The Common Vein Copyright 2010
Definition
The calcaneus bone of the hind foot is characterized by being the largest and strongest bone of the foot. It is colloquially known as the heel bone.
It is part of the tarsal bones of the foot. The calcaneus articulates with the talus, navicular, and cuboid. It consists of bone and cartilage.
Its unique structural feature is its complex three-dimensional anatomy. Superiorly there are three articular facets with the talus. The large posterior facet is saddle shaped and convex and supports the talar body. The anterior and medial facets are flatter and support the talar neck and head. The anterior and medial facets support more weight per area than the larger posterior facet. The oblique nonarticular groove dividing the posterior facet from the anterior and medial facets is where the interosseus ligament, inferior extensor retinaculum, and joint capsule insert.
The medial calcaneus is where the sustentaculum tali is located.
The lateral calcaneus is where the tarsal canal becomes the sinus tarsi. There is a vascular fat pad in this area. The peroneal tubercle is where the peroneal tendons travel on the hind foot.
The anterior calcaneus articulates with the cuboid.
The posterior calcaneus is where the Achilles tendon inserts into the calcaneal tuberosity.
The ossification center of the calcaneus develops during the 4th through 7th fetal month. The calcaneus as well as all other bones, muscles, and ligaments of the body are derived of mesodermal origin in embryo.
The function of the calcaneus is to work as a fulcrum for load transfer through the calf and to support weight bearing. Most of the weight bearing is through the posterior part of the calcaneus.
Common diseases include arthritis, dislocation, fracture, osteomyelitis, coalition, congenital foot disorders, plantar fasciitis, and calcaneal apophysitis (Sever’s Disease). Enthesitis associated with the seronegative spondyloarthropathies can lead to pain at the Achilles tendon insertion site into the calcaneus. These enthestis related arthridities can include anklylosing spondylitis, psoriatic arthritis, Reiter’s/reactive arthritis, and inflammatory bowel disease related arthritis.
Arthritis can occur as a result of aging and use (osteoarthritis), rheumatoid arthritis, seronegative arthritis,or as a result of post-traumatic changes.
Subtalar dislocation involves dislocation of the talonavicular and talocalcaneal joints usually as a result of trauma.
Osteomyelitis is an infection of the bone typically due to bacteria.
A talocalcaneal or calcaneonavicular coalition is an osseous, cartilaginous, or fibrous connection between the two bones. A talocalcaneal coalition occurs between the talus and the calcaneus that usually ossifies between 12 and 15 years of age and can cause pain and limited range of motion. A calcaneonavicular coalition is between the calcaneus and the navicular that usually ossifies between ages 8 to 12 and can cause pain and limited range of motion.
Plantar fasciitis is a condition of inflammation of the plantar fascia/aponeurosis. It is a common hindfoot problem in runners. There is typically point tenderness over the medial tubercle of the calcaneus where the aponeurosis has its origin. There can also be a calcaneus bone spur irritation the plantar fascia.
Sever’s disease is apophysitis of the calcaneus leading to heel pain in the growing athlete. It is thought to be due to repetitive microtrauma and overuse.
Commonly used diagnostic procedures include clinical history, physical exam, plain radiographs, CT scan, bone scan, and MRI.
It is usually treated with either non-operative methods or operative methods. Fractures can be treated non-operatively or operatively. Arthritis can be treated with surgery, physical therapy, or NSAIDs. Fractures and dislocations of the calcaneus can be treated with either closed reduction or surgery. Congenital vertical talus is usually treated surgically at 12 to 18 months of age. Osteomyelitis is treated with surgery and antibiotics. Coalitions may be treated nonoperatively with cast or surgically by excision of the bony bar or joint fusion. Plantar fasciitis is treated with rest, icing, physical therapy, and NSAIDs. Sever’s disease is treated nonoperatively with elevation of the heel, physical therapy, icing, foot orthotics, and NSAIDs. Arthritis and enthesitis due to seronegative arthritis may respond to NSAIDs, steroids, methotrexate, or immunologic medications.
References
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Wheeless’ Textbook of Orthopaedics: Calcaneus Fracture (http://www.wheelessonline.com/ortho/calcaneal_fracture_1)