A typical depressed calcaneal fracture (Figure 1) is perhaps the most serious common foot injury. Depressed (crushed) calcaneal fractures occur when the heel is directly or indirectly loaded with excessive force, such as in a fall from a height or in a motor vehicle accident where the heel may be driven into the floorboard. There are both non-operative and operative treatments available for this injury. Operative treatment allows for the bone fragments to be repositioned so that they can heal in an improved position (it does not speed bone healing which usually takes 8-12 weeks). However, surgery requires a high degree of skill and experience on the part of the surgeon. Surgical complications such as wound breakdown or deep infection are not uncommon, and can be extremely serious. Complications are higher in patients who are smokers, diabetics, have vascular disease, or who have excessive swelling. The long-term prognosis is somewhat guarded with both operative treatment and non-operative treatment, with some hindfoot stiffness and pain being common.
Figure 1A: X-ray of foot showing a normal calcaneus from the side
Figure 1B: X-ray of a depressed calcaneus fracture
Clinical Presentation: Calcaneus Fractures
Patients who have suffered a calcaneus fracture present with acute pain and a large amount of swelling over the heel. They are usually unable to bear weight on the involved foot. The fracture itself occurs when the the lower bone of the ankle (talus) gets driven into the upper part of the heel bone (calcaneus). This causes the calcaneus to break (Figure 2). Therefore falls from a height where the patient lands on their feet is a common mechanism leading to a calcaneus fracture. The calcaneal bone is somewhat analogous to a complicated shaped egg. It has a hard shell (cortical bone) on the outside, and very soft, cancellous bone in the inside. When it breaks, there is a primary fracture line running from the inside distal part of the calcaneus to the outside hind part of the calcaneus (Figure 3).
Figure 2A: Mechanism of Typical Calcaneal fracture – Side view
Figure 2B: Mechanism of Typical Calcaneal fracture – Viewed from the back
Figure 3: Primary Fracture line viewed from the top (also showing secondary fracture lines)
In addition, there is often a series of other fracture lines. The calcaneus, in many ways, breaks the same way as an egg would break into a number of different pieces. The fracture pattern will vary for each patient and injury.
Physical Examination related to Calcaneal Fractures
In patients with calcaneus fractures the physical examination usually demonstrates tremendous swelling around the involved heel. In some patients, there will be a break in the skin, representing an open fracture. Open fractures constitute an orthopedic emergency. Usually, the sensation in the foot is intact. In addition, blood supply to the foot is usually intact, although this does need to be assessed following the injury. It is also common to have other injuries, such as a fracture involving the ankle or another part of the foot. A Lumbar spine burst fracture will occur in about 10% of patients who suffer a calcaneal fracture. This is a fracture in the lower to mid back which essentially crushes one of the vertebras. The same mechanism that produces a calcaneal fracture will predispose a patient to having a lumbar burst fracture.
X-rays are helpful when a calcaneal fracture is suspected. Typically, a lateral x-ray demonstrating the foot from the side (Figure 4), as well as an axillary heel view showing an end-on view of the heel are taken. This allows the basic fracture pattern to be identified.
Figure 4: X-ray of fractured calcaneus from the side
To more thoroughly understand the fracture pattern, particularly if surgery is a possibility, a CT scan will be ordered (Figure 5). On the CT scan, the number of fracture lines extending through the posterior facet of the calcaneus is important.
Figure 5: CT scan of fractured calcaneus
Treatment of Calcaneus Fractures
Calcaneal fractures can be quite difficult to treat, and the recovery can be prolonged. It is not uncommon and, in fact, may be the norm to have some element of post-traumatic subtalar arthritis as a result of this injury.Non-operative management of calcaneal fractures does not mean NO treatment. Non-operative management includes a prolonged period of non-weight bearing to allow the fracture to heal. This typically needs 10-12 weeks to allow the calcaneal fracture to be healed enough to bare weight. During that time, the patient is treated with appropriate pain control. This includes elevation to limit swelling, ice to decrease the swelling and improve local symptoms, and narcotic pain medication.
Operative treatment involves reconstructing the shattered calcaneus, essentially trying to return the calcaneus to the pre-injury shape. For each patient, this treatment needs to be individualized. The operative procedure is technically difficult, and can be associated with an unacceptably high complication rate. It is therefore important that the surgeon involved have confidence and experience with these types of fractures. Operating through excessively swollen tissue has been shown to significantly increase the risk of wound healing problems and infection. For this reason, it is now standard practice to wait until the soft-tissues swelling has settled, often 10-14 or more days after the injury. The worst results of calcaneal fracture treatment occur when an operatively treated fracture is complicated by a bad, deep infection or a significant wound breakdown. It is not unheard of in these situations where the patient will eventually require an amputation.
Figure 6: Calcaneus following surgical fixation
With certain fracture patterns, it is possible to perform a percutaneous procedure. Percutaneous treatment (operating without making a large incision) involves skewering part of the fracture with a straight wire (K-wire), and manipulating it into an improved position. This is done through a few stab incisions. Unfortunately, less than 10% of the calcaneal fractures fit into this category, and most require a large, open procedure if the bone fragments are to be adequately repositioned (reduced). Tongue-type fractures occur when the posterior facet remains in continuity with the posterior aspect of the calcaneus, forming what looks like a tongue. These are the types of fractures that would be potentially amenable to percutaneous repair.
Figure 7: Calcaneus following percutaneous repair
Following surgery, the recovery time is similar to that for non-operative treatment. Essentially, the patient needs 10-12 weeks of non-weight bearing to allow the fracture to heal. However, within 2 weeks of surgery some basic non-weight bearing range of motion exercises should be instituted, in order to limit the hindfoot stiffness.
Complications of operative treatment are not uncommon. The major complications include:
- Deep wound infection: Because of the tenuous skin over the outside of the heel, any type of wound infection commonly goes down to the bone potentially leading to osteomylelitis (bone infection).
- Wound healing can be an issue because the soft-tissue on the outside of the heel has a tenuous blood supply. Meticulous wound closure is required to minimize the risk of this problem.
- Sural Neuritis: The sural nerve, which innervates the outside of the foot, is often stretched or injured in the surgical approach, and can become scarred or injured in the course of the surgery.
- Nonunion of the calcaneus is possible, although it is uncommon.
- Subtalar arthritis is not so much a complication as it is a common long-term effect of the injury, leading to pain and stiffness in the hindfoot. This will manifest itself with symptoms when the patient stands for a prolonged period of time, or walks on uneven ground. This could be a problematic symptom for patients that are on their feet a lot. For these patients, it may even be necessary to eventually perform a primary subtalar fusion.
- Deep Vein Thrombosis (DVT)
- Pulmonary Embolism