The calcaneus, commonly known as the heel bone, is the largest of the seven tarsal bones located in the rear of the foot. It forms the bony foundation of the heel, positioned directly beneath the ankle joint where it articulates with the talus bone. This substantial bone is structurally designed to absorb the immense forces generated during walking, running, and jumping, acting as the foot’s primary shock absorber. A fracture to this bone is considered a serious injury due to its load-bearing function and potential for long-term complications affecting foot mechanics.
Immediate Signs and Sensations
A fractured heel bone presents with immediate and intense symptoms. The most noticeable visual sign is severe, rapid swelling that engulfs the entire heel area and often extends into the ankle. This inflammation occurs almost instantaneously as blood vessels rupture within the tissue surrounding the broken bone.
Significant bruising, medically termed ecchymosis, develops quickly and can be far-reaching. It sometimes appears as a dark discoloration across the sole of the foot (Mondor’s sign) or spreads up the ankle. If the bony fragments are displaced, the heel may visibly widen or shorten, presenting a noticeable change in the normal contour of the foot.
The physical sensation is typically one of sharp, severe pain that makes any attempt to move the foot extremely painful. The most telling functional sign is the acute inability to bear any weight on the injured foot. Attempting to stand or walk triggers a surge of pain, which prevents further damage to the compromised bone structure.
Common Causes of Heel Fractures
The robust nature of the calcaneus means a fracture usually requires a significant amount of force, categorized as high-energy trauma. The most frequent cause is a fall from a substantial height, such as from a ladder or roof, where the person lands directly on their feet. This mechanism drives the talus bone of the ankle downward into the calcaneus, crushing it and often resulting in a “crushed heel injury” with multiple fragments.
Other high-impact scenarios, like motor vehicle collisions, can also generate the necessary force to fracture the calcaneus. In these traumatic events, the force is so great that there is a risk of associated injuries, most notably compression fractures in the spine. Less commonly, a repetitive, lower-energy stress can cause a calcaneal stress fracture, which develops gradually from overuse, such as in long-distance running or military training.
Initial Actions and Medical Confirmation
If a fractured heel is suspected, the first step is to immediately immobilize the foot to prevent movement of the broken fragments. The injured person should not attempt to put any weight on the affected foot, as this can worsen the fracture displacement and soft tissue damage. Applying the principles of R.I.C.E. (rest, ice, compression, and elevation) can help manage the initial swelling and pain.
The foot should be elevated above the level of the heart to reduce internal pressure and swelling. Ice packs should be applied for short intervals, such as 15 to 20 minutes at a time. A clean dressing or elastic bandage can be used for compression, but it should not be wrapped so tightly that it restricts circulation. Once initial stabilization is achieved, professional medical attention must be sought without delay.
Visual inspection and patient symptoms are not sufficient for a definitive diagnosis. The diagnostic process begins with standard X-rays, which provide clear images of dense structures like bone. X-rays confirm the presence of a break and whether the bone fragments are displaced.
Due to the complex, irregular shape of the calcaneus, a Computed Tomography (CT) scan is routinely ordered after the initial X-rays. The CT scan is the preferred imaging study because it produces detailed cross-sectional images, essential for visualizing the fracture pattern in three dimensions. This detailed view allows physicians to determine if the fracture is intra-articular (involving the joint surface) or extra-articular (occurring outside the joint).
Intra-articular fractures account for the majority of calcaneus fractures and are significant because they disrupt the smooth surface of the subtalar joint. The CT images are often used to classify the fracture using systems like the Sanders classification. This classification helps surgeons plan the most appropriate course of treatment, whether it involves non-surgical management or complex surgical reconstruction. The involvement of the joint surface is a major factor in predicting the potential for long-term complications like post-traumatic arthritis.