The subtalar joint sits below the ankle joint, and is
composed of the articulation between the talus and the calcaneus. It plays a crucial role in the normal
function of the foot, and allows for motion along an axis that runs through
three planes of the body; the frontal plane, the sagittal plane, and the
transverse plane. Motion along the
subtalar joint axis is defined as pronation and supination. The pronation and supination allows the foot
to adapt to uneven surfaces, and functions as the connecting joint between the
ankle and the rest of the foot.
The articulation between the talus and the calcaneus is
actually composed of three separate articular surfaces; the posterior articular
facet, the middle articular facet, and the anterior articular facet. Together, these three articulations create a
joint between the two bones.
The joint is stabilized by a number of ligaments that
connect the talus to the calcaneus. The
ankle ligaments also help to stabilize the talus within the ankle joint, and
keep it improper alignment with the calcaneus.
Pathology of the subtalar joint may include primary
osteoarthritis, arthritis secondary to fractures of the ankle and/or calcaneus,
tarsal coalition, inflammatory conditions, and a number of other problems that
can affect bones and joints. Subtalar
joint arthritis is a very common etiology of subtalr joint pain. When the subtalar joint becomes an area of
pain, it is often confused for ankle pain.
Thus, when people come to the doctor with a complaint of ankle pain,
they are often shocked to find out that it is not actually their ankle that
hurts, but their subtalar joint.
Subtalar joint pain, particularly when it is due to
arthritis, can be differentiated from ankle pain with a careful clinical exam,
as well as the use of diagnostic injections.
Diagnostic injections involve injecting a small amount of local
anesthetic, a numbing agent, into the painful joint. If all of the pain is relieved, than it can
be deduced that the subtalar joint is the source of pain. If some, but not all of the pain is relieved,
than it is possible that the ankle or other surrounding joints, or the soft
tissues around the joint may be the source of the problem.
Treating subtalar joint arthritis begins with conservative
therapy. This may consist of various
padding and strapping methods, orthotics, and the use of cortisone injections
into the joint. Oral
anti-inflammatories, ice, physical therapy, and other modalities may be tried
as well.
Occassionally, the arthritis is severe enough to warrant
surgical intervention. Most commonly,
subtalar joint arthritis is treated surgically with a fusion of the joint, also
known as an arthrodesis. In subtalar
joint arthrodesis, the talus is fused to the calcaneus. This removes all motion available at the
joint, thus eliminating the pain associated with its movement. The joint will not move after it has been
fused.
Screws are used to hold the bones in place while they heal
together, and a period of non-weight bearing is generally employed for a minimum
of 6-8 weeks. After this period of time,
the patient may be transitioned to a partial weight-bearing status, for another
period of 4-6 weeks. After the bones
have completely healed, normal activity may begin again.
Central Florida Foot & Ankle Center, LLC 101 6th Street N.W. Winter Haven, FL 33881 Phone: 863-299-4551 http://www.FLFootandAnkle.com
