The calcaneus is the most commonly injured tarsal bone, accounting for 60% of tarsal fractures.1 These injuries are most often sustained from motor vehicle accidents or falls from a height. The patients typically are young and active people.2 Up to 40% of these injuries have complications, including malunion.3 Disability is commonplace following these injuries. The complex anatomy of the calcaneus is directly related to the complex nature of their management. A thorough understanding of the complexity of these fractures along with expertise in managing these injuries is paramount. The biomechanics of the foot and its relationship to the entire lower extremity gait pattern is influenced by any variation in bony anatomy and congruency. Changes in the anatomy of the calcaneus lead to gait dysfunction, ambulation limitations, and pain. This chapter will discuss the sequela following calcaneus fractures and how to systematically evaluate and address them. By no means will this be exhaustive of potential concerns of the foot and ankle following calcaneus fractures. Not only bony issues but also soft tissue alternations and abnormalities must be addressed. Often, multiple procedures, both soft tissue and bony, must be performed concurrently.
The anatomy of the calcaneus is complex in both overall shape and articular surfaces. Variations in the anatomy exist. Examination of the contralateral foot in addition to comparison radiographs may depict a patient’s normal anatomy. The most important bony relationships relate to overall calcaneal height and width. Deformity of these parameters leads to altered mechanics and distribution of weight during ambulation. In addition, these may impart imbalance on associated soft tissues, such as joint capsule, ligament, tendons, and skin. The articular surface displacement of the calcaneus and corresponding subtalar joint not only leads to alterations of gait but also contributes to posttraumatic arthritis, loss of range of motion, and pain. The largest articular surface, the posterior facet, is the most commonly involved facet and thus the primary focus of restoration in reductive surgeries. Common reference angle measurements are the critical angle of Gissane and Böhler angle (Figure 24.1). The angle of Gissane is the angle formed from the lateral aspect of the posterior facet and the lateral portion of the anterior beak of the calcaneus. The angle of Gissane is normally 95° to 100°.2 Böhler angle is formed from a line extending from the highest point of the posterior facet and a line extending from this point to the superior portion of the tuberosity. Normally, this measures 20° to 40°.4 Other important radiologic landmarks include calcaneal height, talar inclination angle, and the talo-first metatarsal angle. These landmarks and measurements serve as a guide to aim the reconstruction and allow for direct feedback from intraoperative imaging. Radiographs of the contralateral calcaneus prove valuable in interpreting these values among individual patients.
Anatomy of a Calcaneus Fracture
Understanding the mechanism of injury and the development of fracture types imparts crucial information. Regardless of the specific classification adhered to, evaluating the entire calcaneus is important to patient outcome. Rarely are plain radiographs sufficient to evaluate calcaneal fractures. Advanced imaging, predominantly computed tomography (CT) scans, are crucial to not only classify these fractures but also to guide treatment options. Standard radiographs include weight-bearing anterior-posterior (AP), lateral, and oblique views of the foot. Broden views, oblique views through the subtalar joint, are also informative5 (Figure 24.2). The calcaneal or Harris view is an axial view of the long axis of the calcaneus which will reveal heel varus or valgus as well as the contour of the lateral wall.
Axial compression fractures of the calcaneus typically leads to heel widening, heel varus, calcaneal shortening, loss of calcaneal height, and lateral wall displacement. Each of these parameters must be addressed to fully treat the patient and resolve these fractures and potential malunions. Often these traits occur simultaneously. Tongue-type fractures may be concerning for soft tissue trauma as well as plantarflexion biomechanics.
Zwipp discussed and classified calcaneal fracture healing into 3 distinct groups: malunion, nonunion, and osteonecrosis.6 Malunion is the most common complication of healing. Calcaneal nonunion is relatively uncommon.7,8 Thomas was the first documented case of fixation of a calcaneal nonunion.9 The nonunion was repaired with a plate and screw construct.
Besides the healing classification, articular cartilage injury, displacement, and ultimately, posttraumatic arthritic changes lead to significant alterations of normal function. Malunion, nonunion, and osteonecrosis most often involve incongruency of the articular surface. These are addressed concomitantly with the associated pathology.
A few comments of the biomechanics of the calcaneus as it related to normal function is warranted. The calcaneus supports a person’s body weight from heel strike to midstance. The calcaneus also serves as a support for the talus and thus aligns the talus beneath the ankle joint. If the calcaneal anatomy is altered, either by articular changes or bony anatomy, these subtalar alterations will impart drastic variations in gait pattern. This will likely lead to altered function, changes in energy expenditure, and pain.
Surgical Approaches for Calcaneal Fractures and Soft Tissue Concerns
One must have great respect of the soft tissues of the calcaneus when treating these fractures. The complications associated with skin compromise represent the earliest, potentially preventable, complications. The timing of surgical intervention must be addressed with any open approach to the fixation of calcaneus fractures. Allowing for the soft tissue envelope to recover from the trauma, bleeding, and edema is crucial. Delaying surgery until appropriate skin wrinkles are present may prevent catastrophic wound dehiscence and subsequent infection (Figure 24.3). Evidence has shown that delayed treatment of these fractures is the mainstay of treatment.10
The sinus tarsi approach limits the dissection necessary for the reduction and fixation at the cost of limited visualization of the fracture. The approach does allow for earlier surgical intervention and lessened wound complications. Again, special attention must be paid to the soft tissue envelope. One should warn against early use of this approach in swollen, traumatized skin.
In the event wound dehiscence occurs, patient outcome and satisfaction are greatly decreased. Proper wound care protocols must be followed. Debridement of the affected or infected region is crucial. Due to the lack of sufficient soft tissue, deep infection is commonplace. This requires serial debridement, hardware removal, and parental antibiotics resulting in increased length of hospital stay and increased cost of care. Skin grafting and soft tissue flaps may be required. Not to mention, amputation may be required if unable to resolve. Prevention and proactive planning attempt to lessen these concerns.
More recent fracture reduction techniques and instrumentation may decrease the risk of wound complications following surgical intervention of calcaneal fractures. This allows the fracture to be reduced intrafocally, from within the calcaneus and stabilized with an intramedullary implant. This permits for minimal manipulation of the soft tissues and thus decreases the incidence of wound complications. Also, since minimal trauma is imparted on the lateral calcaneal skin, surgery may be performed sooner after the injury. The more recent FDA 510-k clearance of the CalcaNail system (FH Orthopedics, Chicgao, IL) serves as an adjunct in the treatment of these fractures (Figure 24.4). In the author’s experience, no wound complications have occurred to date.
Other soft tissue concerns include compartment syndrome, peroneal tendon tears or pain due to calcaneal malunion, tibial or sural neuritis, and heel fat pad injuries. The treatment of these conditions is outside the scope of this chapter. These associated pathologies should be evaluated and addressed concomitantly if present (Table 24.1).
Chronic heel pain, aggravated with activity Fat pad atrophy
Prominent exostosis apparent on radiographs of the calcaneus Decreased height from floor to calcaneus on lateral foot radiograph
Reprinted from Stapleton JJ, Belczyk R, Zgonis T. Surgical treatment of calcaneal fracture malunions and post-traumatic deformities. Clin Podiatr Med Surg. 2009;26:79-90. With permission from Elsevier.
Following calcaneus fractures and loss of height of the calcaneus, the Achilles tendon is effectively shortened. Physical examination will reveal equinus of the ankle. The Silverskiöld test can assist in differentiating between gastrocnemius contracture versus Achilles contracture. The gastrocnemius muscle originates above the knee and joins the soleus to form the Achilles tendon. With the patient’s knee straight, passive ankle dorsiflexion is measured. The knee is then bent slightly and if dorsiflexion improves, a gastrocnemius contracture is present. This would be addressed with a Strayer, Baumann, or similar procedure. If dorsiflexion does not improve, the contracture is within the Achilles tendon, thus necessitating an Achilles lengthening. Calcaneal fractures usually involve contracture of the Achilles tendon.
Patient characteristics also directly influence the timing and outcome after sustaining a calcaneus fracture. Overall health status, vascular compromise, neuropathy, diabetes, tobacco use, or other drug use, may adversely affect the outcome. Evaluation of the entire patient is crucial to the success of the management of these injuries as well as the management of associated sequelae. Associated conditions must be evaluated and optimized prior to proceeding with surgical intervention for calcaneal malunion or nonunion. A multidisciplinary approach in coordination with endocrine, vascular surgery, or neurology may be needed. Laboratory studies such as a hemoglobin A1c will impart useful information concerning diabetic control and the potential for wound healing complications. Lack of pulses or concern for blood flow should prompt vascular evaluation such as ankle-brachial indices or tissue oxygen pressures. If these are abnormal, vascular surgery or interventional cardiology/radiology evaluation is warranted. Smoking and tobacco use are associated with both wound and bone healing compromise and discussion of smoking cessation is needed. If these conditions are overlooked, patient outcome may be adversely affected. If surgical correction is not an option, protective shoe wear may be necessary to offload bony prominences to lessen the development of hyperkeratotic lesions or ulcers. Gastrocnemius or Achilles stretching will assist in decreasing ground reactive forces on the forefoot. Since, most of these deformities are not flexible, corrective orthotics are not useful or recommended.
Isolated Exostoses After Calcaneal Malunion
After sustaining a calcaneus fracture, the fragments may displace and develop bony prominences once healed in a malunited position. The most common regions include a plantar exostosis, lateral exostosis, posterior exostosis, or anterior process of the calcaneus. In isolation, these may cause pain and disability. In addition, concern exists for patients with neuropathy, for these prominences may develop ulcers and impending infections.
The displacement and collapse of the calcaneus may lead to a bony prominence on the plantar portion of the foot (Figure 24.6). This is concerning especially for patients with neuropathy, who are also commonly diabetic. If surgery is not possible due to patient comorbidities, protective shoe inserts to offload the region is necessary to avoid skin compromise, ulcers, infection, and possible amputation. Surgical intervention is recommended and addressed with a lateral incision and excision with osteotomes. Often, this is sufficient to avoid the soft tissue concerns without extensive dissection among this subgroup of patients. Performing extensive corrective surgery may not be in the patient’s best interest.
Posterior Ankle Impingement
The collapse of the calcaneus may lead to a posterior prominence behind the talus, thus leading to posterior ankle impingement. This impingement is exacerbated with plantarflexion of the ankle (Figure 24.7). Jung described a Haglund deformity following malunion of tongue-type calcaneal fractures.11 These may be managed with excision of the Haglund deformity. Lui described posterior ankle impingement in joint depression type calcaneal fractures.12 He illustrated a case involving arthroscopic excision of the posterior spike of bone. These may also be addressed through an open approach to the posterior talus and calcaneus.
Lateral Wall Displacement
Displacement of the lateral wall of the calcaneus is a common finding after axial compression injuries of the calcaneus (Figure 24.8). This displacement alters the normal soft tissue anatomy of the lateral heel, especially the peroneal tendons. Pressure is exerted on the peroneal tendons. Also, the peroneal tubercle may be involved, further disrupting the normal anatomic relationships. Physical examination for peroneal subluxation or dislocation should be examined in the event injury to the retinaculum occurred. These concerns are then addressed along with the bony correction. Evaluation for peroneal tendon tears may be addressed with direct tendon repair or tendon transfers. Sural neuritis or neuroma may also be present. Clinical examination may determine a specific location of compression or neuroma. These associated conditions may be definitively managed as well. More commonly, lateral wall displacement leads to subfibular impingement.13 The subfibular impingement leads to lateral ankle pain and is confirmed on the axial view of the calcaneus. Clinically, the pain is located just distal to tip of lateral malleolus. Removal or decompression of the lateral wall has been shown to improve lateral foot and ankle pain14 in isolation or in combination with other procedures such as subtalar arthrodesis.15–17
The bony deformity of lateral wall displacement may be addressed in a straightforward manner. Several surgical approaches are possible. The surgical approach chosen should depend on associated pathology needing to be addressed. If no soft tissue concerns are present or suspected, a percutaneous approach may be used. This involves a 2 to 3 cm incision anterior to the tuber. Dissection is carefully taken to bone, protecting branches of the sural nerve. The lateral wall may then be gently removed with osteotomes, paying attention to remain intraosseous, thus protecting the soft tissues (Figure 24.9).
Alternatively, and more commonly, an approach from the tip of the lateral malleolus toward the base of the fifth metatarsal is utilized. This allows for direct investigation of the peroneal tendons. The lateral wall exostosis may be removed with osteotomes or a sagittal saw. The remaining lateral wall is rasped smooth. The lateral wall may also be used as bone graft for other associated procedures, such as subtalar joint arthrodesis or bone-block arthrodesis, which will be discussed later.
Bauer et al. discussed an endoscopic approach for the treatment of subfibular impingement using a 2-portal approach.18 They reported on 7 patients with improvement following the procedure. Zhang et al also described a minimally invasive technique for exostectomy of the lateral wall in conjunction with an in-situ arthrodesis of the subtalar joint.19 The subtalar joint was prepared percutaneously with the use of a trephine (Figure 24.10).