Scaphoid Fractures

1

2
Scaphoid Fractures

3
Scaphoid Fractures

• The scaphoid is the most frequently fractured
  carpal bone, accounting for 71 of all carpal
  bone fractures.
• Scaphoid fractures often occur in young and
  middle-aged adults, typically those aged 15-60
  years.
• About 5-12 of scaphoid fractures are associated
  with other fractures
• 70-80 occur at the waist or mid-portion
• 10-20 proximal pole

4
Anatomy

• The scaphoid lies at the radial border of the
  proximal carpal row, but its elongated shape and
  position allow bridging between the 2 carpal rows
  because it acts as a stabilizing rod.
• The scaphoid has 5 articulating surfaces
• with the radius, lunate, capitate, trapezoid,
  and trapezium.
• As a result, nearly the entire surface is covered
  by hyaline cartilage.

5
(No Transcript)
6
Blood Supply

• Vessels may enter only at the sites of
  ligamentous attachment
• the flexor retinaculum at the tubercle,
• the volar ligaments along the palmar surface,
• and the dorsal radiocarpal and radial collateral
  ligaments along the dorsal ridge.

7
Blood Supply

• Classically described as 3 principal arterial
  groups, but in more recent investigations by
  Gelberman and Menon described 2
• Entering dorsally
• Volar side limited to tubercle

8
Blood Supply

• The primary blood supply comes from the dorsal
  branch of the radial artery, which divides into
  2-4 branches before entering the waist of the
  scaphoid along the dorsal ridge.
• The branches course volar and proximal within the
  bone, supplying 70-85 of the scaphoid.
• The volar scaphoid branch also enters the bone as
  several perforators in the region of the
  tubercle these supply the distal 20-30 of the
  bone

9
(No Transcript)
10
(No Transcript)
11
Blood Supply
12
Blood Supply

• Obletz and Halbstein in their study of vascular
  foramina in dried scaphoids found 13 without
  vascular perforations and 20 with only a single
  small foramen proximal to the waist
• Therefore postulated that atleast 30 of
  mid-third fracture would expect AVN of proximal
  polegreater likelihood the more proximal the
  fracture

13
(No Transcript)
14
Pathophysiology

• The primary mechanism of injury to the scaphoid
  bone is a fall on an outstretched hand.
• A scaphoid fracture is part of a spectrum of
  injuries based on 4 factors
• (1) the direction of 3-dimensional loading,
• (2) the magnitude and duration of the force,
• (3) the position of the hand and wrist at the
  time of injury, and
• (4) the biomechanical properties of ligaments and
  bones.
• These factors affect the end result of the fall
  distal radius fracture, ligamentous injury,
  scaphoid fracture, or a combination of these.

15
Pathophysiology

• Essentially fractures of scaphoid have been
  explained as a failure of bone cause by
  compressive or tension load
• Compression, as explained by Cobey and White,
  against concave surface by head of capitate
• Position of radial and ulnar deviation thought to
  determine where it breaks
• Fryman subjected cadaver wrists to loading and
  observed that
• extension of 35 degrees of less resulted in
  distal forearm fractures
• gt90degrees resulted in carpal fractures
• Combination of radial deviation and wrist
  extension locks scaphoid within the scaphoid fossa

16
Diagnosis

• Suggested by
• patients age,
• mechanism of injury and
• signs and symptoms
• Imaging
• Xray
• CT Scan
• MRI
• Bone Scan

17
Radiography

• The 4 essential views (ie, PA, lateral, supinated
  and pronated obliques) identify majority of
  fractures.
• The scaphoid view is a PA radiograph with the
  wrist extended 30 and deviated ulnarly 20. This
  view helps to stretch out the scaphoid and is
  also used for assessing the degree of scaphoid
  fracture angulation.
• A clenched-fist radiograph has also been useful
  for visualization of the scaphoid waist.

18
(No Transcript)
19
(No Transcript)
20
CT Scans

• CT permits accurate anatomic assessment of the
  fracture.
• Bone contusions are not evaluated with CT, but
  true fractures can be excluded

21
(No Transcript)
22
MRI

• T1-weighted images obtained in a single plane
  (coronal) are typically sufficient to determine
  the presence of a scaphoid fracture.
• Gaebler prospectively performed MRI on 32
  patients, at average of 2.8 days post injury
• 100 sensitivity and specificity
• In recent study Dorsay has shown that immediate
  MRI provides cost benefit when compared to
  splintage and repeat xray
• False positives due MRIs sensitivity to marrow
  oedema

23
(No Transcript)
24
(No Transcript)
25
Nuclear Imaging

• Radionuclide bone scanning typically is performed
  3-7 days after the initial injury if the
  radiographic findings are normal.
• Best at 48hours, premature imaging may be
  obscured by traumatic synovitis
• Bone scan findings are considered positive for a
  fracture when intense, focal tracer accumulation
  is identified.
• Negative bone scan results virtually exclude
  scaphoid fracture
• Teil-van studied cost effectiveness and concluded
  that initial xray followed by bone scan at 2
  weeks if patient is still symptomatic is most
  effective management option
• Teil-van also suggested that more sensitive and
  less expensive than MRI

26
?
27
Classification

• Determining optimal treatment depends on accurate
  diagnosis and fracture classification
• Herbert devised an alpha-numeric system that
  combined fracture anatomy, stability and
  chronicity of injury.

28
Herberts Classification

• Type A (stable acute fractures)
• A1 fracture of tubercle
• A2 incomplete fracture
• Type B (unstable acute fractures)
• B1 distal oblique
• B2 complete fracture through waist
• B3 proximal pole fracture
• B4 trans-scaphoid perilunate fracture
  dislocation of carpus

29
Herberts Classification

• Type C (delayed union)
• Type D (established non-union)
• D1 fibrous union
• D2 pseudarthrosis

30
(No Transcript)
31
Russe Classification

• Russe classified scaphoid fractures into 3 type
  according to the relationship of the fracture
  line to the long axis of the scaphoid
• Horizontal
• Oblique
• Vertical (unstable)

32
(No Transcript)
33
Classification according to location

• A tubercle
• B distal pole
• C waist
• Dproximal pole

34
(No Transcript)
35
Management

• Proximal pole
• Depends on size and vascularity of fracture
• Growing sentiment that most should be treated
  operatively because of high propensity for
  non-union and increased duration of
  immobilisation required for non-operative
  management
• If large enough to accommodate a screw than every
  attempt should be made

36
Management

• DeMaagd and Engber showed 11 of 12 patients with
  proximal pole fractures healed with Herbert screw
• Retting and Raskin had 100 union in 17 cases
  with Herbert screw
• If fragment too small then K-wires can be used

37
(No Transcript)
38
(No Transcript)
39
Management

• Distal Pole
• Are infrequent
• Usually extra-articular with good blood supply
• Best treated with short arm thumb spica for 3-6
  weeks

40
(No Transcript)
41
Management of waist fractures

• Most common type of fracture
• High rate of delayed and non-union
• With delays in treatment adversely affect results
• Operative vs non-operative
• Controversial

42
Management of waist fractures

• Most stable fractures can be treated with below
  elbow thumb spica
• Unstable fractures best treated with compression
  screw fixation
• gt1mm displacement
• Fragment angulation
• Abnormal carpal alignment
• With advent of percutaneous techniques of
  cannulated screws under flouroscopic control
  trend towards operative management

43
What about the undisplaced waist fractures???

• Netherlands study
• Average time away from work 4.5 months
• Saeden in prospective randomised study with 12
  year follow-up compared early operative vs cast
  immobilisation
• Return to work quicker in operative
• No significant long term difference in functional
  outcome between 2 groups
• Bond has shown return to work 7 weeks earlier and
  time of union 5 weeks quicker
• Other papers disagree
• Some surgeons published union rates of 100 with
  surgery(Greens volume 1 page 721)

44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
Complication

• Malunion
• Malunion may lead to limited motion about the
  wrist, decreased grip strength, and pain.
• The most frequent pattern of malunion is
  persistent angular deformity, or the humpback
  deformity.
• Malunion usually can be treated with osteotomy
  and bone grafting to correct angular deformity
  and length.
• Literature confusing with no comparative studies
  to document improvement in hand function

49
Complication

• Delayed union and non-union
• Delayed union is incomplete union after 4 months
  of cast immobilization.
• Non-union is an unhealed fracture with smooth
  fibrocartilage covering the fracture site.
• About 10-15 of all scaphoid fractures do not
  unite.
• Some degree of delayed union or non-union occurs
  in nearly all proximal pole fractures and in 30
  of scaphoid waist fractures

50
(No Transcript)
51
Complication

• Delayed union is anticipated if fracture
  treatment is delayed for several weeks.
• The risk of non-union increases after a delay of
  4 weeks.
• These delays may be related to the patient's
  failure to seek treatment for a presumed sprain,
  but they more frequently are related to improper
  or incomplete immobilization or a failure to
  diagnose and treat the acute fracture

52
Delayed union treatment

• If the delayed union is stable and less than 6
  months old relative to the time of injury,
  prolonged cast immobilization with or without
  electrical stimulation may be used.
• Treatment of choice for a symptomatic non-union
  is placement of a bone graft and fixation.
• Russe corticocancellous iliac graft
• Fisk-Fernandez volar wedge graft
• Pronator pedicle graft
• Braun 83 reported 100 union in 8 pts
• Kawai, Kuhlmann, Papp reported 100 37 pts
• Pechlaner reporrted 25 free vascularised iliac
  grafts with 100
• Success rates for the treatment of non-union are
  as high as 82.

53
AVN

• Osteonecrosis occurs in 15-30 of all scaphoid
  fractures, and most of these involve the proximal
  pole.
• Its incidence increases as the fracture line
  becomes more proximal this decreases the
  probability that the blood supply to the proximal
  pole is preserved

54
(No Transcript)
55
Salvage procedures

• Radial styloidectomy
• Distal scaphoid resection
• Proximal row carpectomy
• Partial arthrodesis