Equinus

Equinus is a condition of the foot and ankle that refers to a tight Achilles tendon.  The Achilles tendon is composed of the tendons of two muscles – the gastrocnemius and the soleus.  Together, these two muscles form the strongest tendon in the entire body, which inserts into the calcaneus (heel bone). 

The Achilles tendon can become tight in one of several ways.  Spastic equinus is the oldest recognized form of equinus, and is seen as a result of upper motor neuron disease.  This may include cerebral palsy, stroke, or spinal trauma and disease.  Congenital equinus refers to equinus typically caused by a shortened Achilles tendon, which is present at birth.  This may result in prolonged toe walking in the developing pediatric patient. 

Most commonly, equinus is an acquired deformity, due to a tightness of the gastrocnemius muscle, the soleus, or both.  This tightness develops over time, and can be worsened by wearing high-heeled shoes, being casted for a lengthy period of time, or from overuse without stretching.  Bony equinus can also present, which is a block of both that prevents the ankle from dorsiflexing, or moving upwards. 

Equinus is possibly the most common cause of foot pathology.  When the Achilles tendon is tight, the body compensates for this in order to bring the heel to the ground.  This is often done by pronating at the subtalar joint, which is the joint located just below the ankle.  This extra pronation can lead to a number of foot problems, such as  plantar fasciitis, flatfoot, tendintis, arthritis, bunions, hammertoes, ankle pain, and a number of other conditions.  Thus, equinus is not necessarily a painful problem, but the compensation for it can cause several painful problems. 

Treatment of equinus should begin with an aggressive stretching program to address the tightness of the Achilles tendon.  Because of it’s relationship to the plantar fascia, the two structures forming a type of sling around the calcaneus, plantar fascia stretches are often incorporated as well.  Combined with the use of orthotics to maintain foot structure when walking, conservative treatment is often helpful for those with equinus.  Heel lifts may also be used to address some of the compensation for equinus at the subtalar joint, as it effectively lessens the amount of space that must be compensated for. 

Occassionally surgery may be necessary if the equinus is not relieved with conservative measures, and is causing significant foot pathology.  Surgery may involve lengthening of the Achilles tendon itself, or lengthening of either the gastrocnemius muscle, the soleus muscle, or both.  These procedures are often combined with foot procedures such as flatfoot or bunion correction, as they are often indicated as the deforming force in a foot deformity.  

Central Florida Foot & Ankle Center, LLC 
101 6th Street N.W. 
Winter Haven, FL 33881 
Phone: 863-299-4551 
www.FLFootandAnkle.com

Fractures of the Anterior Process

The anterior process of the calcaneus is an important structure to consider in the incidence of ankle sprain.  The bifurcate ligament attaches to this portion of the calcaneus, and attaches dorsally to both the cuboid and navicular.  In a plantarflexion-inversion injury, the most common mechanism of ankle sprain, the ligament is tensioned and avulsion fracture of the anterior process can occur.  The anterior process may be injured less commonly in a compression type injury, where the foot is forced to dorsiflex and evert, thereby crushing the bone. 

The calcaneocuboid joint is an important consideration in assessing these types of fractures.  The articular surface of the anterior process of the calcaneus may become damaged from this type of trauma.  This can lead to significant pathology at the joint.

Degan and colleagues pointed out in an article in 1982 that the extent of damage to the anterior process directly effects the outcome of treatment.  They suggested a classification system that took into consideration treatment options.  Type I injuries consisted of fractures of the anterior process that did not involve the joint, and were non-displaced.  These types of fractures were treated successfully with immbolization in a cast.  Type II injuries were also extra-articular, but were displaced.  These fractures were also treated conservatively with cast immobilization.  Type III injuries involved the calcaneocuboid joint, and led to long-term disability.  This was most commonly treated with surgical excision of the fragment.  Prior to the publishing of this article, removal of fracture fragments for anterior process injuries was controversial.  Today, it is commonplace. 

Another point made in Degan’s article is that it may take a long time for patients to be completely symptom-free following conservative treatment, even when the joint is not involved.  In some cases, patients remained symptomatic for up to one year following injury.  When this is the case, a small amount of local anesthetic can be injected into the fracture fragment.  If this is found to alleviate the pain, the fracture fragment removal is indicated. 

Removal of the fragment involves a small incision placed over the calcaneoocuboid joint.  The fragment is removed, along with any other diseased tissue that may be causing pain within the joint.  The surgical wound is then closed with suture.  Typically this is enough to alleviate symptoms, however, some pain and swelling is to be expected following surgery.

Because of the propensity for these fractures to be missed, it is quite common to see old fractures of the anterior process of the calcaneus.  Often times by the time they present themselves, the fracture fragment has either healed in a poor position or damage to the joint surfaces has already occurred.  

Central Florida Foot & Ankle Center, LLC 
101 6th Street N.W. 
Winter Haven, FL 33881 
Phone: 863-299-4551 
www.FLFootandAnkle.com