Calcaneal Fracture

The calcaneus is the largest tarsal bone and forms the posterior subtalar articulation.

Calcaneal fractures are divided into:

• Extraarticular fractures

• Intra articular fractures involving the posterior subtalar facet

Most major intra articular fractures result from axial loading, commonly after a fall from height.

The force drives the talus downward into the calcaneus, producing:

• Posterior facet depression

• Heel shortening

• Heel widening

• Varus deformity

• Lateral wall blowout

• Subfibular impingement

Associated lumbar spine fractures must be considered after axial load injuries.

Essex Lopresti classification

Based on the secondary fracture line.

Tongue type

The secondary fracture line exits posteriorly, producing a large posterior tuberosity fragment attached to the Achilles tendon.

The Achilles can pull the fragment superiorly, threatening the posterior heel skin.

Joint depression type

The secondary fracture line exits superiorly behind the posterior facet, leaving a separate depressed articular fragment.

These patterns require different reduction strategies.

Sanders CT classification

Based on the number and location of fracture lines through the posterior facet on coronal CT.

Type I

Nondisplaced or minimally displaced fracture, generally less than approximately 2 mm displacement, regardless of the number of fracture lines.

Type II

One primary fracture line divides the posterior facet into two articular fragments.

Subgroups A, B and C reflect the position of the fracture line from lateral to medial.

Type III

Two fracture lines divide the posterior facet into three articular fragments.

Subgroups AB, AC and BC reflect fracture line location.

A central depressed fragment is frequently present.

Type IV

Three or more fracture lines produce four or more articular fragments.

These are severely comminuted injuries with poor reconstructive prognosis and high risk of post traumatic subtalar arthritis. Increasing Sanders grade correlates with increasing reconstructive difficulty.

Patients have severe hindfoot pain, swelling and inability to bear weight.

Ecchymosis extending to the plantar heel is strongly suggestive.

Inspect posterior heel skin carefully.

A displaced tongue type fracture can create a prominent posterior tuberosity beneath thin skin.

Blanching, tenting or threatened posterior skin is an orthopaedic emergency because skin necrosis can occur rapidly.

Assess:

• Sural nerve sensation
• Tibial nerve function
• Distal perfusion
• Foot compartment tension

High energy calcaneal fractures may be open medially.

Evaluate the spine, pelvis and contralateral hindfoot after a major fall.

Obtain:

• Lateral foot or hindfoot radiograph
• Axial Harris view where useful
• AP foot

Böhler angle

Measured on lateral radiograph.

Normal is approximately 20° to 40°.

Loss or reversal suggests posterior facet collapse.

Critical angle of Gissane

Normally approximately 120° to 145°.

Distortion reflects disruption around the posterior facet.

CT hindfoot: essential for most displaced intra articular fractures and provides Sanders classification.

Immediate care

Elevate aggressively.

Apply a well padded splint.

Avoid constrictive circumferential casting during major swelling.

Treat open fractures immediately.

Urgent posterior skin threat

A displaced tongue type or tuberosity avulsion threatening the posterior heel skin requires urgent reduction and fixation, even if the rest of the definitive reconstruction must wait.

Do not delay until routine swelling has subsided if the posterior skin is blanching.

Nonoperative treatment

Appropriate for:

• Sanders I fracture
• Nondisplaced extraarticular fracture
• Minimally displaced intra articular injury with preserved heel anatomy
• Patients with prohibitive surgical risk
• Selected patients with very high wound complication risk

Non weight bearing is commonly required for approximately 8 to 12 weeks, with early subtalar and ankle range of motion once swelling permits. Sanders I fractures and fractures retaining near normal Böhler angle can often be treated without surgery.

Operative indications

Consider fixation for:

• Displaced intra articular fracture with posterior facet incongruity
• Significant heel widening
• Varus deformity
• Loss of calcaneal height
• Displaced tuberosity fracture
• Open fracture
• Tongue type fracture threatening skin
• Anterior process fracture with major calcaneocuboid articular involvement

The decision must also account for:

• Smoking
• Diabetes
• Peripheral vascular disease
• Soft tissue condition
• Functional demand

These factors substantially influence wound complication risk.

Timing

Except for urgent skin threatening patterns and open fractures, delay large surgical approaches until swelling has subsided and skin wrinkling has returned.

This often takes approximately 10 to 14 days.

Do not perform an extensile lateral exposure through tense oedematous skin.

Reduction objectives

Restore:

• Posterior facet congruity
• Calcaneal height
• Heel length
• Heel width
• Hindfoot valgus relationship, avoiding residual varus
• Calcaneocuboid alignment

A perfectly reduced posterior facet with a severely widened varus heel is not an adequate reconstruction.

Fixation techniques

Options include:

• Percutaneous reduction and screws
• Sinus tarsi approach
• Extensile lateral ORIF
• Plate fixation

The sinus tarsi approach provides direct access to the posterior facet with less soft tissue disruption than a traditional extensile lateral flap in selected fractures.

Sanders II and III

Reconstruction is generally feasible in appropriate surgical candidates.

Elevate and anatomically reduce the posterior facet, restore the tuberosity and support with screws or plate fixation.

Sanders IV

The posterior facet may be too fragmented for durable reconstruction.

Options include:

• ORIF when reconstructable
• ORIF combined with primary subtalar arthrodesis
• Primary subtalar arthrodesis in selected severely comminuted injuries

The decision depends on cartilage destruction, patient age and reconstructability.

Postoperative care

Maintain non weight bearing until sufficient fracture healing, generally approximately 8 to 12 weeks.

Begin ankle and subtalar movement when soft tissues permit.

Major complications include:

• Wound necrosis
• Deep infection
• Sural nerve injury
• Heel widening
• Varus malunion
• Subfibular impingement
• Peroneal tendon irritation
• Chronic heel pain
• Subtalar stiffness
• Post traumatic subtalar arthritis

Late painful subtalar arthritis with preserved ankle function can be treated with subtalar arthrodesis.