INTRODUCTION
Tendonitis
in the foot is a common problem because we use our feet continuously.
It is a common example of an overuse injury. One of the most
frequently affected tendons is the posterior tibial tendon,
a structure that is normally hard at work, helping to hold
the arch up and prevent over-pronation or rolling in of the
foot.
ANATOMY
The posterior tibial tendon (below) runs behind the inside bump on the
ankle (the medial malleolus), across the instep, and attaches
to the bottom of the foot.
WHAT'S THE PROBLEM?
Posterior tibial tendon dysfunction
actually runs the gamut from initial strain and minor degeneration
of the posterior tibial tendon to frank rupture. It is now
known that the problem is caused by a degenerative tendinosis
rather than inflammation. Inflammation when it does occur
is secondary.

HOW DOES IT FEEL?
The symptoms of tendonitis of the
posterior tibial tendon include pain (below) in the instep
area of the foot and swelling along the course of the tendon.
The patient may also experience pain and swelling right behind
the inner ankle bone. There is pain upon palpation along
the course of the posterior tibial tendon behind the inner
ankle. There may also be burning, shooting, tingling, stabbing
pain , because the nerve is inflamed inside the tarsal tunnel.
Patients experience significant pain when walking, steadily
worsening toward the end of the day. There is significant
pain when the patient inverts his/her foot, as well as pain
upon passive stretching of the posterior tibial tendon, and
on eversion or flattening of the foot.
In some cases the tendon may actually rupture or tear, due to weakening of
the tendon by the inflammatory process. Rupture of the tendon leads to a fairly
pronounced flatfoot deformity (.avi movie) that is easily recognizable.

LET'S DO A TEST!
1. The patient is viewed standing
from behind. The amount of heel valgus on the affected
side is noted. The patient is then
asked to stand on his toes. The heel should invert upon
standing in the normal foot without
posterior tibial tendon dysfunction.
2. A very popular test for posterior tibial tendon dysfunction is the single
heel rise. The patient is asked to stand on his toes
standing on one foot. They will not be able to perform this maneuver and
if they are, there will be significant pain upon single heel rise. If the patient
is able to do the test, they are asked to repeat it
and will soon start feeling intense pain if a tendonitis is present.
3. In some difficult cases, an MRI scan may be useful to determine whether
the tendon has ruptured.
HOW DID THIS HAPPEN?
Behind the medial malleolus, the ankle
bone on the side of the ankle facing the other foot, there
is a concavity which is called the medial retromalleolar
sulcus. Within this groove runs the tendon of the posterior
tibial muscle. The groove and the fibrous covering which
envelopes it, is known as the Tarsal Tunnel. The section
of the tendon where it passes through the tunnel is a relatively
hypovascular area, where this tendon becomes strained and
degeneration develops. If activity and injury continues,
the problem increases and the tendon begins to degenerate.

Problems with the posterior tibial tendon
seem to occur in stages. Initially, irritation of the outer
covering of the tendon called the paratenon causes a paratendonitis
(.avi movie). This simply indicates that there is inflammation
around the tendon as it runs through the tarsal tunnel.
As we age, the tendon is subject to degeneration within
the substance of the tendon. This creates a situation where
the tendon becomes thickened, sometimes to the extent that
a nodule forms within the tendon. The normal arrangement
of the fibers of the tendon (similar to a nylon rope) becomes
jumbled, and the tendon loses strength. This condition
is called tendonosis. In many cases, the two conditions
are present simultaneously. The weakened, degenerative
tendon sets the stage for the possibility of actual rupture
(above, left) of the posterior tibial tendon. Flat foot
types, with equinus influences (tight heel cords, pronation
during late stance, too low a heel and inadequate support
in footwear are factors which can lead to Posterior Tibial
Tendon Dysfunction. Walking up and down hills (golf course)
hyperpronating and supinating activities (golf swing) can
bring on symptoms.
WHAT CAN I DO FOR IT?
When the foot is acutely painful,
rest, ice, nonsteroidal anti-inflammatory drugs like Advil
are recommended, and a compressive dressing may be applied.
WHAT WILL MY DOCTOR DO FOR IT?
Cast immobilization holding
the foot in slight inversion and plantar flexion for 4-6 weeks may be started.
After the acute period, a custom orthosis or brace may be fitted. An air stirrup
brace or lace-up ankle support is beneficial during the rehabilitation period.
Your foot doctor may prescribe special shoes with external additions to the
medial side(.i.e., medial heel wedge), to support the foot and prevent arch
collapse.. The doctor may prescribe a custom foot orthotic based on the flexibility
of the foot. The orthosis may be constructed of leather or plastic. Medial
posting may be placed along the hindfoot. A UCBL orthosis with a rearfoot varus
post is sometimes used for posterior tibial dysfunction as the foot begins
to change shape and flatten. If the foot becomes both flat and rigid, an Ankle-foot
orthosis may become necessary.

If the condition becomes severe and chronic,
the doctor may suggest surgical intervention, which consists
of tendon transfers and osteotomies to improve function,
and parts of the thickened tendon may be removed, to decrease
symptoms.
If the tendon has ruptured, surgery may be required to either repair the ruptured
tendon - or to replace it with a tendon graft. Most tears will not simply be
repairable, unless they only recently occurred. Usually, another tendon in
the foot, such as the tendon that flexes the four lesser toes (bends them down)
is used as a tendon graft to replace the function of the posterior tibial tendon.
Finally, in cases which have been neglected, and a fixed flatfoot deformity
is present, a fusion (or arthrodesis) of the foot may be required. A fusion
is an operation where a joint between two bones is removed and the two bones
on either side of the joint are allowed to grow together - or fuse. This type
of operation is used to stop pain from joints that are worn out and can be
used to realign the bones when the normal mechanisms for maintaining normal
alignment are deficient - such as when the tendons and ligaments no longer
work properly. Usually, several joints must be fused to control the flatfoot
deformity occurring after posterior tibial tendon rupture.
Following surgery, you will most likely be placed in some sort of brace or
cast if the tendon has been repaired or grafted. You will probably be in a
cast for 6-8 weeks if a fusion has been performed.
Author: Ellen Sobel, DPM, Ph.D.
LINKS TO MORE INFORMATION
The Rothman Institute at
Jefferson - Posterior Tibial Tendon Dysfunction