1 Scaphoid Fractures Abdulaziz Al-Ahaideb PGY2 March 23/2001.

1

Scaphoid FracturesScaphoid Fractures

Abdulaziz Al-AhaidebAbdulaziz Al-Ahaideb

PGY2March 23/2001

2

Scaphoid Fractures

• Introduction• Anatomy• Biomechanics• History• Clinical examination

• Radiographic evaluation

• DDx• Classification• Treatment• Complications

3

Scaphoid fracturesIntroduction

• Scaphoid fractures constitute 60-70 % of all carpal bone fractures

• Second only to the distal radius in frequency• Due to the importance of scaphoid in wrist

mechanics and because of the frequency of the fracture in young adult male, it has an economic as well as physical significance

• Uncommon in children because the physis of distal radius fails first

4

Anatomy

• Also called Navicular• An irregular shaped

bone ,more resembling a twisted peanut than the boat for which it is named

• Scaphoid represents floor of the anatomic snuff box

5

Anatomy

• Articular cartilage covers 80 % of the scaphoid surface - only narrow area of its neck, & even smaller distal portion, are accessible to blood vessels

• Distally, it articulates with the trapezium and trapezoid in a gliding motion, The articulation with the trapezium forms a base for independent movement of the thumb

• On the ulnar side, it articulates distally with the capitate, and proximally with the lunate in a rotary motion

• Proximally, its large, biconvex surface allows articulation with the radius

6

Anatomy -ligaments

7

AnatomyBlood Supply

• Major blood supply comes from the scaphoid branches of the radial artery entering the dorsal ridge at or just distal to waist area and supplying 70-80 % of the bone including the entire proximal pole - in a retrograde fashion

• Second group of vessels, arise from palmar & superficial palmar branches of radial artery & enter the distal tubercle, it perfuses distal 20-30 % of bone, including tuberosity

8

Blood Supply

• There are no anastomoses between the dorsal and palmar vessels

• Vessels enter thru dorsal ridge in 79 %, distal to waist in 14 %, & proximal to waist in 7 %

• Fractures across scaphoid may destroy blood supply to its proximal part

9

BiomechanicsBiomechanics

• Mechanically scaphoid links the proximal and distal rows

• Scaphoid spans both carpal rows and therefore has less mobility than other carpal bones

• Scaphoid carries the compressive loads from the hand across the wrist to the distal forearm

10


• Scaphoid flexes with wrist flexion & extends with wrist extension

• It also flexes during radial deviation & extends during ulnar deviation

• These factors make immobilization of scaphoid fractures difficult especially when there is displacement

11


• Scaphoid is a principal bony block to dorsiflexion of hand & wrist , and is susceptible to frx during fall on outstretched hand

• With scaphoid fx, distal scaphoid tends to flex, & proximal scaphoid extends with the proximal carpal row ,, because of this, angulation occurs at fx site, which gradually leads to a humpback deformity

12

Mechanism of injury

Two different mechanisms1. Compression injury :

usually results in non displaced fx

2. Hyperextension bending injury : usually results in displaced fx

13

Diagnosis

• A strong index of suspicion is the key to early diagnosis

• The diagnosis should be based on :

History

Clinical examination

Radiographic evaluation

14

History

• Occurs after a fall on an outstretched hand, athletic injury, or MVA

• Usually happens in young adult men

• Pain at the radial side of the wrist

• Associated injuries

15

Clinical Examination • Should demonstrate tenderness in the

anatomic snuff box • Tenderness to palpation over scaphoid

tuberosity and/or proximal pole just distal to Lister's tubercle

• Tenderness with axial compression of thumb toward the snuff box

• Tenderness as patient supinates forearm against resistance

16

Clinical Examination

• Radial & ulnar deviation results in pain on radial side of wrist

• Forced dorsiflexion usually elicits significant tenderness

• There is usually pain at extremes of motion

• Limitation of wrist motion – but not dramatically

• Swelling – usually not present

18

Radiographic Evaluation

• The best method for determining the presence of a fracture

• Many different views have been recommended

• The useful initial views are : PA, lateral, scaphoid view ( PA with ulnar deviation )

19


• Motion views of the wrist ( flexion-extension-radial & ulnar deviation ) may demonstrate fracture displacement

• If a diagnosis still can’t be confirmed with confidence on routine films, further oblique views can be taken

• If certainty still exists after all these maneuvers , the patient should be placed in a cast for 2 to 4 weeks and the clinical & radiographic evaluation repeated

20


• If the second radiographic examination is still equivocal , a technetium bone scan, polytomography, CT or MRI of the wrist is recommended

• The bone scan is the most sensitive but the least specific of these modalities, thus if the bone scan is negative , a scaphoid fx is ruled out

21


• If the bone scan is positive, more specific studies ( e.g. polytomography, CT or MRI ) can be helpful

22

DDx

• It is the same DDx of radial sided wrist pain • Lunate dislocation or fx• Sapholunate instability• Radial styloid fx • Trapezium fx• Rupture of FCR tendon• ECRB or ECRL avulsion

23

Classifications of scaphoid fx

A. Location of the fracture : 5 different fracture sites :

Proximal third ( proximal pole ) .. 25%

Middle third ( waist )… most common 65%

Distal third …..10%

Tuberosity

Distal articular surface ( osteochondral fx )

25


B. Direction of the fracture : Horizontal Oblique , Transverse , and

Vertical Oblique (Russe’s Classification )

27


C. Time since injury :• Acute fracture - less than 3 weeks

old

• Delayed union - 4 to 6 months old

• Nonunion - more than 6 months old

28


D. Amount of fracture displacement ( stability ) :

• Undisplaced ---- stable

• Displaced ---- unstable

29

• The unstable fracture (displaced) is defined as :

- presence of a fracture gap > 1 mm on any radiographic projection

- scapholunate angle > 60

- radiolunate angle > 15

- or intrascaphoid angle > 20

30

Herbert’s ClassificationHerbert’s Classification

31

Prognosis

• Negative prognostic factors are : late diagnosis proximal location displacement angulation obliquity of the fracture line smoking carpal instability

32

Treatment

Is determined by:

Location

Degree of displacement

Fresh vs old fracture

33

Treatment

• Undisplaced ( stable) fracture :

Nonoperative ( cast immobilization )--- there have been three main areas of disagreement in non-operative treatment of acute non displaced fractures of scaphoid :

1- the position of the wrist in the cast

2- the need to include joints other than the wrist in the cast

3- the duration of the immobilization

34

Treatment

Many types of cast immobilization have been described in the literature

No evidence exists to prove greater efficacy for one casting position over another. Although above elbow casts may have a slightly shorter time to union, the final rate of union is the same for below or above elbow casts. The key factor in treatment of scaphoid fractures is the duration of immobilization rather than the specific position

35

• The current recommendation is to use a short arm thumb spica with the thumb interphalangeal joint free. The wrist is placed in radial deviation

• Long arm cast is recommended for nondisplaced proximal pole fx

36

• Consider changing the cast every 10-14

days for the first 6 weeks so that it remains firm around forearm muscles and the wrist

• Time to healing by location : – Distal third fx heals in 6-8 weeks – Middle third fx 8-12 weeks – Proximal third fx 12-24 weeks

• A 95 % union rate can be expected with this management

37

• Removal of the cast should not occur until union has been documented on CT or tomography

• Prognosis is excellent in undisplaced, stable fractures if diagnosed and immobilized early (95 % with x-ray evidence of beginning consolidation at 6 weeks )

38

• Initial delay in treatment does not preclude casting • If treatment is instituted within four weeks no effect

on healing time or rate of union has been shown • Delay beyond six months invariably requires

operative treatment • The difficulty lies in fractures between six weeks

and six months. If no evidence of bony resorption exists, casting may result in union. If bony resorption or displacement greater than 1 mm exists, operative reduction and bone grafting will be needed

39

Treatment

• Cast immobilization and electrical stimulation : the M/A isn’t fully understood

• It is worthwhile to try electrical stimulation (esp.when there is nonunion ), though there is a lack of reliable double-blind study which compares between series of patients treated with immobilization alone and those treated with immobilization and ES,

40

• If the patient will not tolerate prolonged cast immobilization (e.g. professional athletes and manual laborers ) early internal fixation should be performed

• Internal fixation for fresh nondisplaced proximal pole fractures has been recommended by some authors

41

Treatment

• Displaced fractures :

– Primary internal fixation is treatment of choice for unstable scaphoid frxs

– Fractures treated by primary internal fixation, average time for return to work is 3.7 weeks with union rate 97 %

42

• Indications of Surgery in Scaphoid fractures

Displaced acute fracture

Delayed union or nonunion when bone grafting is insufficient to provide adequate internal fixation

S.Fx associated with a perilunate fx or dislocation

Ligamentous injury

Non displaced fx of proximal pole

Non displaced fx if the pt will not tolerate prolonged cast immobilization (e.g. professional athletes and manual laborers )

43

• The choice of the surgical procedure will vary with the surgeon’s preference and experience, the type of the fracture, the patient’s age, and the presence of periscaphoid arthrosis

• The most important aspect of the treatment is meticulous technique and not the device or equipment selected

• Reduction of the fracture should be anatomic

44

• ORIF of scaphoid fractures can be done by many ways :

K-wires ( easy insertion ) Herbert screws ( headless,

multipitched,difficult insertion ) AO screws Herbert-whipple screw Ender’s plate Staples

47

• The surgical approaches :– Volar approach -- is most of the time the

preferred approach to limit the injury to the blood supply of the scaphoid

– Dorsal approach – will be used to address the fractures of the proximal approach

48

Volar approach: between FCR and the radial artery

49

Treatment of middle third fxs

They are the commonest (65%)

If fresh stable: short-arm thumb spica cast

If fresh undisplaced but potentially unstable (e.g. vertical oblique) and stable fx older than 3 wks : long-arm thumb spica cast

If fresh displaced : ORIF (k-wires or screws)

50

Proximal Pole Fractures

• challenging• Often difficult to heal• Prolonged immobilization- snug , well

molded long arm cast- (sometimes exceeds 9 mos) has been necessary with conventional casting

• Early incorporation of PES has been recommended

51


• There is increasing favor to proceed to ORIF• A dorsal approach allow s direct visualization of

the fracture• If it is a fresh fx, can be fixed by 2-3 k-wires • The k-wires are extracted in a retrograde fashion

in 6-8 weeks• Alternatively ,one may use a Herbert screw which

may be inserted retrograde while the fragment is stabilized in a k-wire

52


• Determination of bony union is not easy

• Tomography or CT is needed

• Multiple follow up films should be obtained for several months after the assumed healing

53

Distal Pole Fractures

• These are often avulsion injuries of the tuberosity and can be expected to heal promptly with cast treatment

• Fresh and undisplaced should heal in 4-8 wks in a cast

• Displaced fx needs ORIF

54

After treatment care

• After achieving a rigid fixation , there is a big controversy about the need for immobilization

• Some authors recommend a long arm cast after k-wire or compression screw fixation for 2-3 weeks

• New literature is in favor of early mobilization

55

Complications of Scaphoid Fx

• Delayed union or Nonunion

• Malunion (Humpback deformity)

• SLAC wrist

• Osteonecrosis

56

Nonunion

• The incidence of scaphoid nonunion for undisplaced fx is 5-10%

• The incidence increases up to 90% in displaced proximal pole fxs

• Risk factors :– Proximal pole fx– Displacement– Late diagnosis– Inadequate immobilization– Associated ligamentous injuries

57

Nonunion• Failure to heal after 6 months establishes the Dx of

nonunion• Recent studies indicated that virtually that all unstable

nonunions lead to carpal collapse and posttraumatic arthritis,, for this reason treatment is recommended for all scaphoid nonunions even if asymptomatic

• Thin cut CT scan show more details than conventional tomograms

• Sagittal views are helpful in determining the degree of carpal collapse and humpback deformity

58

Treatment of NonunionA) Bone grafting :

• 2 types of bone grafting are indicated for tx of nonunion:

• Russe bone graft (inlay): used for stable nonunions .the initial procedure used a single corticocancellous strut across the fracture line;a later modification involved two corticocancellous struts inserted into the scaphoid excavation with their cancellous sides facing each other,the remainder of the cavity is filled with cancellous chips. Usually k-wires are added to secure the construct.

59

Inlay graft

60

Con’t Russe bone graft

• The time to union with this procedure is relatively long ,generally requiring cast immobilization for 6-4 months

• Healing rates of 85-90 % have been reported• Satisfactory relief of symptoms has been

reported ; 78 % of painful wrist became free of symptoms and 88 % of patients were satisfied with the results

61

Con’t Bone Grafting

• Fernandez bone graft (interpositional graft): angulated nonunions with a dorsal humpback deformity require interpositional grafting. Fernandez has described the use of a trapezoidal iliac graft to correct the angulation and carpal collapse pattern.Fixation is achieved with screws or k-wires

• In both types of bone grafting ,a volar approach is used, and care must be taken to preserve the vascularity of the fragments

62

Interpositional graft

63

Treatment of Nonunion

• B) Electrical stimulation:– Pulsed Electromagnetic Field ( PEMF )

stimulation has been investigated as a noninvasive treatment for scaphoid nonunion.Although controversial, there appears to be some benefit (shorter healing time)when electric stimulation is combined with bone grafting procedures

64


• C) Proximal pole excision: when a small proximal fragment is not amenable to bone grafting ,proximal pole excision and fascial hemiarthroplasty are recommended

65


• D) Salvage procedures :Are indicated when nonunion has lead to carpal

collapse and secondary degenerative changes

Proximal row carpectomy,intercarpal arthrodesis, or radiocarpal arthrodesis is recommended in patients with chronic wrist pain and stiffness

Radial styloidectomy and scaphoid interposition arthroplasty may be combined with other procedures or performed independently in the younger patient with less severe symptoms

Silicone implants have been used in the past but are now avoided because of silicone synovitis

66

Malunion• Malunion of the scaphoid may occur when a displaced or

angulated fracture is allowed to heal without anatomic reduction

• In most of cases , there is a dorsal angulation resulting in a fixed humpback deformity

• DISI pattern ensues ,resulting in pain ,loss of motion, and decreased grip strength

• Treatment in a young patient includes osteotomy,volar wedge bone graft,and internal fixation

• Once degenerative arthritis has begun ,treatment is limited to a salvage procedure such as proximal row carpectomy,intercarpal arthrodesis,or complete wrist fusion

67

Osteonecrosis

68

SLAC

• scapholunate advanced collapse (SLAC) refers to a specific pattern of osteoarthritis and subluxation which results from untreated chronic scapholunate dissociation or from chronic scaphoid nonunion

69

Case # 1

•J.D. 24 y.o male . Fell on his out stretched hand while snowboarding on March 7/2000

•C/0 pain Lt wrist , no other injuries.

•O/E : Lt wrist tenderness, neurovascular intact

•X-rays:

70

ER x-ray

71

Lateral view

72

Post -reduction

73

ORIF March7/2000

74

May1/20007 wks post ORIF

75

May1/20007 wks post ORIF

76

May 29/200011 wks

77

May 29/2000

1 Scaphoid Fractures Abdulaziz Al-Ahaideb PGY2 March 23/2001.

Documents

Transcript of 1 Scaphoid Fractures Abdulaziz Al-Ahaideb PGY2 March 23/2001.