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

2. Scaphoid Fractures Introduction Anatomy Biomechanics History
Clinical examination
Radiographic evaluation
DDx
Classification
Treatment
Complications

3. Scaphoid fractures Introduction
Scaphoid fractures constitute % 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
Has economic as well as physical significance due to the importance of scaphoid in wrist mechanics and because of the frequency of the fracture in young adult male.
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. Anatomy Blood 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 % 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 % 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. Biomechanics 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. Biomechanics
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
- as wrist rotates from neutral to ulnar deviation, proximal row dorsiflexes & x-ray profile of the scaphoid appears longer; - in radial deviation, proximal carpal row volar flexes & scaphoid appears foreshortened; - hence, ulnar deviation AP is necessary for visualization of scaphoid;

11. Biomechanics
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 mechanisms
Compression injury : usually results in non displaced fx
Hyperextension bending injury : usually results in displaced fx
Compression injury results from a more longitudinal load or impaction of the wrist leads to intraction of the scaphoid without displacement
Hyperextension bending injury :tensile stresses generated palmarly when excessive hyperextension is applied to the wrist and when the excessive tensile forces exceed bone strength produce a fx thru the scaphoid that commonly results in fx displacement

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
limitation of wrist motion – but not dramatically

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
Ecchymosis or swelling is not present except in fracture-dislocation

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 )
Scaphoid view is
- consider obtaining a CT scan of the scaphoid on the day of injury, if is essential to know the diagnosis (such as w/ a surgeon or an athlete)

19. Radiographic Evaluation
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
The same x-rays should be repeated if the initial films were negative because resorption may assist identification by widening the fracture line,,,, it is imperative for the orthopedist to make the Dx at this time because a delay in the Dx increases the incidence of the scaphoid nonunion
-- Terry and Ramin have called attention to a small radiolucent area normally present next to the scaphoid in anteroposterior view radiographs,which they named the navicular fat stripe, a fracture on the radial side of the wrist can either displace or obliterate this line. A preserved fat stripe is a strong indication that a fracture has not occurred. This sign is valuable only in fresh fracture..

20. Radiographic Evaluation
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
Bone radionuclide imaging was performed 2-3 hours after administration of technetium-99m methylene diphosphonate, 4 days after injury
- false-positive rate: 6-16% - false-negative rate: 0%;

21. Radiographic Evaluation
If the bone scan is positive, more specific studies ( e.g. polytomography, CT or MRI ) can be helpful
polytomography, or CT ………..axial views
Intrascaphoid angle Normal is 32

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
Location of the fracture : different fracture sites :
Proximal third ( proximal pole ) .. 25%
Middle third ( waist )… most common 65%
Distal third …..10%
Tuberosity
Distal articular surface ( osteochondral fx )

25. Classifications of scaphoid fx
Direction of the fracture :
Horizontal Oblique , Transverse , and Vertical Oblique (Russe’s Classification )
Vertical oblique fractures are considered unstable

27. Classifications of scaphoid fx
Time since injury :
Acute fracture - less than 3 weeks old
Delayed union to 6 months old
Nonunion more than 6 months old
Time since injury : these are - of course – arbitrary definitions and no one can say with certainty when a delayed union begins or ends
Nonunion more than 6 months old however many clinicians diagnose these fractures as nonunions regardless of the time period if bone resorption ,cyst formation , or sclerosis is present.

28. Classifications of scaphoid fx
Amount of fracture displacement ( stability ) :
Undisplaced stable
Displaced unstable
Amount of fracture displacement this is the most important classification and the practical one.
As mentioned earlier undisplaced fx results from an impaction injury while the displaced fx results from hyperextension bending injury

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
intrascaphoid angle > 35 (Normal angle is 32)

30. Herbert’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
It is in this area that most of the controversy regarding scaphoid fx still exists,,this is due to 1.s fx isn’t always isolated fx 2. The definition of successful result isn’t well known ( one def, is adequate motion and no significant pain ….a better def. Is treatment results in a radiologiclly proven healed scaphoid with normal carpal alignment
Almost every position of the wrist have been advocated ,including flexion,extension,radial deviation,ulnar deviation,neutral and various combinations
re: casting -- most surgeons leave the IP joint free

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. Time to healing by location : Distal third fx heals in 6-8 weeks
Consider changing the cast every 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 weeks
Proximal third fx weeks
A 95 % union rate can be expected with this management
times to union increasing for more proximal fractures
- immobilization for 16 weeks to 6 months is sometimes required - undisplaced fractures unite in 8 to 12 weeks many surgeons will cast for an additional 4-6 weeks once trabeculation is seen crossing the frx site (on radiographs), since the same frx seen on CT scanning may demonstrate a persistent frx gap; - if x-rays fail to clearly demonstrate trabeculae crossing site of frx, CT scan along axis of carpal scaphoid is performed; - this allows assessment of possible scaphoid nonunion

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,
electrical stimulation……in the absence of controlled studies showing the efficacy of electrical stimulation,,we prefer the bone grafting as the next step after failure of cast treatment

40. If the patient will not tolerate prolonged cast immobilization (e. g
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 %
this compares very favorably with conservative treatment

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
Volar approach : between FCR tendon and the radial artery
Dorsal approach:through the third dorsal compartment,,the incision is centered over Lister’s tubercle,,retracting EPL

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. Proximal Pole Fractures
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. Proximal Pole Fractures
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 Nonunion
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.
Bone grafting is the oldest method for nonunion and delayed union treatment.
The original Matti technique as described in 1937 consisted of excavation of the proximal and distal fragments through adorsal approach and placement of a cancellous strut within these two cavities to act as an internal fixationdevice as well as a nidus for osteogenesis
In 1960,Russe described a volar approach .

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 % 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. Treatment of Nonunion C) Proximal pole excision:
when a small proximal fragment is not amenable to bone grafting ,proximal pole excision and fascial hemiarthroplasty are recommended

65. Treatment of Nonunion 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
Fracture scaphoid and perilunate dislocation

71. Lateral view

72. Post -reduction

73. ORIF March7/2000
Volar approach, we placed 2 k-wires through the proximal and distal fracture fragments of the scaphoid to use them as joysticks , we were then able to reduce the scaphoid.we then placed a guide wire for the herbert screw from distal to proximal perpendicular o the transfer fracture. We then used a no. 18 mm Herbert screw to affix the scphoid fracture. To aid in the reduction we placed percutaneously a k-wire through the radial aspect of the scaphoid to help maintain the reduction
We also placed a k-wire from the triquterum to the lunate to hold the carpal bones stable

74. May1/ wks post ORIF
Still the fracture line is visible

75. May1/ wks post ORIF
So the pins are out May 1/2000

76. May 29/ wks

77. May 29/2000
?union ??AVN