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Journal of the American Academy of Orthopaedic Surgeons
112
The loss of function of the posterior
tibial tendon has been associated
with the development of a progres-
sive flatfoot deformity in adults
and children.
1,2
The exact etiology
of this condition remains contro-
versial. While rupture of the pos-
terior tibial tendon has been asso-
ciated with various underlying
pathologic conditions, the idio-
pathic nature of this problem in
most patients adds to a growing
level of interest in the problem
among the general orthopaedic
community. There is a sizable
group of patients in whom symp-
tomatic discomfort is associated
with dysfunction of this tendon as
well as concomitant deformities.
The purpose of this report is to
illustrate the spectrum of posterior
tibial tendon insufficiency, to high-
light recently described techniques
for reconstruction, and to review
options for surgical and nonopera-
tive management.
History

The original description of posteri-
or tibialis insufficiency and its asso-
ciated tendinitis is credited to
Kulowski in a 1936 article. Fowler
3
and Williams
4
described early
series of patients who had apparent
tendinitis of the posterior tibialis
tendon that required surgical treat-
ment. However, for many years,
few reports were published about
this pathologic condition. Consid-
erable interest in posterior tibial
tendon insufficiency has developed
over the past 15 years. This interest
has largely stemmed from efforts to
understand the pathomechanics of
the hindfoot as well as reports of
clinical series describing a variety
of methods for surgical treatment of
this condition.
Dr. Beals is Assistant Professor, Department of
Orthopedics, University of Utah School of
Medicine, Salt Lake City. Dr. Pomeroy is
Clinical Assistant Professor of Orthopaedic
Surgery, University of New England; and
Director, Portland Orthopedic Foot and Ankle
Center, South Portland, Me. Dr. Manoli is

Professor and Chairman, Department of
Orthopedic Surgery, University of South
Alabama, Mobile.
Reprint requests: Dr. Beals, University of
Utah School of Medicine, 50 North Medical
Drive, Salt Lake City, UT 84132.
Copyright 1999 by the American Academy of
Orthopaedic Surgeons.
Abstract
Posterior tibial tendon insufficiency is the most common cause of acquired
adult flatfoot deformity. Although the exact etiology of the disorder is still
unknown, the condition has been classified, on the basis of clinical and radio-
graphic findings, into four stages. In stage I, there is no notable clinical
deformity; patients usually present with pain along the course of the tendon
and local inflammatory changes. Stage II is characterized by a dynamic
deformity of the hindfoot. Stage III involves a fixed deformity of the hindfoot
and typically also a fixed forefoot supination deformity but no obvious evi-
dence of ankle abnormality. In stage IV, ankle involvement is secondary to
long-standing fixed hindfoot deformities. The initial treatment of patients in
any stage should be nonoperative, with immobilization, a nonsteroidal anti-
inflammatory drug, and perhaps an orthotic device. The role of corticosteroid
injections continues to be controversial. When nonoperative management
fails, the treatment options consist of soft-tissue procedures alone or in com-
bination with osteotomy or arthrodesis. Stage I insufficiency is generally
treated with debridement and tenosynovectomy. Soft-tissue transfer does not
appear to correct the underlying deformity in stage II disease; however, there
is growing interest in joint-sparing operations that attempt to compensate for
the underlying deformities with osteotomies or arthrodeses, supplemented
with dynamic transfers to replace the insufficient posterior tibial tendon.
Subtalar, double, or triple arthrodesis is the procedure of choice for stage III

disease, frequently in conjunction with heel-cord lengthening. Tibiocalcaneal
arthrodesis or pantalar arthrodesis is most commonly used to treat stage IV
disease.
J Am Acad Orthop Surg 1999;7:112-118
Posterior Tibial Tendon Insufficiency:
Diagnosis and Treatment
Timothy C. Beals, MD, Gregory C. Pomeroy, MD, and Arthur Manoli II, MD
Timothy C. Beals, MD, et al
Vol 7, No 2, March/April 1999
113
Anatomy and
Biomechanics
The posterior tibial muscle origi-
nates on the posterior aspect of the
tibia, the fibula, and the interos-
seous membrane. It courses poste-
riorly and medially around the
ankle in a groove adjacent to the
medial malleolus and inserts on the
midfoot in the area of the navicular
tuberosity. The tendon has bands
that attach to the plantar aspect of
the cuneiforms; the second, third,
and fourth metatarsals; and the
sustentaculum tali. It runs posteri-
or to the axis of the ankle joint and
medial to the axis of the subtalar
joint. Therefore, the tendon func-
tions as a plantar-flexor of the
ankle and as an invertor of the sub-

talar joint complex.
The posterior tibial muscle initi-
ates the process of inversion of the
hindfoot during gait, bringing it
into a neutral position and maxi-
mizing the mechanical advantage
of the more laterally positioned
Achilles tendon as the individual
rises onto the forefoot. The poste-
rior tibial muscle truly drives the
position of the hindfoot and deter-
mines the flexibility of the foot by
its control over the transverse tarsal
joints. The loss of the force of
inversion of the muscle explains
why patients with posterior tibial
tendon insufficiency have only a
limited ability, or are completely
unable, to rise onto their toes from
a position of single-leg stance. The
posterior tibial muscle is normally
opposed by the peroneus brevis,
and it has been theorized that it is
the lack of opposition of the per-
oneus brevis muscle that leads to
the clinical deformities recognized
in patients with rupture or dys-
function of the posterior tibial ten-
don. The posterior tibial and per-
oneus brevis muscles both function

during the midstance phase of gait.
Several pertinent anatomic fac-
tors relate to reconstruction tech-
niques and explain the problems
patients experience with insuffi-
ciency of the posterior tibial ten-
don. These include the fact that
the posterior tibial muscle is large
in comparison to those that can be
transferred to replace it. It has a
cross-sectional area of 16.9 cm
2
,
compared with 5.5 cm
2
for the flex-
or digitorum longus muscle and
6.7 cm
2
for the peroneus brevis
muscle. The medial capsular and
ligamentous structures of the hind-
foot and midfoot certainly play a
role in the development of flatfoot
deformities. The talonavicular
joint capsule, as well as the spring-
ligament
5
and deltoid-ligament
complexes, have been implicated

in the progressive loss of the medi-
al longitudinal arch of the foot and
the ankle dysfunction seen in long-
standing cases of posterior tibial
tendon insufficiency.
Diagnosis
The diagnosis of posterior tibial
tendon insufficiency is primarily a
clinical one. Patients typically
complain of pain medially around
the ankle that may radiate into the
arch of the foot. Some patients in
the later stages of the condition
complain of pain on the lateral
aspect of the foot, where the calca-
neus abuts against the fibula, due
to an excessive valgus position of
the hindfoot. Roughly half of all
patients give a history of some sort
of trauma that was initially thought
to be a sprain. Patients often expe-
rience swelling along the course of
the posterior tibial tendon and sig-
nificant pain, most typically several
centimeters proximal to the inser-
tion onto the navicular tuberosity.
Pain is exacerbated by activity, and
the ability to walk distances de-
creases. Some patients present
simply with pain and apparent

inflammation along the tendon
without any evidence of clinical
deformity, but most patients have
some collapse of the foot.
The rate of development of clini-
cal deformity is variable, and there
are no adequate studies of the nat-
ural history of posterior tibial ten-
don insufficiency. In some pa-
tients, the deformity increases, and
eventually the hindfoot valgus,
notable even during relatively
early stages of the condition, be-
comes fixed. In the latest stages of
the condition, the ankle is affected
and has a tendency toward valgus
tilting from laxity of the medial
deltoid complex.
Clinical evaluation includes
observing the patient in a standing
position. When viewed from be-
hind, the Òtoo many toesÓ sign is
typically seen, which is evidence of
abduction of the midfoot relative to
the hindfoot.
6,7
Excessive hindfoot
valgus is noted in the affected limb,
as well as loss of the longitudinal
arch when viewed from either the

side or the front. Typically, soft-
tissue swelling around the medial
aspect of the ankle is evident. The
tissues below the medial malleolus
appear prominent due largely to
excessive hindfoot valgus (Fig. 1).
Patients asked to rise onto their
Fig. 1 Clinical appearance of a patient
with stage II posterior tibial tendon insuffi-
ciency. Note the too-many-toes sign on the
left, the excessive hindfoot valgus, and
medial soft-tissue swelling.
Posterior Tibial Tendon Insufficiency
Journal of the American Academy of Orthopaedic Surgeons
114
toes from a position of single-leg
stance either are completely unable
to comply or can do so only to a
limited degree. They may attempt
to compensate by vaulting forward
to raise themselves with use of the
Achilles tendon.
While some authors dismiss its
utility, manual testing of muscle
units is helpful for both diagnosis
and the determination of treatment
options. Resistance against the tib-
ialis posterior is assessed, as well as
testing of the peroneus brevis, flex-
or hallucis longus, and flexor digi-

torum longus. To evaluate the tib-
ialis posterior, the foot is placed in
an everted, plantar-flexed position,
and the patient is asked to invert
the foot. This method is more
accurate than testing the foot in an
inverted position; with that tech-
nique, the function of the tibialis
anterior may confuse the examiner.
Contracture of the Achilles ten-
don complex is often noted when
the foot is placed in a reduced posi-
tion. In cases of excessive hindfoot
valgus, patients are able to achieve
a relatively dorsiflexed position by
rotation through the transverse
tarsal joints into a Òcompensated
equinusÓ position. The hindfoot
equinus often seems most directly
related to the gastrocnemius mus-
cle and is not necessarily related to
the entire gastrocnemius-soleus
complex. This distinction is made
by testing with the knee extended
and flexed. During gait evaluation,
recruitment of the long extensor
tendons can be seen in patients
who have a tight Achilles tendon
complex.
Thorough evaluation is neces-

sary to ensure that insufficiency of
the posterior tibialis tendon is an
isolated problem and not indica-
tive of a more generalized condi-
tion, such as rheumatoid arthritis
or seronegative arthropathy. Ex-
amination of the contralateral limb
and upper extremities is often
helpful.
Radiographic evaluation should
include four weight-bearing films:
an anteroposterior view of both
ankles, an anteroposterior view of
both feet, and lateral foot and ankle
radiographs of each side. This
allows comparison in patients who
have unilateral disease and often
serves as an excellent teaching tool
when explaining the nature of the
problem to the patient. Arthrosis
of the hindfoot joints should be
determined, as this may affect
treatment. Typical deformity in-
cludes apparent shortening of the
hindfoot on the weight-bearing
anteroposterior ankle radiograph,
which is indicative of collapse
through the subtalar joint complex.
A rare finding in advanced poste-
rior tibial tendon insufficiency is an

ossicle in the medial ligament com-
plex, which seems associated with
failure of the deltoid.
On weight-bearing lateral radio-
graphs, the inclination of the talus
is plantarward in comparison to
normal, with collapse typically
through the talonavicular joint. On
some occasions, the collapse seems
equally evident through the navic-
ulocuneiform and tarsometatarsal
articulations. Comparison of the
inferior portion of the medial
cuneiform to the inferior portion of
the fifth metatarsal can be helpful
to allow objective measurement of
the degree of collapse (Fig. 2).
Anteroposterior foot radiographs
typically demonstrate lateral peri-
talar subluxation of the navicular
and associated abduction of the
midfoot. The amount of the talar
head that is uncovered appears
increased in comparison to the con-
tralateral side.
Evaluation with adjunctive mo-
dalities, such as tomography, injec-
A B
Fig. 2 A, Lateral weight-bearing radiograph of a foot with stage II posterior tibial tendon insufficiency. The inferior border of the medial
cuneiform (medial column) is even with the base of the fifth metatarsal (lateral column). Note the plantar inclination of the talus. B, The

normal contralateral foot is shown for comparison.
Timothy C. Beals, MD, et al
Vol 7, No 2, March/April 1999
115
tion tenography, ultrasonography,
and magnetic resonance imaging,
has been advocated by some.
Indeed, there are case reports docu-
menting utility in cases in which the
diagnosis is uncertain. Although
this is not routinely recommended,
such tests should be considered.
Classification of Posterior
Tibial Tendon
Insufficiency
Johnson and Strom
7
initially de-
scribed a classification scheme for
posterior tibial tendon insufficiency.
Although the classification is not
predictive and does not consider
the contracted gastrocnemius, the
initial three-stage scheme is useful
in developing algorithms for treat-
ment. However, it has been found
helpful to also consider a fourth
stage of the disorder in developing
a treatment plan.
Stage I

Stage I is defined as the absence
of a fixed deformity of the foot or
ankle with the possible exception of
a contracted gastrocnemius-soleus
complex. The foot is in normal
alignment when the patient is stand-
ing. Patients typically present with
pain along the course of the poste-
rior tibialis tendon and evidence of
local inflammatory changes.
Stage II
Stage II is characterized by a
dynamic deformity of the hindfoot.
The standing patient displays an
increased degree of hindfoot valgus,
apparent weakness of tibialis poste-
rior function, the characteristic too-
many-toes sign, and inability to do a
single-leg heel rise. However, pat-
ients still have a relatively normal
arc of subtalar motion, and the foot
can be placed into a neutral posi-
tion, with the possible exception of
contraction of the gastrocnemius-
soleus complex.
Stage III
Patients with stage III posterior
tibial tendon insufficiency have a
fixed deformity of the hindfoot.
With the hindfoot in a fixed valgus

position, it is not possible to re-
duce the talonavicular joint. Typi-
cally, these patients also have an
accompanying fixed forefoot supi-
nation deformity that is a compen-
satory change to accommodate the
hindfoot valgus in order to main-
tain a plantigrade foot. Patients
with stage III disease do not have
obvious evidence of ankle abnor-
malities.
Stage IV
A relatively small subset of
patients have ankle involvement
secondary to long-standing fixed
deformities of the hindfoot. They
may present with ankle arthritis
due to eccentric loading of the
ankle. Some have a valgus talar tilt
with loss of competence of the del-
toid ligament complex.
Pathophysiology
The etiology of posterior tibial ten-
don insufficiency is elusive. In an
epidemiologic study, Holmes and
Mann
8
correlated the development
of posterior tibial tendon insuffi-
ciency to hypertension and obesity.

This condition affects more women
than men. Controversy exists
about the development of posterior
tibial tendon insufficiency in
patients with rheumatoid arthritis,
with some authors emphasizing
the role of the tendon and others
implying dysfunction secondary to
subtalar arthrosis.
The blood supply in the region
of tendon failure has been stud-
ied.
9,10
Some theorize that there is
an area of diminished perfusion at
the site of tendon failure, which
may have implications regarding
the etiology of the injury and its
apparent inability to heal. Mechani-
cal causes of posterior tibial tendon
insufficiency have been described,
including an association with a
contracted gastrocnemius-soleus
complex.
Recent immunohistologic stud-
ies imply a lack of an inflammatory
appearance in stage II disease. The
histologic appearance is consistent
with mechanical failure of the col-
lagen architecture of the tendon in

the area of elongation and rupture,
with mucoid degeneration. Com-
plete rupture of the tibialis poste-
rior tendon is not common, as most
patients have longitudinal failure
of the tendon substance. In gross
appearance, the tendon has been
described as being the color of
poached fish, often with longitudi-
nal tears on the lateral side of the
tendon (Fig. 3). In cases of chronic
posterior tibial tendon insufficiency,
the gross appearance and histo-
logic structure of the tendon are
abnormal.
Nonoperative Management
The initial management of patients
who present in any stage of poste-
rior tibial tendon insufficiency is
nonoperative. Some success has
been achieved by immobilization of
patients who have symptoms of
acute tendinitis with or without
deformity. A trial with an accom-
modative orthotic device that is
supportive of the medial longitudi-
nal arch is usually worthwhile.
Although there are no published
studies documenting the efficacy of
orthotic devices in the treatment of

the various stages of this condition,
there is certainly a population of
patients who report a decreased
level of symptoms associated with
the use of such a device. An ankle
brace or ankle-foot orthosis will be
helpful to some patients. Nonster-
oidal anti-inflammatory medication
can decrease pain and associated
swelling.
Posterior Tibial Tendon Insufficiency
Journal of the American Academy of Orthopaedic Surgeons
116
The role, benefit, and appropri-
ateness of corticosteroid injections
for this problem continue to be
controversial. Published reports
associate the use of steroid injec-
tions with rupture of the tendon,
although it is possible that in these
instances rupture might have
occurred without injection due to
the underlying pathologic changes
in the tendon. There are no con-
trolled studies of the use of such
injections. Therefore, at this time,
routine use of injections in this area
cannot be recommended as part of
the nonoperative treatment of this
condition.

Operative Management
The operative treatment of patients
in whom nonoperative manage-
ment has failed consists of either
soft-tissue procedures alone or soft-
tissue procedures combined with
either osteotomies or arthrodesis.
It is important to account for all the
fixed and dynamic structural defor-
mities present when defining a spe-
cific operative plan for a given
patient.
Stage I
Patients who have stage I poste-
rior tibial tendon insufficiency often
do not have a notable clinical defor-
mity. They have an inflammatory
condition involving the tendon, but
the tendon remains competent in
terms of function, and there are no
secondary deformities that have
developed due to the tenosynovitis.
These patients have been treated
with debridement of the tendon
and tenosynovectomy around the
posterior tibial tendon. There is
only one recent study providing
follow-up, and it supports the con-
cept that the combination of
debridement and tenosynovectomy

is effective in relieving pain.
11
However, there are no published
studies on this patient population
that provide long-term follow-up
data. Consideration could be given
to augmentation of the posterior
tibial tendon with the flexor digito-
rum longus and to a gastrocnemius
or heel-cord lengthening.
Stage II
It is in the treatment of this sub-
set of patients where there is the
greatest degree of controversy
regarding the optimal surgical
management. The historical foun-
dation for treatment of this stage of
posterior tibial tendon insufficiency
is provided by a study reporting on
the debridement of the posterior
tibial tendon and transfer of the
flexor digitorum longus to the navic-
ular.
1
The results in 17 patients
with a mean follow-up of less than
3 years have been very acceptable
in terms of relieving pain. How-
ever, it appears that the soft-tissue
transfer does not correct the under-

lying deformity.
A recent article describes the
results in a series of 13 patients fol-
lowed up for a mean of 27 months
after primary repair of the poste-
rior tibial tendon and tenodesis of
the flexor digitorum longus.
12
The
results were considered to support
the idea that these procedures re-
lieve pain and improve the ability
to ambulate. Similarly, good re-
sults have been achieved with
spring-ligament repair or recon-
struction in addition to tendon
transfer.
5
There is growing interest in oper-
ations for stage II disease that
attempt to compensate for the under-
lying deformities and deforming
forces with osteotomies or arthrode-
ses. The bone procedures are sup-
plemented with dynamic transfers to
replace the insufficient posterior tib-
ial tendon. Recent reports
13,14
have
highlighted the early successful

results of joint-sparing operations,
such as a medializing osteotomy of
the calcaneal tuberosity in addition
to tendon transfer and a procedure
that combines a medializing cal-
caneal osteotomy, a lateral columnÐ
lengthening osteotomy through the
anterior calcaneus, a flexor digito-
rum longus tendon transfer to the
medial cuneiform, and heel-cord
lengthening (Fig. 4). These two stud-
ies demonstrate improved radio-
graphic appearance, and the study
by Pomeroy and Manoli
14
docu-
ments statistically significant im-
Fig. 3 Gross appearance of a degenerated posterior tibial tendon. Note the disruption of
the fibers on the lateral side of the tendon.
Timothy C. Beals, MD, et al
Vol 7, No 2, March/April 1999
117
provement in function as indicated
by the score on the ankle-hindfoot
rating scale of the American Ortho-
paedic Foot and Ankle Society.
15
The
early reports of the success of joint-
sparing operations allow optimism

that it may be possible to treat stage
II posterior tibial tendon insufficiency
with procedures that do not necessi-
tate a significant loss of hindfoot
motion and adaptability.
Lateral-column lengthening
through the calcaneocuboid articu-
lation with medial soft-tissue
reconstruction has been advocated.
The biomechanical and radio-
graphic implications of such proce-
dures have been studied by
Sangeorzan et al
16
and Deland et
al.
17
Subtalar arthrodesis is still
suggested by many experienced
foot and ankle surgeons, both alone
and in concert with medial soft-
tissue debridement and/or tendon
transfer. The results of a study of
patients treated with isolated talo-
navicular arthrodesis demonstrated
improved function and decreased
pain.
18
In another study,
19

the
implications of a talonavicular
fusion in terms of the effect on
hindfoot motion implied a signifi-
cant loss of mobility.
Stage III
The foot with stage III posterior
tibial tendon insufficiency has fixed
deformities that cannot be corrected
by osteotomies or soft-tissue proce-
dures alone. Typically, there is some
degree of arthrosis present in the
subtalar joint complex. The proce-
dures of choice in this stage of the
disease include subtalar arthrodesis,
double arthrodesis, and triple ar-
throdesis. These are frequently done
in conjunction with heel-cord length-
ening. The arthrodesis selected
should be able to correct all of the
deformities. Once the subtalar joint
has been taken out of an excessive
degree of hindfoot valgus, fixed fore-
foot supination necessitates a talo-
navicular arthrodesis to rotate the
foot into a plantigrade position. In
some cases with more extreme defor-
mity, it may even be necessary to
perform an operation to plantar-flex
the first ray if full correction of the

deformity cannot be accomplished
with a triple arthrodesis. The funda-
mental goal is a plantigrade foot in a
good position that supports the
ankle in optimal alignment.
Graves et al
20
reported on 17
patients who had undergone triple
arthrodesis, 10 of whom had poste-
rior tibial tendon insufficiency. The
mean follow-up interval was 3
1
Ú2
years. The postoperative complica-
tions were significant, and the
authors recommended that triple
arthrodesis be reserved as a salvage
procedure. They also emphasized
the risk of increased arthrosis in
joints adjacent to the arthrodesis.
Stage IV
Patients with long-standing
severe hindfoot valgus deformities
and secondary ankle arthrosis are
difficult to treat. Fortunately, few
patients fall into this category.
Most commonly, tibiocalcaneal
arthrodesis or pantalar arthrodesis
is performed to address all of the

deformities simultaneously.
Summary
Posterior tibial tendon insufficiency
is a disorder with a broad spectrum
of clinical presentations. It is
essential that treatment be closely
correlated to the particular static
and dynamic deformities in the
patient. The classification system
initially outlined by Johnson and
Strom
7
is helpful in determining
A B
Fig. 4 Preoperative (A) and postoperative (B) radiographic appearance of a patient who underwent a medializing calcaneal tuberosity
osteotomy and lateral columnÐlengthening calcaneal osteotomy.
Posterior Tibial Tendon Insufficiency
Journal of the American Academy of Orthopaedic Surgeons
118
the stage of disease and the treat-
ment options available. However,
without a documented natural his-
tory of the disorder or a known
time frame for the progression
from one stage to another, it re-
mains a challenge to counsel pa-
tients regarding the optimal treat-
ment. Recently described joint-
sparing operations and limited
arthrodeses combined with soft-

tissue reconstruction allow opti-
mism that patients with this dis-
abling hindfoot condition can
resume relatively normal function.
The long-term outcome of patients
treated with these techniques re-
mains unknown.
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