Fractures of the calcaneus (heel bone) is the most common tarsal bone fracture. Most calcaneal fractures occur as the result of a fall from a height greater than 14 feet. Calcaneal fractures are common among roofers and rock climbers. The second most common contributing cause to these traumatic fractures are automobile accidents. Calcaneal fractures are most commonly found in males age 30-50 y/o.
Calcaneal fractures have a track record of being difficult to treat and have frustrated doctors for years. The problem in treating calcaneal fractures is in trying to rebuild the fracture so that healing may take place. The calcaneus is much like an egg; an outer firm shell and soft on the inside. As a result, the calcaneus often shatters when broken. Calcaneal repair not only requires re-apposition of multiple fracture patterns, but also requires restoration of the subtalar joint. The subtalar joint is the interface between the calcaneus and talus and is a primary load bearing joint of the foot. In some cases, additional joint surfaces may be affected (the calcaneal cuboid joint) but are of lesser importance due to their limited weight bearing roles.
Two classifications are used for the classification of calcaneal fractures. The Rowe classification and the Essex-Lopresti classification both describe calcaneal fractures. The Essex-Lopresti classification describes subtalar joint depression fractures (very severe fractures) in a bit more detail than the more commonly used Rowe classification. Plain xrays and CT scans are often used to determine the extent and classification of calcaneal fractures.
The Rowe Classification Of Calcaneal Fractures
Type 1a - Tuberosity fracture medial or lateral
Type 1b - Fracture of the sustentaculum tali
Type 1c - Fracture of the anterior process of the calcaneus
Type 2A - Beak fracture of the posterior calcaneus
Type 2b - Avulsion fracture involving the insertion of the tendo-Achillles
Type 3 - Oblique fracture not involving the subtalar joint
Type 4 - Body fracture involving the subtalar joint
Type 5 - Body fracture with stj depression and comminution
The Essex-Lopresti Classification Of Calcaneal Fractures
Type A - Tongue type
Type B - Joint depression type
Stress fractures of the calcaneus
Stress fractures of the calcaneus are typically the result of a sudden abrupt injury but can occur without a history of trauma. The most common injury seen our practice is a fall from a height of more than 6 feet. A stress fracture of the calcaneus is a condition that is often overlooked as a differential diagnosis of heel pain. Plantar fasciitis (also called heel spur syndrome) is so common that most health care providers will defer to plantar fasciitis as a primary diagnosis when evaluating heel pain. A good patient history, and particularly one that notes the onset and character of the pain, is very important when differentiating between plantar fasciitis and calcaneal stress fractures.
The diagnosis of calcaneal stress fractures can be difficult at times. Stress fractures, regardless of where they occur in the body, are different than what we would tend to think of when we discuss fractures. The appearance of a stress fracture on x-ray are not always evident.. Quite often, the only x-ray findings that we'll see are those that show up towards the end of the healing process, sometimes as long as several months after the injury. We don't actually visualize the fracture, but rather we see the calcification that occurs in the late phases of the healing process. Should the symptoms of heel pain not respond to treatment for plantar fasciitis, or initial clinical findings seem suggestive of a stress fracture, there are several tools that can be used to help differentiate between calcaneal stress fractures and each of the other common conditions considered in treating heel pain.
Plain x-rays may be able to see a calcaneal fracture, but quite often, due to the lack of disruption of the bone, plain films lack the ability to 'see' the fracture. As fractures heal, many times the healing process can be seen on plain x-ray films. The healing process will increase the amount of calcium surrounding the fracture. This process of calcification typically takes about 4-6 weeks to see on plain x-ray, therefore, periodic follow-up x-rays may aid in diagnosing a stress fracture of the heel.
A three phase technitium bone scan can help differentiate the location and degree of inflammation in the calcaneus thereby helping to diagnose a calcaneal stress fracture. Bone scans are a test where a radioactive nucleotide is injected into the patient and a scan is taken of the injured area three times over the course of three hours. Each of the scans show a different degree of inflammation based upon the increased blood flow to the inflamed area. In the case of a calcaneal fracture, a bone scan can help in many ways. First, the scan will locate the area of the fracture based upon the inflammation seen in fracture healing. Second, the bone scan will help to differentiate between many other potential problems of the heel such as plantar fasciitis. And lastly, a scan can help to determine the acuteness of an injury. For instance, we may see a questionable area on an x-ray but we'll not be able to tell whether the suspected injury is old or new. The bone scan will help us in that a new injury will 'light up' on the scan due to its' current inflammation. An old injury on the other hand will not 'light up' on the scan due to its' lack of current inflammation.
MRI's are also helpful in differentiating calcaneal fractures from plantar fasciitis. MRI's can identify small areas of bone edema suggestive of a fracture.
Treatment of calcaneal fractures
As previously mentioned, calcaneal fractures can be very difficult to manage. Closed reduction is a term used when doctors will manipulate the fracture under anesthesia without surgery. Closed reduction can be successful in treating calcaneal fractures in many cases depending upon the stage of fracture. Open reduction (surgical reduction of the fracture) is not guaranteed to produce more successful outcomes. Calcaneal fractures can range from simple to explosive. Follow-up following reduction (whether close or open) varies but will include a period of non-weight bearing, splinting or casting to allow for fracture healing.
In severe cases of joint depression fractures (Rowe type 4 and 5) additional surgery may be required to fuse the subtalar joint. If the subtalar joint is significantly damaged in the injury, fusion of the stj is the only solution. Most doctors will stage these procedures, performing a subtalar fusion long after the immediate trauma of the injury.
Treatment of calcaneal stress fractures varies with the severity of the fracture and the degree of pain. Many cases of calcaneal stress fractures are simply treated with rest and a decrease of activity. Others may necessitate a walking cast or period of non-weight bearing. Surgical intervention is rarely indicated. Healing of calcaneal stress fractures can be prolonged and may require a period of several months to heal.
Nomenclature:
Calcaneus - The bone of the heel
Subtalar Joint - (STJ) the joint between the two major bones of the rearfoot, the talus and calcaneus. The STJ is a common site of residual arthritis following calcaneal fractures.
Technitium - a radioactive substance that is attracted to area of inflamation. Used as the active substance in bone scans.
Anatomy:
The calcaneus is very firm on its' outer surface but soft and spongy on the inside, much like an egg. It is an unusually shaped bone with numerous surfaces making up the support for the subtalar joint and the calcaneal cuboid joint.
Biomechanics:
The biomechanics of calcaneal stress fractures has not been defined. Due to the fact that most calcaneal stress fractures happen due to a random traumatic incident, no defined pathway for the fractures has been established.
Symptoms:
The diagnosis of a calcaneal stress fracture is usually based upon pain that continues following an incident of trauma. Occasionally a calcaneal stress fracture will have an insidious onset, but most with have an acute onset. Edema (swelling) and erythema (redness) may or may not be present.
The most common symptom of a calcaneal stress fracture, and the one symptom that can help to differentiate stress fractures from fasciitis, is the nature of the pain. Stress fracture pain is constant. It hurts when a person's body weight is first applied and continues to hurt. Pain due to plantar fasciitis is sharp at the beginning of weight bearing but soon subsides, to a degree, over 5-10 minutes
The location of pain is also important. Stress fracture pain will typically (and not always) be in the body of the calcaneus. Pressure to the medial and lateral walls of the calcaneus result in pain. Plantar fascial pain is specific to the bottom of the heel and is moderate with direct pressure, but sever with weight bearing.
Differential Diagnosis:
Baxter's nerve entrapment - an entrapment of the recurrent branch of the posterior tibial nerve
Gout - deposition of monosodium urate crystals (hyperuricemia)
Heel spur syndrome - see plantar fasciitis
Plantar fasciitis - a common condition of the heel that results in pulling by the plantar fascia and a tearing pain at the attachment of the fascia on the bottom of the heel. Pain is severe with the first few steps out of bed in the morning or after a brief period of rest.
Retrocalcaneal bursitis (Albert's Disease) - this is the formation and inflammation of a bursa at the back of the heel between the heel bone and Achilles tendon
Rheumatoid arthritis
Rheumatic Fever
Septic Arthritis
Sero-negative arthropathies such as Reiter's Syndrome
Sever's Disease - and inflammatory condition typically found in young over weight boys age 10 to 15 years old
Tarsal Tunnel Syndrome - also known as posterior tibial nerve neuralgia. Tarsal Tunnel Syn. characteristically has pain that does not decrease with rest. Also has numbness or 'tingling' of the toes
References:
Rowe CR, Sakellarides HT, Freeman PA, et al. Fractures of the os calcis: long term follow-up study of 146 patients. JAMA 1963;184:920-923
Hermann OJ. conservative therapy for fractures of the os calcis. J Bone Joint Surg 1963:45-A:865-867
Parker JC. Injuries of the hindfoot. Clin Orthop 1977; (122):28-36
Palmer I. The mechanism and treatment of fractures of the calcaneus: open reduction with the use of cancellous grafts. J Bone Joint surg 1948;30-A(1):2-8
About the Author
Jeffrey A. Oster, DPM, C.Ped is a board certified foot and ankle surgeon. Dr. Oster is also board certified in pedorthics. Dr. Oster is medical director of Myfootshop.com and is in active practice in Granville, Ohio.
Written by: Dr. Jeffrey A. Oster, Medical Director Of Myfootshop.com.
