|
FOOT AND ANKLE
FOOT
METATARSAL HEAD
Due to the collapsed appearance, Freiberg originally
termed the process an infraction of the second metatarsal
head, therefore, it is now often termed Freiberg's infraction.
It is now known that the process is that of true osteonecrosis
resulting in collapse. While the second metacarpal head is
the most common, involvement of the third is not uncommon.
The demographics of Freiberg's disease is quite distinct.
It is much more commonly observed in females than males, approximately
3-4:1. The average age range seen is 13-18 years of age and
is most commonly unilateral .
The cause of Freiberg's infraction is trauma, either
acute or chronic. It is thought that the second metatarsal
is most commonly involved because of its relative length and
fixation as compared to the rest of the metatarsals. High
heels, most commonly worn by females combined with the microtrauma
that they cause to the heads of the metacarpals is often is
blamed for the onset of Freiberg's disease.
Clinically, as with other forms of osteonecrosis, local pain,
swelling, and redness are typical. Restriction of motion at
the involved joint is also seen. The symptoms may start out
as mild, but may progress to a chronic debilatating state
eventually.
If you see one Freiberg's infraction, you've seen them all,
as they say. The radiographic signs are very consistent and
typical as seen below.
|
Freiberg's of the second metatarsal
|
Freiberg's
|
The radiographic signs of Freiberg's infraction
seen here include increased sclerosis, fragmentation and collapse/flattening
of the second metatarsal. Other signs specific for this location
include widening of the metatarsal head and widening and cortical
thickening of the metatarsal shaft.
|
Freiberg's of the third metatarsal
|
Figure 3 illustrates AP and medial oblique views of a foot
revealing Freiberg's disease of the head of the third metatarsal
head with very similar radiographic changes as described in
figures one and two.
Treatment is difficult. Some treatment regimes may include
a felt donut cushion to ease pressure off the metatarsal head,
ice to reduce pain and swelling, and ultrasound if there is
no fragmentation. Properly fitted new shoes may be suggested
if there is a history of routine use of high heel shoes.
NAVICULAR
Kohler's disease was thought by many to be avascular
necrosis of the tarsal navicular primarily based on the radiographic
signs. It is now a much more controversial subject. Kohler's
disease is can be a very confusing and ambiguous entity due
to uncertain etiology and often times vague symptoms. A history
of trauma is only elicited in approximately 35% of cases and
symptoms that correlate with the radiographic signs are very
sporadic.
When a diagnosis of Kohler's disease is made, the typical
patient is a young male, typically between 3 and 7 years of
age. It is unilateral approximately 75% of cases.
The controversy of Kohler's disease stems from the fact that
many authorities feel that this process is not a "disease"
at all, but rather a process of altered, but completely normal,
ossification of the tarsal navicular which leads to the radiographic
appearance.
There are two main reasons for the idea that this often times
is not osteonecrosis is the fact that 1) there are a lack
of symptoms and 2) it is a self-limiting condition.
The radiographic appearance is sclerosis, overall flattening
and deformity of the navicular. But, again, it's the associated
signs and symptoms, as described that must be present for
a confident diagnosis. MRI or bone scan may help confirm the
diagnosis, but because of its self-limiting nature, it most
likely is not warranted.
SESAMOIDS
Avascular necrosis of the sesamoids do not have an eponym
to memorize, thank goodness. This condition is most present
in active individuals commonly involved with dancing or running.
Symptoms consist of focal pain, swelling and restricted range
of motion. When it becomes revascularized, normal function
and resolution of symptoms are expected.
|
