Calcaneal Stress Fracture: A Less Common Cause of Heel Pain
A calcaneal stress fracture is an uncommon, but potentially debilitating source of heel pain. It typically occurs in patients with lower bone density who have recently increased their activity level. Unlike more common sources of heel pain, such as plantar fasciitis and overload heel pain syndrome, pain from a stress fracture of the heel bone creates a deeper ache. This pain does not settle quickly. The source of this pain is microscopic fractures in the calcaneus -essentially tiny cracks through the heel bone. Imagine a hard boiled egg that is repetitively tapped on a hard countertop. Cracks will develop in the eggshell, although it will still retain its overall shape. This is essentially what happens when the heel bone develops a stress fracture. In response to these microscopic fractures, the body increases blood and inflammatory mediators to the fractured area as part of the bone healing process. This creates a localized aching pain in the heel.
Symptoms of a Calcaneal Stress Fracture
Patient with a stress fracture of the heel bone will give a history of pain in the heel area which is often aching. The pain usually arises after an increase in weight-bearing activities (ex. starting a new running program, or going for an extra long hike). Often the pain comes on gradually, but it can also arise suddenly during or shortly after an inciting activity. Patients often have low bone density. Osteoporosis commonly occurs due to aging. However, abnormally low bone density can also occur in younger female endurance athletes whose intense training has caused an excessively low body weight.
It may be difficult to differentiate between a calcaneal stress fracture and other more common causes of heel pain, such as plantar fasciitis or overload heel pain syndrome. However, in general, the pain from a calcaneal stress fracture is more diffuse and aching. Whereas typical pain from plantar fasciitis or overload heel pain syndrome is usually quite localized. In patients with a stress fracture of the calcaneus performing a “squeeze test” where the heel is squeeze will often create discomfort. Patients with a stress fracture of the heel will usually walk with a limp. They will have to limit their activity levels considerably. In some situations, they will find weight-bearing to be difficult or impossible and will need to use crutches.
Standard x-rays of the ankle may not initially identify a calcaneal stress fracture. This is because most stress fractures of the heel are microscopic and do not change the overall architecture of the heel bone. However, after a few weeks of bone healing the new bone formation will be visible on a plan x-ray.
To establish an early diagnosis advanced imaging such as an MRI or CT scan may need to be performed.
Treating Calcaneal Stress Fractures
Fortunately, calcaneal stress fractures can be treated conservatively. However, treatment may be prolonged as considerable bone healing and strengthening is required before the patient can begin to return to more normal activity level. Bone healing often requires 6–8 weeks of immobilization in a CAM boot or a cast with limited or no weight-bearing to allow the stress fracture to heal solidly. Following this physical therapy to improve muscle strength and allow the heel pad to get use to bearing weight again will be required.
In addition, any cause leading to low bone density, such as osteoporosis, must also be addressed as part of the treatment plan. Without addressing this contributing factor, a recurrent of the stress fracture is a possibility.
Edited January 27, 2024