Scaphoid Fractures
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
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.
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.
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
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
Blood Supply
•All studies consistently demonstrated poor supply
to the proximal pole
•The proximal pole is an intra-articular structure
completely covered by hyaline cartilage with a
single ligamentous attachment
–Deep radioscapholunate ligament
•Is dependent on intraosseous blood
supply
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 midthird fracture would expect AVN of proximal
pole…greater likelihood the more proximal the
fracture
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.
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
– >90degrees resulted in carpal fractures
 Combination of radial deviation and wrist extension locks
scaphoid within the scaphoid fossa
Diagnosis
 Suggested by:
– patient’s age,
– mechanism of injury and
– signs and symptoms
 Imaging
–
–
–
–
Xray
CT Scan
MRI
Bone Scan
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.
CT Scans
 CT permits accurate anatomic assessment of the fracture.
 Bone contusions are not evaluated with CT, but true fractures
can be excluded
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 MRI’s sensitivity to marrow oedema
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
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.
Herbert’s 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
Herbert’s Classification
Type C (delayed union)
Type D (established non-union)
– D1: fibrous union
– D2: pseudarthrosis
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)
Classification according to location
 A: tubercle
 B: distal pole
 C: waist
 D:proximal pole
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
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
Management
Distal Pole
– Are infrequent
– Usually extra-articular with good blood supply
– Best treated with short arm thumb spica for 3-6
weeks
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
Management of waist fractures
 Most stable fractures can be treated with below
elbow thumb spica
 Unstable fractures best treated with compression
screw fixation
– >1mm displacement
– Fragment angulation
– Abnormal carpal alignment
 With advent of percutaneous techniques of
cannulated screws under flouroscopic control trend
towards operative management
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(Green’s volume 1 page 721)
Complication$$
• Malunion
– Malunion may lead to limited motion about the wrist,
decreased grip strength, and pain.
– The most frequent pattern of malunion is persistent
angular deformity, or the humpback deformity.
– Malunion usually can be treated with osteotomy and bone
grafting to correct angular deformity and length.
• Literature confusing with no comparative studies to
document improvement in hand function
Complication$$
• 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
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
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%.
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
Salvage procedures
Radial styloidectomy
Distal scaphoid resection
Proximal row carpectomy
Partial arthrodesis