The Extensor Digitorum Brevis originates from the anterior
part of the dorsal surface of the calcaneus. Four tendons insert into the
proximal phalanx of the big toe and long extensor tendons to toes 2, 3, and 4. The
medial part of the muscle is known as the extensor hallucis brevies and ends in
a tendon that is inserted into the dorsal surface of the base of the proximal
phalanx of the big toe.
The other three tendons insert into the lateral side of
the tendons of the extensor digitorum longus of toes number 2, 3, and 4. The extensor
digitorum brevis helps to extend the first four digits. The extensor digitorum
brevis is innervated by the deep peroneal nerve (predominantly L5 nerve root). The
EDB muscle has the same innervation as a disc herniation at L4-L5 which will
also involve the L5 nerve root. It is probably the only muscle of the foot that
is innervated by the deep peroneal nerve. The deep peroneal nerve supplies
sensation to the first web space. The EDB is the only muscle on the foot that
makes a fleshy enlargement anterior to the lateral malleolus. The extensor
digitorum brevis can cause pain on the top of the foot. Irreducible dislocation
of the medial subtalar joint can result from interposition of the extensor digitorum
brevis muscle. Irreducible dislocation of the lateral subtalar joint can result
from interposition of the tibialis posterior tendon.
Plantar fascia rupture is not a very common injury, and it
has the characteristic of acute pain in the arch of the foot. It occurs due to
a tear in the plantar fascia, and that tear is painful. Rupture is often
associated with long standing flat feet deformity or can occur from steroid
injections. Another predisposing factor for plantar fascia rupture is plantar
fasciitis.
Anatomy
The plantar fascia is formed by three bands: the medial, the
central, and the lateral. The plantar aponeurosis is the central part of the
plantar fascia. The plantar fascia is inserted into the medial tuberosity of
the
calcaneus and extends distally, becoming broader and thinner. The plantar
fascia acts as a bow string.
The rupture of the plantar fascia may be misdiagnosed as
plantar fasciitis. When the plantar fascia tears, the patient will describe a
tearing pain that usually occurs during athletic activity. The tear may be
complete or incomplete. Complete tear of the plantar fascia occurs from sudden
trauma or injury. The patient feels “popping” or “snapping” suddenly. Walking will
be very difficult with tenderness, swelling and significant bruising on the
sole of the foot (the condition is painful). Some patients may have a noticeable
tightness of the calf muscle (equinus contracture) in association with rupture
of the plantar fascia. Partial rupture is less common and occurs from overuse,
as in running. MRI will identify the rupture, and it can also identify if the
rupture is partial or incomplete. Rupture is often in the arch of the foot
opposed to where the plantar fascia inserts into the heel (calcaneus). Ultrasound
has the same accuracy as MRI for imaging the plantar fascia. Interpretation of
the plantar fascia rupture may be difficult. You may need dynamic maneuvers
with dorsal flexion of the forefoot to stretch the plantar fascia. Usually the
proximal part of the plantar aponeurosis is clearly visualized on ultrasound.
MRI is probably better in diagnosis plantar fascia rupture.
Treatment of Plantar Fascia Rupture
-Non-Weight Bearing for 2-3 Weeks
-Walking Boot
-Crutches
-Physical Therapy
-Surgical Treatment is the last resort.
-Could be used in some athletes who
continue to have pain despite a well conducted conservative treatment
-Surgery is done to release the
fascia and the excise the scar
Patients with rupture of the plantar fascia typically
achieve a favorable outcome with return to full activity.
Ganglion
cysts can occur anywhere. They usually occur at the wrist area, however,
ganglion cysts may occur at the foot (usually at the top of the foot). This mass
can change in size, and it may grow slowly. The patient notices a mass usually
on the top of the foot. The mass is usually asymptomatic. The patient may have
a burning sensation due to irritation of the nerve when the ganglion compresses
the nerve. The patient may have skin irritation and also may have difficulty
walking and wearing shoes. If the ganglion is pushing on a nerve and causing
irritation, aspiration or surgical removal of the cyst can help relieving the
symptoms. We need to differentiate ganglion cyst of the foot from plantar
fibromatosis. Plantar fibromatosis occurs at the bottom of the foot. Ganglion cysts
usually occur at the top of the foot. Ganglion cysts will transilluminate. Plantar
fibromatosis does not transilluminate
Ganglion Cyst of the Ankle (Tarsal Tunnel Syndrome)
What is
Tarsal Tunnel Syndrome?
Tarsal
tunnel syndrome is a compressive neuropathy which is caused by compression of
the tibial nerve around the ankle region. A ganglion cyst can be one of the
intrinsic causes of tibial nerve compression. In the tarsal tunnel, the patient
may have pain and burning sensation. An MRI is probably needed for the
diagnosis of a ganglion cyst in the tarsal tunnel. They found that they best
result after surgery occurs when there is a ganglion cyst compressing on the
nerve, and this cyst is removed.
