Transcript Smith`s fracture

Distal radial fractures
• The distal radial fracture is the most common
forearm fracture. It is usually caused by a fall
onto an outstretched hand (FOOSH). It can
also result from direct impact or axial forces.
The classification of these fractures is based
on distal radial angulation and displacement,
intra-articular or extra-articular involvement,
and associated anomalies of the ulnar or
carpal bones.
Distal radial fractures
• Kirmani et al at the Mayo Clinic noted that distal
forearm fractures peak during the adolescent growth
spurt but that the structural basis for this is unclear.
They concluded, on the basis of their study findings,
that regional deficits in cortical bone may underlie the
adolescent peak in forearm fractures.
• In the United States, 17% of all emergency room visits
result from wrist injuries. McMurtry and colleagues
reported that distal radial fractures account for one
sixth of all fractures seen in the emergency
department.
Distal radial fractures
• Most wrist fractures occur in older
postmenopausal women, with a female-to-male
ratio of 4:1.[11 ]However, in adolescent boys and
girls, the ratio is 3:1, reflecting a differing level of
sports involvement between boys and girls.
• A bimodal age distribution has been documented
for distal radial fractures; peaks occur at ages 514 years and at ages 60-69 years.
Distal radial fractures
• Extra-articular metaphyseal fractures occur in elderly
patients because of the thin osteoporotic cortex. Intraarticular fractures with joint surface displacement
occur in young patients.
• Age influences the location of fractures in the forearm
and wrist. Young children present with metaphyseal
fractures of the radius and ulna; adolescents, with
physeal separations of the radius; and young adults,
with scaphoid fractures. Middle-aged and elderly
patients present with fractures of only the distal radius
or of the radius and ulna.
Anatomy
• The radiocarpal joint is a synovial joint
that connects the hand to the forearm. The distal
radius and ulna articulate at the radioulnar joint.
• The pronator quadratus muscle is located across
the volar aspect of the distal radius and ulna. This
muscle is associated with an underlying fat pad
that is seen as a flat, lucent line anterior to the
distal end of the radius on the lateral image and
that, if a bulge is present, is indicative of a softtissue injury.
Presentation
• Wrist injuries that cause pain, edema,
crepitus, deformity, or ecchymosis should be
evaluated for radial fractures. Missed distal
radial fractures can lead to significant
morbidity.
Distal radial fractures
• Common complications of distal radial
fractures also include ulnar nerve injury,
carpal tunnel syndrome, posttraumatic
radiocarpal osteoarthritis with possible limited
range of motion, heterotopic ossification,
reflex sympathetic dystrophy (RSD), tendon
rupture, nonunion, and radial shortening.
Distal radial fractures
• The most common complication of associated
soft-tissue injury is peripheral nerve dysfunction.
The median nerve is most commonly affected,
but the ulnar nerve also may be injured.
Mechanisms for neuropathy of the median nerve
include direct trauma by fracture or
displacement, injury through a proximal radial
fragment, and injury from displacement of a volar
fragment. The ulnar nerve is damaged by medial
displacement of the radial fragment or by the
ulnar head being volarly displaced.
Distal radial fractures
• Injury to arteries occurs with open and closed
fractures. It can also occur with markedly
displaced fractures and with dislocations of the
radius and ulna.
• Tendon lacerations occur from high-energy
injuries and should be suspected with open
fractures and high-velocity injuries. The incidence
of tendon rupture is less than 0.2%, and tendon
rupture is a late sequela of distal radial fractures.
Distal radial fractures
• Intercarpal injuries may accompany fracture
dislocations of the distal forearm. Scaphoid
fractures are not uncommon. Intercarpal
ligament injuries also may occur. Fractures
through the radial styloid can disrupt the
radioscapholunate and scapholunate
interosseous ligaments, causing a disruption
between the 2 bones.The extensor pollicis
longus tendon is most frequently ruptured.
Diagnostics
• Posteroanterior (PA), lateral, and oblique
radiographs of the injured forearm should be
obtained. Oblique views reveal intra-articular
involvement that is not apparent on the other
views. The semisupinated, oblique view
demonstrates the dorsal facet of the lunate
fossa, whereas the partially pronated, oblique
PA view allows visualization of the radial
styloid.
Radial height is assessed on the PA view. It is a measurement between 2 parallel lines that are
perpendicular to the long axis of the radius. One line is drawn on the articular surface of the
radius, and the other is drawn at the tip of the radial styloid. The normal radial height is 9.9-17.3
mm. Measurements of less than 9 mm in adults suggest the presence of comminuted or
impacted fractures of the radial head. Comparison with the contralateral normal wrist is
recommended if the diagnosis is unclear. Shortening of RH may indicate impaction of the radial
head when compared with a normal contralateral wrist.
• Radial inclination is measured on the PA view; this is a measurement of
the radial angle. A line is drawn along the articular surface of the radius
perpendicular to the long axis of the radius, and a tangent is drawn from
the radial styloid. The normal angle is 15-25º. Angulation of the radial
head also provides impaction clues
• The volar tilt, or palmar
inclination, is measured on
the lateral view. A line
perpendicular to the long
axis of the radius is drawn,
and a tangent line is drawn
along the slope of the
dorsal-to-palmar surface of
the radius. The normal
angle is 10-25º. A negative
volar tilt indicates dorsal
angulation of the distal,
radial articular surface.
Barton’s fracture
John Rhea Barton characterized the Barton fracture in 1838. This
fracture involves a dorsal rim injury of the distal portion of the
radius. Carpal displacement distinguishes this fracture from a
Smith's or a Colles' fracture and that the dislocation is the most
striking radiographic finding.
2 types
Volar Barton fracture is thought to occur with the same mechanism as
the Smith fracture, with more force and loading on the wrist.
Dorsal Barton fracture is caused by a fall on an extended and pronated
wrist, increasing carpal compression force on the dorsal rim. The
salient feature is a subluxation of the wrist in this die-punch injury.
Barton’s fracture
• The Barton fracture involves either the palmar
or dorsal radial rim, and the mechanism is
intra-articular. By definition, this fracture has
some degree of carpal displacement, which
distinguishes it from a Colles or Smith
fracture. The palmar variety is more common
than the dorsal type
Differential diagnosis
Colle’s fracture
• Most common distal radial fracture.
• The injury is usually produced by a fall onto an outstretched
hand (FOOSH) mechanism with the wrist in dorsiflexion.
• The fracture is dorsally displaced and may be comminuted.
• The fracture pattern is often described as a silver or dinnerfork deformity.
• The fracture fragments are usually impacted and
comminuted along the dorsal aspect; the fracture can
extend into the epiphysis to involve the distal radiocarpal
joint or the distal radioulnar joint.
• Lateral view of the wrist demonstrates a Colles fracture
(in which there is a dorsal angulation of the fracture
fragment)
Differential diagnosis
Smith’s fracture
• An impact to the dorsum of the hand or a
hyperflexion or hypersupination injury is thought
to be the cause.
• Smith’s fracture is usually called a reverse Colles
fracture because the distal fragment is displaced
volarly.
• It is often described as a garden-spade deformity.
• The ulnar head can be displaced dorsally
• Smith’s fracture (in which there is a volar
displacement of the distal fracture fragment).
Barton’s fracture: radiographs
PA and lateral views of the wrist involve a
minimal examination, but a true lateral
projection is needed to evaluate the degree of
carpal subluxation. In 1992, Wood and
Berquist suggested that trispiral tomograms or
coronal and/or sagittal CT scans could be used
to evaluate articular congruity of the distal
radius
• Posteroanterior
radiograph of a
Barton fracture.
Note the intraarticular fracture
of the radius with
the widening of
the space between
the scaphoid and
lunate structures.
• Lateral radiograph
of a Barton
fracture. Note the
volar displacement
of the scaphoid
associated with an
intra-articular distal
radial fracture.
Barton’s fracture: treatment
Non Operative Treatment:
- many of these frxs will fail nonoperative treatment;
- manipulative reduction is same as for Colles Fracture;
- stability of reduction of dorsal Barton frx is best obtained with
wrist extension to take advantaage of intact volar carpal
ligament;
- immobilization for 6 weeks in short arm plaster cast;
Operative Treatment:
- is best treated by closed reduction, application of external
fixation, followed by percutaneous pin insertion;
- if reduction is not anatomic, fraying of the tendon at this level
may to late rupture;
- tendency to redisplace may require ORIF thru dorsal approach;