Ankle
Sprains in the Runner
Ankle sprains are one of the most
common joint injuries runners experience. The injury can
occur when one rolls over a rock, lands off a curb, or
steps in a small hole or crack in the road. Usually the
sprain is only mild, but on occasion it may seriously
injure the ligaments or tendons surrounding the ankle
joint. Management of this injury relies on early and
accurate diagnosis, as well as an aggressive
rehabilitation program directed toward reducing acute
symptoms, maintaining ankle stability, and returning the
runner to pre-injury functional level.
General Anatomy of the Ankle
The ankle is comprised of three main
bones: the talus (from the foot), the fibula and tibia
(from the lower leg). The three bones together form a
mortise (on the top of the talus), as well as two joint
areas (on the inside and outside of the ankle),
sometimes called the "gutters". The ankle is surrounded
by a capsule, as well as tissue (the synovium) that feed
it blood and oxygen.
Some of the more important structures
that hold the ankle together are the ankle ligaments.
Most ankle sprains involving the
ligaments are weight bearing injuries. When a runner's
foot rolls outward (supinates) and the front of the foot
points downwards as he or she lands on the ground,
lateral ankle sprain can be a result. It is usually this
situation that causes injury to the anterior talo-fibular
ligament. However, when the foot rolls inwards (pronates)
and the forefoot turns outward (abducts), the ankle is
subject to an injury involving the deltoid ligament that
supports the inside of the ankle. This can occur when
another runner steps on the back of the ankle, as at the
beginning of a race, or when a runner trips and falls on
the runner in front of him.
Diagnosis
When assessing an ankle sprain, your
podiatrist will want to know the mechanism of injury and
history of previous ankle sprains. Where the foot was
located at the time of injury, "popping" sensations,
whether the runner can put weight on the ankle are all
important questions needing an answer. If past ankle
sprains are part of the history, for example, a new
acute ankle sprain can have a significant impact.
The physical examination should
confirm the suspected diagnosis, based on the history of
the injury. One looks for any obvious deformities of the
ankle or foot, black and blue discoloration, swelling,
or disruption of the skin. When crackling, extreme
swelling and tenderness are present, together with a
limited range of motion, one may suspect a fracture of
the ankle. A feeling of disruption on either the inside
or the outside of the ankle may indicate a rupture of
one of the ankle ligaments.
To check for ankle instability, the
runner should be evaluated while weight bearing. Manual
muscle testing is also valuable when checking for ankle
instability. One of the more critical tests that a
runner should be able to perform before allowing
resumption of activity is a "single toe raise" test. If
the runner is unable to do this, one might suspect
ligamentous injury or ankle instability.
X-rays help rule out fractures,
"fleck fractures" inside the ankle joint, loose bodies,
and/or degenerative joint disease (arthritis). Stress
X-rays are taken when ligamentous rupture or ankle
instability is suspected. When a stress test is taken of
your ankle, don't be surprised if the same test is
performed on the other ankle. This is done to compare
the two ankles, particularly in cases of ligamentous
laxity (loose ligaments).
In the past, more commonly, ankle
arthrography has been used. This involves injecting a
dye into the ankle joint as it is X-rayed. This helps
determine if a rupture of a ligament or tear of the
ankle capsule has occurred. However, this procedure does
involve some discomfort during the injection process,
and, on rare occasions, an allergy to the dye occurs.
Other diagnostic tests include
computerized tomography (CT Scan) to discover injuries
of the bone, and magnetic resonance imaging (MRI) to
isolate and diagnose specific soft tissue injuries
(ligaments, tendons, and capsule). The MRI is very
specific, and gives a clear-cut view of these important
structures.
Treatment
Treatment of an acute ankle injury
usually begins with an aggressive physical therapy
program that controls early pain and inflammation,
protects the ankle joint while in motion, re-strengthens
the muscles, and re-educates the sensory receptors to
achieve complete functional return to running activity.
Modalities that decrease pain and
control swelling include icing, electrical nerve
stimulation, ultrasound, and/or iontophoresis patches.
Easy, mild motion, with the limits of pain and swelling,
can actually reduce the effects of inflammation. A
continued passive motion (CPM) machine can be very
helpful in decreasing pain and swelling.
Resumption of running activity is usually dependent
on the runner's limits of pain and motion, and is begun
to tolerance. As the runner improves, diagonal running
can be prescribed. It is important to protect the runner
with braces such as air casts, ankle braces, etc., which
help to allow motion at the ankle joint under weight
bearing.
Home exercise programs are very helpful for the
post-ankle sprain runner. Proprioception re-education is
critical for both the acute as well as the chronic ankle
sprain. It may involve using a simple tilt board or more
sophisticated proprioceptive training and testing
devices.
For the acute grade III lateral ankle sprain, or
complete deltoid tear, complete immobilization is
usually recommended for at least four weeks. Afterwards,
a removable cast is used to restrict motion and allow
for physical therapy. If the ankle does not respond and
ankle instability is diagnosed, surgical intervention
may be required.
Today, ankle arthroscopy is a much less invasive
procedure than other surgery and allows the ligament to
be stabilized with tissue anchors. This eliminates an
extended period of immobilization, joint stiffness and
muscle atrophy. Post-operatively, this primary ligament
repair is protected for approximately a two-to
three-week period of time in either a cast or removable
cast boot, with daily-continued passive motion, cold
therapy, and controlled exercise.
At three weeks, a simple air cast or ankle brace is
applied for an additional three weeks while therapy and
rehabilitation is progressing. At six weeks, these
devices are used only during running and other athletic
activity as a safeguard. As the runner resumes strength
and proprioceptive capabilities, the devices are
discontinued.
Conclusion
When an acute or chronic ankle sprain is not treated,
as unfortunately is all too often the case, repeated
ankle sprains may occur. Because chronic ankle injuries
do not show acute inflammation even when the ankle is
weak and unstable, this may set the runner up for
another ankle sprain when least suspected. A successive
sprain may be more severe than the first, and cause an
even more significant injury.
The most important point to keep in mind when talking
about ankle injuries, then, is to prevent the condition
from becoming chronic or recurrent.
So the next time you roll over that stone, or land in
that small hole, make sure that your simple ankle sprain
is just that: "simple".
If you don't want to have a swollen ankle all the
time while running, don't ignore early warning signs. If
you have any doubts about its seriousness, have your
podiatrist check your injury. |