Fibrous cortical defects have been reported in 27% of pediatric patients, with the distal tibia being the most common site of pathologic fracture.15-17 Although lesions mea-suring more t
Trang 1Ankle fractures are distal tibial and
fibular fractures that occur at or
dis-tal to the level of the metaphysis
Defining the cutoff between a
pedi-atric and an adult fracture is
some-what arbitrary; the upper age limit
of 18 years is often used
Alterna-tively, pediatric fractures may be
de-fined as those that occur in
individ-uals with open physes regardless of
chronologic age
Ankle fractures account for
ap-proximately 5% of pediatric
frac-tures and 15% of physeal injuries.1-4
Such fractures occur twice as
fre-quently in boys.1-4 Peak incidence
is in the age range of 8 to 15 years
The annual incidence of ankle
frac-tures in the pediatric population is
approximately 0.1%
Ligamentous injuries in the
growing child are unusual Due to
the fact that ligaments are generally
stronger than open physes,
low-energy trauma (such as an inversion
injury) that might result in a
liga-mentous injury in an adult often
results in a physeal fracture in a skeletally immature individual
During the evaluation of children, it
is important to correlate physical and radiographic findings, because accessory ossification centers may
be misread as fractures
There are two important goals when treating children with ankle fractures: achieving a satisfactory reduction and avoiding physeal arrest so as to minimize the risks of angular deformity, early arthrosis, leg-length inequality, and joint stiff-ness The amount of physeal dam-age incurred at the time of injury is beyond the physician’s control;
however, the amount of additional damage can be minimized by limit-ing the number of reduction at-tempts (ideally, only one will be necessary) For fractures crossing the physis, open reduction and in-ternal fixation is frequently used to minimize the risk of physeal arrest
as well as to enhance articular con-gruity Understanding the anatomy
of the foot and ankle aids in the as-sessment and treatment of these fractures
Anatomy
The ankle is a true hinge joint and is stable due to its inherent articular congruity and the surrounding liga-mentous structures Because the dome of the talus is wider anteriorly than posteriorly, there is potentially more translation and rotation when the ankle is plantar-flexed There-fore, plantar-flexion places the an-kle at a higher risk for injury The medial and lateral collateral ligaments support the ankle The medial superficial deltoid ligament originates on the distal tibia and in-serts onto the talus, the calcaneus, and the navicular The deep portion
of the deltoid ligament inserts onto the talus There are three lateral lig-aments: the anterior talofibular
liga-Dr Kay is Assistant Professor of Orthopaedic Surgery, University of Southern California School of Medicine, Los Angeles, and Attending Surgeon, Childrens Hospital Los Angeles, Los Angeles, Calif Dr Matthys is Resident in Orthopaedic Surgery, University of Southern California School of Medicine Reprint requests: Dr Kay, Pediatric Ortho-paedics, Childrens Hospital Los Angeles, 4650 Sunset Boulevard, Mailstop 69, Los Angeles,
CA 90027.
Copyright 2001 by the American Academy of Orthopaedic Surgeons.
Abstract
Pediatric ankle fractures account for approximately 5% of pediatric fractures
and 15% of physeal injuries The biomechanical differences between mature
and immature bones, as well as the differing forces applied to those bones, help
explain the differences between adult and pediatric fractures The potential
complications associated with pediatric ankle fractures include those seen with
adult fractures (such as posttraumatic arthritis, stiffness, and reflex
sympathet-ic dystrophy) as well as those that result from physeal damage (including
leg-length discrepancy, angular deformity, or a combination thereof) The goals of
treatment are to achieve and maintain a satisfactory reduction and to avoid
physeal arrest A knowledge of common pediatric ankle fracture patterns and
the pitfalls associated with their evaluation and treatment will aid the clinician
in the effective management of these injuries.
J Am Acad Orthop Surg 2001;9:268-278
Robert M Kay, MD, and Gary A Matthys, MD
Trang 2ment, the calcaneofibular ligament,
and the posterior talofibular
liga-ment Three structures between the
tibia and the fibula further support
the ankle mortise: the distal
contin-uation of the interosseous
mem-brane and the anterior and posterior
inferior tibiofibular ligaments The
anterior inferior tibiofibular
liga-ment attaches to the lateral aspect of
the distal tibial epiphysis and is
important in the pathomechanics of
transitional (Tillaux and triplane)
fractures The tibiofibular
syndes-mosis is a mobile articulation that
allows fibular motion during
dorsi-flexion and plantar-dorsi-flexion
The anatomy of the distal tibial
physis has been extensively studied
The initial contour of the physis is
transverse An anteromedial
undu-lation appears within the first 2
years, which essentially separates
the physis into medial and lateral
halves This is important in
under-standing the anatomy of certain
fracture patterns Closure of the
distal tibial physis progresses from
central to medial and then lateral
over the course of approximately 18
months
The secondary ossific nucleus of the distal tibial epiphysis generally appears between the ages of 6 and 24 months The medial malleolus, which begins to ossify between 7 and 8 years of life, forms most commonly from an elongation of the main ossific nucleus of the distal tibia However,
it originates from a separate ossifica-tion center, the os subtibiale, in as many as 20% of cases and may be mistaken for a fracture.5 The distal tibial physis provides 3 to 4 mm of growth annually and contributes approximately 15% to 20% of the length of the lower extremity and 35% to 40% of tibial length Distal tibial physeal closure is generally completed by age 14 years in girls and age 16 years in boys, although there is minimal longitudinal growth
of the distal tibia after age 12 years in girls and age 14 years in boys
The ossific nucleus of the distal fibula typically begins to ossify be-tween 18 and 20 months of life, al-though ossification may be delayed until age 3 years The lateral malle-olus may also have an accessory ossification center, the os fibulare
Ogden and Lee6 have shown that
the medial and lateral malleolar accessory ossification centers are actually a portion of the cartilage anlage of the malleolus and are sep-arated from the secondary ossifica-tion center by epiphyseal cartilage
Classification
Pediatric ankle fractures can be clas-sified by using either an anatomic (radiographic) or a mechanism-of-injury scheme The Salter-Harris classification of physeal fractures (Fig 1) is the most commonly used anatomic system, because of its sim-plicity and the prognostic signifi-cance of each injury type Type I and II injuries have lower risks of physeal arrest than injuries classi-fied as types III, IV, and V Types III and IV generally require open re-duction and internal fixation to min-imize articular incongruity as well
as to decrease the risk of physeal arrest by enhancing the reduction of the physis The increased risk of growth arrest in type IV injuries stems from the fact that all levels of the physis are disrupted In type V
Figure 1 Salter-Harris classification of fractures Type I is characterized by physeal separation; type II, by a fracture line that extends
transversely through the physis and exits through the metaphysis; type III, by a fracture that traverses the physis and exits through the epiphysis; type IV, by a fracture line that passes through the epiphysis, across the physis, and out the metaphysis Type V is a crush injury
to the physis.
Trang 3injuries, the increased risk of
growth disturbance is due to the
local crush injury to the physis
Type V fractures cannot generally
be classified accurately at the time
of injury, thus precluding a correct
initial prognosis However, type V
fractures account for only 1% of
physeal injuries about the ankle
Rang added a sixth type,
compris-ing perichondral rcompris-ing injuries that
result from direct open injuries (e.g.,
those due to lawnmower accidents)
or from the trauma of surgical
dis-section.7
In 1950, Lauge-Hansen, on the
ba-sis of a series of experimental studies
and clinical observations, proposed a
classification for ankle fractures in
adults Combining the mechanistic
principles of Lauge-Hansen and the
Salter-Harris classification, Dias and
Tachdjian devised a classification
of pediatric ankle fractures using
four basic mechanisms:
supination-inversion, supination–plantar-flexion,
supination–external rotation, and
pronation/eversion–external
rota-tion.7,8 In the description of each
mechanism, the first term refers to
the position of the foot, and the
sec-ond term refers to the direction of
the applied force at the time of
in-jury Two additional fracture
pat-terns were included, the juvenile
Tillaux fracture and the triplane
frac-ture These are termed transitional
fractures to indicate their occurrence
during the time of physeal closure
Dias subsequently added a
ver-tical compression–type fracture,
which has the same implications as
a Salter-Harris V injury.7 Such a
mechanistic classification scheme
theoretically has the advantages of
being both precise and useful in
selecting the appropriate method to
reduce the fracture The fracture
type serves as a guide to the
direc-tion of force and the posidirec-tion of the
foot at the time of injury The
direc-tion of the force is usually reversed
during closed or open reduction
However, the interobserver
repro-ducibility of this classification sys-tem is low, and it is, therefore, of limited value
Diagnosis
A lower-extremity injury must ini-tially be considered in the context of the patient’s overall condition In the polytrauma patient, concomitant orthopaedic injuries are common,9
but stabilization of airway, breath-ing, and circulation always takes precedence
A careful neurovascular exami-nation of the extremity should be performed, although a precise motor and sensory examination may be difficult in a frightened child Cap-illary refill should be assessed
Pulses may not be palpable in the child who has had marked blood loss and has low or low-normal blood pressure If pulses are not palpable, a Doppler study may aid
in the assessment of arterial inflow
If the child cannot cooperate with the examination of light-touch sen-sation distal to the injury, the physi-cian may need to check whether the child responds to painful stimuli, such as needle sticks
Many pediatric ankle injuries occur in patients without injuries to other organ systems Despite this, a complete history is extremely im-portant Child abuse and pathologic lesions should be considered if the reported mechanism of injury does not appear to match the fracture type present Approximately 1% of all children are abused annually, and approximately 2 million reports
of child abuse are filed each year in the United States.10,11 The incidence
of physical abuse has been reported
as 0.5%, and 1 of every 1,000 abused children will die as a result of the inflicted trauma.12 Classic radio-graphic findings, such as corner fractures and multiple fractures in different stages of healing, may be seen in child abuse; however, isolated
fractures are seen in 50% of child abuse cases, and the fracture patterns are often unremarkable.13 Any sus-picion of child abuse warrants im-mediate referral to the local child protective services agency
Pathologic fractures may be due
to systemic or local disease A care-ful patient and family history may alert the orthopaedist to an underly-ing metabolic bone disease Sys-temic signs and symptoms or pain preceding the fracture should raise the treating physician’s index of suspicion of a pathologic fracture Bone pain is the presenting com-plaint in approximately 25% of cases
of childhood leukemia.14 Radio-graphs may demonstrate a focal le-sion Fibrous cortical defects have been reported in 27% of pediatric patients, with the distal tibia being the most common site of pathologic fracture.15-17 Although lesions mea-suring more than approximately 3.3
cm in diameter or occupying more than 50% of the diameter of a bone appear to carry an increased risk of pathologic fracture, the need for pro-phylactic treatment remains contro-versial.15,16,18,19
Three radiographic views should
be obtained in the evaluation of pediatric ankle injuries Tillaux fractures and other subtle injuries may be easily missed if only two views are obtained For some inju-ries (such as Salter-Harris I fractures), the only radiographic abnormality visible may be soft-tissue swelling adjacent to the physis or slight widening of the physis Numerous anatomic variations may be present around the ankle, and interpretation
of the radiographs must be corre-lated with the physical examination Medial accessory ossicles (ossa sub-tibiale) are found in as many as 20%
of patients and lateral ossicles (ossa fibulare) in about 1%.6 Tenderness
in these areas may indicate an acute fracture of the ossicle
Stress radiographs are rarely needed to evaluate pediatric ankle
Trang 4injuries Although some authors
have recommended stress views
for the diagnosis of nondisplaced
Salter-Harris I fractures, they are
probably unnecessary and may
result in iatrogenic physeal
dam-age Appropriate indications are to
rule out ligamentous injuries and
to differentiate an acute fracture
from an accessory ossicle
Computed tomography is a
use-ful diagnostic aid, especially for the
evaluation of intra-articular
tures, including transitional
frac-tures If there is unexpected stiffness
after treatment, magnetic resonance
(MR) imaging may be indicated to
look for intra-articular cartilaginous
fragments
A thorough evaluation can
pro-vide insight into the mechanism of
injury and can aid in planning the
reduction Urgent reduction may
be required to restore neurovascular
function or to relieve skin tenting
over a displaced fracture
Treatment of Distal
Tibial Fractures
Salter-Harris I and II Fractures
Salter-Harris I and II fractures
have a low incidence of physeal
arrest and are generally treated in
similar fashion Type I fractures
account for approximately 15% of
distal tibial physeal fractures1-3,20
and generally disrupt the physis
through the zone of hypertrophy
Salter-Harris II fractures account for
approximately 40% of distal tibial
fractures.1-3,20 In type II fractures,
the fracture line extends through
the zone of hypertrophy but then
exits through the metaphysis,
creat-ing a triangular Thurston-Holland
fragment The periosteum is
typi-cally torn on the side opposite to
the Thurston-Holland fragment and
may be interposed in the fracture
site
Salter-Harris I and II fractures
should be reduced so as to minimize
physeal injury The patient should
be well sedated or anesthetized, and reduction should be attempted only once or twice Closed reduction is used for displaced fractures (Fig 2)
Generally, reduction within a few millimeters is possible, and cast treatment for 4 to 6 weeks results in
a successful outcome Adult cadaver studies have shown that distal-third tibial fractures that heal in 10 de-grees of angulation can markedly
decrease the tibiotalar contact area and increase tibiotalar contact pres-sure21,22; however, comparable data are not available for children
If closed reduction is not success-ful, open reduction should be per-formed Failure of closed reduction
is often due to interposed soft tis-sue, such as periosteum, tendons, and neurovascular structures After removal of these impediments, the fracture can be reduced and will
Figure 2 Plain radiographs of a 13-year-old boy with a Salter-Harris II distal tibial fracture
and a Salter-Harris I fibular fracture A and B, AP and lateral preoperative films obtained
in the emergency department C and D, Films obtained 3 months after a single closed
reduction attempt.
Trang 5generally be stable Internal fixation
is rarely necessary If fixation is
re-quired for an unstable fracture and
the metaphyseal fragment is large
and accessible, a 3.5- or 4.0-mm
can-nulated lag screw parallel to the
physis is effective If the physis
must be crossed with hardware,
smooth wires should be used
The child should be followed up
for signs of healing as well as for
evidence of growth arrest after a
physeal fracture Leg-length
dis-crepancy and sagittal- or
coronal-plane deformity may be seen
clini-cally Growth disturbance lines are
common radiographic findings after
a fractured bone resumes normal
longitudinal growth These lines
should be parallel to the physis; if
they are absent or not parallel to the
physis, growth arrest has occurred
Although complete growth arrest
will result in leg-length discrepancy,
it may not necessitate intervention if
the child is nearing skeletal
matu-rity In contrast, partial arrest will
lead to a progressive angular
defor-mity in addition to the leg-length
discrepancy and generally
necessi-tates intervention Medial growth
arrest causes varus angulation,
leg-length discrepancy, and relative
fibular overgrowth with resultant
lateral impingement (Fig 3)
Com-plete distal tibial growth arrest does
not lead to angular deformity, but
relative fibular overgrowth and
lat-eral impingement are potential
con-sequences
Salter-Harris III Fractures
Salter-Harris III fractures account
for approximately 25% of distal
tib-ial fractures.1-3,20 Because these
fractures traverse the physis and
exit through the epiphysis, there is
often an intra-articular step-off, as
well as injury to the subarticular
physis These are commonly seen
with medial malleolus fractures as
well as with Tillaux fractures
Me-dial malleolus fractures frequently
have a large cartilage component,
and the fracture fragment is often much larger than the ossified por-tion that is apparent radiographi-cally
Risks following Salter-Harris III fractures are joint incongruity and growth disturbance Closed reduc-tion under sedareduc-tion may be at-tempted Open reduction and inter-nal fixation is recommended for all such fractures with more than 2 mm
of residual displacement In one series,23 growth disturbance devel-oped in only 1 of 20 patients with Salter-Harris III or IV fractures treated with open reduction and internal fixation, but 5 of 9 patients with such fractures who were treated with casting subsequently had radio-graphic evidence of a bone bridge crossing the physis
If possible, fixation devices should be placed parallel to (and avoiding) the physis Screw fixation
is preferable, but smooth wires may
be used If smooth wires are inserted parallel to the physis, the two wires should not be exactly parallel in all planes, as postoperative displace-ment may occur after such fixation
Screws or threaded wires should never be placed across an open physis Smooth pins may cross a physis if necessary for fracture fixa-tion Pins traversing physes should
be removed when the fracture becomes stable, generally within several weeks
Tillaux Fractures
Tillaux fractures are Salter-Harris III fractures of the anterolat-eral portion of the distal tibia, and result from an epiphyseal avulsion
at the site of attachment of the ante-rior infeante-rior tibiofibular ligament (Fig 4) These fractures are most commonly seen in children nearing skeletal maturity (generally 12 to 14 years old) during the approximately 18-month period during which the distal tibial physis is closing Tillaux fractures account for 3% to 5% of pediatric ankle fractures.20,24 The
anterolateral location is due to the order of closure of the distal tibial physis (initially centrally, then medi-ally, and finally laterally) Depend-ing on the severity of trauma, there may be an associated distal fibular fracture The mechanism of injury is typically supination–external rota-tion
Treatment is directed at obtain-ing and maintainobtain-ing reduction of the intra-articular surface of the dis-tal tibia Nondisplaced fractures are immobilized with a long leg cast for
4 weeks A short leg cast may be used for an additional 2 weeks if physeal tenderness is present on removal of the long leg cast Com-puted tomographic (CT) scans are used to rule out intra-articular in-congruity
Patients with displaced fractures are treated with closed reduction under sedation The mechanism of injury (supination–external rotation)
is reversed, and direct pressure may also be applied to the anterolateral fragment After reduction, plain
Figure 3 AP radiograph of a 14-year-old girl approximately 4 years after a distal tib-ial fracture complicated by medtib-ial growth arrest There is a 1.7-cm leg-length
dispari-ty and a 15-degree varus deformidispari-ty of the ankle Growth-disturbance lines (arrow) converge medially due to the medial growth arrest.
Trang 6radiographs and CT scans will
con-firm the adequacy of reduction If
the intra-articular step-off measures
2 mm or more, reduction and
inter-nal fixation is warranted
In the operating room, closed
reduction may first be attempted If
an essentially anatomic reduction
can be obtained, percutaneous
fixa-tion with cannulated screws or
wires may be used However, if
such a reduction is not possible,
open reduction should be
per-formed through an anterolateral
approach to the ankle, so that direct
visualization of the fracture
frag-ments and the intra-articular surface
can be obtained Schlesinger and
Wedge25 have described
percuta-neous manipulation of a displaced
Tillaux fracture with a Steinmann
pin followed by percutaneous
frac-ture fixation
Fracture fixation may cross the
physis in the patient with a Tillaux
fracture who is nearing skeletal
maturity, as the distal tibial physis
is in the process of closing and
crossing the physis will not,
there-fore, result in clinically important
growth arrest If the child has
con-siderable growth remaining, the
physis should not be violated with screws
Salter-Harris IV Fractures
Salter-Harris IV fractures traverse the metaphysis, physis, and
epiph-ysis to enter the ankle joint, and appear to account for as many as 25% of distal tibial fractures.1,3 Type
IV fractures are seen with triplane fractures and with shearing injuries
to the medial malleolus Patients with nondisplaced fractures should
be treated in a non-weight-bearing long leg cast for 4 weeks, which may
be followed by a short leg walking cast for another 2 weeks
If there is more than 2 mm of residual displacement, treatment is open reduction and internal fixa-tion to minimize articular incon-gruity and the risk of physeal bar formation (Fig 5) The fracture and the articular surface of the distal tibia should be visualized to ensure anatomic reduction The perichon-dral ring should not be elevated from the physis, and screw fixation should be parallel to the physis Fibular fractures accompanying Salter-Harris IV distal tibial frac-tures are most commonly Salter-Harris I and II injuries The fibular fracture is usually stable after
reduc-Tibia
Ligament
Fibula
Figure 4 A, Tillaux fracture (Adapted with permission from Weber BG, Sussenbach F:
Malleolar fractures, in Weber BG, Brunner C, Freuler F [ed]: Treatment of Fractures in
Children and Adolescents New York: Springer-Verlag, 1980.) B, As visualized from below,
the Tillaux fragment is seen to be avulsed by the anterior inferior tibiofibular ligament.
Figure 5 A, AP radiograph demonstrates a displaced Salter-Harris IV fracture of the distal
tibia and a Salter-Harris I fracture of the distal fibula B, Radiograph obtained 3 months
after open reduction and internal fixation of the tibial fracture and closed reduction of the fibular fracture demonstrates good alignment and fixation parallel to the physis The dis-tal fibular physis has closed, and the disdis-tal tibial physis is in the process of closing.
Trang 7tion of the tibial fracture If the
fib-ula remains unstable after reduction
of the tibial fracture, internal
fixa-tion is indicated, often with an
intra-medullary Kirschner wire
Triplane Fractures
Triplane fractures are Salter-Harris
IV fractures that challenge the
orthopaedist’s three-dimensional
per-ception Triplane fractures have
com-ponents in the sagittal, coronal, and
transverse planes and may be two-,
three-, or four-part fractures They
account for 5% to 7% of pediatric
ankle fractures.20,24 These fractures
are also considered transitional
frac-tures, but may occur in younger
chil-dren than Tillaux fractures do The
average age of patients with triplane
fractures is approximately 13 years,
although they have been reported in
children as young as 10.20,24,26,27
Triplane fractures involve both a
metaphyseal fragment posteriorly
and an epiphyseal fragment, which is
generally lateral Lateral triplane
frac-tures are more common than medial
triplane fractures Lateral fractures appear similar to Tillaux fractures on anteroposterior (AP) plain radio-graphs of the ankle, but can be distin-guished from them on the basis of evidence of a Salter-Harris II or IV fracture line on the lateral view
Medial triplane fractures are distin-guished from lateral triplane fractures radiographically by the more medial location of the epiphyseal and me-taphyseal fractures, as well as by the fact that the metaphyseal fracture occurs in the sagittal plane in medial triplane fractures and in the coronal plane in lateral triplane fractures
The epiphyseal fragment is usu-ally connected to the metaphyseal fragment (two-part fracture), al-though they may be separate frag-ments In two-part lateral triplane fractures, one fragment is composed
of the anterolateral and posterior portions of the epiphysis joined to the posterior metaphyseal fragment
The other part consists of the ante-romedial epiphysis connected to the remainder of the distal tibia (Fig 6)
Three-part lateral fractures differ from two-part lateral fractures in that an additional fracture line sepa-rates the anterolateral epiphyseal fragment from the fragment con-taining the posterior metaphyseal fragment and posterior epiphysis (Fig 7) The distinction between three- and four-part fractures often can be demonstrated only on CT scans Four-part fractures are com-minuted variants
As with Tillaux fractures, nondis-placed triplane fractures may be treated with immobilization in a long leg cast for 4 weeks, followed by use
of a short leg walking cast for an addi-tional 2 weeks Also as with Tillaux fractures, CT scans are imperative for assessing fracture alignment
Performed with the patient under conscious sedation, closed reduction
of two-part triplane fractures (with internal rotation of the distal frag-ment for lateral triplane fractures and with eversion for medial tri-plane fractures) may be successful Such reduction is less commonly
Figure 6 A, Two-part lateral triplane fracture One fragment is composed of the anterolateral and posterior portions of the epiphysis
joined to the posterior metaphyseal fragment The other part consists of the anteromedial epiphysis connected to the remainder of the
dis-tal tibia (Adapted with permission from Jarvis JG: Tibial triplane fractures, in Letts RM [ed]: Management of Pediatric Fractures.
Philadelphia: Churchill Livingstone, 1994, p 739.) B, Two-plane medial triplane fracture (Adapted with permission from Rockwood CA
Jr, Wilkins KE, King RE: Fractures in Children Philadelphia: JB Lippincott, 1984, p 933.)
Trang 8successful with three- or four-part
fractures Postreduction CT
scan-ning is imperative to assess the
re-duction Ertl et al27have shown that
residual intra-articular displacement
of 2 mm or more compromises
treat-ment results
Intra-articular displacement of 2
mm or more or displacement at the
level of the physis of more than 2 mm
in a child with more than 2 years of
growth remaining mandates the use
of open reduction and internal
fixa-tion Open reduction is generally
carried out through an anterolateral
approach for lateral fractures or an
anteromedial approach for medial
fractures in order to visualize the
fracture fragments and joint surface
Depending on fracture
configura-tion and surgeon preference, either
the metaphyseal or the epiphyseal
fragment may be fixed initially
Ar-ticular congruity must be restored
to maximize patient outcome
Triplane fractures can result in clinically important growth distur-bance if they occur in children with
at least 2 years of growth remaining
Growth disturbance appears to occur
in fewer than 10% of patients after triplane fractures, although Cooper-man et al26 reported this complica-tion in 3 (21%) of 14 patients If more than 2 years of growth remains, fixa-tion traversing the physis should be avoided if possible
Cannulated screw systems allow accurate hardware placement and appear to minimize incidental phys-eal damage Fixation may be neces-sary when a high-energy injury results in a comminuted fibular frac-ture that is likely to shorten (Fig 8)
Fibular fractures proximal to the physis are more common in children nearing skeletal maturity These fractures are often spiral fractures, which are not stable after reduction
of the tibia The portion of the fibula
distal to the fracture site may be reflected distally to enhance expo-sure for tibial fracture reduction Ertl et al27reported marked dete-rioration in the results of treatment
of triplane fractures at a follow-up interval of 3 to 13 years compared with the results at 1.5 to 3 years This deterioration was seen even in those patients who had undergone accurate open reduction and inter-nal fixation
Salter-Harris V Fractures
Salter-Harris V injuries account for 1% of distal tibial physeal inju-ries and involve a compressive force across the germinal layer of the phy-sis.1-3,20 Displacement of the epiphy-sis is rare If the fracture is accu-rately identified as a type V injury initially, excision of the damaged portion of the physis and placement
of a fat graft may prevent the devel-opment of growth arrest However, these fractures are generally catego-rized as type V injuries when a pa-tient is noted to have a leg-length discrepancy or angular deformity months or years after a suspected type I physeal injury The prognosis
of this injury is poor due to the sequelae of physeal arrest With late diagnosis, treatment is directed toward addressing the leg-length discrepancy or angular deformity
Treatment of Distal Fibular Fractures
Isolated Fractures
Salter-Harris I and II injuries account for approximately 90% of isolated distal fibular fractures, and frequently result from low-energy trauma An isolated Salter-Harris I fracture can be distinguished from a lateral ankle sprain by the presence
of local tenderness over the distal fibular physis rather than over the anterior talofibular, calcaneofibular, and posterior talofibular ligaments Such isolated injuries generally heal
2
3
2
3
1
1
Talus
Figure 7 A, Lateral view of a three-part lateral triplane fracture, which differs from a
two-part lateral fracture in that a coronal fracture line separates the anterolateral epiphyseal
fragment from the fragment containing the posterior epiphyseal and metaphyseal
frag-ments (1 = anterolateral epiphyseal fragment; 2 = fragment containing the posterior
metaph-yseal fragment and posterior epiphysis; 3 = tibia) B, View from below shows relationship
of the fracture components (Adapted with permission from Marmor L: An unusual
frac-ture of the tibial epiphysis Clin Orthop 1970;73:132-135.)
Trang 9well within 3 weeks in a short leg
walking cast Salter-Harris III and
IV injuries are rare and must be
distinguished from an accessory
ossification center (os fibulare)
Re-duction is rarely necessary, but
may be required for the rare distal
fibular Salter-Harris III or IV
frac-ture with marked residual
dis-placement
Avulsion of accessory
ossifica-tion centers of the distal fibula may
be symptomatic Ogden and Lee6
noted that these avulsion fractures are analogous to Salter-Harris II fractures if the accessory ossification center is considered an epiphysis
They recommended immobilization
in a short leg walking cast for 2 to 3 weeks They also reported that non-operative treatment sometimes fails and surgical treatment becomes nec-essary, although this seems to be quite rare
Fractures Combined With Distal Tibial Fractures
Fibular fractures seen in con-junction with distal tibial fractures are routinely reduced with re-duction of the tibial fracture These fibular fractures tend to be stable after reduction and rarely re-quire fixation in the skeletally im-mature individual Fixation may
be indicated for the child nearing skeletal maturity with a severely
C
Figure 8 A and B, AP and lateral
radio-graphs of a 90-kg 14-year-old boy reveal a two-part lateral triplane fracture and a comminuted distal fibular fracture Arrows indicate the apparent gap between
the fracture fragments C, CT scan shows
the marked external rotation of the lateral portion of the distal tibia, the marked frac-ture displacement, and the mild
comminu-tion of the medial tibia D and E,
Radio-graphs obtained 1 year after operative treatment demonstrate healed fractures in
a satisfactory position and closure of the distal tibial and distal fibular physes.
Trang 10comminuted fracture at risk for
shortening
Complications of Ankle
Fractures
Growth Arrest
Growth arrest is most common
after distal tibial Salter-Harris III and
IV fractures, and often leads to both
a leg-length discrepancy and an
angular deformity of the ankle
Leg-length discrepancy is related to the
child’s age at the time of fracture and
usually is between 1 and 2 cm.23,28
In one series, growth disturbance
developed in only 1 (5%) of 20
patients with Salter-Harris III or IV
fractures treated with accurate open
reduction and internal fixation, in
contrast to 5 (56%) of 9 patients with
similar fractures treated with closed
reduction.23 If the growth arrest is
detected before considerable
angu-lar deformity develops, the main
issue is the ultimate leg-length
dis-crepancy predicted If considerable
angular deformity is already
pre-sent at the time the physeal arrest is
detected, an osteotomy is the only
possible solution to correct the
me-chanical axis The amount of
angu-lar deformity that is acceptable has
not been established, although
an-gulation in distal tibial fractures has
been shown to markedly increase
contact pressure in the ankle joint in
adult cadaver studies.21,22
For children nearing skeletal
ma-turity, epiphysiodesis of the part of
the physis that remains open may
be all that is necessary if no angular
deformity is present For example,
because the distal tibia grows only 3
to 4 mm annually as the child nears
skeletal maturity, a child with 2
years of growth remaining will lose
less than 1 cm of leg length if a
com-plete arrest occurs Epiphysiodesis
of the distal fibula should be
consid-ered to prevent fibular overgrowth
and lateral impingement In
youn-ger children, physeal bar resection
may be considered if the bar encom-passes less than 50% of the physis as delineated on MR images
Osteoarthritis
Osteoarthritis may result from chondral damage at the time of in-jury or articular incongruity at the time of fracture healing In a long-term study an average of 27 years after injury, 12% of all 71 patients with physeal ankle fractures had radiographic evidence of osteoar-thritis, compared with 29% of pa-tients with a Salter-Harris III or IV fracture.28 In the same study, the late results correlated most strongly with the initial fracture displace-ment and with the residual dis-placement after reduction In a study of triplane fractures, Ertl et
al27concluded that anatomic reduc-tion of intra-articular fractures may reduce the incidence of late arthritis
Ankle Stiffness
Posttraumatic ankle stiffness is likely due to a combination of inju-ries to both the soft tissues and the osseous structures Caterini et al28
reported this complication in 4 (6%)
of 71 patients at long-term
follow-up and found that it correlated with radiographic evidence of osteoar-thritis in 3 of the 4 patients with ankle stiffness Physical therapy should be used to treat all patients with severe injuries as well as to treat those patients with marked residual ankle stiffness 1 month after cast removal
Reflex Sympathetic Dystrophy
As in adults, reflex sympathetic dystrophy (RSD) in children is char-acterized by pain out of proportion
to an injury in conjunction with signs of autonomic dysfunction of the injured extremity The condition
is more common in lower-extremity injuries and often follows trivial trauma In the largest reported series of RSD in children, the au-thors noted a 1-year delay from the
onset of symptoms to the diagno-sis.29 In that series, 84% of the pa-tients were girls
The most important aspect of treatment of RSD is prompt recog-nition Potential components of treatment include physical therapy, psychological counseling, drug therapy, and sympathetic blockade Wilder et al29reported that, at a me-dian follow-up interval of 3 years,
38 (54%) of 70 patients with RSD had persistent symptoms despite aggressive treatment
Summary
Pediatric ankle fractures are com-mon injuries Appropriate treat-ment is guided by the accurate assessment of the injury itself, as well as its potential ramifications The goals of treatment are a satisfac-tory reduction and the avoidance of growth disturbance Closed reduc-tion of physeal injuries should be carried out a minimal number of times (preferably once) and should
be done only in well-sedated or anesthetized patients It is impor-tant to recognize that even injuries that appear benign initially may have poor long-term results
Closed treatment and casting of Salter-Harris I and II distal tibial fractures generally yield good re-sults Salter-Harris III and IV distal tibial fractures have high incidences
of articular incongruity, physeal arrest, and late arthritis if treated by closed means, and require open reduction and internal fixation if there is more than 2 mm of residual displacement Computed tomo-graphic scans are more useful in the evaluation of residual displacement than plain radiographs, which are often out of plane with the fracture Salter-Harris V injuries account for only 1% of distal tibial fractures, and are often recognized only retro-spectively Growth disturbance lines should be carefully monitored,