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