1.1 Introduction

Fractures of the calcaneus are common and account for approximately 60% of tarsal injuries.

The etiology of calcaneal fractures is usually high-energy trauma, such as a fall from height or a motor vehicle crash.

During axial loading the talus is forced caudally into the calcaneus. The severity, type, and location of the fracture are determined by the position of the foot, the direction and magnitude of the applied force and the quality of bone and result in a number of frequently observed fracture patterns. Fractures to the spine and the extremities are frequently associated and require careful assessment. Significant soft-tissue swelling is common and related to a combination of forces producing the injury and persisting fracture displacement. In highly displaced tongue-type patterns, the posterior skin may be severely compromised due to pressure from the posterior calcaneal tuberosity, which is pulled proximally by the Achilles tendon. Similarly, in displaced joint depression patterns, fracture displacement may produce significant medial or lateral skin tension resulting in blisters ( Fig 6.10.1-1 ). Patients with open fractures and those who will undergo percutaneous operative treatment need urgent surgery. Patients requiring open reduction and internal fixation (ORIF) should be delayed until soft-tissue swelling resolves: elevation of the limb is essential.

1.2 Evaluation and diagnosis

A thorough history must be taken from the patient and include medical history, occupation, sport interests, and smoking.

The radiographic assessment of the calcaneus begins with three views of the foot (AP, lateral, and oblique) as well as an axial (Harris) view. The basic fracture pattern (tongue type versus joint depression type) is best demonstrated on the lateral view. A decrease in Böhler′s angle, measured as the angle between lines connecting the cranial portion of the tuberosity, the posterior articular surface of the talus, and the anterior process of the calcaneus is determined on the lateral x-ray ( Fig 6.10.1-2 ). The oblique and AP views delineate fracture extension into the calcaneocuboid joint.

The axial view shows the primary displacements and angulations of the tuberosity (shortening and varus) as well as any increase in heel width. Broden′s views (oblique views of the posterior articular surface of the talocalcaneal joint) are helpful preoperatively and intraoperatively. An x-ray comparison with the uninjured, contralateral extremity can be useful for assessing the injury pattern and planning surgical fixation.

Computed tomographic (CT) scans in the axial and coronal planes are necessary to fully understand the fracture pattern.

The axial images demonstrate any anterior process extensions of the fracture into the calcaneocuboid joint ( Fig 6.10.1-3a ). The coronal images depict the involvement of the posterior articular calcaneal surface as well as shortening and position of the tuberosity ( Fig 6.10.1-3b ). Sagittal CT reconstructions can further be used to identify the injury.

1.3 Anatomy

An understanding of the complex calcaneal anatomy requires a 3-D appreciation of the multiple articulations and bony processes. There are two articulations (with three facets) with the talus and one saddle-shaped articulation with the cuboid. Frequently, the anterior and middle facets are contiguous with one another as they form one articulation, and are separated from the larger posterior articular surface by the floor of the tarsal canal. The sustentaculum tali is the dense bone beneath the middle articular facet, which bears the greatest weight. The lateral wall of the calcaneus is thin and has attachments for the calcaneofibular ligament and the osseus reflection of the peroneal tendons. On the medial aspect, the bone is thicker and there is close proximity to the toe flexors and posterior tibial neurovascular structures.

It is essential to understand the vascular supply (angiosomes) to the skin of the lateral hindfoot as wound healing complications may be encountered after ORIF using an extensile lateral approach. The lateral calcaneal artery, the lateral hindfoot artery, and the lateral tarsal artery contribute to the vascularity of the lateral skin and soft tissues of the foot. The lateral calcaneal artery is responsible for the majority of the blood supply to the corner of the flap in the extensile lateral approach. There is also a very special structure—the heel pad—on the bottom of the foot. It is irreplaceable as a tissue and must be respected when operating or trying to save a badly injured foot.

1.4 Classification

Fracture classification assumes an understanding of major fracture displacements and fragments that are commonly observed ( Fig 6.10.1-4a–b ). Essex-Lopresti differentiated joint depression patterns and tongue-type fractures, depending on the exit point of the secondary fracture line ( Fig 6.10.1-4c–d ). In tongue-type patterns, a variable portion of the posterior articular surface remains in continuity with the tuberosity fragment. In joint depression types, the fracture line exits anterior to the tuberosity. The Sanders CT classification is based on the location and number of fracture lines of the posterior articular surface as demonstrated by the coronal images at the widest part of the calcaneus, ie, the sustentaculum. The AO/OTA Fracture and Dislocation Classification is comprehensive and includes a description of both intraarticular and extraarticular fractures ( Fig 6.10.1-5 ).

1.5 Surgical indications

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  Surgical indications—absolute [1]:

  
  
  
  
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    – Open fractures

    
    
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    – Skin compromise (posterior skin [tongue-type fracture])

    
    
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    – Poor foot shape and heel position

    
    
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    – Fracture dislocation of hindfoot

  
  
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  Surgical indications—relative:

  
  
  
  
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    – Severe comminution of joint (best served by primary fusion of subtalar joint and calcaneal shape reconstruction)

    
    
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    – Displacement of articular surface greater than 2 mm

    
    
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    – Bilateral calcaneal fractures (each foot treated on respective CT characteristics)

    
    
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    – Nonsmoker

  
  
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  Surgical contraindications:

  
  
  
  
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    – Swollen, blistered foot

    
    
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    – Peripheral vascular disease

    
    
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    – Neuropathy

    
    
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    – Medically unwell patient

    
    
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    – Noncompliant, permanent head injury or psychiatric patient

    
    
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    – Alcohol and/or drug abuse

  
  
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  Other key factors to consider:

  
  
  
  
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    – Soft tissue condition: wrinkle sign on skin on lateral hindfoot

    
    
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    – Patient older than 60 years but medically optimized

1.6 Preoperative planning

The management of displaced intraarticular calcaneal fractures remains controversial. Closed management may be indicated in patients with minimal articular involvement, adequate heel position and in patients with contraindications to operative treatment. Closed management consists of early functional treatment. This comprises ankle and subtalar joint exercises that encompass a full range of motion, but only after an appropriate decrease of soft-tissue swelling. Weight bearing should be limited until fracture healing has occurred, which is usually after 6–12 weeks.

Careful patient assessment is critical if operative treatment is considered.

The prognosis is worse if the patient is male, has medium to heavy labor requirements at work or has a worker′s compensation claim, very diminished Bohler′s angle, or bilateral injuries [2]. Moreover, patients with open fractures, patients who smoke, and patients with diabetes have been identified as having a higher incidence of wound complications after surgery [3].

The condition of the soft tissues is the primary determinant for the timing of surgery in the treatment of displaced calcaneal fractures.

Patience is required to optimize the local surgical environment and to minimize the incidence of wound complications.

The return of skin wrinkles to the lateral foot at the surgical incision site should be used as a guide for timing of surgery, which is usually possible 7–14 days after injury [4].

Longer delays may be associated with increased difficulty in obtaining a reduction and closing the surgical incision once heel height has been restored.

If soft-tissue condition does not allow a full surgical approach, then limited percutaneous techniques can be useful and help to reduce the posterior articular surface to a more acceptable position [1].

Instruments and implants include K-wires, laminar spreaders, small-fragment screws and plates, and calcaneal implants. A 4.0 or 5.0 mm Schanz screw helps to manipulate a tuberosity fragment. Dental picks and small elevators can be useful for the reduction of articular fragments. Bone substitutes may be useful to fill the large bone defect left after the reduction of impacted fragments.

1.7 Operating room set-up

The exposed area of the limb is disinfected with the appropriate antiseptic and the pelvic crest is disinfected in case this is required for bone harvesting. The iliac crest is draped first with a single-use waterproof drape and then the limb with a limb drape ( Fig 6.10.1-6 ). The image intensifier is also draped.

The surgeon stands (or sits) facing the patient′s calcaneus, and the assistant is opposite. The operating room personnel stand next to the surgeons. A sterile bump is put beneath the surface of the affected ankle, which allows the foot to fall slightly into varus. The image intensifier is brought in from the foot of the operating room table for lateral and axial images. The image intensifier display screen is placed in full view of the surgical team and the radiographer ( Fig 6.10.1-7 ).

1.8 Surgery

A recent study [5] has shown that operative results are poor, with high complication rates if calcaneal fracture surgery is undertaken by surgeons performing low-volumes of this complex procedure.

An understanding of the common fracture displacements is essential for operative treatment. Both intraarticular and extraarticular fracture displacement must be considered. The extraarticular displacement determines the loss of heel height, the increase in heel width and the varus position of the heel. The intraarticular displacement may include the calcaneocuboid joint, the posterior articular surface, and/or the anterior and middle articular surfaces. The primary fracture line for intraarticular fractures ( Fig 6.10.1-4a–b ) typically extends obliquely from the posteromedial to the anterolateral calcaneus ( Fig/Animation 6.10.1-8 ). This fracture line produces a posterolateral segment consisting of the tuberosity, the lateral wall, and a variable portion of the posterior articular surface. The anteromedial segment consists of the anterior process, the medial sustentaculum, and the remaining medial aspect of the posterior articular surface. Secondary fracture lines ( Fig 6.10.1-4c–d ) are common and can extend into the calcaneocuboid joint (separating the anterior process into anteromedial and anterolateral fragments) or medially (separating the sustentacular fragment from the anteromedial fragment). A lateral fragment of the posterior articular surface characterizes joint depression patterns and is produced by extension of a secondary fracture line to the cranial portion of the tuberosity ( Fig/Animation 6.10.1-9 ).

Because of the strong ligamentous attachments between the talus and the sustentacular fragment, this fragment is “constant” and usually nondisplaced. The location of this fragment and the density of bone in this area are critical for reduction and fixation of calcaneal fractures. Lateral patient positioning optimizes the approach and the reduction. An extensile lateral approach, first described by Letournel, allows access to the entire lateral calcaneus, the anterior process, and the middle articular surface. In this approach the vertical limb courses parallel to the Achilles tendon, while the horizontal limb is parallel to the plantar aspect of the calcaneus ( Fig 6.10.1-10 ). This is the edge of the angiosome and is defined, clinically, by the edge of the bruising. A full-thickness, periosteal-fascial-cutaneous flap is created by subperiosteal dissection of the lateral calcaneus [6]. The flap includes the sural nerve, the peroneal tendons, and the calcaneofibular ligament. The sural nerve is at risk at the proximal and distal parts of the incision. Distally, the calcaneocuboid joint is exposed. The flap can be retracted manually or with K-wires placed into the talus and/or lateral malleolus as well as the cuboid. Care should be taken to protect the flap throughout exposure and reduction.

The bone of the lateral wall may need to be reflected to expose the lateral posterior articular fragment and the calcaneofibular ligament. In rare situations, a medial approach alone may be needed to reach the sustentaculum for reconstruction.

Reduction of the calcaneus should restore the entire calcaneal morphology as well as the articular surfaces of the subtalar and calcaneocuboid joints.

There are several key aspects of the reduction. The medial sustentacular fragment is usually in a stable position and the remaining osseus segments are reduced in relation to this “constant” fragment. The anterior process is usually separated from the medial sustentacular fragment and lateralized. A secondary fracture line that extends into the calcaneocuboid joint requires reduction. The reduction of the posterior articular surface can only be accomplished after the tuberosity segment has been distracted from its impacted position between the fragments of the posterior articular surface ( Fig 6.10.1-11 ). This is usually the final stage of the articular reduction.

The sequence of fracture reductions depends on the experience and preference of the surgeon. Each strategy has its proponents and some flexibility is required in these difficult injuries.

One strategy is to perform the reduction in the following sequence:

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  Reduction of the anterior process (and, hence, the calcaneocuboid joint)

  
  
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  Reduction of the anterior process to the medial sustentacular fragment

  
  
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  Reduction of the tuberosity fragment to the medial sustentacular fragment

  
  
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  Reduction of the lateral articular fragment of the posterior articular surface

  
  
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  Replacement of the lateral wall

The common approach is to reduce the entire calcaneus and maintain this reduction with peripheral K-wires to allow an intraoperative assessment, by both inspection and image intensifier. Intraoperative use of an image intensifier and/or plain x-rays (Broden′s views) in the lateral, axial, and oblique planes can help to assess the reduction of the tuberosity, the posterior articular surface, and height and length of the calcaneus.

After assessment of the reduction, definitive fixation can be accomplished. Ideally, a lateral plate should span between the tuberosity fragment and the anterior process, while simultaneously allowing screw fixation through the plate and into the medial sustentacular fragment. Smaller, low profile implants have been shown to have biomechanical properties similar to larger, bulkier implants [7]. Special locking plates allow fixation of all commonly observed fractures but are not mechanically stronger than traditional nonlocking plate fixation [7]. Lag screw fixation across the reduced posterior articular surface can be placed through the plate or independently before application of the plate.

Impaction results in a large bone defect below the posterior articular surface of the calcaneus after reconstruction. Some surgeons do not fill the defect, while others use autograft, allograft, or bone substitutes to fill the defect. However, this may not be necessary with the locking calcaneal plate ( Fig 6.10.1-12 ). The surgical incision should be closed in layers. The deep closure consists of multiple, interrupted sutures that incorporate the periosteum and are usually tied from peripheral to central. Care should be taken to ensure that this portion of the closure adequately re-approximates the deep tissues. The skin can then be closed without tension using interrupted, modified Allgöwer-Donati sutures (see chapter 3.1.2).

Minimally invasive techniques are also helpful if indicated by the patient′s general condition and the soft-tissue condition. This technique may be particularly helpful for tongue-type fractures and joint depression-type fractures with a primary fracture line alone. Limited incisions under the guidance of an image intensifier may allow for indirect or direct reduction of joint surfaces. Limited internal fixation or percutaneous fixation, with carefully placed pins or screws, will maintain these reductions in patients whom it is unsafe to undergo a major surgical procedure ( Fig 6.10.1-13 ).