Topics discussed on this page:
Posterior Tibial Tendon (PTT)
Tibialis Posterior Tendon
Posterior Tibial Tendon Dysfunction (PTTD)
What is the Posterior Tibial Tendon?
The Posterior Tibial Tendon (PTT),
also known as the Tibialis Posterior Tendon, is a major muscle on the
back of the tibia and fibula, (the lower leg bones). It comes down
the back of the leg, passing behind the
malleolus (the bump on the inside of the ankle), and attaches to
the foot at the
Navicular Bone on the medial (inside) border of the foot.
The tendon is very strong and very important in gait.
The tendon's primary function is to supinate the foot--to raise the arch, lock
bones into a stable position and help push you off from the ground.
Because it is used so much in gait, the PTT undergoes a great
deal of stress. For this reason, the tendon is vulnerable to injury,
particularly when certain other conditions are present.
When the Posterior Tibial Tendon is injured, several things
may occur. First, if the injury is not severe, the tendon may simply
become inflamed, a condition known as
If the injury is chronic, the tendon may be gradually become attenuated, or
stretched out. In this case, the tendon no longer able to function as it
once did, and the foot becomes non-functional. This is known as "Posterior Tibial Tendon Dysfunction"
or PTTD. Finally, if the injury is
severe enough, the tendon may completely rupture, a problem that usually
requires surgical intervention.
What conditions predispose someone towards
There are many predisposing factors to developing posterior
tibial tendon problems:
Excessive weight (It's obvious, perhaps, but the more force
applied to the tendon, the more stress it's under, and the more likely it is
Aging (Except for acute tendon rupture, which is usually
seen in younger patients), most PTTD patients are over 60.)
Gender (Females get problems more than males.)
Menopause (There is a hormonal link to this
condition. In fact this appears to be the single most common factor in
patients with PTTD.)
Steroid use (Steroids weaken tendon, and this is one reason
why steroids like cortisone should not be used to treat this condition.)
Smoking (Smoking disrupts circulation and weakens the
Rheumatological (arthritic) conditions (Certain types of
arthritis tend to also weaken the tendon and may
crystalline deposition within the tendon)
A history of injury (This may mean sudden trauma or
chronic, reptetitive, low-grade trauma.)
A fracture of the navicular (This is the bone where the tendon
Biomechanical abnormalities such as:
pronated Foot type
(A pronated foot is one that flattens too much).
A leg-length difference.
Calcaneal Valgus (This is a condition where the heel bone is no
longer straight, but rolls inwards relative to the leg).
Forefoot Varus (This is a condition where the front of the
foot--the metatarsals and toes, e.g.--is positioned inverted relative to
The presence of an
Os Tibiale Externum,
or OTE. (The OTE is an extra bone near the navicular.
What kind of problems does the patient
experience with PTTD?
Stage One describes the condition
when the patient has some sort of biomechanical or predisposing factor before
is the point
when the tendon begins to develop some symptoms (tendinitis) along the course of
the tendon or in the calf (shin splints). There may be a mild weakness of
is the stage when the
tendon begins to become attenuated or stretched out (tendinosis) and functions
poorly. It may be hard for the patient to stand on his toes.
Stage Four describes the point
where the foot begins to collapse, causing instability in the foot and arthritis
in the joints of the foot.
Arthritis develops, and the pain usually
worsens. To the left is a good example of a foot where the arch has
collapsed as a result of posterior tibial tendon dysfunction.
How is PTTD diagnosed?
While it's not usually hard to diagnose PTTD
once you know to look for it,
the condition is very much under-diagnosed and overlooked. The condition
is also fairly common. Our office sees the condition once every week or
In most cases the diagnosis can be made by
history and physical alone. Pain along the course of the tendon, muscle
weakness on one side over the other, and a collapsing arch are all
Tendons don't typically show up on
radiographs may be of some use when calcification of the tendon, a fractured
navicular, a collapsing arch or degenerative changes in the join are suspected
clinically. A physician with a good biomechanical background will also be
able to see many associated biomechanical abnormalities on film.
Bone scans and
CT may also be of some use, but
MRI is generally more useful, as it images tendons and other soft tissues
better, and it is highly sensitive and specific for this injury. A
tenogram, (a test where dye is injected into the tendon sheath) is still another
alternative, though its invasive nature means other diagnostic tests are more
How is PTT treated?
This condition may be rapidly progressing, so treatment should
In the acute cases, the
primary direction of treatment is based upon stabilizing the joint and calming
To stabilize the joint, treatment may range from taping and
padding for mild injuries to complete immobilization with a soft or hard
The tissues may be calmed down with conservative care like
ice, compression, anti-inflammatories, and ultrasound. Steroid
injections are not suggested, as they tend to weaken tendons.
In chronic cases,
orthoses is useful for most patients, even many severe
ones. New advances in orthotic therapy, such as inverted orthoses, are particularly
helpful and may frequently postpone surgery. In fact, with the newer types
of orthotic therapy, we find that less than 10% of PTTD patients end up
If orthoses do not adequately resolve the complaint, surgical
intervention may be indicated. Procedures range from repair of the
degenerative portions of the tendon and performing tendon transfers to
stabilizing or fusing one or a combination of joints in the mid and
rearfoot. The procedure chosen is variable from patient to patient.