Content uploaded by Christopher M LaPrade
Author content
All content in this area was uploaded by Christopher M LaPrade on May 19, 2015
Content may be subject to copyright.
VOLUME 65 . N.2 . APRILE 2014
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 125
The purpose of this review is to highlight
recent advances regarding the diagnosis
and treatment of bular (lateral) collateral
ligament (FCL) injuries in the knee.
Anatomy and biomechanics
The bular collateral ligament (FCL), also
known as the lateral collateral ligament, is
the posterolateral corner (PLC) structure re-
sponsible for primary varus and secondary
external rotation stability. This ligament is
on average 69.6-mm-long and courses from
the lateral aspect of the femur to the bular
head, deep to the iliotibial band and biceps
femoris muscle.1 The femoral attachment of
the FCL is located in a small depression 1.4
mm proximal and 3.1 mm posterior to the
lateral epicondyle of the femur. This loca-
tion is directly 18.5 mm posterosuperior to
the center of the popliteus tendon attach-
ment (Figure 1). The average cross-section-
al area of the femoral footprint is 48 mm2,
with some bers extending anteriorly over
1CenterforOutcomes‑basedOrthopedicResearch
SteadmanPhilipponResearchInstitute
Vail, CO, USA
2DepartmentofBioMedicalEngineering
SteadmanPhilipponResearchInstitute
Vail, CO, USA
3TheSteadmanClinic, Vail, CO, USA
MINERVA ORTOP TRAUMATOL 2014;65:125-39
E. W. JAMES 1, A. M. JOHANNSEN 2, C. M. LAPRADE 2, R. F. LAPRADE 2, 3
Recent advances in the treatment of bular
(lateral) collateral ligament injuries
The purpose of this review is to highlight
recent advances regarding the diagnosis
and treatment of bular (lateral) collateral
ligament (FCL) injuries in the knee. The FCL
originates just proximal and posterior to the
lateral epicondyle on the femur and inserts
distally in a bony depression on the lateral
aspect of the bular head. The FCL functions
as the primary restraint to varus laxity at all
knee exion angles and as the primary re-
straint to external rotation when the knee is
in extension. Depending on the grade of FCL
injury, treatment ranges from non-operative
management to surgical reconstruction. For
patients with grade I or II (partial) FCL tears,
non-operative management consisting of an
accelerated physical therapy program is of-
ten the rst line treatment. Indications for
FCL surgical reconstruction include patients
with grade III (complete) FCL tears or pa-
tients who fail to improve with conservative
management. Reconstruction is favored over
repair for midsubstance tears due to a re-
ported increased failure rate associated with
repair. In addition, reconstruction functions
to minimize the risk of complications asso-
ciated with chronic lateral knee instability
such as medial compartment osteoarthritis,
medial meniscus tears, and failure of cruci-
ate ligament reconstruction grafts. Outcomes
after FCL reconstruction have demonstrated
improvement in both subjective and objective
measures.
Key words: Collateral ligaments, injuries - Diag-
nosis - Surgical procedures, operative.
Corresponding author: R. F. LaPrade, MD, PhD, Complex
Knee and Sports Medicine Surgeon, The Steadman Clinic,
181 W. Meadow Dr., Suite 400, Vail, CO 81657, USA.
E-mail: drlaprade@sprivail.org
Anno: 2014
Mese: April
Volume: 65
No: 2
Rivista: MINERVA ORTOPEDICA E TRAUMATOLOGICA
Cod Rivista: MINERVA ORTOP TRAUMATOL
Lavoro: 3618-MOT
titolo breve: RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
primo autore: JAMES
pagine: 125-39
126 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
ies.2-6 This ligament acts as the primary
restraint to varus laxity at all knee exion an-
gles and is the primary restraint to external
rotation when the knee is near extension.4, 5
As the knee increases its exion angle, the
popliteus tendon and popliteobular liga-
ment become the primary restraint to ex-
ternal rotation, and the forces on the FCL
diminish. On radiographic evaluation, varus
gapping of 2.7-4.0 mm following the appli-
cation of a varus directed force is indicative
of an isolated FCL injury.3
Fibular collateral ligament deciency can
profoundly inuence gait pattern and over-
all knee mechanics. Complete FCL disrup-
tion leads to increased forces on ACL and
PCL grafts, putting them at higher risk of
failure.5, 6 In addition, varus instability may
lead to a varus thrust gait pattern, develop-
ment of medial meniscal tears, and medial
compartment arthritis if left untreated.7-9
Therefore, restoration of normal knee me-
chanics and correction of varus instability
is crucial to preventing further injury and
disability.
Etiology of FCL and other
lateral knee injuries
Injuries to the bular collateral ligament
and posterolateral corner of the knee often
occur as a result of a blow to the medial or
anteromedial corner of the knee causing
varus stress, a contact or non-contact hy-
perextension injury, or a varus noncontact
injury.9, 10 Young men are the most likely
to sustain injuries to the FCL and postero-
lateral corner.11 Isolated injuries to the FCL
are extremely rare and are almost always
associated with meniscal tears, anterior
cruciate ligament, posterior cruciate liga-
ment, popliteus tendon, or popliteobular
ligament injury. One study reported that
isolated posterolateral corner injury occurs
in only 28% of all posterolateral corner
knee injuries.12 Thorough neurovascular
evaluation must occur, as up to 15% of
patients with posterolateral corner injury
also present with common peroneal nerve
injury.9
the lateral epicondyle. The bular attach-
ment of the FCL is located on the lateral
aspect of the bular head, on average 8.2
mm posterior to the anterior margin of the
bular head and 28.4 mm distal to the apex
of the bular styloid process. This footprint
is located in a bony depression with a 43
mm2 cross sectional area.
The biomechanics of the FCL have been
thoroughly evaluated through both sequen-
tial sectioning and force measurement stud-
Figure 1.—An illustration demonstrating the anatomic at-
tachment sites of the bular collateral ligament (lateral
view, right knee). FCL, bular collateral ligament; PLT,
popliteus tendon. Reproduced with permission from:
LaPrade et al.1
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 127
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
lized on the edge of the examination table
(Figure 2).14 The leg is then allowed to hang
freely from the examination table while the
clinician stabilizes the knee by placing his
or her hand over the tibiofemoral joint line.
A varus stress force is then applied to the
lower leg by grasping the patient’s foot. The
test is performed at both 0° and 30° of ex-
ion, while the amount of the lateral com-
partment gapping and presence or absence
of a solid endpoint is assessed. An increase
in lateral compartment gapping is indicative
of a positive varus stress test. A grade I FCL
sprain is dened as a positive varus stress
test with mild lateral compartment gapping
and a rm endpoint. A grade II sprain is
dened as moderate gapping with an ap-
preciable endpoint. Finally, a grade III FCL
sprain is dened as markedly increased
lateral compartment gapping without the
presence of a solid endpoint. A positive va-
rus stress test at 30° of exion usually indi-
cates a complete FCL tear, while gapping
at both 0° and 30° of exion may indicate
a combined ligament injury to lateral and
posterior knee structures.9, 14
Hughston et al. described two tests to de-
tect posterolateral knee instability: the pos-
terolateral drawer test and the external ro-
tation recurvatum test.17 The posterolateral
drawer test is performed with the patient
supine, the hip exed at 45°, and the knee
exed to approximately 80° to 90°. The foot
is then externally rotated approximately 15°
Diagnosis
The diagnosis of FCL injuries can some-
times be difcult. A correct diagnosis is es-
sential to determine an appropriate treat-
ment and to prevent long-term sequelae
associated with chronic lateral knee insta-
bility. Approximately 73.4% and 31.6% of
FCL injuries are combined ligament injuries
with the ACL and PCL, respectively.13 In ad-
dition, 56% of PLC injuries involve two or
more of the major PLC structures (FCL, pop-
liteobular ligament, and popliteus tendon),
while only 13.3% of FCL tears are isolated
injuries. Numerous diagnostic techniques
have been developed to diagnose complex
injury patterns involving the FCL and other
knee structures in order to mitigate the risk
of long-term complications associated with
non-treatment.
Diagnosis with physical examination
A thorough history and physical exam
is an essential rst step to diagnosing FCL
injury. On inspection of an acutely injured
knee, there may be signicant edema, red-
ness, and bruising. Palpation may reveal
tenderness over the lateral aspect of the
joint line and pain at the bular head.14 Ac-
tive range of motion is often intact, though
may be limited depending on the amount
of swelling in the injured knee. In addi-
tion, rotational instability is often present
in both acute and chronic injury.15, 16 The
patient may report instability associated
with feelings of knee hyperextension while
ascending or descending stairs, twisting, or
pivoting.16 Specic physical examination
maneuvers, including the posterolateral
drawer test, external rotation recurvatum
test, dial test, varus stress test, and reverse
pivot-shift test, may be especially helpful in
distinguishing between an isolated FCL tear
versus a complete grade III posterolateral
corner injury. Finally, signs of common per-
oneal nerve injury must also be evaluated.
The varus stress test is the most impor-
tant physical examination maneuver for di-
agnosing FCL injury. In this test, the patient
is positioned supine, with the femur stabi-
Figure 2.—The varus stress test is performed at 0° and
30° of knee exion and is the best physical exam ma-
neuver to assess for lateral knee instability secondary to
FCL injury.
128 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
test, the patient is positioned supine on the
examination table.17 The patient is told to
relax their quadriceps muscle while the ex-
aminer grasps both great toes, lifting the
patient’s lower legs off the examination
table (Figure 3). A positive test is dened
as a side-to-side difference in heel heights
in the injured knee compared to the un-
injured knee.14 While the external rotation
recurvatum test is an essential test in the
diagnostic armamentarium, it is less sensi-
tive than other physical exam maneuvers.
In one series, LaPrade et al. reported that
the test detected just 7.5% of posterolateral
corner injuries compared to 30% of com-
bined ACL-PLC injuries.18 No positive test
results were documented for patients with
combined PCL-PLC injuries. Therefore, cau-
tion is advised with interpreting the results
of this test.
The dial test is performed with the patient
in a supine or prone position.14, 19 The knee
and stabilized while the clinician applies a
posterolateral drawer force to the anterior
tibia.14, 17 A positive test is dened as in-
creased rotational instability compared to
the contralateral uninjured knee. From an
anterior perspective, a positive test appears
as posterior displacement of the lateral tibial
plateau relative to the medial tibial plateau.
From a medial or lateral perspective, the lat-
eral tibial plateau moves posterior while the
medial side does not displace. By contrast,
testing the knee in neutral or internal tibial
rotation is utilized to assess PCL integrity
and a positive test should not be confused
with a posterolateral corner injury. Previous
studies have reported that a positive poste-
rolateral drawer test was found in approxi-
mately 71-80% of PLC injuries and the test
is therefore an excellent indicator of lateral
knee instability.15, 16
The external rotation recurvatum test is
also used to evaluate FCL integrity. In this
Figure 3.—An illustration demonstrating the sagittal plane relationship of the tibia with respect to the femur in a posi-
tive external rotation recurvatum test (lateral view, right knee). A positive test is dened as increased heel height in
the injured knee compared to the uninjured knee. Reprinted with permission from: LaPrade et al.18
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 129
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
while physical examination offers excellent
assessment of functional decits, structural
decits and the presence of concomitant
injuries may still be unclear. Therefore, nu-
merous techniques using plain, long-leg,
and varus stress radiographs and magnetic
resonance imaging (MRI) have been devel-
oped to assist with diagnosing FCL injury.
Plain radiographs should be obtained in
all patients to assess for fractures and bony
avulsions. In a consecutive series of 12 pa-
tients with acute isolated posterolateral in-
stability, DeLee et al. reported that plain ra-
diographs detected bular head fractures in
ve patients, a displaced medial tibial pla-
teau in one patient, and a Segond fracture in
another patient.23 In addition, medial com-
partment narrowing due to osteoarthritis
is readily detected on plain radiographs.24
Finally, while plain radiographs are unable
to detect an FCL midstubstance tear, a bony
ossicle can sometimes be visualized when
an FCL avulsion is present.
Long leg radiographs are also helpful to
assess the patient’s weightbearing axis. The
weightbearing axis is established by pass-
ing a line from the center of the femoral
head to the center of the ankle mortise.
In a varus axis deformity, the weightbear-
ing axis line passes through the medial
aspect of the tibial plateau, medial to the
medial tibial eminence (Figure 4). A varus
mechanical axis places increased strain on
the FCL and other PLC structures and may
contribute to chronic instability. When a va-
rus mechanical axis is discovered, a medi-
ally based opening wedge proximal tibial
osteotomy with bone graft is recommended
to restore alignment to neutral prior to pro-
ceeding with surgical FCL reconstruction.
In one case series, twenty-one patients with
varus alignment and posterolateral corner
injury were treated with a proximal tibial
osteotomy.25 Thirty-eight percent of patients
experienced resolution of lateral knee insta-
bility and did not require subsequent surgi-
cal reconstruction.
Varus stress radiographs are an objective
and reproducible technique for differenti-
ating between an isolated FCL tear and a
grade III PLC injury (Figure 5). Varus stress
is exed to 30° and 90° while an external
rotation force is applied. When performing
the test with the patient in the supine posi-
tion, the knee is allowed to hang freely from
the edge of the examination table with the
thigh resting on the table to provide stabi-
lization. The foot is then externally rotated
and the side-to-side difference in external
rotation is compared. A side-to-side differ-
ence of 10° is considered a positive test and
is indicative of lateral knee injury.19, 20 How-
ever, when markedly increased external
rotation is discovered, medial knee injury
should also be considered.21 Injury to one
or more of the PLC structures is typically as-
sociated with a positive dial test at 30° and
a negative test at 90°.14, 19 Positive dial test
results at both 30° and 90° of exion are
typically associated with a combined PCL-
PLC injury. Therefore, while the dial test of-
fers excellent information regarding rotary
stability, it is best interpreted in concert
with other physical exam maneuvers.
The reverse pivot shift is performed with
the patient in the supine position while
grasping the ankle of the patient. The knee
is then placed in 80° of exion while a val-
gus and external rotation force is applied
to the tibia.9, 14 With the examiner holding
the patient’s leg in this position, the knee is
drawn down into extension. A positive test
is dened as palpable subluxation of the
tibia relative to the femur as the iliotibial
band reduces the tibia.14, 22 This usually oc-
curs at approximately 20° to 30° of knee
exion. As with any knee exam maneu-
ver, the test must be repeated and the re-
sults compared with the contralateral knee.
LaPrade et al. reported that a positive test is
associated with injury to the FCL, popliteal
complex, and mid-third lateral capsular lig-
ament.9 A positive reverse pivot shift test
should be interpreted along with results of
other physical exam maneuvers due to the
test’s high false positive rate.22
Diagnostic imaging
In many cases, physical examination alone
may yield inconclusive results, especially in
cases of low grade FCL injury. Moreover,
130 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
2.7 mm after a simulated isolated FCL in-
jury and 4.0 mm after a grade III PLC injury
compared to the intact state.3 In addition to
assisting with diagnosis, stress radiographs
can be utilized to document lateral knee
stability at various time points following
surgical treatment. In a consecutive series
of 20 patients with FCL injury, preoperative
stress radiographs demonstrated an average
side-to-side difference of 3.9 mm in lateral
compartment gapping, while postoperative
stress radiographs found -0.4 mm of gap-
ping following an anatomic FCL reconstruc-
tion.26
Magnetic resonance imaging (MRI) is an-
other diagnostic imaging tool that can be
used to distinguish between isolated FCL
injury and grade III PLC injury. LaPrade et
al. examined the MRI appearance of indi-
vidual PLC structures.27 The authors report-
ed that the FCL was best visualized on MRI
in the axial, coronal, and coronal-oblique
views (Figure 6). The coronal-oblique view
is usefully because the FCL traverses ob-
liquely from its femoral attachment on the
lateral epicondyle to its bular attachment
adjacent to the long head of the biceps
femoris muscle. In addition, an avulsion of
the femoral FCL insertion and an arcuate
fracture of the bular head are best visual-
ized in the axial and coronal planes. The
authors also reported diagnostic accuracy
parameters for the ability of MRI to detect
posterolateral corner injuries. For detection
of FCL tears, MRI showed a sensitivity of
94.4%, specicity of 100%, positive predic-
tive value of 100%, and a negative predic-
tive value of 66.7%.
Additionally, MRI can be used to assess
the presence of bone bruising on the tibial
plateau and femoral condyles. Geeslin and
LaPrade reported that 60.7% of patients with
isolated injury to the PLC ligaments also had
bone bruising to the anteromedial femoral
condyle, while 21.4% of patients had a frac-
ture of the anteromedial tibial plateau.11 In
patients with a combined PLC injury plus
injury to the ACL, PCL and/or MCL, 87.8% of
patients had bone bruising. Of these, 60%
were located in the anteromedial femoral
condyle. Therefore, bone bruising on the
radiographs are performed with the knee
in 20° of exion while a clinician applies a
varus directed force to the medial aspect of
the knee. In a cadaveric study using manual
varus stress, lateral gapping increased by
Figure 4.—A long leg radiograph demonstrating a varus
mechanical axis deformity in the setting of a chronic
bular collateral ligament tear.
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 131
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
by intra-articular pathology including ACL,
PCL, and meniscus tears.13 For this reason,
arthroscopic surgery is often required in pa-
tients with an FCL tear. The most important
sign to look for on arthroscopic evaluation
is the presence of the “drive through sign,”
which may indicate injury to the FCL or
other posterolateral corner structures.28 In
a series of 30 consecutive knees with pos-
terolateral knee instability, lateral compart-
ment gapping of >1 cm was present in all
knees with the application of varus stress at
30° of knee exion. Therefore, the presence
of a “drive-through” should increase suspi-
cion of an FCL or associated posterolateral
corner injury.
The natural history of FCL and plc
injury: factors affecting healing
Several in vivo animal model studies have
been performed to determine the natural
history of posterolateral corner injuries in
the knee.29-31 One study looked at the effect
of chronic posterolateral knee instability in
a rabbit model.31 After sectioning the FCL
and popliteus tendon, none of the popli-
anteromedial femoral condyle may indicate
PLC injury, including the injury to the FCL.
Arthroscopic diagnosis
While the FCL is not an intra-articular
structure, FCL tears are often accompanied
Figure 5.—Varus stress radiographs demonstrating increased lateral compartment gapping indicative of an isolated
FCL tear.
Figure 6.—A PD TSE FS coronal MRI demonstrating an
acute FCL tear (arrow).
132 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
and increased radiographic indications of
osteoarthritis when compared to grade II
sprains.8 Strobel et al. reported signicantly
higher rates of osteoarthritis on the medial
femoral condyle in combined PLC-PCL inju-
ries verus isolated PCL injuries.32
In addition, the bony geometry of the lat-
eral tibial plateau and lateral femoral condyle
creates “inherent… instability” in the lateral
aspect of the knee, which contributes to the
low healing response observed after FCL in-
jury.31 Both the lateral tibial plateau and lat-
eral femoral condyle have convex contours,
which lead to instability that is not condu-
cive for healing of the PLC structures (Fig-
ure 7).29, 31 By comparison, the medial tibial
plateau and medial femoral condyle have a
concave on convex geometry, which con-
fers additional stability to the medial knee.
The geometry of the medial compartment
may explain the excellent healing response
often found following medial collateral liga-
ment injury.33-35 Furthermore, the lateral
meniscus is reportedly approximately twice
as mobile as the medial meniscus, which
further contributes to instability.36 Together,
these structural and morphological factors
contribute to lack of healing response ob-
served following lateral knee injuries.
teus tendons injuries and only one FCL inju-
ry healed after a 12-week follow-up. In ad-
dition, biomechanical testing revealed that
signicantly less varus force was needed to
produce 10 mm of varus displacement in
the injured knees at 30°, 60°, and 90° of
knee exion compared to the contralateral
control knee. In a second study with longer
follow-up in 10 rabbits, none of simulated
the FCL or popliteus tendon injuries healed
after 6 months.30 Biomechanical testing
demonstrated a signicant difference in
varus displacement at 30°, 60°, and 90° of
knee exion and a signicant increase in
external rotation at 30° and 60° of exion.
In addition, osteoarthritis was found on the
medial tibial plateau, but not on the lateral
tibial plateau. In a third study using an in
vivo canine model with sectioning of the
FCL, PFL, and popliteus tendon, increased
varus angulation at 0°, 60°, and 90° of knee
exion, external rotation at 0°, 60°, and 90°,
and internal rotation at 0° and 60° were re-
ported at six months follow-up.31
Similar results of poor healing have been
observed in humans. Kannus reported that
chronic grade III PLC injuries resulted in
signicantly worse clinical outcome scores,
lower thigh strength, lower knee stability,
Figure 7.—A, B) The convex on convex conguration of the lateral compartment articulating surfaces (A) compared
to the convex on concave conguration of the medial compartment articulating surfaces (B) contributes to chronic
instability following FCL injuries.
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 133
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
ping and establish a baseline against which
future evaluations can be measured. If non-
operative management fails to resolve lat-
eral compartment instability, surgical inter-
vention should be considered.
Surgical treatment
Repair
Primary repair of FCL injuries is recom-
mended in only very select cases. Repair
should only be attempted during the rst
two to three weeks following an FCL avul-
sion and very rarely in patients with a mid-
substance tear.14 In effect, most repairs oc-
cur in skeletally immature patients. After
several weeks pass, the FCL becomes re-
tracted and entrapped by scar tissue, mak-
ing reapposition and repair of the torn ends
difcult. Moreover, tissue quality deterio-
rates as the FCL becomes necrotic leading
to suture pull-out failure. Therefore, in the
acute setting, the authors recommend re-
construction for all FCL midsubstance tears
and for FCL avulsions that present greater
than three weeks after injury.
Reconstruction
Indications for surgical reconstruction
include patients with grade III (complete)
FCL tears, acute midsubstance tears, avul-
sions presenting greater than three weeks
after injury, or those who fail to improve
with conservative treatment measures. Dur-
ing the preoperative workup, bilateral varus
stress radiographs should be obtained to
establish an objective baseline assessment
of lateral compartment laxity. After surgery,
these values can be compared to assess for
resolution of lateral compartment laxity and
to detect graft attenuation or failure. In ad-
dition, long leg radiographs are necessary
to determine the patient’s weightbearing
axis. If a varus axis deformity is discovered
in a patient with a chronic FCL or PLC in-
jury, reconstruction should proceed in a
staged fashion beginning with an opening
wedge proximal tibial osteotomy followed
Finally, O’Brien et al. reported that undi-
agnosed PLC injuries are a leading cause of
ACL reconstruction failure.37 This has since
been validated in biomechanical studies
which demonstrated that sectioning of the
FCL, PFL, and popliteus tendon resulted in
signicantly higher forces on both ACL and
PCL reconstruction grafts.5, 6 In one study,
the FCL was sectioned and forces on the
anterior cruciate ligament (ACL) were meas-
ured. Results demonstrated signicantly in-
creased forces on the reconstruction graft
during varus loading at 0° and 30° of knee
exion.5 In addition, simulated grade III
PLC injuries, including injuries to the FCL,
resulted in signicantly increased forces
on PCL reconstruction grafts when a varus
force at 30°, 60° and 90° of knee exion
was applied.6 These ndings demonstrate
that posterolateral corner injuries often do
not heal and may lead to failure of other
reconstruction grafts.
Non-operative treatment
Non-operative treatment is an important
rst step in management of grade I and II
FCL injuries using an accelerated rehabilita-
tion program to promote healing.14 In the
early phases, the rehabilitation program
typically consists of edema management,
range of motion exercises, and quadriceps
activation. Once the patient achieves full
extension, exion to 120°, and is able to
perform a supine straight leg raise with out
lag, the focus shifts to developing muscu-
lar strength and restoring normal gait. Neu-
romuscular coordination and functional
exercises are added to continue building
muscular strength. A medial unloader brace
can also be used during higher-level activi-
ties, especially in athletes who may require
protection of the healing FCL while return-
ing back to activities. Finally, exercises fo-
cused on sport- or activity-specic move-
ments are initiated to facilitate the transition
from rehabilitation to return to sport. In all
cases of lateral knee injury, it is essential
to obtain varus stress radiographs to objec-
tively document lateral compartment gap-
134 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
anatomic technique using a semitendinosus
tendon autograft and an arthroscopically
assisted, mini-open surgical approach.46
The authors’ preferred technique is an
open anatomic FCL reconstruction using a
semitendinosus autograft, which has been
validated biomechanically to improve ob-
jective knee stability (Figure 8).7, 26 The pa-
tient is positioned with the operative leg
hanging freely at 70° to 80° of exion with
the foot of the operating table folded down.
The non-operative leg is abducted and se-
cured in a leg holder for the duration of the
procedure. A tourniquet is placed around
the distal thigh and inated once proper
draping is achieved and the surgical site is
prepared.
A standard laterally based hockey stick
by surgical reconstruction if lateral knee in-
stability fails to improve.25, 38
Numerous surgical techniques for FCL
treatment have been reported including ad-
vancement of the proximal FCL attachment,39
augmentation with the biceps femoris ten-
don,40 biceps femoris tendon tenodesis,41 a
doubled over semitendinosus autograft re-
construction,42 quadriceps tendon-patellar
bone autograft reconstruction,43 and iso-
metric bone-patellar tendon-bone recon-
struction.44, 45 More recently, there has been
an increased emphasis on anatomic-based
reconstruction techniques.7, 26, 46 LaPrade et
al. has described an anatomic reconstruc-
tion technique utilizing an open surgical
approach and a semitendinosus tendon
autograft.7, 26 Liu et al. described a similar
Figure 8.—A, B) An illustration demonstrating posterior (A) and lateral (B) views of an anatomic bular collateral
ligament reconstruction using a semitendinosus graft. FCL, bular collateral ligament; PFL, popliteobular ligament;
PLT, popliteus tendon. Reproduced with permission from: LaPrade et al.26
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 135
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
positioning, a 6-mm closed socket tunnel is
reamed to a depth of 30 mm and nished
with a 7 mm tap to complete the femoral
reconstruction tunnel.
In autograft reconstruction cases, an inci-
sion is made over the pes anserine bursa
on the medial aspect of the proximal tib-
ia to locate the semitendinosus tendon. A
standard hamstring harvesting instrument is
used to harvest the semitendinosus tendon
graft. Once harvested, the graft is cleaned
of all residual muscle and tubularized us-
ing number two nonabsorbable sutures to
allow easy graft passage through the recon-
struction tunnels.
Next, attention is turned to perform any
required intra-articular arthroscopic proce-
dures. Since the majority of posterolateral
corner injuries are combined ligament in-
juries, it is likely that many patients may
require a cruciate ligament reconstruction.
In addition, chronic lateral knee injuries are
associated with medial meniscus tears and
medial compartment degenerative cartilage
lesions. These should be addressed at this
time. Cruciate ligament grafts should be se-
cured in their respective femoral tunnels,
but tibial xation should not be performed
until after the FCL reconstruction graft is se-
cured.
Once the arthroscopic procedures are es-
sentially completed, the FCL graft is passed
into the femoral tunnel with the assistance
of passing sutures and secured using a
7x23 mm bioabsorbable screw (Figure 9).
Secure xation is conrmed by applying
a lateral traction force to the graft xed in
the femoral tunnel. The FCL graft is guided
deep to the iliotibial band and aponeurosis
of the long head of the biceps femoris be-
fore emerging adjacent to the lateral aspect
of the bular head (Figure 10). As with the
femoral tunnel, passing sutures help pull the
graft into the bular reconstruction tunnel.
The FCL graft is tensioned with the knee in
20º of exion and the leg in neutral tibial
rotation while applying a valgus force to
eliminate any lateral compartment gapping.
A 7x23 cannulated bioabsorbable interfer-
ence screw is used to x the graft in place
in the bular tunnel. Once securely xed, a
incision is made over the posterolateral
knee extending proximally along the iliotib-
ial band to distally at the level of Gerdy’s tu-
bercle.47 The incision is then carried down
to develop a posteriorly based skin ap
over the long and short heads of the biceps
femoris muscle. A peroneal neurolysis is
performed by carefully dissecting through
the subcutaneous tissue to release the nerve
from its connective tissue entrapments,
minimizing the risk of foot drop postopera-
tively due to swelling. The peroneal nerve
can be located either by palpating two to
three centimeters posterior to the long head
of the biceps femoris or carefully dissecting
along the lateral aspect of the bular head.
Extreme care should be followed in cases
where the biceps femoris is avulsed off the
bular head because the peroneal nerve
may be displaced over the bular head.
Next, the biceps bursa is identied and a 1
cm incision is created to access the bular
head. Through this interval, the distal FCL
attachment site is readily identied.1 A trac-
tion stitch can be placed in the FCL remnant
to assist with later identication of the FCL
femoral attachment.
Once the position of the distal FCL at-
tachment is conrmed, a guide pin is drilled
from the center of the native FCL attach-
ment on the bular head to the posterome-
dial aspect of the bular styloid near the
popliteobular ligament. To prevent guide
pin over penetration, a retractor is placed
along the posteromedial aspect of the bu-
lar head. Finally, a 6-mm reamer is used to
create the bular reconstruction tunnel over
the guide pin.
Attention is next turned to the femoral
reconstruction tunnel. A longitudinal inci-
sion is made through the iliotibial band by
splitting its bers lengthwise. Through this
interval, the femoral attachment of the FCL
is identied proximal and posterior to the
lateral epicondyle. The distally placed trac-
tion stitch can also be used to isolate the
proximal FCL footprint if it is not readily
visualized. Once correct positioning is con-
rmed, an eyelet tipped guide pin is aimed
anteromedially to avoid breaching the in-
tercondylar notch. After conrming correct
136 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
es as pain allows. Once range of motion
reaches 105° to 110° of exion, stationary
bike and low resistance muscular endur-
ance base building exercises are initiated.
Low impact exercises such as walking and
swimming are added at twelve weeks. Once
an adequate muscular endurance base is
achieved, an increased emphasis is placed
on restoring muscular strength.
Varus stress radiographs are obtained at
between ve to six months postsurgically
to assess for lateral compartment stability.
A side-to-side difference of less than two
millimeters is considered successful resolu-
tion of lateral instability, while gapping of
greater than two millimeters suggests graft
attenuation or failure. The goal is return to
varus stress exam is performed to verify res-
olution of lateral knee stability before trim-
ming excess graft near the posteromedial
aperture of the bular reconstruction tunnel
while the common peroneal nerve is gently
retracted (Figure 11). At this time, tibial xa-
tion can be completed for any concomitant
cruciate ligament reconstructions. Once all
grafts are secured, the incisions are closed
and the patient is placed in an immobilizer
brace.
Rehabilitation
Postoperative restrictions include non-
weightbearing and avoidance of external
rotation and varus stress for the rst six
weeks.26 An immobilizer brace is used to
protect the grafted FCL. Straight leg raises
and quadriceps sets should be performed
with the knee in the immobilizer brace.
Early range-of-motion exercises are empha-
sized during the rst phases of rehabilitation
to minimize the risk of arthrobrosis. Pas-
sive range of motion is allowed from 0° to
90° of exion for the rst two weeks, stating
on postoperative day one, and increased as
tolerated thereafter, with the goal of achiev-
ing full range of motion by the end of week
six. After two weeks, straight leg raises and
quadriceps sets can be completed without
the immobilizer brace in the absence of an
extensor lag. After six weeks, patients are
allowed to progressively wean off crutch-
Figure 11.—The FCL graft is secured in the bula and
trimmed prior to closing.
Figure 10.—The FCL graft is passed distally and deep to
the iliotibial band before being pulled through the bular
reconstruction tunnel.
Figure 9.—The FCL reconstruction graft is secured in a
closed socket femoral tunnel using a 7 mm bioabsorb-
able screw.
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 137
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
Outcomes following anatomic FCL re-
construction have demonstrated a signi-
cant improvement in subjective and ob-
jective outcome measures. LaPrade et al.
performed anatomic FCL reconstructions
in 20 patients with an average age of 24
years (range, 16-45 years).26 After a mean
of two years, the average modied Cincin-
nati score improved signicantly from 28.2
preoperatively to 88.5 postoperatively and
the average International Knee Documen-
tation Committee (IKDC) subjective score
increased signicantly from 34.7 preopera-
tively to 88.1 postoperatively. The Cincin-
nati symptom and functional subscores
also improved signicantly. Objective out-
comes were evaluated using varus stress
radiographs, which improved from a mean
side-to-side difference in lateral compart-
ment gapping of 3.9 mm preoperatively to
-0.4 mm postoperatively. Together, these
outcomes demonstrate that an anatomic
FCL reconstruction was able to signicant
improve patient function and lateral knee
stability.
Conclusions
Numerous advances have been made
recently in the understanding of postero-
lateral corner anatomy and biomechanics,
which in turn have led to the development
and validation of FCL reconstruction tech-
niques. Lateral knee injuries frequently do
not heal due to the inherent bony instability
of the lateral compartment. Patients present-
ing with an acute knee injury should always
be evaluated for signs and symptoms of va-
rus instability, especially in cases of cruci-
ate ligament injury, which may indicate an
injury to the FCL. For patients with chronic
lateral knee instability, it is essential to eval-
uate the patient’s weightbearing axis prior
to performing an FCL reconstruction. While
several FCL reconstruction techniques have
been described in the literature, the authors
recommend an anatomic FCL reconstruc-
tion utilizing a semitendinosus allograft or
autograft because it has been demonstrat-
ed to restore objective knee stability and
full activity within six to nine months. Re-
turn to high-level activity should only occur
after passing functional testing such as the
Vail sports test and being cleared by a phy-
sician.48
Complications
Standard surgical complications includ-
ing infection, blood clot, or delayed healing
should be discussed prior to surgery. Iatro-
genic peroneal nerve palsy is a rare but se-
rious complication. Risk of peroneal nerve
palsy is minimized by performing a pero-
neal neurolysis prior to FCL reconstruction,
which diminishes the effect of compressive
forces on the nerve due to post-operative
swelling and allows the nerve to be safely
retracted. In addition, the tourniquet should
be let down prior to closing to cauterize
bleeding vessels since hematoma formation
at the bular head may lead to peroneal
nerve palsy.49 As with any ligament recon-
struction, graft attenuation or failure is also
possible.
Outcomes
While direct FCL repair has been de-
scribed by several authors,14, 15 it is only rec-
ommended in select patients with acute FCL
avulsions. Outcomes following posterolater-
al corner repair demonstrate poor outcomes
compared to reconstruction.50, 51 Stannard et
al. followed 57 patients following poster-
olateral corner reconstructions for a mini-
mum of two years and reported that 37% of
repairs versus 9% of reconstructions result-
ed in failure.51 Levy et al. also studied pos-
terolateral repair versus reconstruction.50 In
a series of 28 knees followed for a mean of
34 months, signicantly more repairs (40%)
failed compared to reconstruction (6%).
While these results document outcomes
after total posterolateral corner repair and
reconstruction, results indicate that recon-
struction of posterolateral corner structures
following injury, including reconstruction of
the FCL, yield superior results.
138 MINERVA ORTOPEDICA E TRAUMATOLOGICA April 2014
JAMES RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES
rolateral rotatory instability of the knee. J Bone Joint
Surg Am 1983;65:614-8.
16. Hughston JC, Jacobson KE. Chronic posterolateral
rotatory instability of the knee. J Bone Joint Surg
1985;67:351-9.
17. Hughston JC, Norwood LA Jr. The posterolateral
drawer test and the external rotation recurvatum test
for posterolateral rotatory instability of the knee. Clin
Orthop Relat Res 1980;82-7.
18. LaPrade RF, Ly TV, Grifth C. The external rotation
recurvatum test revisited: reevaluation of the sagit-
tal plane tibiofemoral relationship. Am J Sports Med
2008;36:709-12.
19. Bae JH, Choi IC, Suh SW, Lim HC, Bae TS, Nha KW,
Wang JH. Evaluation of the reliability of the dial test
for posterolateral rotatory instability: a cadaveric
study using an isotonic rotation machine. Arthros-
copy 2008;24:593-8.
20. Jung YB, Lee YS, Jung HJ, Nam CH. Evaluation of
posterolateral rotatory knee instability using the
dial test according to tibial positioning. Arthrscopy
2009;25:257-61.
21. Coobs BR, Wijdicks CA, Armitage BM, Spiridonov SI,
Westerhaus BD, Johansen S et al. An in vitro analysis
of an anatomical medial knee reconstruction. Am J
Sports Med 2010;38:339-47.
22. Cooper DE. Tests for posterolateral instability of the
knee in normal subjects. Results of examination un-
der anesthesia. J Bone Joint Surg Am 1991;73:30-6.
23. DeLee JC, Riley MB, Rockwood CA Jr. Acute poste-
rolateral rotatory instability of the knee. Am J Sports
Med 1983;11:199-207.
24. Hughston JC, Andrews JR, Cross MJ, Moschi A. Classi-
cation of knee ligament instabilities. Part II. The lat-
eral compartment. J Bone Joint Surg Am 1976;58:173-
9.
25. Arthur A, LaPrade RF, Agel J. Proximal tibial open-
ing wedge osteotomy as the initial treatment for
chronic posterolateral corner deciency in the varus
knee: a prospective clinical study. Am J Sports Med
2007;35:1844-50.
26. LaPrade RF, Spiridonov SI, Coobs BR, Ruckert PR,
Grifth CJ. Fibular collateral ligament anatomical re-
constructions: a prospective outcomes study. Am J
Sports Med 2010;38:2005-11.
27. LaPrade RF, Gilbert TJ, Bollom TS, Wentorf F, Chaljub
G. The magnetic resonance imaging appearance of
individual structures of the posterolateral knee. A
prospective study of normal knees and knees with
surgically veried grade III injuries. Am J Sports Med
2000;28:191-9.
28. LaPrade RF. Arthroscopic evaluation of the lateral
compartment of knees with grade 3 posterolateral
knee complex injuries. Am J Sports Med 1997;25:596-
602.
29. LaPrade RF, Wentorf FA, Crum JA. Assessment of
healing of grade III posterolateral corner injuries: an
in vivo model. J Orthop Res 2004;22:970-5.
30. LaPrade RF, Wentorf FA, Olson EJ, Carlson CS. An in
vivo injury model of posterolateral knee instability.
Am J Sports Med 2006;34:1313-21.
31. Grifth CJ, Wijdicks CA, Goerke U, Michaeli S, Eller-
mann J, LaPrade RF. Outcomes of untreated postero-
lateral knee injuries: an in vivo canine model. Knee
Surg Sports Traumatol Arthrosc 2011;19:1192-7.
32. Strobel MJ, Weiler A, Schulz MS, Russe K, Eichhorn
HJ. Arthroscopic evaluation of articular cartilage le-
sions in posterior-cruciate-ligament-decient knees.
Arthroscopy 2003;19:262-8.
33. Inoue M, McGurk-Burleson E, Hollis JM, Woo SL.
Treatment of the medial collateral ligament injury. I:
improve clinical outcomes. In the future,
additional long-term outcome studies are
needed to assess clinical and structural out-
comes following FCL reconstruction.
References
1. LaPrade RF, Ly TV, Wentorf FA, Engebretsen L. The
posterolateral attachments of the knee: a qualitative
and quantitative morphologic analysis of the bular
collateral ligament, popliteus tendon, popliteobu-
lar ligament, and lateral gastrocnemius tendon. Am J
Sports Med 2003;31:854-60.
2. LaPrade RF, Bollom TS, Wentorf FA, Wills NJ, Meister
K. Mechanical properties of the posterolateral struc-
tures of the knee. Am J Sports Med 2005;33:1386-91.
3. LaPrade RF, Heikes C, Bakker AJ, Jakobsen RB. The
reproducibility and repeatability of varus stress radio-
graphs in the assessment of isolated bular collateral
ligament and grade-III posterolateral knee injuries.
An in vitro biomechanical study. J Bone Joint Surg
Am 2008;90:2069-76.
4. LaPrade RF, Tso A, Wentorf FA. Force measurements
on the bular collateral ligament, popliteobular liga-
ment, and popliteus tendon to applied loads. Am J
Sports Med 2004;32:1695-701.
5. LaPrade RF, Resig S, Wentorf F, Lewis JL. The effects
of grade III posterolateral knee complex injuries on
anterior cruciate ligament graft force. A biomechani-
cal analysis. Am J Sports Med 1999;27:469-75.
6. LaPrade RF, Muench C, Wentorf F, Lewis JL. The ef-
fect of injury to the posterolateral structures of the
knee on force in a posterior cruciate ligament graft: a
biomechanical study. Am J Sports Med 2002;30:233-8.
7. Coobs BR, LaPrade RF, Grifth CJ, Nelson BJ. Biome-
chanical analysis of an isolated bular (lateral) col-
lateral ligament reconstruction using an autogenous
semitendinosus graft. Am J Sports Med 2007;35:1521-
7.
8. Kannus P. Nonoperative treatment of grade II and III
sprains of the lateral ligament compartment of the
knee. Am J Sports Med 1989;17:83-8.
9. LaPrade RF, Terry GC. Injuries to the posterolateral
aspect of the knee. Association of anatomic injury
patterns with clinical instability. Am J Sports Med
1997;25:433-8.
10. LaPrade RF, Wentorf F. Diagnosis and treatment of
posterolateral knee injuries. Clin Orthop Relat Res
2002; 10-21.
11. Geeslin AG, LaPrade RF. Location of bone bruises and
other osseous injuries associated with acute grade III
isolated and combined posterolateral knee injuries.
Am J Sports Med 2010;38:2502-8.
12. Geeslin AG, LaPrade RF. Outcomes of treatment of
acute grade-III isolated and combined posterolateral
knee injuries: a prospective case series and surgical
technique. J Bone Joint Surg Am 2011;93:1672-83.
13. LaPrade RF, Wentorf FA, Fritts H, Gundry C, Hight-
ower CD. A prospective magnetic resonance imaging
study of the incidence of posterolateral and multiple
ligament injuries in acute knee injuries presenting
with a hemarthrosis. Arthroscopy 2007;23:1341-7.
14. Lunden JB, Bzdusek PJ, Monson JK, Malcomson KW,
LaPrade RF. Current concepts in the recognition and
treatment of posterolateral corner injuries of the
knee. J Orthop Sports Phys Ther 2010;40:502-16.
15. Baker CL Jr, Norwood LA, Hughston JC. Acute poste-
Vol. 65 - No. 2 MINERVA ORTOPEDICA E TRAUMATOLOGICA 139
RECENT ADVANCES IN THE TREATMENT OF FCL INJURIES JAMES
ment reconstruction using quadriceps tendon-patel-
lar bone autograft with bioscrew xation. Arthros-
copy 2001;17:551-4.
44. Latimer HA, Tibone JE, ElAttrache NS, McMahon PJ.
Reconstruction of the lateral collateral ligament of the
knee with patellar tendon allograft: report of a new
technique in combined ligament injuries. Am J Sports
Med 1998;26:656-62.
45. Noyes FR, Barber-Westin SD. Posterolateral knee
reconstruction with an anatomical bone-patellar
tendon-bone reconstruction of the bular collateral
ligament. Am J Sports Med 2007;35:259-73.
46. Liu P, Wang J, Zhao F, Xu Y, Ao Y. Anatomic, arthro-
scopically assisted, mini-open bular collateral liga-
ment reconstruction: an in vitro biomechanical study.
Am J Sports Med 2014;42:373-81.
47. Terry GC, LaPrade RF. The posterolateral aspect of
the knee. Anatomy and surgical approach. Am J
Sports Med 1996;24:732-9.
48. Garrison JC, Shanley E, Thigpen C, Geary R, Osler M,
Delgiorno J. The reliability of the Vail sport test™ as a
measure of physical performance following anterior
cruciate ligament reconstruction. Int J Sports Phys
Ther 2012;7:20-30.
49. Girolami M, Galletti S, Montanari G, Mignani G,
Schuh R, Ellis S et al. Common peroneal nerve palsy
due to hematoma at the bular neck. J Knee Surg
2013;26(Suppl 1):S132-5.
50. Levy BA, Dajani KA, Morgan JA, Shah JP, Dahm DL,
Stuart MJ. Repair versus reconstruction of the bu-
lar collateral ligament and posterolateral corner in
the multiligament-injured knee. Am J Sports Med
2010;38:804-9.
51. Stannard JP, Brown SL, Farris RC, McGwin G Jr, Vol-
gas DA. The posterolateral corner of the knee: repair
versus reconstruction. Am J Sports Med 2005;33:881-
8.
Conicts of interest.—Dr. LaPrade is a paid consultant for
Arthrex and Smith and Nephew. However, no funding was
received directly related to this work.
The importance of anterior cruciate ligament on the
varus-valgus knee laxity. Am J Sports Med 1987;15:15-
21.
34. Weiss JA, Woo SL, Ohland KJ, Horibe S, Newton PO.
Evaluation of a new injury model to study medial
collateral ligament healing: primary healing versus
nonoperative treatment. J Orthop Res 1991;9:516-28.
35. Woo SL, Young EP, Ohland KJ, Marcin JP, Horibe S,
Lin HC. The effects of transection of the anterior cru-
ciate ligament on healing of the medial collateral liga-
ment. A biomechanical study of the knee in dogs. J
Bone Joint Surg Am 1990;72:382-92.
36. Thompson WO, Thaete FL, Fu FH, Dye SF. Tibial me-
niscal dynamics using three-dimensional reconstruc-
tion of magnetic resonance images. Am J Sports Med
1991;19:210-215; discussion 215-216.
37. O’Brien SJ, Warren RF, Pavlov H, Panariello R, Wickie-
wicz TL. Reconstruction of the chronically insufcient
anterior cruciate ligament with the central third of the
patellar ligament. J Bone Joint Surg Am 1981;73:278-
86.
38. LaPrade RF, Engebretsen L, Johansen S, Wentorf FA,
Kurtenbach C. The effect of a proximal tibial medial
opening wedge osteotomy on posterolateral knee
instability: a biomechanical study. Am J Sports Med
2008;36:956-60.
39. Noyes FR, Barber-Westin SD. Surgical restoration to
treat chronic deciency of the posterolateral complex
and cruciate ligaments of the knee joint. Am J Sports
Med 1996;24:415-26.
40. Veltri DM, Warren RF. Operative treatment of pos-
terolateral instability of the knee. Clin Sports Med
1994;13:615-27.
41. Fanelli GC, Giannotti BF, Edson CJ. Arthroscopically
assisted combined posterior cruciate ligament/pos-
terior lateral complex reconstruction. Arthroscopy
1996;12:521-30.
42. Buzzi R, Aglietti P, Vena LM, Giron F. Lateral collateral
ligament reconstruction using a semitendinosus graft.
Knee Surg Sports Traumatol Arthrosc 2004;12:36-42.
43. Chen CH, Chen WJ, Shih CH. Lateral collateral liga-
This document is protected by international copyright laws. No additional reproduction is authorized. It is permitted for personal use to download and save only one file and print only one copy of this Article. It is not permitted to make additional copies
(either sporadically or systematically, either printed or electronic) of the Article for any purpose. It is not permitted to distribute the electronic copy of the article through online internet and/or intranet file sharing systems, electronic mailing or any other
means which may allow access to the Article. The use of all or any part of the Article for any Commercial Use is not permitted. The creation of derivative works from the Article is not permitted. The production of reprints for personal or commercial use is
not permitted. It is not permitted to remove, cover, overlay, obscure, block, or change any copyright notices or terms of use which the Publisher may post on the Article. It is not permitted to frame or use framing techniques to enclose any trademark, logo,
or other proprietary information of the Publisher.
