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Cruells Vieira, Rua Paraná, 35, ap. 111, 18035-590 Sorocaba, SP.
© 2007 by the Arthroscopy Association of North America
An Anatomic Study of the Iliotibial Tract
Eduardo Luís Cruells Vieira, M.Sc., Eduardo Álvaro Vieira, Ph.D.,
Rogério Teixeira da Silva, M.Sc., Paulo Augusto dos Santos Berlfein, M.D.,
Rene Jorge Abdalla, Ph.D., and Moisés Cohen, Ph.D.
Purpose: To identify the structure of the iliotibial tract at knee level, as well as its insertions, layer
arrangement, and relationship with other structures of the lateral region of the knee and to compare the
findings with available literature. Methods: Ten detailed anatomic dissections were performed by using
incisions as recommended by the literature in fresh cadaver knees identifying the iliotibial tract compo-
nents. Results: The authors observed an iliotibial tract arrangement in superficial, deep, and capsular-
osseous layers. Insertions have been described as follows: at linea aspera, at the upper border of the lateral
epicondyle, at the patella, and at Gerdy’s tibial tuberculum and across the capsular-osseous layer.
Conclusions: The iliotibial tract (ITT) has important interconnections to the femur, the patella, and the
lateral tibia; the iliopatellar band joins the ITT to the patella through the superficial oblique retinaculum
and the lateral femoropatellar ligament, and the ITT capsular-osseous layer presents differentiated fibers
in an arched arrangement that borders the femoral condyle and inserts laterally to the Gerdy’s tubercle.
Clinical Relevance: The iliotibial tract can be considered as an anterolateral knee stabilizer, particularly
its capsular-osseous layer, which, together with the anterior cruciate ligament, constitutes a functional unit
forming a spatial “horseshoe” form. The detailed description of the structures forming iliotibial tract plays
an important role in the study of knee instabilities. Its important tibial, femoral, and patellar conections are
described so that better understanding of tibial femoral instability on the lateral side as well as patel-
lofemoral instability can be achieved and mechanisms of repair can be conceived. Key Words: Iliotibial
tract—Knee functional anatomy—Pivot shift.
certainly constitutes the rationale for understanding
pathologies, particularly those resulting from trau-
matic lesions. The perfect interaction of such struc-
tures contributes for the development of 2 essential
functions (apparently opposite): stability and motion.
For a normal knee function, it is essential to have
stability in all sections and joint movement ranges.
he critical study of the functional anatomy and of
the stabilizing elements of the complex knee joint
Such stability is achieved by joint surfaces geometry,
the menisci, ligaments, and periarticular muscles.
Here, we present our contribution for the study of
the iliotibial tract (ITT), which has called our attention
because of its extension and of its many components
and because of its involvement in the anterolateral
stabilization of the knee, as well as in the pivot shift
genesis and in the patellar lateral restraint. By this
study, we aim to identify this structure in detail, of
which comprehension is crucial for the study of the knee
and its instabilities.
The anatomist Vasalius,1in 1543, described the
tensor fascia lata as one of the tibial muscles. The
description of its insertion at the tibia is assigned to
Gerdy.2,3In 1958, Kaplan4developed a comparative
study of the ITT and pointed it out as a unique struc-
ture found only in the human specimen. The eponym
Maissiat’s band is because of the important research
performed by this French anatomist in 1843.4
According to Gardner,5the ITT is a complex structure
receiving the insertions of the gluteus maximus and
tensor fascia lata muscles. It is formed by the coales-
From the Sports Traumatology Center (Cete), Department of
Orthopedics and Traumatology, Federal University of São Paulo
(UNIFESP-EPM) (E.L.C.V., R.T.d.S., P.A.d.S.B., R.J.A.), São
Paulo, Brazil; and Medical and Biological Sciences Center, Pon-
tifícia Universidade Católica de São Paulo, (E.A.V., M.C.) São
The authors report no conflict of interest.
Address correspondence and reprint requests to Eduardo Luís
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 23, No 3 (March), 2007: pp 269-274
Author's personal copy
have made 4 different incisions recommended by
Terry et al.2(Fig 1), which would enable a better
identification and documentation.
An incision across the ITT oriented to the coronal
cence of both and of the thigh fascia and continues
proximally up to the iliac crest as gluteus aponeurosis. It
extends to the inside of the linea aspera and of the lateral
supracondylar line, as a lateral intermuscular septum
and, below, it fuses to the patellar lateral retinaculum and
inserts into the lateral tibial condyle and into the leg
fascia. Tandler6says that the parallel muscle bundles in
the gluteus region continue just behind the greater tro-
chanter, as a flat and large tendon, which is continuous to
the strengthened portion of the fascia lata, constituting
the iliotibial ligament or Maissiat’s band, which extends
from the iliac crest to the tibial lateral condyle. It is one
of the components of the superficial layer of the lateral
structure of the knee.7
The ITT together with the fascia tensor and the
gluteus maximus fibers play a role on the stance and
monopodal balance. This important dynamic structure
is described as “pelvic deltoid,”8,9allowing the swing-
ing of the knee along with the hip.
The ITT is a knee’s front-section stabilizer, function-
ing as a synergist of the knee flexion and extension and
contributing to the rotational movements of this joint.4
Although one may think that the ITT is a fascial tissue
that inserts only at the Gerdy tubercle, it is rather a
complex structure that has important interconnections to
the femur, patella, and tibia and seems to play an impor-
is to describe the structure of the iliotibial tract at knee
level, as well as its insertions, layer arrangement, and
relationship with other structures of the lateral region of
the knee showing the anatomic basis for its functional
and biomechanical importance.
Ten fresh cadaver knees, with ages ranging from 33 to
66 years and with no previous pathology or injury iden-
tifiable, have been dissected. From those, 9 were men
and 1 was a woman (9 right knees and 1 left knee). All
dissections were made at the Death Verification Service
in São Paulo City. Data for corpses have been recorded,
such as initial letters of the names, gender, height,
weight, and age, with photographic documentation being
performed for each dissection. The results of that re-
search have been carefully analyzed.
With the cadaver positioned in the lateral decubitus
and with extended knee, skin and subjacent fascia’s
subcutaneous cellular tissue separation was per-
formed. To probe the deep structures of the knee, we
section from the lateral intermuscular septum to the
anterior portion of Gerdy’s tubercle; an incision between
the ITT and the short head of the biceps femoris muscle;
a lateral parapatellar incision with Gerdy’s tubercle os-
teotomy, obtaining a view from inside out of the entire
ITT; and an incision of the superficial portion of the ITT
together with the thigh fascia and its lateral reflex, show-
ing the ITT’s relationship with the crural fascia and the
lateral intermuscular septum (Fig 1).
Occasionally, more than one of those incisions has
been performed in the same cadaver, aiming to show
the highest number of structures in each dissection. In
all studies, other structures of the posterolateral aspect
of the knee have been dissected, and their relationship
with the ITT have been observed.
The results of our anatomic study have been de-
scribed by means of layers, from the superficial layer
to the deep layer, and across its various insertions.
This layer is constituted by the superficial portion of
the vastus lateralis and biceps crural muscles aponeu-
rosis and through curvilinear fibers that cover the
anterior surface of the patella and patellar tendon,
constituting the superficial oblique retinaculum (Figs
2A and B). Those fibers, referred to as arciform fibers,
are angulated by 70° to 80° compared with those
directed to Gerdy’s tubercle. Fibers covering the pa-
tellar tendon exist in a higher number and are more
differentiated than the ones over the patella.
in the study. (A) Vastus lateralis aponeurosis, (B) patella,
(C) oblique superficial retinaculum, (D) patellar tendon, (E) Ger-
dy’s tubercle, (F) biceps femoris tendon, (G) biceps femoris (short
head), and (H) fibular head.
Lateral view of the knee, showing the incisions made
E. L. C. VIEIRA ET AL.
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probably because they remained adhered to the super-
ficial layer. Distal to the lateral epicondyle, the deep
layer fuses itself to the superficial layer and travels to
the patella and Gerdy’s tubercle (Fig 3).
The anterior border of the superficial layer is formed
by the patella and by lateral patellar ligament of the tibia
and its posterior border is formed by the biceps muscle.
The ITT insertion at Gerdy’s tubercle is wide and pre-
sents an aponeurotic expansion to the leg fascia.
This can be viewed when the superficial layer is
medially flapped. A wide fixation is noticed at the
linea aspera by means of the lateral intermuscular
septum and also at the lateral epicondyle, through a
strong ligament. This anatomic structure could be seen
by us when Gerdy’s tubercle osteotomy was being
performed, and the ITT superficial portion was being
flapped. When dissection was performed from proxi-
mal to distal, these fibers’ structure was less evident,
This layer has a very well-defined ligament structure
that starts from the lateral supraepicondylar region, bor-
dering the lateral edge of the lateral epicondyle and
inserting laterally to the Gerdy’s tubercle (Fig 4). That
retentive barrier allows the deep layer to extend its ori-
gins to proximal and anterior toward the lateral capular.
In fact, it acts as a true knee anterolateral ligament.
Posteriorly, this layer is continuous along the fascia,
which covers the gastrocnemius and plantaris mus-
cles. Its posterior border is the posterior edge of the
This layer’s fibers, which extend to the patella, form
a strong ligament known as lateral femoropatellar
ligament (Fig 5), and it can be separated only through
about 1.3 cm in width. On sectioning, the patella is
spontaneously travels medially.
Insertions of the Iliotibial Tract
We observed that the ITT does not present only 1
ITT has a wide periarticular insertion. We noticed during
the course of our research the following insertions:
1. Insertion at the linea aspera: this is done across
many fibrous bundles fixating to the deepest
portion of the ITT through the lateral intermus-
cular septum to the lateral portion of the femoral
diaphysis (Figs 3 and 5).
2. Insertion at the epicondyle: this is done through
a strong ligament inserting at the upper edge of
the lateral epicondyle at the same section of the
lateral collateral ligament (Fig 3).
3. Patellar insertion: it is wide and fuses itself to
the lateral retinaculum; at its medium portion it
thickens, constituting the lateral patellofemoral
ligament (Figs 2 and 5).
4. Direct insertion: this is done through the con-
fluence of the superficial and deep layers; it is
ribbon-shaped, and it inserts widely at Gerdy’s
tubercle and around it (Figs 2 and 5).
5. Capsular-osseous insertion: this also known as
lateral femorotibial ligament (Figs 4 and 6).
Other expansions and strengths can be mentioned
including expansion to the anterior aponeurosis of the
leg and patellotibial expansion or patellotibial liga-
ment, which is originated on the lateral border of the
patella and is inserted at the superolateral border of the
tibial lateral plateau.
the ITT at the patella and at Gerdy’s tubercle: (1) vastus lateralis
muscle, (2) superficial oblique retinaculum, (3) superficial layer of
the ITT, and (4) biceps femoris muscle.
Superficial oblique retinaculum and the insertions of
THE ILIOTIBIAL TRACT
Author's personal copy
patella to the tibia and to the lateral meniscus.
Adjacent to the patella, the superficial layer is not
differentiated from the deep layer. However, Terry
et al.2noticed that the capular-osseous layer connects
The lateral compartment of the knee extends from
the lateral portion of the patellar tendon to the poste-
rior cruciate ligament.12In this compartment, we no-
ticed ligament and musculotendinous components that
are essential to both static and dynamic stability of the
joint. The ITT plays an important role in this function.
After a detailed study of the ITT’s macroscopic
structure, we could see its importance as a static and
dynamic stabilizer for the knee. Because of its inser-
tion at the linea aspera and at the lateral epicondyle,
the ITT is a connective element for the knee and hip
functions.9Those insertions are very important be-
cause they enable the ITT to be tense in the entire joint
Fulkerson and Gossling14consider that the fibers on
the superficial layer travel to the patellar region, where
they are known as superficial oblique retinaculum and
reach the anterior portion of the patellar tendon. The
deepest portion, which they named as deep transverse
retinaculum, has its fibers oriented directly to the patella.
Below the deep transverse retinaculum, they find the
a ligament known as patellotibial ligament connects the
the femur to the patella through the lateral femoropa-
tellar ligament and that its differentiation from the
aponeurosis to the oblique portion of the vastus late-
ralis muscle is very difficult (Fig 5).
Our findings confirm those by Fulkerson and Gos-
sling because we could see the oblique orientation of
the superficial retinaculum, of which fibers cover
mainly the anterior portion of the patellar tendon. In
this region, layers arrangement is less defined. How-
ever, the lateral femoropatellar ligament is a well
differentiated structure and, when sectioned, the pa-
tella travels medially, indicating the prevalence of this
ligament in the patella stability on a frontal section.
Jeffreys15observed an abnormal band of the ITT up to
the superolateral portion of the patella in patients with
recurrent luxation of the latter. We agree with Fulkerson
and Gossling, who believe that this is not an abnormal
structure, but a hypertrophic femuropatellar ligament.
The importance of ITT’s Insertions at the Linea
Aspera and Epicondyle
The insertions at the linea aspera and epicondyle,
which were emphasized by Kaplan4and whose im-
portance was not highlighted by others, are crucial in
the ITT dynamics. We agree that those insertions play
the role of a tension band for the ITT at the thigh and
keeps it always tense in the entire joint movement
range,4,10being important for the functional stability
of the ITT.
aspera and lateral epicondyle: (1) superficial layer, (2) patella, (3) Gerdy’s tubercle after osteotomy, (4) insertion at the linea aspera, (5) lateral
epicondylar insertion of the ITT, (6) lateral epicondylar insertion of fibular collateral ligament, (7) fibular collateral ligament, and (8) head
of the fibula. (B) The superficial and deep layer of the ITT: (1) superficial layer, (2) patella, (3) Gerdy’s tubercle after osteotomy, (4) insertion
at the linea aspera, (5) lateral epicondylar insertion of the ITT, (6) lateral epicondylar insertion of fibular collateral ligament, (7) fibular
collateral ligament, and (8) head of the fibula.
(A) Lateral view of the distal extremity of the femur after osteotomy of Gerdy’s tubercle with the insertions of the ITT at the linea
E. L. C. VIEIRA ET AL.
Author's personal copy
the varus joint opening with the knee flexed at 30°.
Those authors12,16have also classified the various
joint instabilities into straight, rotatory, and combined.
Among those, they described the anterolateral rotatory
The Anterolateral Ligament of the Knee
Kaplan4defines as the main importance of the ITT
its stabilizing action. Terry et al.,2,17because of its
function, named it as anterolateral ligament of the
knee, particularly regarding its capsular-osseous layer.
Hughston et al.12divided the lateral compartment into
3 portions: anterior, medium, and posterior. Strength-
ening the medium portion of the lateral capsular lig-
ament are the ITT and the iliotibial band. The poste-
rior fibers of the ITT act as static stabilizers restricting
instability, caused by the injury on the medium third
of the lateral capsular ligament, which was shown by
a positive jerk test, positive anterior drawer test with
the tibia in neutral rotation, and negative or slightly
positive varus stress test at 30°.
Hughston et al.12disagree with Kaplan4and do not
consider ITT as the main structure of the lateral sta-
bilization because they have seen 4 patients who pre-
sented with a lateral compartment rupture with no
lesion on the ITT. In our opinion, the ITT is a structure
composed by many elements and probably only its
direct portion has been analyzed.
Hughston, together with Terry et al.,1716 years
after their original article had been published, in a
subsequent series of 82 patients with acute knee le-
sion, regarded as anterolateral and anteromedial insta-
bility, noticed that 98% of those patients had an ACL
lesion, and the association with lesion to any of the
ITT components has occurred in 93% of the examined
knees, which reinforces our hypothesis.
According to Terry et al.,17the reason for the wide
spectrum of clinical findings resulting from the ACL
failure is related to the lesion of the many ITT com-
ponents. It denies, therefore, the hypothesis that the
ACL lesion would be always responsible for all vari-
ations of the abnormal tibial anteriorization.
As per Terry et al.17the ITT acts as a synergist of the
ACL in the frontal section. The layer, named by them as
ITT’s capsular-osseous layer, which we consider as an
expansion for lateral capsular strengthening, located
more posterolaterally, provides an important fascial re-
supraepicondylar region of the femur, the arched direction of its
fibers, and the insertion lateral to Gerdy’s tubercle: (1) patella,
(2) quadriceps tendon, (3) lateral femoral condyle, (4) anterior
cruciate ligament, (5) lateral meniscus, (6) capsular-osseous layer,
(7) capsular-osseous insertion of the ITT, and (8) Gerdy’s tubercle.
Capsular-osseous layer of the ITT with its origin at the
superficial layer of the ITT showing the continuation of the fibers
with the lateral intermuscular septum: (1) vastus lateralis, (2) oblique
vastus lateralis, (3) lateral patellofemoral ligament, (4) direct inser-
tion at Gerdy’s tubercle, (5) fusion of the fibers of the vastus
lateralis aponeurosis and the superficial layer of the ITT, and
(6) short head of the biceps femoris muscle.
Section of the vastus lateralis aponeurosis with the
THE ILIOTIBIAL TRACT
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straint behind the lateral femoral condyle. With the ex-
tension of the knee, the femoral and tibial fixations
dispel, causing a tensioning of this portion of the ITT.
This tensioning, combined with the coronal orientation
of its fibers, promotes a restraint preventing the antero-
lateral subluxation of the tibia. This action additionally
restricts the anterior translation of the tibia.
We agree with Terry et al.17in the sense that the
capsular-osseous layer forms, in conjunction with the
ACL, the figure of an inverted “U” or a horseshoe
shape, being the ACL the medium portion of the “U”
and the capsular-osseous layer of the ITT its lateral
portion. We noticed in our dissections that the capsu-
lar-osseous portion of the ITT is a well-defined func-
tional and anatomic structure. Because of its strategic
location and to its thickness, it can be considered as a
true anterolateral ligament of the knee (Fig 6).
The ITT has important interconnctions to the
femur, the patella, and the lateral tibia. The iliopa-
tellar band joins the ITT to the patella through the
superficial oblique retinaculum and the lateral
femoropatellar ligament. The ITT capsular-osseous
layer presents differentiated fibers in an arched ar-
rangement that borders the femoral condyle and
inserts laterally to the Gerdy’s tubercle.11,13
Acknowledgment: The authors thank Paulo Roberto
Godoy for the illustrations of the anatomic dissections.
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layer of the ITT and the ACL (based on the concept of the inverted
“U” of Terry et al.17)
The horseshoe figure formed by the capsular-osseous
E. L. C. VIEIRA ET AL.