Calcaneal stress injures can present in different ways, from inflammation of the periosteum (periostitis), a membrane that covers the surface of all bones (but not on the articulating surfaces of joints), to partial or full fractures. In simple terms, a calcaneal stress fracture is a small crack in the heel bone due to prolonged stress on the tissue.
Stress fractures can be caused by fatigue or insufficiency. Fatigue fractures occur when the heel bone is subjected to repeated stress that is below the threshold needed to cause a sudden fracture, but is enough to cause gradual changes to the bone before leading to a fracture. This is common in people who take part in high-impact sports, such as running, and soldiers who spend a lot of time marching, and is mostly due to overuse. These excessive stresses on the heel bone can cause the cells that break down bone cells (osteoclasts) to become more active than the cells that create new bone tissue (osteoblasts). This causes the bone to weaken, increasing the risk of stress fractures of the calcaneus. Insufficiency fractures occur when the person has a systemic condition, inflammatory arthritis, or is not eating sufficient quantities of the nutrients needed to maintain sufficient bone density (osteoporosis).
Common symptoms of a calcaneal stress fracture include increased pain in the heel when standing or otherwise weightbearing. The pain will be reduced by resting. Unlike a traumatic injury, such as falling off a ladder onto your heels, which causes a sudden, violent pain, the pain from a stress fracture comes on gradually, often getting worse over time if not treated. The affected area affected area will also be swollen, red, hot and tender if pressed. Calcaneal stress factures often occur after a person begins to exercise more intensely or for longer, or after starting a new exercise routine. There is usually no history of injury.
A podiatrist may suspect a calcaneal stress fracture when the history of the condition and the patient’s medical history and current health match up with the symptoms and risk factors for this condition. They can also carry out a “calcaneal squeeze test”, which if positive, would indicate a possible calcaneal stress fracture. Unfortunately, stress fractures cannot be diagnosed definitively without imaging techniques, such as plain radiographs (X-Ray), bone scans, or MRI. X-Ray imaging is not the first choice for diagnosing this condition, as it may only identify fractures that are already healing, more than 2-3 weeks old, and may not pick up on the fracture at all. An MRI or a bone scan is preferred for an accurate diagnosis and speedy recovery.
Treatment involves offloading the heel using specialist, orthopaedic footwear, using crutches, casting, or in mild cases, functional foot orthoses (medical-grade insoles) and other in-shoe devices, such as heel cushions.