Keywords
calcaneus - fracture fixation, internal - fractures, bone - intra-articular fractures
- subtalar joint - tarsal bones
Palavras-chave
articulação talocalcânea - calcâneo - fixação interna de fraturas - fraturas intra-articulares
- fraturas ósseas - ossos do tarso
Introduction
The calcaneus is the largest tarsal bone. Among foot bones, the calcaneus is the most
frequently injured (60%), accounting for 1 to 2% of all fractures in the body. Additionally,
75% of them are intra-articular fractures.[1]
[2] These are some of the most challenging articular fractures to manage, often yielding
unsatisfactory outcomes for both patients and physicians.[3]
Most calcaneal fractures result from high-energy trauma and primarily occur in young,
active patients.[4]
There is controversy regarding the optimal treatment for these fractures. Both surgical
and non-surgical approaches have their advantages and disadvantages. However, over
time, surgical management has emerged as the preferred approach for calcaneal fractures.[2]
[4]
[5]
[6]
[7]
The literature demonstrates that anatomical reduction and internal fixation provide
the best outcomes in terms of rapid recovery and early restoration of subtalar joint
function.[7]
[8] The gold standard in treatment should include anatomical reduction of the subtalar
joint, restoration of the normal width, alignment, and length of the calcaneus, and
stabilization with rigid fixation.[5]
Anatomy
The calcaneus, along with the talus, forms the hindfoot. It features four articular
surfaces: a calcaneocuboid and a subtalar joint, which is further divided into anterior,
middle, and posterior facets. The posterior subtalar facet is the largest and most
critical for load support during gait, presenting a convex shape oriented distally
and laterally at a 45° angle to the sagittal plane.[9] The middle facet is located on the upper surface of the sustentaculum tali, anterior
and medial to the posterior facet. The anterior facet, which is the smallest one,
is found on the anterior aspect of the calcaneus, situated laterally to the sustentaculum
tali.[9]
[10]
The medial surface of the calcaneus contains a thick cortex that supports its medial
projection, the sustentaculum tali. This structure provides stability to the head
and neck of the talus, playing a key role in maintaining hindfoot alignment. It serves
as the insertion site for the tibiocalcaneal component of the deltoid and the spring
ligaments.[10]
Trauma Mechanism
Although calcaneal fractures can result from pathological conditions such as tumors
or stress injuries, most cases are caused by high-energy axial trauma affecting the
calcaneal joints.[2]
[11]
[12]
Intra-articular calcaneal fractures arise from axial forces that disrupt the subtalar
and calcaneocuboid joints, as well as the calcaneal body and surrounding soft tissues.[4]
[13] The resulting fracture pattern depends on the direction and intensity of the force,
the position of the foot at the time of injury, and the patient's bone quality.[1]
Axial forces compress the calcaneus against the talus, with the lateral talar process
impacting the calcaneal cortex at the Gissane angle. Because the talus's load axis
is more medial than that of the calcaneus, an eversion moment occurs, producing the
primary fracture line.[1]
This primary fracture line divides the calcaneus coronally into an anteromedial and
a posterolateral fragment. The anteromedial fragment, which includes the sustentaculum
tali and the middle subtalar facet, remains congruent with the talus. Due to its consistent
anatomical relationship, this fragment—termed the “constant fragment”—is an important
reference for reduction.[2]
[14]
Hindfoot valgus at the time of trauma results in a more lateral primary line and a
larger anteromedial fragment, whereas hindfoot varus generates a more medial line
and a smaller fragment, complicating reduction and fixation during surgery.[1]
As trauma energy dissipates, secondary fracture lines create comminution across the
calcaneal body and the subtalar and calcaneocuboid joints.[7]
[14]
[15] Typical deformities include varus alignment of the calcaneal tuberosity, depression
of the posterior subtalar joint, and lateral wall widening, with proximal displacement
of the tuberosity and reductions in both calcaneal pitch and Böhler's angle.
The resulting tuberosity varus is a composition of movement of this segment in the
three planes. Lateral translation of calcaneal tuberosity in conjunction with medial
rotational movement results in varus of the coronal axis of the tuberosity.[1]
Physical Exam
Calcaneal fractures are often associated with injuries to other musculoskeletal regions
and body systems. A comprehensive evaluation of patients, following Advanced Trauma
Life Support (ATLS) protocols, is essential. Commonly associated injuries include
fractures of the tibial plafond, tibial plateau, and spine.[4]
During the foot examination, it is crucial to assess pain and deformities in the hindfoot,
midfoot, and forefoot, along with skin lesions, sensory deficits, pulses, and perfusion.
Diagnosing compartment syndrome at this stage is vital, as it manifests as tense edema,
pain unresponsive to potent analgesics, severe pain during toe movement, perfusion
deficits, and paresthesia.[2]
Common clinical findings in calcaneal fractures include plantar ecchymosis, pain,
edema, hindfoot deformities, and difficulty bearing weight. Soft-tissue integrity
is critical in determining surgical timing and planning. The presence of phlyctenae
often indicates delayed surgical intervention. Surgery is typically scheduled after
edema reduction, when skin wrinkling and phlyctena healing are observed.[1]
Diagnostic Imaging Techniques
Diagnostic Imaging Techniques
Radiographic Evaluation
Radiography is the primary imaging modality for diagnosing calcaneal fractures and
should include lateral, anteroposterior, and oblique foot views, along with axial
views of the calcaneus.[16]
Lateral radiographs are used to measure Böhler's and Gissane's angles. Böhler's angle
is formed by the intersection of lines connecting the anterior process, the posterior
subtalar joint, and the calcaneal tuberosity. Normal values range from 20 to 40°.[17] Gissane's angle, measured from the lateral calcaneal wall, lies between 95° and
105°[18] ([Fig. 1]).
Fig. 1 Radiographic evaluation. (A) Böhler angle in normal foot (values range from 20–40°). It is formed by the intersection
of lines connecting the anterior process, the posterior subtalar joint, and the calcaneal
tuberosity. (B) Gissane's angle in normal foot (values between 95–105°). It is formed by the line
of the posterior facet and the line from the sulcus to the most superior portion of
the anterior calcaneal process. (C) Anteroposterior incidence, with calcaneal fracture. (D) Oblique incidence, with calcaneal fracture. (E) Axial incidence, with calcaneal fracture. (F) Lateral incidence, with calcaneal fracture. Yellow arrow – calcaneocuboid articular
fracture. Blue arrow – Lateral wall enlargement. Black arrow – Posterior subtalar
joint depression. White arrow – Constant fragment.
The anteroposterior view better visualizes the calcaneocuboid joint and lateral wall
widening. Oblique views show the calcaneocuboid joint and tuberosity displacement
relative to the lateral wall. Axial radiographs reveal lateral-medial widening, varus
or valgus deviation, and posterior subtalar joint misalignment ([Fig. 1]).
The adjustment during the reduction of the Böhler's and Gissane's angles, especially
the Böhler, restores the shape of the calcaneus body and hindfoot, providing better
functional results.[4]
[12]
[17]
The Broden incidence complements radiographic evaluation.[4] With the patient supine and the ankle in a neutral position, the leg is internally
rotated by 30 to 40°. Images are taken at cephalad angles of 40°, 30°, 20°, and 10°,
centered on the lateral malleolus, providing detailed visualization of the posterior
subtalar joint. Intraoperatively, these views are particularly useful for assessing
joint reduction.[4]
[19]
Computed Tomography
Computed tomography (CT) enhances fracture diagnosis, classification, and prognosis,[3]
[14]
[15] particularly in identifying associated injuries and understanding three-dimensional
fracture displacement for surgical planning[16]
[20] ([Fig. 2]).
Fig. 2 Tomographic evaluation. (A) Sagittal computed tomography (CT). Subtalar joint depression. (B) Axial CT. Blue arrow – constant fragment; Yellow arrow – subtalar joint depression.
(C) Coronal CT. Lateral wall enlargement and subtalar articulation incongruence. (D) 3D CT reconstruction. Blue arrow – constant fragment. (E) 3D CT reconstruction. Blue arrow – constant fragment. Note rotational displacement
of the tuberosity, with lateral translation. (F) Axial soft tissue CT window. White arrow – peroneal tendons.
As CT is a submilimetrical sectional study, it provides better visualization of the
articular displacement, assisting in the treatment decision. Furthermore, the CT reconstructions
allow better comprehension of the fracture anatomy, helping with the surgical planning,
with possible reductions maneuvers and fixation choices.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI), though less commonly available and more expensive,
is valuable for diagnosing occult and pathological fractures (e.g., tumors, stress
fractures), as well as those associated soft-tissue injuries.[21]
Classification
Several classifications have been described for calcaneal fractures.
Böhler was the first to present an extensive classification of calcaneal fractures.
In 1952, Essex-Lopresti described a new system classifying calcaneal fractures into
two groups based on the fracture mechanism: tongue-type and joint-depression fractures.[22]
In 1989, Rammelt and Zwipp[1] introduced a 12-point classification system for calcaneal fractures, incorporating
factors such as the number of joint surfaces involved, main fracture fragments, extent
of soft-tissue trauma, and associated fractures of neighboring bones.
In 1993, Sanders et al.[3] published a series of 132 displaced calcaneal fractures, proposing a CT-based classification
system. This system is based on coronal sections in an oblique direction, evaluating
the posterior facet and talar support in the same section, identifying three fracture
lines, A, B and C (from lateral to medial).
-
Type-1 fractures do not show displacement, regardless of the number of fracture lines.
-
Type-2 fractures involve 2 fragments (a single fracture line) and are further categorized
as 2a, 2b, or 2c, depending on the primary fracture line's location.
-
Type-3 fractures involve 3 fragments (2 fracture lines) with a depressed central fragment
and are similarly classified into 3ab, 3bc, or 3ac.
-
Type-4 fractures involve 4 or more fragments with significant comminution.[3]
Treatment of Calcaneal Articular Fractures
Treatment of Calcaneal Articular Fractures
In general, surgical treatment provides superior functional outcomes in displaced
subtalar joint fractures, regardless of the classification.[23]
[24] In cases of posttraumatic subtalar osteoarthritis, the outcomes of arthrodesis are
better if the acute fracture is initially treated surgically since the alignment of
the calcaneal body and the joint has been previously reestablished.[24]
Special considerations, such as vascular diseases, smoking, diabetes, advanced age,
systemic illnesses, borderline clinical conditions, and extensive soft-tissue injuries,
must guide surgical decision-making. Surgical treatment is indicated when the posterior
subtalar joint deviation exceeds 2 mm, as defined by Sanders.[3]
[14]
[15]
Following the AO principles (Arbeitsgemeinschaft für Osteosynthesefragen, AO, in German), anatomical reduction and absolute stability should be prioritized
for articular regions.[25] Direct visualization of articular components during open reduction is the preferred
method to achieve these goals.
Aligning the calcaneal body is critical to restoring functional relationships within
the hindfoot and midfoot. Surgical objectives include correcting Böhler's angle, calcaneal
height, length, and morphology.[17]
[26] In the sagittal plane, posterior and plantar repositioning of the tuberosity are
performed, while in the coronal plane, varus alignment, tuberosity translation, and
lateral wall widening are corrected.
The reduction of the calcaneal body must realign the fracture components with an indirect
functional reduction, which can be achieved by closed means. Relative stability is
adequate for body fixation.
In most cases, lateral approaches are used for this purpose. The lateral “L” extended
approach allows for open reduction of the subtalar and calcaneocuboid joints and the
body of the calcaneus, whereas the minimally invasive approach, the sinus tarsi approach,
allows for open reduction of the subtalar and calcaneocuboid joints and closed reduction
of the body.
Prather et al.,[27] in an experimental study on cadavers, compared the extended approach with the sinus
tarsi and demonstrated that both approaches provide equivalent joint exposure area,
although the extended approach provides better visualization of the lateral wall.
Surgical Approach
Sinus Tarsi
The sinus tarsi approach minimizes damage to surrounding soft tissues, reducing the
risk of dehiscence and infection.[28]
[29]
[30]
Yao et al.[30] in a systematic review with a meta-analysis of 12 studies, compared wound complications
and quality of reduction between patients with calcaneal fractures treated with sinus
tarsi and extended approaches. The authors demonstrated that the sinus tarsi group
had a lower incidence of wound complications, with comparable quality of reduction.
This approach provides reductions comparable to the extended lateral “L” approach,
with similar functional outcomes but fewer complications. However, the sinus tarsi
technique is technically demanding and requires a longer learning curve.[5]
[31]
[32]
[33]
[34]
With the patient in the lateral decubitus position, the incision begins posterior
to the lateral malleolus and extends toward the base of the fourth metatarsal. The
length depends on fracture involvement of the calcaneocuboid joint. Subcutaneous dissection
reaches the extensor digitorum brevis muscle, which is reflected distally to expose
the anterior calcaneus. Care must be taken with the sensitive branches of the sural
nerve.
Dissection at the Gissane angle exposes the sinus tarsi, allowing visualization of
the interosseous ligaments and posterior subtalar joint. Fibular tendons are moved
posteriorly to increase exposure. If necessary, fibulocalcaneal and subtalar interosseous
ligaments are released.
Plantar to the lower edge of the incision, under the fibular tendons, with blunt dissection,
we gain access to the lateral wall of the calcaneus and, posteriorly, to the tuberosity.
Therefore, the sinus tarsi approach allows direct visualization of the posterior subtalar
and calcaneocuboid joints, the upper part of the lateral wall of the calcaneus, and
the fibular tendons ([Fig. 3]).
Fig. 3 Sinus tarsi approach. (A) Incision parameters. (B) Fragments visualization through the incision. Yellow arrow – subtalar joint depression;
White arrow – constant fragment; Black arrow – calcaneal anterior portion; Green arrow
– lateral wall. (C) Subtalar joint direct reduction. Yellow arrow – subtalar joint depression; White
arrow – constant fragment. (D) Temporary fixation with Kirshner wires.
The Essex-Lopresti maneuver,[22] visualized through the sinus tarsi approach, is particularly effective for tongue
fractures. In these cases, the fractured lateral fragment of the posterior subtalar
joint remains attached to the tuberosity. The goal of the maneuver is to elevate the
articular fragment by pushing the tuberosity distally. The sinus tarsi approach enables
direct visualization of the anatomical reduction of the lateral subtalar fragment
in alignment with the medial constant fragment.
The procedure begins by plantarflexing the ankle and using a Steinmann wire or Schanz
pin to push the calcaneal tuberosity distally. Blunt instruments assist in achieving
a precise reduction of the joint. Once reduction is achieved, temporary fixation with
Kirschner wires ensures the anatomical alignment of the joint and the functional reduction
of the calcaneal body. Definitive fixation is then performed using traction screws
for the subtalar joint and positioning screws for the tuberosity.
Depression fractures, which are more comminuted and challenging to reduce, require
the release of bone fragments from the joint and calcaneal body to create space for
alignment.[2] Reduction begins with manipulation of the anterior calcaneus to restore the calcaneocuboid
joint, establishing an additional parameter for reduction with the sustentaculum tali.
Fragments of the posterior subtalar joint are then elevated proximally using blunt
instruments, aligning them with the medial joint remnants at the sustentaculum tali.
The tuberosity is repositioned by introducing a blunt instrument laterally beneath
the sustentaculum tali, forcing medial translation to centralize the tuberosity under
the tibial load axis. A Steinmann wire or Schanz pin serves as a joystick to guide
the tuberosity posteriorly and plantarly, increasing calcaneal length and height.
Coronal rotation is also corrected during this process, reducing varus alignment.
Once fragment reduction is complete, the lateral wall is pushed medially to correct
widening. Temporary fixation with Kirschner wires is verified through fluoroscopy,
followed by definitive fixation ([Fig. 3]).
The ideal fixation strategy aims to achieve absolute stability of the subtalar and
calcaneocuboid joints, using traction screws anchored to the sustentaculum tali. However,
in cases with significant comminution, achieving absolute stability is challenging,
requiring the use of positioning screws to maintain anatomical reduction.
The posterior tuberosity, lateral wall, and anterior portion of the calcaneus are
fixed with relative stability, achieved through screws or plates, depending on the
fracture's morphology and comminution.
Discussing synthesis options in these situations, Ni et al.[35] (2016) demonstrated that the mechanical stability of fractures fixed with locking
plates is comparable to that achieved with screws alone. Subsequent studies confirmed
similar rigidity, postoperative function, and rehabilitation outcomes between screws
and plates.[25]
[36]
[37] Therefore, screw fixation is preferred in most cases due to less soft tissue envelope
injury and lower cost.
Maintenance of the reduction of the tuberosity is achieved with a positioning screw,
which is fixed to the anterior portion of the calcaneus. The screw can be directed
from posterior to anterior or from dorsal and posterior to anterior and inferior,
depending on the bone quality suitable for the screw to remain fixed[12]
[20]
[38] ([Fig. 4]).
Fig. 4 Screws and plate fixation. (A–C) Screws fixation reducing all the calcaneal fractures components. (D–F) Calcaneal anterior portion comminuted. Subtalar joint fixated with screws and calcaneal
with locked plate.
When comminution and lack of bone mass preclude stable screw fixation, locking plates
are used to stabilize reductions between the anterior and posterior calcaneal elements.[2] Specific plates designed for the sinus tarsi approach or conventional calcaneal
locking plates can be shaped for proper placement ([Fig. 4]). The calcaneal nail is a current fixation option, following the same concepts described
earlier, with encouraging initial results, providing stability comparable to that
of the locked plate. However, more clinical studies are needed to understand in which
situations its use adds the most benefits.[39]
In cases of extensive joint and body comminution, in which fixation between fragments
is unfeasible, even with plates, primary arthrodesis of the subtalar joint may be
performed. This approach maintains calcaneal shape and hindfoot alignment.[6]
Extended Lateral Approach
Extended Lateral Approach
Understanding the vascular anatomy is critical for planning surgical approaches effectively.
This approach, described by Benirschke[40] in 1993, positions the patient in a lateral decubitus position. An “L”-shaped lateral
incision is used. ([Fig. 5A]) The deeper soft tissues are incised precisely along the skin incision and dissected
together in a single plane down to the periosteum of the lateral wall. The vertical
portion begins 2 cm proximally to the lateral malleolus tip, between the posterior
third of the fibula and the anterior third of the Achilles tendon, with the sural
nerve and lateral calcaneal artery located anteriorly. The horizontal portion between
the dorsal and plantar skin, demarcated by compressing the heel, extending to the
base of the fifth metatarsal. The two portions of the incision meet at an obtuse angle
to minimize the risk of necrosis at the apex.[2]
Fig. 5 Extended Lateral Approach. (A) “L”-shaped lateral incision. (B) Schanz laterally for manipulation of tuberosity. (C) Calcaneal plate. (D) Lateral fluoroscopy view. (E) Axial fluoroscopy view. (F) Broden fluoroscopy view.
The flap is gently retracted during subperiorteal dissection along the lateral wall
to the tip of the fibula. The entire flap is elevated as a single unit and maintained
with two K-wires: one in the fibula and another in the talar neck. The flap is not
manipulated again during the remainder of the procedure.
This approach provides 74% visualization of the subtalar joint (similar to the sinus
tarsi approach), 71% of the lateral wall, and 3% of the anterior tuberosity.[27]
The impacted superolateral articular fragment of the lateral wall is carefully elevated
and placed in saline on the auxiliary table. Two K-wires are inserted from the posterior
tuberosity without crossing the fracture line. Manipulation of the posterior tuberosity
is performed using a 4.5-mm Schanz pin, placed laterally to medially, as described
by Benirschke,[40] or posteriorly, as indicated by Rammelt and Zwipp[1] ([Fig. 5B]).
Manipulation follows a sequence: traction to restore length, medial translation, and
then lateral translation to achieve physiological valgus. Once the correct position
is obtained, the previously placed K-wires are advanced from the tuberosity into the
sustentacular fragment, achieving temporary stabilization and restoration of the medial
wall.
Subtalar joint reduction is performed from medial to lateral under direct vision,
Broden projections, or dry arthroscopy. Compression is achieved with one or two screws.
The tuberosity is aligned with the reduced joint, height and varus-valgus alignment
are controlled, and fixation is completed with pins. The anterior process is reconstructed
medially to laterally, using the cuboid as a guide.[2]
Finally, the lateral wall is repositioned and fixed with a periarticular calcaneal
plate, secured with screws in the posterior tuberosity, subtalar region, and anterior
process. The plate aids in maintaining the calcaneal axis ([Fig. 5C]).
Postoperative period
Postoperative care focuses on the evolution of the soft tissue envelope. A slightly
compressive dressing is applied post-surgery to control bleeding. A removable orthosis
supports early mobility while preventing equinus deformity.
After 10 to 14 days, sutures are removed, and efforts to improve range of motion and
strength are intensified. At 10 weeks, progressive partial weight-bearing with the
orthosis begins. By 12 weeks, with clinical and radiographic evidence of consolidation,
full weight-bearing in firm-soled footwear is permitted. Radiographic follow-up is
conducted periodically.
The moment to start weight bearing is still under debate, although most authors postpone
it. Chongmuenwai and Thitirangsi [12] evaluated an earlier postoperative weight-bearing protocol. The authors compared
a group that started progressive partial weight bearing as tolerated at 4 weeks postoperatively,
with another group starting at 8 weeks. They observed no difference in maintenance
of reduction between groups.
Complications
Common complications of calcaneal fractures include posttraumatic osteoarthritis,
neurological injuries, suture dehiscence, infections, nonunion, malunion, and fibular
tendonitis.[4]
Conclusion
Calcaneal fractures significantly impact patients' lives, often leading to social
and occupational challenges. A thorough understanding of the bone's anatomy and fracture
patterns is critical for achieving optimal reduction. This process begins with the
release of fracture fragments to allow precise anatomical positioning.
Surgical intervention via the sinus tarsi approach offers comparable functional outcomes
to the extended lateral “L” approach while reducing soft tissue complications. Despite
the longer learning curve, this approach should be strongly considered.
Articular and calcaneal body fixation can often be achieved with screws, provided
an adequately sized constant fragment and sufficient bone density are present. Screws
produce results comparable to those of locking plates, with soft tissue envelope injury
and cost.
Locking plates are indicated when severe comminution precludes stable screw fixation.
In cases of extensive joint and body comminution, primary subtalar joint arthrodesis
can ensure calcaneal and hindfoot stability.
Bibliographical Record
Rafael Barban Sposeto, Germán Matías-Joannas, Alexandre Leme Godoy-Santos. Current
Concepts in Intra-articular Calcaneus Fractures. Rev Bras Ortop (Sao Paulo) 2025;
60: s00451809886.
DOI: 10.1055/s-0045-1809886
