Calcaneus Fracture
A calcaneus fracture is a heel bone fracture. It is a rare type of fracture but has potentially debilitating results. Traditionally, a burst fracture of the calcaneus was known as "Lovers Fracture" as the injury would occur as a suitor would jump off a lover's balcony (axial loading) to avoid detection.
Symptoms
Initially, a patient may present with an above mentioned traumatic event with the following clinical features:
Patients will present with diffuse pain, edema, and ecchymosis at the affected fracture site.
The patient is not likely able to bear weight, walk, and move the foot.
Swelling in the heel area
Plantar ecchymosis extending through the plantar arch of the foot should raise suspicion significantly.
There may be associated disability of the Achilles tendon.
Skin quality around the heel must be evaluated for tenting and/or threatened skin. This is especially important in the setting of Tongue-type calcaneus fractures.
Generalised pain in the heel area that usually develops slowly (over several days to weeks) - most common with stress fractures
Deformity of the heel or plantar arch: Secondary to the displacement of the lateral calcaneal border outward, there is a possible widening or broadening of the heel.
Causes
Calcaneal fractures are mostly the result of high energy events leading to axial loading of the bone.
Predominantly, falls from height and automobile accidents (a foot depressed against an accelerator, brake, or floorboard) are common mechanisms of injury. The talus acting as a wedge causes depression and thus flatten, widen, and shorten the calcaneal body.
Calcaneal fractures can also occur with less severe accidents like an ankle sprain or a stress fracture in runners.
Jumping onto hard surfaces, blunt or penetrating trauma and twisting/shearing events may also cause calcaneus fracture.
Mostly, injuries occur in isolation. Most seen concomitant injuries were lower limb (13.2%) or spinal injuries (6.3%).
The posterior tibial neurovascular bundle runs along the medial aspect of the calcaneal body and is shielded by the sustentaculum tali thus neurovascular injuries are uncommon with calcaneal fractures
Diagnosis
Radiological examination:
X-ray of left calcaneus fracture
X-ray: AP, lateral, and oblique plain films of the foot and ankle are needed. A harris view may be obtained which demonstrates the calcaneus in an axial orientation.
Axial - Determines primary fracture line and displays the body, tuberosity, middle and posterior facets.
Lateral - Determines Bohler angle.
Oblique/Broden’s view - Displays the degree of displacement of the primary fracture line.
CT scan of anterior process of calcaneus fracture with soft tissue swelling
CT scan: It is gold standard for traumatic calcaneal injuries.
Bone scan or MRI: are recommended in stress fracture of the calcaneus.
Some of the reference angle and sign in the radiographic images are:
Mondor's Sign is a hematoma identified on CT that extends along the sole and is considered pathognomic for calcaneal fracture.
Bohler's Angle is defined as the angle between two lines drawn on plain film. The first line is between the highest point on the tuberosity and the highest point of posterior facet and the second is the highest point on the anterior process and the highest point on the posterior facet. The normal angle is between 20-40 degrees. It may be depressed on plain radiographs if it's calcaneus fracture.
The Critical Angle of Gissane is defined as the angle between two lines drawn on plain film. The first along the anterior downward slope of the calcaneus and the second along the superior upward slope. A normal angle is 130-145 degrees. It may be an increase in calcaneus fracture.