Residency · Residency · Orthopedic Surgery

Calcaneus Fractures: Operative Indications and Approaches

Introduction

Calcaneus fractures are the most common tarsal bone fracture, typically resulting from axial loading injuries such as a fall from height. These fractures are challenging to treat due to the complex three-dimensional anatomy of the calcaneus, the thin soft tissue envelope, and the high rate of complications. The decision between operative and nonoperative management requires careful consideration of fracture pattern, soft tissue condition, and patient factors.

Anatomy

The calcaneus is composed primarily of cancellous bone with a thin cortical shell, making it susceptible to comminution. The posterior facet is the primary weight-bearing articular surface with the talus. The sustentaculum tali is the medial process that supports the talar neck and serves as the constant fragment to which other fragments are reduced during surgical reconstruction. The angle of Gissane, formed by the downward and upward slopes of the calcaneal sulcus, normally measures 120 to 145 degrees. Bohler angle, the angle between the posterior facet and the superior tuberosity, normally measures 20 to 40 degrees, and a flattened angle indicates articular depression. The sural nerve and peroneal tendons are at risk laterally during surgical approaches.

Mechanism and Associated Injuries

Axial loading from a fall or motor vehicle accident drives the talus into the calcaneus. The lateral process of the talus acts as a wedge, splitting the posterior facet. Bilateral involvement occurs in approximately 10% of cases. Associated injuries include lumbar spine compression fractures in 10% of patients, other lower extremity fractures, and compartment syndrome of the foot. The spine and contralateral calcaneus should always be examined.

Classification

Essex-Lopresti Classification

The Essex-Lopresti classification is based on the primary fracture line on the lateral radiograph. In the joint depression type, the posterior facet is depressed into the body while the tuberosity fragment maintains height. In the tongue-type, the primary fracture line exits posteriorly through the tuberosity, creating a large posterior fragment that includes the posterior facet and tuberosity.

Sanders Classification (CT-Based)

The Sanders classification is the most widely used system for surgical planning and is based on the number of articular fragments on the coronal CT slice through the widest part of the posterior facet. Type I fractures are nondisplaced regardless of the number of fracture lines. Type II fractures are two-part fractures of the posterior facet, subdivided into IIA, IIB, and IIC based on the location of the fracture line. Type III fractures are three-part fractures with a central depressed fragment. Type IV fractures are comminuted with four or more articular fragments and are often considered for primary arthrodesis.

Imaging

The lateral radiograph is used to assess Bohler angle, angle of Gissane, and overall calcaneal height and length. The Harris axial view evaluates heel width, varus or valgus alignment, and the subtalar joint. CT scanning is essential for operative planning, with coronal, axial, and sagittal reconstructions. Three-dimensional CT reconstructions aid in understanding complex fracture patterns and planning surgical approaches.

Nonoperative Management

Indications

Nonoperative management is indicated for Sanders Type I (nondisplaced) fractures, patients with severe medical comorbidities precluding surgery (diabetes, peripheral vascular disease, heavy smoking), open fractures with severe soft tissue compromise, Sanders Type IV fractures in some hands (though primary subtalar arthrodesis may be preferred), and low-demand, elderly, or non-ambulatory patients.

Protocol

Initial management focuses on elevation, ice, and compression for swelling control. Non-weight-bearing in a removable boot or cast is maintained for 8 to 12 weeks. Early subtalar and ankle range of motion exercises begin once acute swelling resolves, with progressive weight-bearing at 10 to 12 weeks. Expected outcomes include residual heel widening, loss of height, subtalar stiffness, and possible late subtalar arthritis requiring fusion.

Operative Management

Timing

Surgery should be delayed until soft tissue swelling resolves, typically 10 to 21 days after injury. The wrinkle test determines when surgery is safe: the skin should wrinkle with gentle lateral compression, indicating resolution of edema. Premature surgery increases wound complication rates dramatically.

Extensile Lateral Approach (ELA)

The extensile lateral approach is the traditional workhorse approach providing excellent visualization of the posterior facet, lateral wall, and calcaneocuboid joint. An L-shaped incision extends from posterior to the fibula, curving below the fibular tip, and extending to the calcaneocuboid joint. A full-thickness flap is raised in a no-touch technique to protect the sural nerve and lateral calcaneal artery, allowing direct reduction of the posterior facet under visualization. The wound complication rate ranges from 10 to 25%, including wound edge necrosis, infection, and sural nerve injury. Higher complication rates occur in smokers, diabetics, and with premature surgical timing.

Sinus Tarsi Approach (STA)

The sinus tarsi approach is a minimally invasive technique gaining significant popularity. A 3 to 4 cm incision over the sinus tarsi extends from the tip of the fibula toward the base of the fourth metatarsal. It provides direct visualization of the posterior facet through the sinus tarsi with significantly reduced wound complication rates of 2 to 5% compared to the extensile lateral approach. Limitations include less visualization of the medial wall and tuberosity and the requirement for fluoroscopic assistance. It is best suited for Sanders Type II and select Type III fractures.

Percutaneous Reduction and Fixation

For tongue-type fractures, a percutaneous technique using a Steinmann pin (Essex-Lopresti maneuver) levers the tuberosity fragment to restore Bohler angle. This is combined with percutaneous screw fixation and involves minimal soft tissue stripping with a very low wound complication rate.

Fixation Methods

Perimeter plating with a lateral locking plate is the standard with the extensile approach. Headless compression screws are commonly used with the sinus tarsi approach, placed from posterior to anterior or from lateral to medial. Smaller-profile locking plates specific to the sinus tarsi approach are also available. All reduction is referenced to the sustentaculum tali, which is the constant fragment.

Primary Subtalar Arthrodesis

Primary subtalar arthrodesis is considered for Sanders Type IV fractures with severe articular comminution. In situ fusion at the time of fracture treatment avoids a second procedure for inevitable post-traumatic arthritis. It restores calcaneal height, width, and alignment while eliminating the painful subtalar joint. Results may be comparable to or better than ORIF for Type IV fractures.

Complications

Wound complications are the most common problem, ranging from superficial dehiscence to deep infection requiring flap coverage. Subtalar arthritis develops in 20 to 30% of operatively treated fractures and up to 70% of nonoperatively treated displaced fractures, and may require secondary subtalar fusion. Sural nerve injury causes numbness along the lateral foot in 10 to 15% of cases. Peroneal tendon impingement results from lateral wall blowout and heel widening. Malunion causes loss of calcaneal height, heel varus, and anterior ankle impingement. Hardware irritation from prominent lateral plates often requires removal.

Clinical Pearls

A CT scan should always be obtained for displaced calcaneus fractures, as the Sanders classification on coronal CT guides operative planning and provides prognostic information. The wrinkle test must be positive before operating through an extensile lateral approach, since premature surgery dramatically increases wound complication rates. The sinus tarsi approach has significantly lower wound complication rates than the extensile lateral approach and is preferred for Sanders Type II and select Type III fractures. The lumbar spine should be examined in all calcaneus fracture patients, as associated compression fractures are present in approximately 10% of cases.

References

1. Sanders R, Fortin P, DiPasquale T, Walling A. Operative treatment in 120 displaced intraarticular calcaneal fractures: results using a prognostic computed tomography scan classification. Clin Orthop Relat Res. 1993;(290):87-95.
2. Buckley R, Tough S, McCormack R, et al. Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: a prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am. 2002;84(10):1733-1744.
3. Schepers T. The sinus tarsi approach in displaced intra-articular calcaneal fractures: a systematic review. Int Orthop. 2011;35(5):697-703.
4. Radnay CS, Clare MP, Sanders RW. Subtalar fusion after displaced intra-articular calcaneal fractures: does initial operative treatment matter? J Bone Joint Surg Am. 2009;91(3):541-546.

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