Operative Management of Calcaneal Fractures: Surgical Guide

Introduction to Calcaneal Fractures

The calcaneus is the most frequently fractured tarsal bone, accounting for approximately 60% of all tarsal fractures and 2% of all fractures in the human body. Historically, the management of displaced intra-articular calcaneal fractures was shrouded in therapeutic nihilism. However, advancements in computed tomography (CT), a deeper understanding of hindfoot pathoanatomy, and the evolution of specialized internal fixation have revolutionized our approach.

Drawing upon decades of landmark research—from the early anatomical descriptions by Böhler and Essex-Lopresti to the modern, prospective multicenter trials by Buckley and the CT-based prognostic classifications by Sanders—this masterclass provides a definitive, textbook-level guide to the operative management of calcaneal fractures.

Pathoanatomy and Mechanism of Injury

The vast majority of intra-articular calcaneal fractures result from high-energy axial loading, such as a fall from a height or a motor vehicle collision.

The Primary Fracture Line

When an axial load is applied, the talus acts as a wedge. The lateral process of the talus is driven downward into the crucial angle of Gissane. This force splits the calcaneus, creating a primary fracture line that runs obliquely from posteromedial to anterolateral. This primary line divides the calcaneus into two main fragments:
1. The Anteromedial (Sustentacular) Fragment: This fragment includes the sustentaculum tali and the medial portion of the posterior facet. Because it is securely tethered to the talus by the robust interosseous talocalcaneal and deltoid ligaments, it remains anatomically aligned with the talus. It is universally considered the "constant fragment" to which the rest of the calcaneus must be reduced.
2. The Posterolateral (Tuberosity) Fragment: This fragment is displaced laterally, superiorly, and into varus by the deforming forces of the Achilles tendon and the initial impact.

Secondary Fracture Lines

As the axial load continues, secondary fracture lines develop, dictating the specific fracture pattern as described by Essex-Lopresti:
* Joint Depression Type: The secondary fracture line exits just behind the posterior facet. The articular segment is driven into the cancellous body of the calcaneus, resulting in severe joint incongruity.
* Tongue Type: The secondary fracture line exits posteriorly through the calcaneal tuberosity. The posterior facet remains attached to the tuberosity, creating a lever arm that can compromise the posterior soft tissue envelope.

Clinical Pearl: Tongue-type fractures can cause severe pressure on the posterior skin, leading to rapid full-thickness necrosis. This is an orthopedic emergency requiring urgent reduction, often via a percutaneous Essex-Lopresti maneuver or a Schanz pin joystick technique.

Clinical Evaluation and Imaging

Soft Tissue Assessment

The timing of surgical intervention is dictated entirely by the soft tissue envelope. The classic "wrinkle test" must be positive before proceeding with an open approach. Operating through edematous, blistered skin exponentially increases the risk of catastrophic wound complications. Surgery is typically delayed 10 to 14 days to allow for the resolution of swelling.

Radiographic Evaluation

Standard radiographic evaluation includes:
* Lateral View: Assesses the Böhler angle (normal 20°–40°) and the crucial angle of Gissane (normal 100°–130°). A depressed Böhler angle correlates with loss of calcaneal height and poorer outcomes if left unreduced.
* Harris Axial View: Evaluates heel width, varus/valgus alignment of the tuberosity, and the primary fracture line.
* Broden’s Views: Used intraoperatively to visualize the posterior facet.

Computed Tomography (CT)

CT is the gold standard for evaluating calcaneal fractures. Coronal, sagittal, and axial planes are mandatory. The coronal images dictate the Sanders classification, while sagittal images are crucial for identifying anterior process involvement and the exact nature of the posterior facet depression.

The Sanders Classification

Developed by Roy Sanders in the early 1990s, this classification is based on coronal CT images showing the widest portion of the posterior facet. It is highly prognostic for surgical outcomes. The posterior facet is divided into three potential fracture lines (A, B, and C), moving from lateral to medial.

• Type I: Nondisplaced fractures (regardless of the number of fracture lines). Treated nonoperatively.
• Type II: Two-part fractures of the posterior facet (one fracture line). Subdivided into IIA, IIB, and IIC based on the location of the line.
• Type III: Three-part fractures (two fracture lines), featuring a central depressed fragment. Subdivided into IIIAB, IIIAC, and IIIBC.
• Type IV: Four-part (or more) highly comminuted fractures.

Surgical Pitfall: Sanders Type IV fractures have historically poor outcomes with primary Open Reduction and Internal Fixation (ORIF). Many master surgeons advocate for primary subtalar arthrodesis in these severe injuries, as supported by the work of Myerson and Buch.

Indications for Operative Management

The landmark prospective randomized trial by Buckley et al. (2002) clarified the indications for surgery. While the overall cohort showed no significant difference between operative and nonoperative treatment, subgroup analysis revealed that ORIF provides significantly better outcomes in:
* Women
* Younger patients
* Patients not receiving Worker's Compensation
* Patients with a lower initial Böhler angle (indicating severe displacement)
* Patients with a lighter workload

Absolute Contraindications:
* Active smoking (relative to absolute, depending on the surgeon, due to a massively increased risk of wound necrosis).
* Severe peripheral vascular disease.
* Uncontrolled diabetes mellitus with neuropathy.
* Non-ambulatory patients.

Surgical Approaches

1. The Extensile Lateral Approach

Popularized by Benirschke and Sangeorzan, this is the workhorse approach for complex intra-articular fractures, providing unparalleled visualization of the lateral wall, posterior facet, and calcaneocuboid joint.

Positioning: The patient is placed in the lateral decubitus position on a radiolucent table. All bony prominences are padded. A high thigh tourniquet is applied.

Incision: An L-shaped incision is made. The vertical limb is placed midway between the fibula and the Achilles tendon. The horizontal limb runs parallel to the plantar surface, at the junction of the glabrous and non-glabrous skin.

Flap Creation:
* The incision is carried straight down to bone in a single sweep.
* A full-thickness subperiosteal flap is elevated. This "no-touch" technique is critical; the skin edges must never be handled with forceps.
* The sural nerve is elevated within the flap.
* Retraction is achieved using 1.6mm K-wires placed into the lateral malleolus, the talar neck, and the cuboid. Bending these wires back holds the flap out of the surgical field without the need for self-retaining retractors, which cause tissue ischemia.

2. The Sinus Tarsi Approach

Due to the high wound complication rates associated with the extensile lateral approach (up to 25% in some historical series, as noted by Folk et al.), the minimally invasive sinus tarsi approach has gained immense popularity for Sanders Type II and select Type III fractures.

Technique: A 3-5 cm incision is made directly over the sinus tarsi, extending from the tip of the lateral malleolus toward the base of the fourth metatarsal. This provides direct access to the posterior facet and the anterolateral fragment. While it limits visualization of the entire lateral wall, it drastically reduces wound complications and allows for earlier intervention.

Step-by-Step Surgical Technique: ORIF via Extensile Lateral Approach

Step 1: Debridement and Exposure

Once the flap is elevated, the lateral wall blowout is encountered. The thin cortical shell of the lateral wall is carefully reflected outward like a trapdoor. The hematoma within the calcaneal body is evacuated. This exposes the depressed articular fragments of the posterior facet.

Step 2: Tuberosity Reduction

The first goal is to restore the length, height, and axis of the calcaneus.
* A 5.0mm Schanz pin is inserted transversely into the posteroinferior aspect of the calcaneal tuberosity.
* Using a T-handle, axial traction is applied to pull the tuberosity out of varus, downward, and posteriorly.
* Once aligned with the constant sustentacular fragment, K-wires are driven from the posterolateral tuberosity, across the primary fracture line, into the sustentaculum tali to hold the provisional reduction.

Step 3: Articular Reduction

With the tuberosity reduced, attention turns to the posterior facet.
* The depressed articular fragments are elevated using a periosteal elevator.
* They are anatomically reduced against the medial sustentacular fragment.
* Direct visualization and intraoperative Broden's views confirm the reduction.
* Subchondral lag screws (typically 3.5mm or 4.0mm) are placed from lateral to medial, securing the posterior facet to the sustentaculum.

Clinical Pearl: The trajectory of the sustentacular screws is critical. They must be directed slightly anteriorly and inferiorly to avoid penetrating the subtalar joint or injuring the flexor hallucis longus (FHL) tendon medially.

Step 4: Anterior Process and Lateral Wall Reduction

If the calcaneocuboid joint is involved, it is reduced and provisionally pinned. Finally, the lateral wall trapdoor is closed. This prevents lateral impingement against the fibula, which is a major cause of postoperative pain.

Step 5: Plate Fixation

A low-profile, perimeter calcaneal plate is applied. The plate acts as a neutralization device.
* Screws are placed into the dense bone of the anterior process, the sustentaculum, and the posterior tuberosity.
* The use of locking plates (as biomechanically validated by Richter et al.) is particularly beneficial in osteoporotic bone or highly comminuted patterns.
* The use of bone graft or calcium phosphate cement to fill the large metaphyseal void remains debated. Studies by Thordarson have shown that injectable cements increase construct stiffness, though Longino and Buckley demonstrated that structural autograft is rarely necessary for union.

Step 6: Closure

Closure is meticulous. A deep drain is often placed. The subcutaneous tissue is closed with inverted absorbable sutures, and the skin is closed with a modified Allgöwer-Donati technique using non-absorbable monofilament to minimize tension on the epidermal edges.

Postoperative Protocol

The success of calcaneal ORIF relies heavily on strict postoperative adherence.
* 0-2 Weeks: The patient is placed in a bulky Jones dressing and a well-padded posterior splint. Strict elevation is mandatory. Non-weight-bearing (NWB) status is enforced.
* 2-6 Weeks: Sutures are removed at 2 to 3 weeks once the wound is completely healed. The patient is transitioned to a removable CAM boot. Active range of motion (ROM) exercises for the ankle and subtalar joint are initiated immediately to prevent stiffness. The patient remains strictly NWB.
* 6-10 Weeks: Radiographs are obtained to assess healing. If callus is present and fracture lines are blurring, progressive partial weight-bearing is initiated.
* 10-12 Weeks: Transition to full weight-bearing in regular footwear, often utilizing a custom orthotic with medial arch support and a cushioned heel cup.

Complications and Salvage Procedures

Wound Complications

Wound edge necrosis and deep infection are the most feared complications. Superficial necrosis can often be managed with local wound care and oral antibiotics. Deep infections involving the hardware or bone (osteomyelitis) require aggressive surgical debridement, hardware removal (once union is achieved or via external fixation), and potentially soft-tissue coverage with a free flap (e.g., anterolateral thigh flap), as detailed by Levin and Nunley.

Post-Traumatic Subtalar Arthritis

Even with anatomical reduction, the initial cartilage impact can lead to post-traumatic arthritis. Patients present with pain exacerbated by walking on uneven ground.
* Treatment: In situ subtalar arthrodesis is the treatment of choice for isolated arthritis without deformity.

Malunion

Nonoperative treatment or failed ORIF can result in a classic calcaneal malunion characterized by:
1. Loss of calcaneal height (causing anterior ankle impingement).
2. Increased heel width (causing lateral fibular impingement).
3. Varus deformity of the tuberosity.

• Salvage: As described by Carr, Myerson, and Romash, the salvage procedure for a severe malunion is a Subtalar Distraction Bone Block Arthrodesis. This complex procedure involves resecting the lateral wall exostosis, distracting the subtalar joint to restore calcaneal height, inserting a tricortical iliac crest bone graft, and fusing the joint. This simultaneously decompresses the subfibular space, corrects the anterior ankle impingement, and eliminates arthritic pain.

Conclusion

The operative management of calcaneal fractures is a technically demanding endeavor that requires a profound understanding of hindfoot biomechanics, meticulous soft-tissue handling, and precise articular reduction. By adhering to strict patient selection criteria, utilizing appropriate surgical approaches (whether extensile lateral or sinus tarsi), and executing rigid internal fixation, orthopedic surgeons can reliably restore hindfoot anatomy and maximize functional recovery for these challenging injuries.

📚 Medical References

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• Vosburgh CL, Gruel CR, Herndon WA, et al: Lawn mower injuries of the pediatric foot and ankle: observations on prevention and management, J Pediatr Orthop 15:504, 1995.
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• Wiley JJ: Tarsometatarsal joint injuries in children, J Pediatr Orthop 1:255, 1981.