius

• Mechanism:

• It is due to palmar tensile stress and dorsal shear stress and is usually combined with radial styloidfracture.

Dorsal Barton fracture. Volar Barton fracture

Chauffeur’s fracture/hutchisonfracture• It is an intraarticular fracture involving the radial

styloid,the radius is cleaved in a sagittal plane and the fragment is displaced proximally.Isolated fracture of the radial styloid are fairly common from backfiring of starting handle of car

Lunate load/Die punch fracture

• It is an intraarticular fracture with displacement of the medial articular surface which usually represents a depression of dorsal aspect of lunate fossa

Universal classification• A)Extraarticular farcture

• Type 1-unstable and stable

• Type2-dispalced

a)Reducible and stable

b)reducible and unstable

c)irreducible

B)Intraarticular fracture

Type1-undisplaced and stable

Type 2-Displaced

a)Reducible and stable

b)Reducible and unstable

c)irreducible

d)complex

Other Classifications1)Based on radiographic appearance or fracture

displacement direction

a.AO classification

b.serminto classification

c.lidstrom classification

2)Based on mechanism of injuries

a.Fernandez classification

b.casting classification

c.lischeid classification

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3)Based on articular joint surface involvement

a.Mayo classification

b.Jupitor classification

c.McMurthy classification

d.Melone classification

4)Based on degree of communition

a.Gartland and werley classification

(a) metaphyseal comminution;(b) intra-articular extension; and (c) displacement of the fragments.

Group I: Simple distal radius fracture with no involvement of the radial articular surfaces

Group II: Comminuted distal radius fractures with intra-articular extension without displacement

Group III: Comminuted distal radius fractures with intra-articular extension with displacement

Group IV: Extra-articular, undisplaced

Gartland and Werley proposed a classification system that assessed the three basic components of these injuries

Frykman established a classification that incorporated individual involvement of the radiocarpal and radioulnarjoints.Type I: Extra-articular fractureType II: Extra-articular fracture with ulnar styloid fractureType III: Radiocarpal articular involvementType IV: Radiocarpal involvement with ulnar styloid fractureType V: Radioulnar involvementType VI: Radioulnar involvement with ulnar styloid fractureType VII: Radioulnar and radiocarpal involvementType VIII: Radioulnar and radiocarpal involvement with ulnarstyloid fracture

Frykman classification considers involvement of radiocarpal& RU joint,in addition to presnce or absence of frx of ulnar styloidprocess;

classification does not include extent or direction of initial displacement, dorsal comminution, or shortening of the distal fragment;

hence, it is less useful in evaluating outcome of treatment;

such as Colles (dorsal angulation) or Smith (volar angulation) fractures. One cortex fails in tension, and the opposite cortex is comminuted and impacted.

volar Barton, dorsal Barton and radial styloidfractures.

extra-articular bending fractures of the metaphysis

fractures are shearing fractures of the joint surface

FERNANDEZ CLASSIFICATION

TYPE – 1

TYPE 2

Type 3

cause intraarticular fractures and impaction of metaphyseal bone. These include complex articular fractures.

compression fractures of the joint surfacewith impaction of subchondral and metaphyseal cancellous bone

avulsion fractures of ligament attachments, includes dorsal rim and radial styloid fractures associated with radiocarpal fracture-dislocations.

TYPE 4

high-velocity injuries that involve combinations of bending, compression, shearing, and avulsion mechanisms or bone loss

TYPE 5

Melone emphasized the effect of the impaction of the lunate on the radial articular surface to create four characteristic fracture fragments.Type I: Stable fracture without displacement. This pattern has characteristic fragments of the radial styloid and a palmar and dorsal lunate facet.Type II: Unstable “die punch” with displacement of the characteristic fragments and communition of the anterior and posterior cortices

Type IIA: ReducibleType IIB: Irreducible (central impaction fracture)

Type III: “Spike” fracture. Unstable. Displacement of the articularsurface and also of the proximal spike of the radiusType IV: “Split” fracture. Unstable medial complex that is severely comminuted with separation and or rotation of the distal and palmar fragmentsType V: Explosion injury

The OTA/AO classification emphasizes the increasing severity of the bony injury.Type A: Extraarticular fracture. Subgroups are based on direction of displacement and comminution.Type B: Partial articular fracture. Subgroups are based on lateral (radial styloid) palmar or dorsal fragments.Type C: Complete articular. Subgroups are based on the degree of comminution of the articular surface and the metaphysis

CLINICAL FEATURESA) SYMPTOMS

• History of a fall on the outstretched hand or an episode of trauma

• A visible deformity of the wrist is usually noted, with the hand most commonly displaced in the dorsal direction.

• Movement of the hand and wrist are painful.

• Adequate and accurate assessment of the neurovascular status of the hand is imperative, before any treatment is carried out

• On Examination

Dorsal aspect of hand and wrist are usually swollen and ecchymosed

The wrist should be examined for tenderness

Median nerve function and flexor and extensor tendon action should be tested

Radial and ulnar styloids at same level(laugier sign)

Dinner fork deformity occurs in colles and dorsal barton farcture

Gardenspade deformity occurs in smith or palmarbartons fracture

CONTINUE

• associated fractures of either the radial head or supracondylar humerus.

• An effort should also be made to identify an ipsilateral scaphoid fracture, which may direct the surgeon to consider operative versus nonoperativemanagement.

• attention should be directed to the extensor pollicislongus, which may be injured acutely at Lister's tubercle or may present with a late spontaneous rupture.

MANAGEMENT• X-ray picture of normal wrist:

• Styloid process of the radius extends I cm beyond that of the ulna

• The articular surface of the radius projects proximally and towards the ulna (average 23°) - Radial angulation or inclination

• The plane of the radial articular surface slopes downwards and forwards (average 11°).

The distal articular surface of the radius

Volar tilt/palmar tilt of 11 degressRadial inclination of average 22 degrees ie;inclination of distal radius towards the ulnaRadial length of 11-12 mmUlnar variance of 0-2 mm which indicates radial shortening

Ulnar side of the wrist is supported by TFCC, which articulates with both the lunate and triquetrum

1) Dorsal/Palmar Tilt On a true lateral view a line is drawn connecting the most distal

points of the volar and dorsal lips of the radius. The dorsal or palmar tilt is the angle created with a line drawn along the longitudinal axis of the radius.

2) Radial LengthRadial length is measured on the PA radiograph. It is the distance in millimeters between a line drawn perpendicular to the long axis of the radius and tangential to the most distal point of the ulnar head and a line drawn perpendicular to the long axis of the radius and at the level of the tip of the radial styloid.

3) Ulnar VarianceThis is a measure of radial shortening and should not be confused with measurement of radial length. Ulnar variance is the vertical distance between a line parallel to the medial corner of the articular surface of the radius and a line parallel to the most distal point of the articular surface of the ulnar head, both of which are perpendicular to the long axis of the radius

4)Radial InclinationOn the PA view the radius inclines towards the ulna. This is measured by the angle betwee a line drawn from the tip of the radial styloid to the medial corner of the articular surface of the radius and a line drawn perpendicular to the long axis of the radius.

5)Carpal Malalignment

On a lateral view one line is drawn along the long axis of the capitate and one down the long axis of the radius. If the carpusis aligned, the lines will intersect within the carpus. If not, they will intersect outwith the carpus

Continue• X-ray PA VIEW• For extraarticular asses 1)radial shortening/communition

2)ulnar styloid fracture location

• For intraarticular asses 1)depression of the lunate facet 2)gap b/n scaphoid and lunate facet 3)central impaction fragements4)interruption of the proximal carpal row

• X-ray lateral viewFor extraarticular fracture asses1)palmar tilt 2)extent of metaphyseal communition 3)displacement of the volar cortex

4)scapholunate angle 5)position of the DRUJ

For intraarticular asses 1)depression of the palmarlunate 2)depression of central fragement 3)the gap b/n palmar and dorsal fragement

• Oblique view

1)For extraarticular asses radial communition

2)For intraarticular asses 1)the radial styloid for split or depression2)depression of the dorsal lunate facet

Tilted lateral view

It eliminates the shadow of radial styloid

And provide a clear tangential view of the lunate facet

Continue• CT scan:For conformation of occult fracture like

intraarticular fracture of lunate fossa

• MRI scan:For evaluation of suspected soft tissue injuries

1. Flexor or extensor tendon injuries

2. Median nerve injuries

3. Early diagnosis of necrosis of sacphoid or lunate

4. Perforation of TFCC

5. Rupture of carpal ligaments

Preserve hand and wrist function

Realign normal osseous anatomy

promote bony healing

Avoid complications

Allow early finger and elbow ROM

Goals of treatment

RATIONALE FOR TREATMENTThe goal of treatment of these fractures is a wrist that provides sufficient pain-free motion and stability to permit vocational and avocational activities in all age groups without the propensity for future degenerative changes in the young

Palmar Tilt

Clinical studies have implicated the loss of the normal 11 degrees to 12 degrees of palmar tilt as having a significant effect on functional outcome.The reason for the loss of function is probably multifactorial. Short et al. found that as little as a 10-degree loss of palmar tilt causes the area of maximum load on the radius to become more concentrated and to shift dorsally. This change in load concentration may explain the clinical findings relating dorsal tilt to radiographically apparent degenerative changes at long-term follow-up.Inaddition, the change in palmar tilt increases the tension on the palmar and dorsal radioulnar ligaments, resulting in an increased load required for forearm rotation

Radial Length/Ulnar Variance

Although collapse of the lunate facet results in radiocarpal incongruity, collapse of the radial metaphysis results in radioulnar incongruity.Adamsfound that positive ulnar variance resulted in the most significant changes in the kinematics of the radioulnar joint when compared with loss of radial inclination and palmar tilt because of loss of strength

Radial Inclination

Cadaver data indicate that the carpus shifts ulnarly in response to loss of radial inclination, thereby resulting in increased load on the triangular fibrocartilage complex (TFCC) and the ulna.

Carpal malalignment after distal radius fracture is usually an adaptive process in response to dorsal or excessive palmar tiltof the distal radius. The lunate tilts in the same direction as the distal radius and the carpus adapts to this at the midcarpal joint with flexion of the midcarpal joint in dorsal tilt and extension in volar tilt in order to realign the hand on the forearm.

Carpal Malalignment

TREATMENTUniversal classification based treatment

TYPE TREATMENT

1)Non articular undisplaced Cast/splint

2)Non articular displaced Close reduction and cast applicationPercutaneous pin fixation/external fixation

3)Articular undisplaced Cast/percutaneous pin fixation

4)Articular displaced

A)Reducible,stableCast/percutaneous fixation/external fixation

B)Reducible,unstableExternal fixation/ex fix with percutaneouspin fixation

C)Irreducible ORIF with plateExternal fixationCombined external and internal fixation

Articular congruity (to reduce the wear of articular cartilage and degenerative changes

Radial alignment and length (to restore kinematics of the carpus and radioulnar joint

Motion (digits, wrist, and forearm to optimize return to functional activities)

Stability (to preserve length and alignment until healing of the fracture

Principle goals of intervention

Stable Fractures

A fall on the outstretched hand may result in (1) a metaphysealbending fracture, (2) a lunate impaction fracture, or (3) an articularshear fracture. The stability of the avulsion fractures is based on the prognosis of the ligamentous injury, and combined injuries are generally too unstable to be treated with cast immobilization.

A metaphyseal bending fracture that failed under tension must be able to resist (a) axial load and (b) dorsal displacement

Lunate impaction fractures typically result secondary to axial load.

Instability• LeFontaine et al identified five factors indicative

of instability

1) Initial dorsal angulation of more than20 degrees

2) Dorsal metaphyseal communition

3) Intraarticular involvement

4) An associated ulnar fracture

5) Patient age older than 60 years

Continue• 2)Secondary instability-is present when closed reduction

and cast immobilisation fails to maintain the initial reduction and there is residual dorsal angulation of 20 degrees and more and greater than 5mm of radial shortening

• 3)Stable fracture are usually extraarticular with mild to moderate displacement

• 4)Other factors influence operative interventions are

a)open farcture

b)associated carpal fracture

c)associated neurovascular and impaired contralateral extremity

Current trend in treatment of distal radius fracture

• A)Conservative treatment with closed reduction and cast application

• B)Surgical treatment

1. Percutaneous direct pinning

2. External fixation

3. External fixation and direct pinning

4. Bone grafting

5. Plate fixation

6. Wrist arthroscopy

A)Conservative treatment• Stable fractures can be successfully treated with closed

reduction and immobilisation initially with a splint followed by cast and weekly radiographic evaluation for 3 weeks

• Close reduction and cast application

A)Step 1-Disimpaction

B) step 2-Reduction

C)Step3-Locking the fracture by pronation

D)Application of plaster cast

Reduction of the distal metaphysis is reduced by increasing the degree of the deformity and then applying longitudinal traction. Only when sufficient traction has been applied can the distal metaphyseal fragment be reduced on the shaft. The initial goal is to reapproximate the palmar cortex. When the palmar cortex is re-established then the cast has only to resist dorsal angulation Finally, palmar tilt is restored using gentle pressure on the distal fragment. In recalcitrant cases Agee's technique of palmar translation of the hand relative to the forearm may be successful in restoring volartilt. Care is taken to avoid excessive palmar flexion of the radiocarpal joint, which can result in an acute carpal tunnel syndrome

A careful examination of the patient is performed with particular attention to (1) skin quality and integrity, (2) median and ulnar nerve function as measured by 2-point discrimination, and (3) continuity of the extrinsic digital flexor and extensor tendons, most importantly those to the thumb.

Post reduction management1. Take x-ray immedaitely after the application of the

cast.If reduction is not satisfactory,another attempt to acheive accurate reduction should be made

2. If there is any circulatory embarrassment,split the cast along the dorsum of its entire length

3. Elevate the arm with the fingers pointing towards the ceiling for the first 48 hrs

4. Take x ray again on the 5th and 10th days ,check for maintanance of position.

5. Institute physical therapy,heat,gentle massage,watermassage and active exercises for the fingers,wrist,elbow and shoulder

continue

• Six pack exercises(codman type) is advised

1) Maximum extension of all digits

2) Opposition of the thumb

3) The grasp or fist exercise with all finger flexing to the palmar creases or as near as possible to it

4) The claw exercise with the MCP joint of the fingers kept extended but the IP joint maximally flexed

5) The table top exercise with the MCP joint maximally flexed but the IP joint extended

6) Abduction and adduction af all digits

7) Plus use shoulder and elbow is a must

Comlications• Failure or loss of reduction

• Skin complications

• Tendon adhesions and entrapement

• Carpal tunnel syndrome due to excessive palmarflexion

• Nerve complications

• Vascular injury

Operative treatment

1.Percutaneous direct pinning

• Aim of this procedure is to fix the mobile fragment to the opposite cortex proximal to the fracture

• Direct pinning of the fragments especially the intermediate column through the distal ulna add stability to the DRUJ and medial half of articular surrface

• Application is extrafocal where entry point of k wire is away from fracture site mainly 2 types a)transulnar b)transradial

• Indications-a)nonarticular displaced b)articularnondisplaced c)articular displaced,all of which are reducible and stable after reduction

• Contraindications are severebosteoporosis,severecommunition,soft tissue interruption and chauffer fracture

AFTERTREATMENT The arm is immobilized in a cast above the elbow with the forearm and wrist in neutral position. The Kirschnerwires that have been cut off just beneath the skin are removed at 6 weeks. The wrist is supported with a removable ball-peen splint, and gradual range-of-motion exercises are permitted

2.Kapandji techniqueintrafocal pinning with arum pins for nonarticularfracture

• In intrafocal pinning a smooth k-wire is inserted after a manual reduction,through a short skin incision,directlyinto the fracture line

• Secondary displacement is made impossible by immediate contact of the distal fragment with the arum nut of the pins which are working as an abutement,notas a resistant component

Kapandji technique of “double intrafocal wire fixation” to reduce and maintain distal radial fractures. A 0.045- or 0.0625-inch Kirschner wire is introduced into the fracture in a radial to ulnar direction. When the wire reaches the ulnar cortex of the radius, it is used to elevate the radial fragment and recreate the radial inclination. This wire is then introduced into the proximal ulnar cortex of the radius for stability. A second wire is introduced at 90 degrees to the first in a similar manner to restore and maintain volar tilt.

3.External fixation

• Three types of external fixation

1) Spanning external fixation

2) Nonspanning external fixation

3) Hybrid external fixation

Bridging/spanning ex-fix

• Bridging external fixation allows distraction across the radiocarpaljoint and directly neutralizes axial load.

• Initially external fixation was felt to provide “ligamentotaxis” to the fracture fragments. The philosophy was that the intact wrist capsule and ligamentous structures would “indirectly” reduce both the metaphyseal displacement and any impacted articularfragments, and open reduction would not be necessary

• Several detailed studies have documented that external fixation alone may not be sufficiently rigid to prevent some degree of collapse and some loss of palmar tilt during the course of healing,so several adjunctives were used.

• Factors that mitigates against adequate reduction include dorsal communition palmar soft tissue interposition.A tendency of dorsal tilt and displacement due to volar taut ligaments

• The external fixator which consists of

1) 3.5mm schantz pins for the radius 2 in number

2) 2.5mm schantz pins for the metacarpal 2 in number

3) Universal clamps

4) 4mm connecting rods

Adjunctive fixation• Supplemental Graft

Supplemental bone graft or a bone graft substitute within the fracture site has been used to fill the fracture gap.

Both bone inductive and conductive, which have been proposed to fill the metaphysis and prevent fracture collapse.

• K-wire fixation

The use of adjunctive percutaneous pins has also been introduced to improve the stability of external fixation and prevent loss of reduction.

The use of crossed wires engaging the contralateral cortex substantially further increases the rigidity of the construct.

The major complication seen with the use of pins is with iatrogenic injury to the superficial radial nerve.

Both bone inductive and conductive, which have been proposed to fill the metaphysis and prevent fracture collapse.percutaneous introduction of a calciumphosphatebone cement to treatment with external fixation or cast application. The radiographic results demonstrated superior maintenance of radial length in the cement group.

Nonbridging external fixation

• Indications-Extra-articular or minimal intra-articulardorsally displaced fractures with metaphyseal instability.

• The technique is not suitable for the treatment of volardisplaced fractures

• The main contraindication for the technique of nonbridging external fixation is lack of space for pins in the distal fragment: approximately 1cm of intact volarcortex is required to give purchase for the pins.

•The main radiological advantage of nonbridging external fixation is therefore restoration and maintenance of the normal volar tilt of the distal radius. In bridging external fixation, reductionof the fracture depends on ligamentotaxis. Volar tilt may not be restored, because the volar ligaments are shorter and stronger than the dorsal ligaments and prevent full reduction. With nonbridging external fixation the reduction is performed using the distal pins as a joystick, allowing the surgeon direct control of the distal fragment and obviating the need for ligamentotaxis.

Combined Open Reduction and Internal Fixation with External Fixation

This technique has been demonstrated to be effective when the articular fragments are felt to be too small and too numerous for internal fixation with plate-screw constructs, and yet the fracture does not reduce anatomically with standard techniques. It has been used primarily for high-energy injuries with comminution both dorsally and palmarly. The technique permits internal fixation of the comminuted fragments palmarly, and the use of the external fixation device prevents collapse on the side opposite the plate

The technique is most often used when external fixation has been performed and persistent incongruity of the palmar lunate facet is demonstrated. It is critical to reduce and stabilize this facet to obtain both articular congruity and distal radioulnar joint stability.

Complications of external fixation

• Overdistraction- Overdistraction of the wrist, particularly if it is combined with palmar flexion, results in relative lengthening of the extrinsic extensor tendons and may prevent full active and passive digital motion. Prolonged loss of full flexion combined with the swelling following a wrist fracture can result in permanent loss of metacarpophalangeal motion.

• Cutaneous Nerve Injury- Injury to the superficial radial nerve may be seen following open pin insertion, percutaneous half pin insertion, or with the use of supplemental K-wires.

• Pin Tract Infections- For K-wires the incidence ranges from 6% to as high as 33%. For external fixation pins the incidence has been reported to range from 1% to 8%

Open Reduction and Internal Fixation

Open reduction of articular fractures of the distal radius is indicated in active patients with good bone quality when anatomic restoration of the joint surface cannot be achieved by closed manipulation, ligamentotaxis, or percutaneous reduction maneuvers or as an alternative to percutaneous fixation at the preference of the patient or surgeon.

Articular fractures in elderly, inactive patients in those with massive osteoporosis

there is a risk for complications, including failure of fixation, nonunion, and reflex sympathetic dystrophy

CONTRAINDICATIONS

However, since the recent introduction of “fixed-angle” internal fixation devices, both unstable extra-articular and simple articular fractures in elderly, active osteoporotic patients have increasingly satisfactory outcomes with ORIF.Subchondral buttressing with fixed-angle pins or screws secured to the plate greatly reduce the incidence of settling or secondary articular displacement

surgical approach depends on the location and direction of displacement of the fracture fragments. Thus, dorsally or radially displaced fractures have been classically approached through dorsal incisions, whereas volarlydisplaced fractures (Smith's and reversed Barton's) are classically approached through palmar exposures.

There has been increased interest in the Mx of dorsally displaced nonarticular and articular fractures with volar fixed-angle plate fixation to decrease the incidence of extensor tendon irritation associated with dorsally applied implants.

Palmar incisions are also appropriate for primary repair of a torn wrist capsule in radiocarpal fracture-dislocations and whenever primary median nerve decompression or fasciotomy of the flexor compartment is indicated.

Dorsal plating

• Internal fixation using a dorsal plate has several theoretical advantages. Technically familiar to most surgeons, the approach avoids the neurovascular structures on the palmar side. Further, the fixation is on the compression side of most distal radius fractures and provides a buttress against collapse. Initial reports of the technique demonstrated successful outcomes with the theoretical advantages of earlier return of function and better restoration of radial anatomy than was seen with external fixation.

•There were increasing reports of extensor tendon ruptures because of prominent hardware, particularly at Lister tubercle. The more distally the plate is applied on the dorsum of the wrist, the more proximally the distal screws need to be directed to avoid articular penetration. This oblique orientation of the screws allows the distal fragment to displace palmarly. The palmar displacement of the fragment is particularly problematic because it results in (1) incongruity at the distal radioulnar joint and (2) prominence of the hardware dorsally with the tendency for extensor tenosynovitis or tendon rupture

Operative Technique

A longitudinal incision is centered over the fracture in line with the ulnar aspect of Lister tubercle. The extensor retinaculum is incised in a z-plasty manner that allows for one limb to be placed over the plate and the second limb to be repaired over the extensor tendons to prevent bow-stringing of the tendons with wrist extension. The extensor pollicis longus tendon is dislocated from its position at the tubercle and subperiosteal dissection is performed radially and ulnarly. Care should be taken to preserve all of the dorsal fragments for re-establishment of radial length. Traction is then applied by either an assistant or by the use of finger traps with weights suspended off the end of the table. Care should be taken to ensure that the hand is not pronated relative to the forearm.

Dorsal Plate Fixation

including irritation, synovitis,attrition,and tendon rupture because of direct contact of these

structures with the dorsal plates

complications,

Volar Plate Fixation

Regardless of the displacement of the distal fragment (dorsal, volar, radial), volar plating of both articular and nonarticular fractures is an effective fixation method that may reduce some of the soft tissue complications associated with dorsal plating. Advantages of palmar exposure and volar plating include the following

Minimal volar comminution facilitates reduction of dorsally displaced fractures.

Anatomic reduction of the volar cortex facilitates restoration of radial length, inclination, and volar tilt.

Avoidance of additional dorsal dissection helps preserve the vascular supply of comminuted dorsal fragments

Because the volar compartment of the wrist has a greater cross-sectional space and the implant is separated from the flexor tendons by the pronator quadratus, the incidence of flexor tendon complications is lessened.

The use of fixed-angle volar plate designs avoids screw “toggling” in the distal fragment and thus reduces the danger of secondary displacement

When stabilized with a fixed-angle internal fixation device that uses subchondral pegs or screws, control of shortening and late displacement of articular fragments are improved and the need for bone grafting reduced

ADVANTAGES

Complications• Locking plates is the potential for articular penetration

with distal plate position on the palmar surface of the radius

• Collapse of the fracture also can lead to joint penetration by the distal screws especially in osteopenic

patients

• Extensor tendon problems can be caused by penetration

Operative technique

• Palmar plates may be applied through either a flexor carpi radialis(FCR)/radial artery interval or through a midline flexor tendon/ulnar neurovascular bundle interval. The FCR/radial artery approach is preferable for (1) fixation of dorsally displaced fractures with dorsal comminution and (2) fixation of partial articular fractures (articular shear fractures). The skin incision is centered over the FCR, with care being taken to avoid injury to the palmar cutaneous branch of the median nerve that lies ulnarto the tendon. The radial artery is mobilized, and dissection is carried radially by releasing the brachioradialis tendon from the radial styloid.

The second surgical approach to the palmar radius is the flexor tendon/ulnar neurovascular bundle interval. The skin incision is centered over the ulnar border of the palmaris longus, the flexor tendons are mobilized radially, and the ulnar neurovascular bundle is taken ulnarly. With this approach the pronatorquadratus is released from the ulna. The incision may be extended distally to release the transverse carpal ligament, particularly if the patient had any median nerve symptoms preoperatively. This incision is preferred when the majority of the comminution is at the palmar lunate facet.

Associated injuries

1) Radial Styloid Fractures

Depressed radial styloid fractures are associated with a high incidence of scapholunate ligament injuries in younger patients

2) Volar Lip Injuries

3) Dorsal Lip Injuries

4) Ulnar Styloid Fractures

5) Interosseous Ligament Injuries

6) Triangular Fibrocartilage(TFCC) Injuries

Complications1) Chronic Regional Pain Syndrome

2) Nonunion

• Nonunion of distal radius fractures is rare but presents unique treatment challenges because of the associated pain, joint contractures, tendon imbalance or rupture, and occasional severe bony deformity

• nonunion of ulnar styloid process fractures in conjunction with distal radius fractures is quite common and yet is rarely symptomatic

• Treatment of distal radius nonunion must be individualized and based on the patient's symptoms, functional deficit, and bony substance

Malunion :

Malunion of the radius results in alterations to (1) the radiocarpal joint, (2) the midcarpal joint, and (3) the radioulnar joint.

Recognition of associated carpal malalignment and DRUJ derangement is mandatory to decide whether additional procedures together with radial osteotomy are necessary to help ensure a good result

Assessment of carpal malalignment with malunited Colles’ fractures includes determination of the presence of (1) dorsal subluxation of the carpus, (2) a type I (adaptive) dorsal intercalated segment instability (DISI) that is

reducible by radial osteotomy, or (3) type II or fixed DISI pattern that does not improve after radial osteotomy

The typical deformity of the distal radius malunion has three components: (1) loss of radial inclination, (2) loss of palmar tilt, and (3) pronation of the fracture fragment. The surgical technique is dependent on the location of and the degree of the deformity

Dorsal Displacement with Loss of Radial Inclination

The osteotomy is best performed at the site of the deformity. Typically an opening wedge osteotomy is performed and a corticocancellous graft is placed. Stabilization of the osteotomy has been described using K-wires, dorsal plates, palmar plates, and external fixators.

Palmar Displacement of the Distal Fragment

Palmar displacement (apex volar angulation) is best approached via a palmarapproach

If radial inclination has been lost then the FCR/radial artery approach allows opening of the radial column and release of the contracted brachioradialis tendon.

Neurologic Injuries

Median Nerve

Ulnar nerve

Sudek’s dystrophy

tendon rupture,

ulnar impaction,

loss of rotation,

finger stiffness, and

rarely, compartment syndrome.