The proximal tibia is highly sus-ceptible to both open and closed soft-tissue damage, with its antero-medial surface being at highest risk.2 Its posterior cortex is inti-mately associate
Trang 1Nonarticular proximal tibia fractures
should be distinguished from more
distal injuries Higher rates of
mal-union and increased incidences of
associated complications have made
these fractures particularly
problem-atic Accounting for approximately
5% to 11% of all tibial shaft injuries,1
they occur as a result of a variety of
mechanisms, each of which
gener-ates a distinctive injury pattern, with
individual treatment requirements
The proximal tibia is highly
sus-ceptible to both open and closed
soft-tissue damage, with its antero-medial surface being at highest risk.2 Its posterior cortex is inti-mately associated with the posterior tibial vessels; as a result, there is a high incidence of arterial injury associated with displaced fractures
As most of the muscle mass is con-centrated in the proximal region, higher rates of compartment syn-drome have also been recorded.3
Proximal tibia fractures pose sev-eral treatment challenges Because the proximal fragment is short,
Dr Bono is Chief Resident, Department of Orthopaedics, New Jersey Medical School, Newark Dr Levine is Attending Surgeon, Union Memorial Hospital, Baltimore, Md Dr Rao is Clinical Professor of Orthopaedics, New Jersey Medical School Dr Behrens is Pro-fessor and Chairman, Department of Ortho-paedics, New Jersey Medical School.
Reprint requests: Dr Bono, Department of Orthopaedics, New Jersey Medical School, MSB, Room G-574, Newark, NJ 07107 Copyright 2001 by the American Academy of Orthopaedic Surgeons.
Abstract
Nonarticular proximal-third fractures account for 5% to 11% of tibial shaft
injuries and occur as a result of a variety of mechanisms Treatment is more
challenging than for more distal fractures, and the rates of compartment
syn-drome and arterial injury are higher, especially for displaced fractures Closed
management often leads to varus malunion, especially when the fibula is
intact Closed treatment should therefore be reserved for nondisplaced or
mini-mally displaced fractures with little soft-tissue injury Plating of the proximal
tibia has become a less popular alternative because of the high incidence of
infection and fixation failure However, judicious use of lateral plates as an
adjunct to medial external fixation in comminuted fractures can be effective.
External fixation remains the most versatile method It is indicated for
frac-tures with short proximal fragments and in cases of extensive soft-tissue
injury that would preclude use of other surgical techniques Temporary
joint-spanning external fixation has a role in the initial management of certain
frac-ture patterns, particularly when accompanied by severe soft-tissue injury.
Although intramedullary nailing can lead to valgus malunion in a sizable
per-centage of patients with this injury, it can be useful for stabilizing fractures
with proximal fragments longer than 5 to 6 cm Placing the entry portal more
proximal and lateral, locking in extension, and using specific techniques, such
as blocking screws, can improve alignment after nailing Use of an algorithm
that takes into account the severity of soft-tissue injury, the length of the
frac-ture fragment, and the degree of fracfrac-ture stability allows effective decision
making among current treatment techniques.
J Am Acad Orthop Surg 2001;9:176-186
Treatment Options and Decision Making
Christopher M Bono, MD, Richard G Levine, MD, Juluru P Rao, MD, and Fred F Behrens, MD
closed reduction and immobiliza-tion affords minimal control This is reflected by the disproportionately high rate of varus malunion with closed treatment.4 Although open reduction and plate fixation is tech-nically feasible, serious soft-tissue complications can follow extensive exposure External fixation remains
a versatile option for fixation of both open and closed fractures However, pin-track infection and malunion are frequent complica-tions.5 Intramedullary nailing is used for stabilization of proximal-third fractures, but has resulted in high malunion rates.1,6,7
To address these problems, vari-ous recommendations have been offered to improve both operative and nonoperative management.4,8-14
Although each of the available treatment options has proved use-ful in selected circumstances, none
Trang 2is universally effective Proper
uti-lization of an individual technique
requires recognition of its role in the
continuum of treatment
alterna-tives Understanding the pertinent
anatomy, classification systems,
diagnostic modalities, and results
of treatment with each modality
should increase the appreciation of
the difficulty of treating a given
fracture and help to avoid the
com-plications and pitfalls of the various
treatment methods
Anatomy
The proximal tibia is intimately
re-lated to the popliteal artery, which
lies almost directly on its posterior
cortex It can be directly lacerated
by superoposterior displacement of
a distal fracture fragment or avulsed
during hyperextension injuries This
close relationship may contribute to
the high compartment pressures
recorded with proximal fractures.3
The tibial nerve, which courses
along the posterior aspect of the
knee, is also at risk with posterior
displacement of the proximal
frag-ment The common peroneal nerve
traverses from posterior to anterior
along the subcutaneous surface of
the fibular neck It may be damaged
as a result of direct impact,
pro-longed compression in a cast, or
pen-etration by an external fixation wire
The proximal tibia has muscular
compartments covering its lateral
and posterior surfaces, but is
sub-cutaneous along its anteromedial
aspect The patellar tendon, which
inserts on the tibial tubercle along
the anterolateral cortex, can
con-tribute to anterior angulation of the
proximal fragment The thin
cor-tices of the proximal metaphyseal
region condense as the bone
nar-rows distally to form a thick
diaph-yseal cortical tube The
intramed-ullary zone of the proximal aspect
is wide and ill defined, but narrows
distally to form a distinct canal
Classification
Commonly used classification and grading methods for both the frac-ture and the soft-tissue injury can be helpful in describing injuries and in recognizing particularly severe types However, their predictive values are limited,15and their inter-observer reliability is poor.16 Al-though there is no system that is specific to nonarticular proximal tibia fractures, the systems generally used for characterizing soft-tissue injury can be applied appropriately
The Tscherne system has been employed for classifying soft-tissue injuries that occur with closed frac-tures This system grades injuries from 0 (minor contusions) to III (severe closed degloving, potentially limb-threatening), and has been widely used to characterize closed soft-tissue injury in multiple studies
Fractures in the proximal tibia have proved more severe than
middle-third and distal-middle-third injuries and fre-quently are associated with high-grade soft-tissue lesions.17
The Gustilo-Anderson classifica-tion is the system most commonly used for open fracture grading Al-though limited by low interobserver reliability, it is still a useful clinical tool.16 There are five injury-severity grades, with the higher grades being associated with increased rates of in-fection, amputation, and nonunion Segmental tibial fractures, even those with an apparently small soft-tissue wound, are classified as high-grade (IIIA) injuries because there is severe underlying soft-tissue disruption This is of particular importance as proximal tibia injuries with segmen-tal fracture patterns and little appar-ent soft-tissue loss are in fact high-grade injuries
The AO classification is currently the most comprehensive system for describing tibial fracture patterns (Fig 1) This system considers
non-Type A2.1 (lateral oblique)
Type A2.1 (medial oblique)
Type A2.2 (anterior oblique)
Type A3.1 (intact wedge)
Type A3.2 (fragmented wedge)
Type A3.3 (complex comminution)
Type A2.3 (transverse)
Figure 1 The AO classification is currently the most comprehensive system for describ-ing tibial fracture patterns An advantage is that it distdescrib-inguishes between simple (type A2) and comminuted (type A3) fractures in the proximal extra-articular segment.
Trang 3articular proximal tibia fractures
separately from tibial shaft and
pla-teau fractures Furthermore, it
distin-guishes between simple (type A2)
and comminuted (type A3) fractures
of the proximal extra-articular tibia
Comminuted fractures are generally
more unstable Other factors,
in-cluding initial displacement, fracture
pattern, and severity of soft-tissue
damage, must also be considered to
develop an accurate assessment of
the fracture character; however,
those characteristics are not included
in the AO classification.18,19 Finally,
the reproducibility of the
classifica-tion of individual injuries is suspect,
as intraobserver and interobserver
reliability have not been validated
Evaluation and Diagnosis
After the initial trauma evaluation
addressing life-threatening injuries,
the orthopaedic evaluation begins
with assessment of soft-tissue
in-tegrity and the neurovascular status
of the extremity This is followed
by a systematic survey of all
associ-ated injuries Particular attention
must be paid to indicators of
sub-stantial soft-tissue injury, such as
swelling, lacerations, abrasions, and
areas of contusion
The mechanism of injury of
prox-imal tibia fractures is often impact
to a pedestrian by a motor vehicle
The extent of soft-tissue damage
associated with a tibial fracture
caused by this mechanism is often
grossly underestimated.2 Any small
puncture wound through the dermis
must be presumed to be due to an
open fracture
Compartment pressures are
higher in proximal-third fractures
than in middle- and distal-third
fractures.3 Initial pressure
measure-ments should be performed in all
cases in which a reliable physical
examination is not possible (e.g., in
unconscious, sedated, intoxicated,
or head-injured patients) Serial or
continuous measurement may be warranted if elevated pressures are clinically suspected but not above the threshold for release (i.e., ≤30
mm Hg) on initial evaluation (e.g., tense compartments) In the alert patient, excessive pain, pain with passive extension or flexion of the toes, or neurovascular compromise warrants compartment pressure measurement Only the early recog-nition and treatment of tibial com-partment syndrome will avoid mus-cle necrosis, irreversible nerve dam-age, and the resultant functional loss
Sets of orthogonal radiographs centered on the tibia and knee are the basis for fracture characteriza-tion The degree of comminution, amount of initial displacement, and fracture planes are noted, as well as the distance from the fracture to the tibial plateau and the tubercle
Fracture lines must be visualized in their entirety
In cases of hemarthrosis with radiographically questionable artic-ular involvement, a sterile knee aspi-rate can be obtained to assess the joint The presence of intra-articular fat suggests intra-articular fracture
If articular extension is suspected, further imaging must be pursued
Plateau views (with the tube angled slightly caudad) may reveal hidden fractures of the plateau or tibial spine A computed tomographic study with reconstructions best depicts intra-articular and periartic-ular fracture patterns, although they are of little value in analyzing nonarticular fracture patterns
Soft-Tissue Management
High-energy injuries typically in-volve severe soft-tissue damage
Most severe closed injuries merit observation before fixation The as-sessment of the severity of the soft-tissue injury is one of the major fac-tors in determining the optimal definitive management of a given
fracture Fracture blisters and abra-sions should be covered with non-adherent dressings, and splints should be used to provide tempo-rary stabilization Limb elevation and compressive dressings can di-minish swelling and decrease pain Healing of blood blisters and the return of skin wrinkling after mas-sive swelling are good indicators of resolution of soft-tissue trauma Open fractures require immediate irrigation and debridement of devi-talized tissue With massive skin and muscle damage, early secondary coverage procedures are frequently necessary to effect wound closure Gastrocnemius rotational flaps are useful for proximal tibia injuries, although large wounds or extensive damage may necessitate alternative flap options (i.e., soleus and free flaps)
Closed Treatment
Closed treatment of displaced frac-tures involves traction and manipu-lation of the extremity to restore an acceptable relationship between the proximal and distal fragments by correcting translation or angulation Closed management with either casting or functional bracing is inef-fective in maintaining restored length after reduction Those inju-ries that tend to shorten are, there-fore, best treated by other methods
Technique
For three-point molding to main-tain a reduction, the fracture region must have an intact periosteal sleeve, which must be placed under tension Unfortunately, the short proximal fragment is difficult to manipulate and control with these methods When casting is indicated, most authors agree that a well-molded long leg cast is most effective for the first 2 to 3 weeks.4 By including the knee in approximately 10 to 20 de-grees of flexion, rotational control in
Trang 4the cast is facilitated, although some
authors recommend less flexion to
avoid anterior angulation of the
fracture.4 All bony prominences
re-quire careful padding, with special
attention to the anterior spike of the
proximal fragment
After approximately 3 weeks, the
long leg cast can be replaced with a
hinged fracture brace constructed
of either molded plastic or plaster.4
The thigh component should extend
as far proximally as possible,
gener-ally just distal to the medial
peri-neal crease In injuries at the junction
of the proximal and middle thirds,
a longer proximal fragment may be
controlled in a patellar tendon–
bearing cast or brace Generally,
pa-tients can progress to weight
bear-ing as tolerated until callus is visible
radiographically, at which time full
weight bearing can be initiated
Clinical Results
There are few studies on closed
treatment of extra-articular proximal
tibia fractures Sarmiento et al4
doc-umented treatment of 68 patients
with nonarticular proximal tibia
fractures immobilized in a long leg
cast for an average of 3 weeks,
fol-lowed by conversion to a hinged
molded-plastic fracture brace
Ac-ceptable alignment was maintained
in 84% of 45 cases of combined
frac-tures of the tibia and fibula In cases
in which the fibula was intact, 61%
of patients had varus angulation of
more than 5 degrees at follow-up
The fibula acts as a lateral buttress,
with weight bearing leading to varus
deformity.4 Fibular osteotomy can
minimize this complication, but it
must be emphasized to the patient
that functional alignment, rather
than anatomic reduction, is the
treat-ment goal
The main advantage of closed
treatment is the avoidance of
surgi-cal risks, including postoperative
infection, tissue compromise, and
iatrogenic neurovascular injury
Successful closed management of a
proximal tibia fracture requires an experienced physician and a com-pliant patient Serial radiographs and multiple cast changes necessi-tate frequent clinic visits Early knee motion in either a patellar tendon–
bearing cast or a hinged brace can minimize knee stiffness, although long-term loss of range of motion has not been observed in most clin-ical series.4
Indications
Minimally or nondisplaced frac-tures of the proximal tibia and fibula without major soft-tissue or neuro-vascular injury are considered sta-ble and can be successfully treated
by closed methods even if the fibula
is intact Closed management of unstable fractures is possible if a re-duction can be obtained and main-tained; however, close observation
is necessary to detect the develop-ment of malaligndevelop-ment Closed treatment of an unstable fracture with an intact fibula is not recom-mended, as the rate of varus mal-union is high Although some au-thors recommend fibular osteotomy
to relieve this deforming force, these unstable injuries are best treated by operative fixation of the tibia Cast management is unsuitable for pa-tients with significant closed or open soft-tissue injuries, as these are usually unstable and the soft tis-sues require frequent monitoring
Plating
Open plating entails considerable surgical exposure to directly visual-ize and anatomically reduce the fracture This technique has led to substantial soft-tissue complication rates in some diaphyseal and proxi-mal intra-articular fractures and is a recognized risk with high-energy metaphyseal injuries.12,13,20 Although these complications have not been reported specifically for plate fixa-tion of nonarticular proximal
me-taphyseal fractures, the concepts of limiting soft-tissue dissection and decreasing the length and size of plate constructs are both applicable and prudent
Technique
Unilateral plate osteosynthesis of simple displaced extra-articular me-taphyseal fractures can be achieved with either a medial or a lateral plate A plate is effective as an anti-glide device on the side of the distal spike of an oblique fracture Better soft-tissue coverage is thought to make lateral plating safer so that lat-erally comminuted fractures can be stabilized in this manner With medial comminution, greater dam-age of the thin soft-tissue envelope generally precludes immediate open medial plating These fractures are better stabilized by other methods Fragmentation of both cortices re-quires medial and lateral buttress-ing In these situations, success has been documented with composite fixation, in which a simple external-fixator construct is used to maintain medial length while a lateral metaph-yseal plate is applied through a limi-ted anterolateral incision.13,21
Clinical Results
Bolhofner13examined the out-come of composite fixation in 41 patients with extra-articular proximal tibia fractures with varying degrees
of open and closed soft-tissue injury
In all cases, a medial external fixator was applied after closed reduction After the fracture had been stabilized with single proximal and distal Schanz pins, the metaphysis was sur-gically approached through an ante-rolateral incision Final reduction and fixation were achieved with a contoured 4.5-mm dynamic com-pression plate For additional medial stability, a third fixator pin was added in the distal fragment when necessary (Fig 2) External fixators were removed after an average of 8.4 weeks Pin-track infections occurred
Trang 5in 12% of cases, and surgical
debride-ment for deep wound infection was
required in 5% of cases Only one
malunion (6 degrees of varus
angula-tion) was reported No instance of
hardware failure was observed
In a series of 18 complex
proxi-mal tibia fractures, Gerber and
Ganz21also used lateral plating
with medial external fixation One
case of deep wound infection and
one malunion were reported There
were no pin-track infections that
required surgical intervention Ries
and Meinhard14used a similar
con-struct to treat 8 intra-articular and
metaphyseal injuries However,
they applied the lateral plate first,
followed by medial external fixation
The advantages of plating include
direct visualization and reduction of
the fracture Higher infection rates,
hardware prominence, and stress
risers after plate and screw removal
are potential disadvantages Con-struct failure, particularly in osteo-penic bone, is an important theoreti-cal limitation Lateral plating with medial comminution can lead to varus collapse if additional stability
is not provided
Indications
Plating is useful for simple un-stable (displaced) transverse or oblique fractures in the proximal metaphysis In closed fractures with minimal soft-tissue compro-mise, plates can be strategically placed to control angulation of oblique fractures For comminuted patterns, the best results with these implants have been reported with lateral plating and medial external fixation Combined medial-lateral open plating should be avoided for high-energy comminuted fractures, especially in situations with severe closed or open soft-tissue lesions
For plating techniques to be safely performed, the condition of the soft-tissue sleeve is of foremost importance
External Fixation Technique
External fixation allows satisfac-tory stabilization of most extra-articular proximal tibia fractures
Pins should be placed only through intact skin and soft tissue, and strict adherence to recommended corri-dors is advocated to avoid neuro-vascular damage Behrens and Searls22delineated a 220-degree
“safe arc” through which external fixator wires or pins may be inserted into the proximal metaphysis This arc extends from the proximal tibio-fibular joint anteriorly across the front of the tibia to the posterome-dial cortex Placement of pins out-side this safe corridor risks injury to neurovascular structures
Fractures are reduced with a combination of traction and
manip-ulation and stabilized with percuta-neously inserted pins or wires con-nected to rings and/or longitudinal struts The general principles of ex-ternal fixation, including maximal pin spread, use of large-diameter pins, and minimization of strut-to-bone distance, should be observed to maximize construct stability Bi-planar and multiBi-planar pin fixators are very useful for proximal tibia fractures, as stable fixation of short proximal fragments often necessi-tates placement of at least two pins
at the same transverse level These can be connected to two or more half-pins in the distal fragment with two or more longitudinal rods.22
For example, a delta-type construct, with medial and lateral Schanz pins
in the proximal fragment, is a com-monly used construct If there is sufficient length for placement of two longitudinal pins in the proxi-mal fragment, some fractures are amenable to treatment in a simple monolateral frame
Another option is application of a hybrid external fixator involving insertion of at least three thin cross-ing wires attached to a proximal five-eighths ring.20,23 If only two crossing wires can be safely placed, the addition of a single half-pin can increase fixation to the proximal fragment This is subsequently con-nected to two or more distal shaft pins by two or more longitudinal struts Some surgeons prefer to use tensioned olive wires in the proxi-mal fragment23(Fig 3), which theo-retically limit medial-lateral transla-tion better than nonbeaded implants; however, this benefit has not been demonstrated biomechanically When considering proximal wire placement, it is important to note that the synovial cavity of the knee extends as far as 14 mm below the joint line22,24,25and often includes the proximal tibiofibular joint.26
Placement of external fixation wires through this region of redundant synovium can allow bacterial
seed-Figure 2 A, Additional screws are placed
in the distal portion of the plate, and the
push-pull screw is then removed B, If
ad-ditional stability is required because of the
fracture pattern, the fibular fracture may be
repaired with a 3.5-mm dynamic
compres-sion plate Medial stability may be obtained
by placing an additional medial Schanz
screw (Adapted with permission from
Bolhofner BR: Indirect reduction and
com-posite fixation of extraarticular proximal
tibial fractures Clin Orthop 1995;315:75-83.)
Trang 6ing of the knee joint, with
subse-quent pyarthrosis.5 It is, therefore,
recommended that all external
fixa-tion wires be placed at least 15 mm
distal to the plateau surface.24,25
Some surgeons routinely insert
wires through the fibular head in
an attempt to improve wire offset
In the anterior half of the joint, pin
or wire placement may be possible
without risk of synovial
perfora-tion,24 although staying anterior to
the proximal fibula will generally
avoid perforation of capsular
re-flections
Clinical Results
The availability of clinical data
concerning extra-articular proximal
tibia fractures treated by external
fixation alone is limited Zecher et
al23reported on 5 extra-articular
metaphyseal injuries in a series of 21
high-energy fractures; treatment
with the Monticelli-Spinelli hybrid
fixator yielded satisfactory results
Weiner et al20 reported generally
satisfactory results with use of a
combination of external and internal
fixation to treat 50 proximal injuries,
5 of which were high-energy
nonar-ticular proximal tibia fractures
There is as yet no published series
of nonarticular proximal tibial frac-tures treated by external fixation alone
The main advantage of external fixation is that reduction and stabi-lization of the fracture fragments is possible with minimal additional insult to the soft-tissue sleeve If properly constructed, these devices are strong enough to provide stable fixation for most fracture patterns
in the proximal tibia External fixa-tion enables early range-of-mofixa-tion exercises and secondary adjustment
of initial or secondary malalign-ment.20 Weight bearing is possible with stable reductions and very sta-ble frame constructs
External fixation is limited by the need for close and prolonged super-vision with repeated office visits to assess and ensure acceptable align-ment.27 Pin-track infections are common and require intensive local care and occasionally systemic anti-biotics Secondary knee pyarthrosis, uncommon with plating or nailing, has been observed in periarticular fractures treated with external
fixa-tion and may be attributed to place-ment of wires through the synovial reflection of the knee below the tib-ial articular surface.5,25 However, most reported cases have involved articular injuries, rather than proxi-mal nonarticular fractures, which afford more room for pin placement Severe open or closed injury pat-terns sometimes preclude immedi-ate definitive fixation of the fracture
In these situations, a spanning exter-nal fixator can be placed to provide temporary stabilization without causing further damage to the soft-tissue sleeve of the proximal portion
of the leg Two different techniques have been described Cole et al28 rec-ommended a construct consisting of three laterally placed distal-femoral-shaft pins connected to a transos-seous calcaneal pin by means of two long rods, effectively providing portable traction to the fracture site
In their series of periarticular inju-ries, Anglen and Aleto29 used two anterior femoral and two anterome-dial distal tibial pins spanned by double-stacked rods to maintain length and alignment while soft tis-sues stabilized Other frame
con-Figure 3 A, Preoperative radiographs of a lateral oblique metaphyseal fracture with some comminution Note the apex anterior
angula-tion and posterior translaangula-tion on the lateral view and the marked medial translaangula-tion on the anteroposterior view The proximal fragment
is relatively short B, Multiplanar tensioned olive wires effectively stabilize the proximal fragment in a hybrid external-fixator construct.
Excellent sagittal alignment was achieved, as well as correction of coronal translation.
Trang 7structs are possible, all of which
have the same goal of keeping the
pins outside the zone of injury and
definitive fixation
Indications
External fixators can stabilize
most fractures of the proximal tibia
and are particularly useful for
frac-tures that are complicated by
exten-sive soft-tissue compromise and for
patients who have sustained
poly-trauma Circumferential skin
dam-age at the level of the proximal tibia
may preclude placement of wires or
pins In this situation, immediate
spanning external fixation is
indi-cated for initial management
Intramedullary Nailing
Intramedullary nailing has recently
become more widely used for
non-articular proximal tibia fractures,
although high rates of malunion
have been reported Eccentric
start-ing portals within the wide
intramed-ullary canal of the proximal tibia
can lead to malalignment as the nail
passes into the more constrained
canal of the distal fragment Careful
planning, meticulous attention to
technical detail, and the use of
re-cently described techniques are
helpful in preventing these
deformi-ties (Fig 4)
Clinical Results
Many reports of intramedullary
nailing of tibial shaft fractures have
been documented, but few deal
specifically with proximal tibia
injuries.1,6 In a radiographic
analy-sis of immediately postoperative
alignment in 145 tibial fractures,
Freedman and Johnson6 reported a
58% rate of malunion in
proximal-third injuries, compared with 7%
and 8% rates of malalignment in
middle-third and distal-third
frac-tures, respectively Four cases of
valgus deformity and five cases of
anterior angulation were reported
The propensity for valgus deformity was attributed to the average medial entrance angle of 9.5 degrees, which was potentiated by a medial starting portal The investigators recom-mended a central or lateral portal to avoid angulation The locking con-figuration used with the proximal injuries was not specified; however, many nails used in the series were not locked or were locked dynami-cally In a smaller series in which dy-namically locked nails were used, Templeman et al7documented loss of alignment in 20% of proximal-third fractures, with oblique fractures being among the least stable Nei-ther group of investigators reported proximal fracture-fragment length, which is an important technical and biomechanical consideration.11
Lang et al1 treated 32 nonarticu-lar proximal-third fractures with statically locked intramedullary nails At least 5 degrees of valgus angulation was noted in 18 fractures (56%), and 9 fractures (22%) had 10 degrees or more of apex anterior deformity Loss of fixation was re-ported in 8 fractures, which the authors attributed to proximal lock-ing with only one screw in 50% of cases A single screw does not pre-vent rotation of the proximal frag-ment in the sagittal plane A poste-rior entrance angle and a nail bend distal to the fracture site contributed
to sagittal malalignment, and a me-dial starting portal accentuated by a medial parapatellar approach con-tributed to coronal malalignment
As in previous studies, proximal fragment length was not recorded
The authors illustrated the use of supplemental unicortical plate fixa-tion in conjuncfixa-tion with nailing to improve fracture alignment
The direction and location of prox-imal locking may make a difference
In a biomechanical study, Henley et
al11 compared the axial, torsional, and varus-valgus stiffness of differ-ent proximal locking-screw con-structs in models of both a simple
transverse fracture and a comminuted fracture of the shaft of the proximal tibia In the comminuted bone, two coronal screws were stiffer than two oblique (90-degree) screws under axial tension, although this was ex-plained by insertion of the oblique screws more proximally in the softer metaphyseal bone Valgus-varus stiffness was greater with oblique constructs in both the simple and the comminuted model, with statistically significant differences observed in the former Stability against flexion and extension forces was not tested The authors concluded that more proximal locking enables fixation of a greater number of fractures with bet-ter control of coronal angulation, but that axial stability may be compro-mised
The true intramedullary canal begins about 4 cm distal to the tibial tubercle In the uppermost portion
of the proximal tibia, the intramed-ullary central axis is more often lat-eral rather than medial to the center
Figure 4 Postoperative anteroposterior
(A) and lateral (B) radiographs after locked
nailing of a proximal tibia fracture illus-trate angulatory and translational deformi-ties in both the coronal and the sagittal plane.
Trang 8of the tibial plateau.30,31 It has been
suggested that lateral starting points
may allow better direction of nails
into the canal In addition to
allow-ing better anatomic alignment with
the canal, a lateral portal has been
demonstrated to lower anterior
de-forming forces within the proximal
tibia in cadaveric biomechanical
studies.31
Because a posterior entrance
an-gle is recognized as a cause of
ante-rior angulation, alternative starting
portals have been suggested The
standard techniques utilize an
en-trance through the oblique facet of
the tibial metaphysis 2 cm above the
tubercle Tornetta32 described a
more proximal and posterior portal,
just anterior to the insertion of the
anterior cruciate ligament Similarly,
Buehler et al10described a more
proximal and lateral entry point in
line with the lateral intercondylar
eminence In cadaveric
biomechani-cal studies, similar portals have
dem-onstrated lower angular deforming
forces with nail insertion than have
been found with more distal and
medial sites.33
Alignment adjustments are
diffi-cult after nail insertion Minor
adjust-ments of valgus or varus
malalign-ment can be achieved by rotating the
nail externally or internally,
respec-tively, to use the nail bend to reduce
the malalignment at the expense of
translating the proximal fragment
If this technique is used, the surgeon
must be aware that the locking holes
are no longer in the standard
posi-tion, and, as a result, insertion of the
cross-locking screws may endanger
neurovascular structures
With resistant angulation, coronal
blocking screws can be implanted
before nail insertion to effectively
reduce the posterior intramedullary
space.9 This forces the nail toward
the anterior cortex of the proximal
fragment.28,32 Similarly, sagittal
blocking screws can be used to aid
coronal alignment If malalignment
develops during nail insertion,
ex-traction, placement of blocking screws, and nail reinsertion may im-prove alignment
Extension forces placed on the proximal fragment with knee hy-perflexion during nailing are also believed to contribute to anterior angulation.8,10 To minimize this, Tornetta and Collins8employed a semiextended approach for tibial nailing In 25 fractures, they intro-duced nonreamed nails through a medial parapatellar approach With the patella retracted, the portal was accessible, and the nail was easily in-serted while the knee was held in approximately 15 degrees of flexion, reducing the pull of the patellar ten-don After passage across the frac-ture site, the nail is locked in relative extension, which may be facilitated
by newer L-shaped proximal jig de-signs
Locked intramedullary nail fixa-tion of proximal tibia fractures has the
advantage of a closed reduction, which maintains the integrity of the perifracture soft-tissue sleeve Locked intramedullary nailing has made it possible to stabilize proximal tibia fractures with fragments long enough
to accept two proximal locking bolts (Fig 5) The device is completely internal and thus is acceptable to pa-tients and can facilitate early weight bearing by those with unstable in-juries
Utilization of intramedullary nail-ing is limited by the fact that it is applicable only to fractures with suf-ficiently long proximal fragments, and even in that setting it is techni-cally demanding As locking-screw location and orientation vary among implant types, careful preoperative measurement of fragment length on both anteroposterior and lateral views is crucial In addition, frag-ment length should be considered in regard to the nail bend, which
Figure 5 A, Initial radiograph of a proximal tibia fracture B, The proximal fragment
was long enough (7 cm) to accept two proximal locking nails C, An oblique locking screw
was added to enhance coronal stability The nail bend was located at the fracture site in this case; however, it is preferable for the nail bend to be above the fracture to prevent apex anterior angulation of the proximal fragment.
Trang 9should be kept proximal to the
frac-ture site to prevent posterior
transla-tion Gross contamination or severe
soft-tissue injury should not be
pres-ent at the nail-pres-entry site If these
cri-teria cannot be satisfied, alternative
methods of stabilization, such as
ex-ternal fixation, should be considered
Indications
Fractures with proximal
frag-ments sufficiently long to accept
two locking screws and with
mini-mal soft-tissue injury around the
knee can be successfully nailed In
large part because of the
insuffi-cient clinical data correlating
frag-ment size with outcome, the exact
fragment length remains arbitrary and subject to surgeon experience;
5 to 6 cm is probably a reasonable estimation More proximal injuries
at or above the level of the tibial tubercle are very difficult to control with a nail and are best treated with another method
Decision Making
In the management of proximal tibia fractures, a neglected or mis-judged soft-tissue injury can lead to devastating complications, includ-ing soft-tissue slough and postoper-ative infection, which may
necessi-tate amputation The surgeon must, therefore, consider fractures with a seriously compromised soft-tissue sleeve as different from those with less soft-tissue trauma The severity
of the soft-tissue injury is the first discriminator in the proposed algo-rithm (Fig 6)
Stable, nondisplaced, and mally displaced fractures with mini-mal soft-tissue injury can be treated
in a closed manner If the reduction
is lost or soft-tissue compromise develops, surgical stabilization is recommended External fixation is the most reasonable alternative for unstable fracture patterns with short proximal fragments, although
Proximal tibia fracture
Stable
fracture
Unstable fracture
Short proximal
stabilization
Short proximal fragment
Long proximal fragment
Short proximal fragment
Nonemergent stabilization
Long proximal fragment Long
leg cast
Loss of
reduction
External fixation
(preferred) or plate fixation
Spanning external fixator
Soft-tissue healed, bone covered
Swelling decreased, blisters resolve
Open fracture, compartment syndrome, vascular repair
Intramedullary nailing (preferred)
or external fixation
or plate fixation
External fixation
or unilateral plate fixation or composite fixation
If nail portal intact, external fixation or immediate intra-medullary nailing
Bulky dressing, splint, and observation or spanning external fixator (for very unstable fractures)
Closed fracture,
no limb-threatening condition
Figure 6 Treatment algorithm for proximal tibia fractures with minimal or severe soft-tissue injury.
Trang 10some surgeons prefer plate fixation.
A lateral buttress plate can be used
to stabilize lateral comminution
and can be supplemented with a
medially placed fixator
Intramed-ullary nailing is a good choice for
unstable injuries with minimal
soft-tissue injury and proximal
frag-ments longer than 5 or 6 cm For
surgeons inexperienced or
uncom-fortable with nailing, external
fixa-tion and plate fixafixa-tion remain viable
alternatives
In proximal tibia fractures
com-plicated by severe soft-tissue
inju-ries, the primary focus is on the
soft-tissue lesion In some cases,
definitive fixation is delayed until
the soft tissues have stabilized
Closed lesions with short proximal
fragments warrant prolonged
ob-servation (up to 2 weeks) while
being temporarily stabilized in a
soft dressing and splint If there is
significant fracture displacement
and instability, a joint-spanning
fix-ator may be used Disappearance of
blood blisters, return of skin
wrin-kling, and diminution of swelling
are indicators of resolving
soft-tissue trauma With short proximal
fragments, definitive fixation can be
achieved with an external fixator, plate osteosynthesis, or both With long fragments with more distal closed soft-tissue lesions, primary nailing can be attempted if the nail-entry site is out of the zone of injury, although external fixation is pre-ferred by some surgeons
All open wounds require prompt irrigation, debridement, and fracture stabilization Fractures with severe open wounds and small proximal fragments are best stabilized initially with a spanning external fixator across the knee Delayed conversion
to a fixator applied only to the tibia is the most widely recommended choice for definitive stabilization, although with stable soft-tissue clo-sure, plate fixation remains an alter-native An external fixator supple-mented with a lateral plate is useful for comminuted patterns If the proximal fragment is large and the open wound is not contaminated, ini-tial immobilization can be effected with an intramedullary nail if the entry site is out of the zone of injury
Alternatively, if the wound is conta-minated or if it is the surgeon’s pref-erence, large proximal fragments may be treated with external fixation
Summary
Although there is a wide variety of injury patterns and treatment op-tions, most fractures involving the proximal third of the tibia can be managed successfully by assessing
in sequence the severity of the soft-tissue injury, the length of the bone fragment, and the stability of the fracture pattern Of the available treatment methods, external fixa-tion can be used for any of the de-scribed injury patterns Locked in-tramedullary nails are most useful and have some advantages for proximal tibia fractures with long proximal fragments and adequate soft-tissue coverage However, attention to several important fac-tors is necessary to prevent mal-alignment Plates are still used by some surgeons and have particular utility when there is an oblique fracture line With fracture com-minution, lateral plating should be augmented by medial external fixa-tion In cases of severe open or closed soft-tissue injury, plates should be used only with extreme caution or after the soft-tissue in-jury has completely stabilized
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