Res-toration of normal stability and mo-tion in patients with unstable ankle fractures through open anatomic re-duction and internal fixation yields better long-term outcomes than does c
Trang 1James D Michelson, MD
Abstract
Ankle fractures are common
muscu-loskeletal injuries, and their incidence
and severity are increasing among
people older than 65 years.1
Manage-ment of ankle fractures is governed
by the character of the fracture in the
context of associated medical
condi-tions, such as diabetes or severe
os-teoporosis.2,3Although surgical
pro-cedures for managing ankle fractures
are well established, decision making
is critical so that patients with stable
fractures are not unnecessarily
ex-posed to the risks of surgery
Ankle Anatomy and
Biomechanics
The ankle joint consists of the talus,
which articulates with the malleoli
me-dially and laterally and the tibial
plafond superiorly In a neutral
po-sition, approximately 90% of the load
is transmitted through the tibial
plafond, with the remaining load borne
by the lateral talofibular articulation
The talus in cross section is a trape-zoid that is wider anteriorly than pos-teriorly Consequently, when the ta-lus dorsiflexes, the increased talar width introduced into the ankle mor-tise forces the fibula to translate lat-erally and rotate externally Plantar-flexion is associated with internal rotation of the talus relative to the tibia because of the deltoid ligament, which acts as a checkrein on the talus
The ankle is considered stable when, under physiologic loading, the talus moves in a normal pattern through the full range of motion
Therefore, any ankle injury that re-sults in a stable mechanical configu-ration can potentially be treated non-surgically because biomechanically normal function is not compro-mised.4In contrast, an ankle is con-sidered unstable when the loss of nor-mal constraints around the ankle permits the talus to move in a non-physiologic pattern.4Under such cir-cumstances, the dynamic joint surface contact area within the ankle is
dimin-ished, which predisposes to articular cartilage damage and premature de-generation Measurements of contact area over the entire dynamic range of motion more accurately reflect altered three-dimensional motion4,5than do static measures of contact area ob-tained at a single gait position Res-toration of normal stability and mo-tion in patients with unstable ankle fractures through open anatomic re-duction and internal fixation yields better long-term outcomes than does closed treatment, which may not ad-equately reconstitute either the ana-tomic constraints or the motion.6
Determination of Ankle Instability
Defining the relationship between specific injury patterns and ankle in-stability has been the focus of much clinical and basic science research in the last decade Although some early
Dr Michelson is Professor, Orthopaedic Surgery, and Director, Clinical Informatics, George Wash-ington University Hospital, George WashWash-ington University Hospital Medical Center Medical Ed-ucation and Simulation Center, Washington, DC Reprint requests: Dr Michelson, GWUMC Med-ical Education and Simulation Center, Room 6200,
900 23rd Street NW, Washington, DC 20037 Neither Dr Michelson nor the department with which he is affiliated has received anything of
val-ue from or owns stock in a commercial company
or institution related directly or indirectly to the subject of this article.
Copyright 2003 by the American Academy of Orthopaedic Surgeons.
Ankle fractures are among the most common skeletal injuries; selection of an
op-timal management method depends on ankle stability Stable fractures (eg, isolated
lateral malleolar) generally are managed nonsurgically; unstable fractures (eg,
bi-malleolar, bimalleolar equivalent) usually are managed with open reduction and
in-ternal fixation Stress radiographs may aid in the management of incomplete
del-toid injury in which there is medial swelling and tenderness without radiographic
talar shift A posterior malleolar fracture should be reduced and stabilized if it
com-prises >30% of the articular surface and remains displaced after fibular
stabiliza-tion Ankle fractures with syndesmotic injury have additional tibiofibular
instabil-ity that can be controlled by screw fixation However, the choice between metal and
bioabsorbable screws, screw size, number of cortices fixed, and indications for screw
removal remain controversial Conditions such as diabetes or advanced age are no
longer contraindications to usual management recommendations.
J Am Acad Orthop Surg 2003;11:403-412
Trang 2work suggested that the lateral
mal-leolus was the key to ankle stability,
recent investigations have
conclusive-ly demonstrated that it is not.4,7The
primary stabilizer of the ankle under
physiologic loading is the deltoid
lig-ament, with contributions from both
its deep and superficial components
If the deltoid is rendered incompetent
by either direct rupture or medial
malleolar fracture, the motion of the
talus is markedly changed During
plantarflexion, the talus externally
ro-tates from underneath the tibial
plafond, which is the reverse of its
normal pattern of movement
Stabi-lization of the fibula only partially
corrects this abnormal motion
Addi-tionally, reduction of the fibula can be
anatomically accurate only if the
ta-lus is precisely located in the mortise
at the time of reduction In that
sit-uation, the deltoid is at its resting
length during healing, which
ulti-mately restores the biomechanical
function of the deltoid In the absence
of medial injury, fibular osteotomy or
fracture does not result in abnormal
motion; the talus cannot become
nonanatomic within the mortise
un-less the medial structures are
rup-tured or fracrup-tured Completely
re-moving the fibula will not result in
any talar displacement with respect
to the tibia Therefore, if the talus is
not anatomically located in the
mor-tise, the medial structures must be
compromised Observation of such a
displaced talus is de facto evidence
of an unstable ankle injury
Numerous short- and long-term
clinical studies have borne out this
re-lationship between specific injury
pat-terns and expected clinical results In
a study of nonsurgically treated
iso-lated lateral malleolar fractures
fol-lowed for a mean of 20 years (range,
16 to 25 years), Kristensen and Hansen8
found good clinical results in 89 of 94
patients (95%), with no cases ultimately
requiring salvage surgery for
posttrau-matic arthritis In a comparison
be-tween surgical and nonsurgical
treat-ment in patients with isolated lateral
malleolar fractures, Yde and Kris-tensen9found no clinical advantages
to surgical intervention In another study of nonsurgically treated
isolat-ed lateral malleolar fractures with a mean follow-up of 29 years, 48 of 49 patients (98%) had clinically satisfac-tory outcomes, which was thought to
be equivalent to that expected with surgical intervention.10In a study of
82 isolated lateral malleolar fractures
in which radiographs were scruti-nized to detect any evidence of sub-sequent fibular or talar displacement after the initial injury, none showed any measurable shift in either the ta-lus or fibula, and none required de-layed surgical intervention for sub-sequent evidence of instability.11
No studies have demonstrated im-proved clinical results in the treat-ment of isolated lateral malleolar frac-tures by surgical methods compared with nonsurgical management In contrast, studies in which the sever-ity of injury has been clearly strati-fied have consistently demonstrated that bimalleolar injuries have supe-rior outcomes with surgical reduction and stabilization The same authors who showed the advantages of non-surgical management for isolated lateral malleolar fractures reported re-sults of a companion study of bimal-leolar fractures in which surgical reduction and stabilization was asso-ciated with improved results com-pared with nonoperative treatment.12
Phillips et al6 demonstrated similar findings in a randomized prospective study of 71 patients They found that nonsurgical methods did not reliably achieve and maintain anatomic re-duction of bimalleolar fractures, which is why such management yielded satisfactory results in only 60% to 65% of patients However, sur-gically achieved reduction was al-most always possible and was asso-ciated with 90% good or excellent clinical results in short-term (3 years) follow-up.6Because the instability of
a combined deltoid ligament rupture and fibular fracture is equivalent to
a bimalleolar fracture, the results of treatment of these so-called bimalle-olar equivalent injuries also are op-timized by surgical reduction and in-ternal fixation
Radiographic Evaluation
Classification schemes have been de-veloped to place frequently occurring fracture patterns into groups corre-sponding to the critical components
of ankle stability The Lauge-Hansen system was devised as a way to un-derstand the injury mechanism, thereby guiding closed reduction by precise reversal of the injury mech-anism.13The initial word of the clas-sification (eg, supination, pronation) denotes the position of the foot at the time of injury; the following phrase (eg, external rotation) denotes the di-rection of the deforming force Rota-tional injury patterns are separated into stages I to IV; translational
inju-ry patterns are I or II The more se-vere the degree of injury, the higher the stage number (Fig 1) The most common injury pattern is supination-external rotation, which accounts for
up to 85% of all ankle fractures.14
The Weber/AO classification sys-tem was developed to guide surgical treatment of ankle fractures.15 Be-cause it was developed when the fib-ula was thought to be the primary sta-bilizer of the ankle, it relies mostly on the level of the fibular fracture (Fig 2) Unfortunately, Weber type B, which accounts for most ankle frac-tures, does not constitute a homoge-neous group; fractures with medial injury benefit from surgical interven-tion, whereas isolated lateral fractures
do not Subsequent iterations of this classification scheme have explicitly included subcategories to denote the presence of medial injury,16resulting
in a system as complex as the orig-inal Lauge-Hansen classification Discussion of the merits of a clas-sification system must explicitly ad-dress its reproducibility, reliability,
Trang 3and ability to provide an injury
prog-nosis Because of the complexity of
the Lauge-Hansen classification
sys-tem, several studies have
demonstrat-ed poor interobserver and
intraob-server reliability and reproducibility,
although results with the somewhat
simpler Weber system are no
bet-ter.17In addition, these classifications
have limited prognostic usefulness
because of the uncertain link they
es-tablish between specific fracture
pat-terns and associated soft-tissue
inju-ries (eg, deltoid ligament) and
because of the inherent limitations of
plain radiography of ankle
frac-tures.18
Radiographs are two-dimensional
representations of the
three-dimen-sional talar external rotation
instabil-ity pattern of unstable ankle fractures
This incomplete view has led to the
misconception that lateral translation
causes instability of the talus,
where-as anterolateral rotation is the actual
cause of instability The distal fragment
of the fibular fracture also was thought
to be externally rotated; however, pro-spective studies using computed to-mography (CT) have proved that the distal fibular fragment is
anatomical-ly aligned to the talus.18,19The appar-ent distal fibular external rotation is actually internal rotation of the prox-imal fibular shaft relative to the
tib-ia, which is of no consequence to the mechanical behavior of the ankle (Fig
3) Therefore, surgical criteria based
on so-called distal fibular displacement should be skeptically viewed because they are based on what amounts to
an optical illusion
Another confounding factor in plain radiography is the lack of stan-dardization for magnification, which makes the critical measurement of displacements unreliable The most reliable criterion for instability is lat-eral talar displacement relative to the tibia This displacement is best deter-mined by the presence of a lateral talar shift on the anteroposterior or mortise view A lateral talar shift is defined as a medial clear space
larg-er than the suplarg-erior clear space This assessment is internally controlled for magnification (Fig 4) Although frac-ture classification is equally good with either two or three views of the ankle, three views probably afford greater sensitivity for fracture detec-tion than two (eg, anteroposterior and lateral, mortise and lateral).20
Management
Isolated Lateral Fractures
Most ankle fractures are stable iso-lated lateral malleolar injuries The absolute criterion for diagnosing an isolated lateral malleolar fracture is the radiographic display of a fibular fracture without either medial mal-leolar fracture or disruption of the mortise (as defined by equal medial and superior clear spaces radiograph-ically) and without medial ankle ten-derness or swelling on physical ex-amination Assuming that the sensory examination is intact, the absence of medial tenderness rules out an acute deltoid ligament tear or medial
mal-Figure 1 Transaxial diagrammatic view of
the Lauge-Hansen supination-external
rota-tion injury Stage of injury increases from I
to IV as the injury progresses in an external
rotation (arrow) starting at the anterolateral
ankle (disruption of the anterior-inferior
tib-iofibular ligament) Stage II constitutes a
sta-ble isolated lateral malleolar fracture, while
stage IV is an unstable injury that involves
combined lateral fracture and medial
dam-age (either fracture or deltoid rupture).
AITFL = anterior-inferior tibiofibular
liga-ment; PITFL = posterior-inferior tibiofibular
ligament.
Figure 2 Weber/AO fractures The staging is completely determined by the level of fibular fracture Type A occurs below the plafond, whereas type C starts above the plafond.
Trang 4leolar fracture As noted, long-term
follow-up studies have shown that
stable isolated lateral malleolar
in-juries can be effectively managed
nonsurgically.8-10Additionally, the au-thors of a study designed to specif-ically examine the reliability of the ra-diographic and clinical diagnosis of these injuries found no late adverse sequelae related to delayed displace-ment and no need for subsequent sur-gery.11The immobilization should be designed to protect the ankle from fur-ther injury; a short leg walking cast,
a walking prefabricated cast boot, and
a high-top tennis shoe all have shown similar satisfactory results.21Surgical management of isolated lateral mal-leolar fractures carries a 1% to 3%
chance of serious wound complica-tions or infection and, on average, re-sults in greater long-term swelling about the ankle.22
Bimalleolar and Bimalleolar Equivalent Fractures
Bimalleolar ankle fractures are typ-ically managed with open anatomic reduction and internal fixation Al-though closed reduction can yield sat-isfactory results in up to 65% of cases,
it is generally reserved for patients with severe medical problems that preclude surgery.3,6Bimalleolar fractures that
are initially dislocated or markedly dis-placed should undergo closed reduc-tion and splinting at initial presen-tation to diminish swelling and associated soft-tissue damage Al-though some advocate immediate sur-gical intervention before the onset of swelling, it may be safer to allow the initial swelling to recede first.23 Sur-gical management consists of reduc-tion and stabilizareduc-tion of both the lat-eral and medial malleoli The latlat-eral malleolus generally is reduced and plated first, followed by reduction and stabilization of the medial malleolus using a combination of interfragmen-tary screws and Kirschner wires Dif-ficulty with the fibular reduction gen-erally occurs because of the medial malleolar fragment blocking talar re-duction In this circumstance, the me-dial malleolar fragment should be re-duced and stabilized before the fibula
is plated
For bimalleolar equivalent frac-tures, in which the deltoid is ruptured and the lateral malleolus is fractured, routine repair of the deltoid does not seem to improve clinical results and may lead to a worse long-term
out-Figure 3 A, Mortise view radiograph showing rotational malalignment between the proximal and distal fibular segments B, Transaxial
CT scan proximal to the fracture The space between the tibia (TI) and fibula should be even from anterior to posterior Here, the tibiofibular
space is larger posteriorly than anteriorly, indicating internal rotation of the distal fibular fragment (DF) relative to the tibia C, Transaxial
CT scan through the distal talofibular articulation at the ankle joint shows the distal fibular fragment is anatomic relative to the talus (TA).
Figure 4 Mortise view radiograph showing
increased medial talomalleolar clear space
rel-ative to the superior talotibial space,
indic-ative of an unstable ankle fracture.
Trang 5come.24,25Although the medial
struc-tures are the primary stabilizers of the
ankle, the combination of lateral
mal-leolar reconstruction and either
cast-ing or braccast-ing provides enough
sta-bility while the deltoid is healing to
protect the mechanical integrity of the
ankle Medial exploration should be
undertaken only if the talus does not
reduce anatomically beneath the
plafond, in which case a medial
ar-throtomy is made to extricate the
in-carcerated deltoid ligament that is
blocking reduction of the talus to the
medial malleolus
The most difficult clinical
presen-tation is lateral fracture with medial
deltoid tenderness In the presence of
any radiographic lateral talar shift,
the ankle should be presumed to be
unstable and managed accordingly
In the presence of tenderness but the
absence of a talar shift, either
surgi-cal or nonsurgisurgi-cal management may
be appropriate A recent study has
suggested that a gravity stress view
(ie, anteroposterior radiograph taken
with the leg horizontal [medial side
up] without ankle support) (Fig 5)
may be useful in detecting complete
deltoid ruptures in the absence of a
talar shift on conventional views.26
In-creased talar tilt (≥15°) or talar shift
(≥2 mm) occurred only when both
su-perficial and deep divisions of the deltoid were ruptured The most common variants of the gravity stress view include a valgus stress view to evaluate the deltoid, and the external rotation stress view, in which the foot
is externally rotated under the tibia while a mortise radiograph is taken
Although widely practiced, the inter-pretation and reliability of these views has not yet been studied
Trimalleolar Fractures
The posterior plafond component,
or posterior malleolus, is a postero-lateral avulsion fracture resulting from the pull of the posterior-inferior tibiofibular ligament, which also is at-tached inferiorly to the distal fibular fracture fragment If the posterior malleolar fragment includes >25% to 30% of the articular surface of the plafond and remains displaced >2
mm after lateral malleolar reduction, the tibiotalar joint is rendered unstable.27-29Fortunately, most such fractures reduce spontaneously after the fibular fracture is reduced The need for separate reduction and fix-ation of a posterior malleolar fracture
is determined from intraoperative, not preoperative, radiographs Poste-rior malleolar fractures that remain displaced >2 mm after fibular
reduc-tion and plating should be reduced and stabilized if they constitute >30%
of the articular surface on a lateral ra-diograph.27 The posterior fracture fragment usually can be reduced by digital pressure, typically through the lateral incision It is then stabilized by placing a lag screw from either ante-rior to posteante-rior (through a separate anterior stab incision) or the reverse
Syndesmotic Injuries
Syndesmotic injuries constitute a special subgroup of fracture in which the fibular fracture is above the level
of the tibial plafond and is
associat-ed with disruption of the
syndesmot-ic ligament between the plafond and the level of fibular fracture If the fib-ula is anatomically reduced to the
tib-ia, a syndesmotic screw is not re-quired for ankle stability as long as the deltoid is intact and the medial malleolus is either intact or
surgical-ly stabilized.30,31 In a bimalleolar equivalent injury, in which it is not possible to reestablish medial integ-rity, a syndesmotic screw should be placed whenever the fibular fracture
is≥3.5 cm above the plafond.30The deep deltoid, which usually is rup-tured in medial malleolar fractures,
is generally incompetent after stabi-lization of the medial malleolar
frag-Figure 5 A, Optimal positioning to obtain the gravity stress view B, Gravity stress view of the contralateral normal ankle C, Gravity stress
view of the injured ankle Note the widened medial clear space compared with the contralateral normal ankle.
Trang 6ment (to which the superficial deltoid
is attached) Although this
combina-tion of medial injury and repair was
not tested by Boden et al,30a
prospec-tive clinical study using their criteria
in 21 patients with syndesmotic
in-juries showed good results in the 18
patients who did not undergo
syn-desmotic fixation.32For bimalleolar
equivalent injuries with the fracture
<3.5 cm above the plafond, as well as
any syndesmotic injury in which
me-dial integrity is restored, some
inves-tigators have advocated placement of
a syndesmotic screw if the fibula is
unstable on intraoperative manual
examination The most common
in-traoperative maneuver for
determin-ing syndesmotic stability after fibula
fixation is the Cotton test, in which a
towel clamp or bone clamp is used
to place a direct lateral pulling stress
on the fibula The instability test is
positive when the fibula can be
lat-erally translated more than 1 cm In
addition, intraoperative fluoroscopy
during this maneuver may
demon-strate an increase of tibiofibular
sep-aration, which also would indicate significant syndesmotic instability
Because no standardized intraoper-ative tests for syndesmotic integrity have been validated with follow-up clinical studies, this is an area of con-troversy
An absolute requirement for use of
a syndesmotic screw, regardless of other considerations, is persistent widening of the syndesmosis on in-traoperative radiographs The syn-desmosis should be reduced using an external clamp and stabilized by stan-dard techniques
Several studies address fixation in syndesmotic injuries.31 The usual method is with one or two screws (3.5
or 4.5 mm) placed parallel to the tib-ial plafond, traversing the tibiofibu-lar joint between 1 and 2 cm above the plafond The major controversies
in this treatment regimen concern the number of screws used, screw size, number of cortices engaged by the screws (three or four), material used for the screws (metal or reabsorbable), activity status after surgery, and need
for subsequent hardware removal In general, the ankle should be held in full dorsiflexion while the screw is placed to prevent overtightening of the syndesmosis, which would limit ankle dorsiflexion A recent study raised some doubt about this con-cept,33but the nature of the experi-mental technique made its applicabil-ity to normal ankle function hard to assess An earlier laboratory investi-gation34that demonstrated adverse mechanical consequences of syndes-motic overtightening remains the most clinically applicable study of this issue
Occult Pilon Fractures
In the context of a high-energy in-jury, such as a motor vehicle accident,
a seemingly routine trimalleolar an-kle fracture actually may be a pilon fracture with a posterolateral com-pression fragment (Fig 6) This most commonly occurs in fracture-dis-locations Suspicion should be
elicit-ed when the lateral plafond has a val-gus alignment A less common but
Figure 6 A,Anteroposterior radiograph made at initial injury of an open ankle fracture dislocation Note the dissociation of the articular
surface from the rest of the tibia and the comminution of the fibula B, Immediate postoperative radiograph The posterolateral plafond
surface is not visible The loss of the posterolateral quadrant of the tibial plafond was not noticed at the time of injury and was stabilized with routine ankle fracture stabilization methods The medial malleolus is incompletely reduced, and the fibula may still be short This also was a consequence of the complexity of the injury and likely would have contributed to a poor long-term result had not the plafond injury
been so profound C, Immediate postoperative transaxial CT scan at the level of the plafond indicates loss of the lateral 25% of the tibial articular surface D, Anteroposterior radiograph made 6 weeks postoperative demonstrating posterolateral subluxation of the talus into the
tibial plafond defect from the pilon fracture The only surgical salvage option is arthrodesis.
Trang 7similar injury is encountered with
supination-adduction fractures, in
which the talus impacts the medial
plafond In such fractures, the plafond
assumes a varus position that should
elicit suspicion of a significant
intra-articular component of the injury
Confirmation of the pilon
configura-tion is by CT Managing such an
in-jury with standard ankle fracture
sur-gical techniques will result in an
unstable, valgus ankle Regardless of
treatment, the patient should be
fore-warned that the articular damage
from the initial impaction injury may
lead to rapid joint degeneration
Alternative Surgical
Techniques
Rather than using standard lateral
plating of the fibula, a one-third
tu-bular plate can be placed as an
an-tiglide device in the posterolateral
po-sition.35 Minimal contouring is
required, and all of the screws can be
bicortical because there is no risk of
intra-articular protrusion This tech-nique is very useful in patients with poor bone stock or in whom there is significant comminution.35Also, the use of multiple interfragmentary screws without a plate has been ad-vocated, but that construct has less ro-tational stability than does a standard plating technique and therefore may fail catastrophically (Fig 7) Finally, when there is a relatively small me-dial malleolar fragment (at risk of fur-ther comminution by placement of screws), stabilization can be achieved
by tension band technique
Absorbable implants (eg, pins, screws) also have been investigated for use in stabilizing ankle fractures, primarily to avoid the need for sub-sequent surgery to remove the hard-ware There are two main polymer formulations used clinically, polygly-colic acid (PGA) and polylactic acid (PLA) Both ultimately degrade into water and carbon dioxide, with PLA resorbing approximately one third as fast as PGA.36Although both have been shown to have sufficient
strength for clinical use in ankle frac-tures,36,37PGA implants have been as-sociated with notable inflammatory response in as many as 50% of pa-tients.37This has led investigators to recommend against the use of PGA implants in ankle fractures Prelim-inary results with PLA implants have been more encouraging, with little or
no inflammatory response noted in short-term follow-up.36
Postoperative Management
Postoperative management usually consists of initial splinting in neutral position followed by casting with progressive weight bearing and range
of motion Protected weight bearing may be started immediately in pa-tients in whom stable medial and lat-eral fixation has been achieved.38 Al-though there are theoretic advantages
to early mobilization in patients with ankle fractures, most studies have found minimal benefit associated with starting either weight bearing or
Figure 7 A supination-external rotation injury in a patient with no additional risk factors A, Mortise view postoperative radiograph show-ing multiple interfragmentary screws used for stabilization The patient was immobilized non–weight-bearshow-ing after surgery B, Mortise view radiograph 6 weeks after surgery showing early loss of fixation with rotational displacement of the fibula C, Anteroposterior radiograph
12 weeks after surgery The displacement of the fibula has increased and is accompanied by subtle lateral displacement of the talus.
D,Anteroposterior radiograph 18 months after surgery showing complete disorganization of the ankle architecture The patient was sub-sequently salvaged with an ankle fusion.
Trang 8motion in the first few weeks after
surgery.38-41 However, these studies
also have demonstrated the safety of
instituting such programs, which
gives the surgeon a great deal of
lat-itude in determining the
postopera-tive regimen for each individual
pa-tient
Arthroscopy
Ankle fractures can be accompanied
by occult osteochondral injury to the
talus In one prospective study,4231
of 63 patients (49%) undergoing
sur-gical treatment of displaced ankle
fractures exhibited cartilage damage
to the talar dome when a specific
ex-ploration was done The authors were
able to link such damage to poorer
clinical outcomes a mean of 25
months after treatment, but their
study suffered from a <50%
follow-up rate (25/63) Thordarson et al43
ex-tended this finding with a
prospec-tive randomized study of 19 patients
at a mean follow-up of 21 months
af-ter ankle fracture surgery Control
pa-tients underwent standard fracture
surgery; patients in the experimental
group also had arthroscopy at the
time of fracture surgery, with
dé-bridement done as needed The
ar-throscopy group demonstrated
osteo-chondral injuries in eight of nine
ankles, with one having débridement
of a small fragment The clinical
out-come, measured with the Medical
Outcomes Study 36-Item Short Form
(SF-36) and Musculoskeletal
Out-comes Data Evaluation and
Manage-ment System (MODEMS), was no
dif-ferent between the arthroscopy and
control patients.43Hintermann et al42
arthroscopically examined 288
con-secutive patients with ankle fracture
at the time of fracture surgery They
found talar chondral injuries in 69%
of patients (200/288), with higher
rates in Weber type C than Weber
type B fractures Débridement was
done in 14% (41/288) and pinning of
osteochondral fragments done in 2%
(6/288) The arthroscopic complica-tion rate was 6% (18/288); the authors had no control group for comparison
Based on these studies, routine ar-throscopy of ankle fractures does not seem to be warranted because it does not alter treatment outcome, despite the enhanced appreciation of associ-ated chondral injuries it provides
Ankle arthroscopy for persistent pain after otherwise successful frac-ture healing also has been
investigat-ed Under these circumstances, ar-throscopy for well-localized anterior impingement can be helpful for as many as 75% of patients, while sur-gery for ill-defined symptoms and pain is unlikely to be beneficial.44,45
Intercurrent Medical Considerations
Ankle fractures in diabetics have been a source of concern because of the higher rates of complications
Although surgical infection and wound dehiscence rates are greater
in diabetic than nondiabetic pa-tients, attempts to maintain a closed reduction in unstable fractures is as-sociated with a very high rate of skin breakdown and infection.2,3 This is because of the high contact pres-sures between the skin and cast re-quired to maintain the reduction
Unstable fractures, in which closed reduction is difficult to achieve and maintain, probably should be man-aged surgically to afford greater con-trol over the fracture and may even result in a lower overall complica-tion rate.2,3To minimize the risk of fixation failure and Charcot degen-eration in diabetic patients, the post-operative regimen of progressive weight bearing should be delayed until there is radiographic evidence
of healing
Ankle fractures are the fourth most common fracture in those older than
65 years;1most are the result of
sig-nificant trauma.46Early reports sug-gested that such patients had increased rates of surgical complications, lead-ing some authors to recommend non-surgical management for all ankle frac-tures in patients older than 50 years However, more recent studies have not demonstrated any age-related risks
to surgery beyond those posed by
oth-er comorbidities.47Therefore, the cri-teria for surgery should not be differ-ent for elderly patidiffer-ents than for younger individuals The primary sur-gical concern in people older than 65 years is the increased prevalence of osteoporosis, which may necessitate the use of alternative fixation strat-egies, such as posterolateral fibular an-tiglide plating.35
Summary
Management of ankle fractures is de-termined by the assessment of their mechanical stability Although cur-rent radiographic classifications pro-vide uncertain guidance in determin-ing ankle stability, the most reliable criterion for instability is the radio-graphic presence of lateral talar shift (ie, increased medial clear space rel-ative to the superior tibiotalar clear space) Stable ankle fractures (eg, iso-lated lateral malleolar) are satisfacto-rily treated by closed methods, whereas unstable fractures (eg, bimal-leolar, trimalleolar) have superior clinical outcomes with surgical reduc-tion and stabilizareduc-tion The appropri-ate role for routine arthroscopy to manage unstable injuries before sta-bilization, and the use of biodegrad-able implants for stabilization, are both under continuing investigation, with the benefits of either unproven
at present The presence of intercur-rent medical conditions, such as di-abetes and advanced age, is not a con-traindication to the usual treatment recommendations because surgery can now be relatively safely done in these patients
Trang 91 Barrett JA, Baron JA, Karagas MR,
Beach ML: Fracture risk in the U.S.
Medicare population J Clin Epidemiol
1999;52:243-249.
2 Flynn JM, Rodriguez-del Río F, Pizá PA:
Closed ankle fractures in the diabetic
pa-tient Foot Ankle Int 2000;21:311-319.
3 Blotter RH, Connolly E, Wasan A,
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