Surgical treatment of Comminuted Calcaneal
Fractures using the Sinus Tarsi Approach
with Tibio-Calcaneal Distraction: A Case Series
Johannes Pachinger, Florian Hess, Christoph Knoth, Benedikt Kislinger, Ralph Zettl and Nicolas Kesterke*
Department for Orthopedics and Traumatology, Kantonsspital Frauenfeld, Switzerland
Submission: December 12, 2019;Published: January 10, 2019
*Corresponding author: Nicolas Kesterke, Department for Orthopedics and Traumatology, Kantonsspital Frauenfeld, Pfaffenholzstrasse 3, 8500 Frauenfeld, Switzerland.
How to cite this article: Johannes P, Florian H, Christoph K, Benedikt K, Ralph Z, Nicolas K. Surgical treatment of Comminuted Calcaneal Fractures
using the Sinus Tarsi Approach with Tibio-Calcaneal Distraction: A Case Series. Ortho & Rheum Open Access J 2019; 13(3): 555863.
Objectives: To describe the surgical technique and outcomes in patients with comminuted calcaneal fractures treated with the sinus tarsi approach using tibio-calcaneal distraction. Fractures were fixed with 1/3 tubular or anatomic plates.
Design: Case series
Setting: : Operating room and outpatient care center in hospital
Patients: From 2013-2016 fourteen cases of displaced calcaneal fractures (13 patients) were surgically treated using the sinus tarsi approach with tibio-calcaneal distraction. The fractures were Sanders Type 4 (9), Sanders Type 2B (2), Sanders Type 3BC (2), and Sanders 3AB (1).
Intervention: Surgical treatment using the sinus tarsi approach with tibio-calcaneal distraction. Either a 1/3 tubular (10) or calcaneal (4) plate was used for fixation.
Main Outcome Measures: Clinical and radiological follow-up visits (6, 12, and 36 weeks) in addition to annual postoperative assessments using the American Orthopedics Foot and Ankle Society (AOFAS) scale and the modified ROWE score.
Results: Anatomical reduction of the subtalar joint was achieved for all fracture types and the Bohler’s angle was restored in 71% (10/14) of cases. No skin necrosis or wound healing problems occurred. The mean operation time was 57 minutes (±13.8, range 25-95). At the annual follow-up visit, the mean AOFAS score was 85 (±10.5, range 68-100) and the modified Rowe score was 86 (±12, range 65-100).
Aim: The purpose of this study was to compare tightrope (Arthrex) technique in syndesmotic injury versus 3.5 mm tricortical trans-syndesmotic screw in terms of accuracy and syndesmosis reduction.
Conclusion: The sinus tarsi approach resulted in anatomical restoration in 71% of the cases. No notable differences in clinical and radiological parameters were found between the plate types. Operation time was short, complications were few, and clinical outcomes were favorable.
Calcaneal fractures are rare and account for approximately 2% of all skeletal fractures . However, they are the most common type of tarsal fracture (60%) [2,3]. The injury mechanism is typically associated with an axial load from high energy trauma, such as falls from a height or motorcycle accidents.1 The prognosis for complete recovery is poor, with complication rates as high as 58% [4-6]. The most frequently reported complications are delayed wound healing, postoperative skin necrosis, and malunion due to insufficient intraoperative anatomical reduction [7-9]. Surgical outcomes are correlated with fracture severity and the quality of articular reduction .
The two main surgical approaches used to treat this condition are
an invasive technique using lateral L-shaped access, [11-16] and
a minimally invasive technique using the sinus tarsi approach .
Despite a high rate of soft tissue complications associated with the extended lateral L-shaped approach, it continues to be the most widely used technique over the last decade [18-21]. The L-shaped soft tissue flap created when using this approach contains the lateral calcaneal branch of the peroneal artery. Consequently, surgeons must take care not to damage the sural nerve. Although this approach provides good visualization of the lateral wall and posterior facet,  it has the potential to cause considerable tissue damage, wound healing problems, and skin necrosis.
In recent years, a growing interest in the sinus tarsi approach has been reflected in the increased amount of publications describing its use. Two meta-analyses published in 2017 by Yoa et al.  and Zhang et al.  compared the sinus tarsi and the
extensile lateral approaches. Most studies using the sinus tarsi
approach included a calcaneal plate for fixation. The primary
aim of this case series was to describe our experience with the
sinus tarsi approach in combination with reduction using the AO
distractor, and to assess the accompanying medical outcomes
(e.g., wound healing and fracture reduction). In the majority of the
cases, fixation was done with a 1/3 tube plate.
Between October 2013 and October 2016, 16 displaced
calcaneal fractures (one bilateral) were treated at our institution.
Fourteen of these cases (13 patients) were treated using the sinus
tarsi approach with tibio-calcaneal distraction. According to our
institution’s policy, indications for an “open reduction-internal
fixation” procedure include the following: displaced tongue
fractures, large extra-articular fractures (>1 cm) with detachment
of Achilles tendon and/or > 2 mm displacement, Sanders
Type II and III fractures, anterior process fractures with >25%
involvement of calcaneocuboid joint, and displaced sustentaculum
fractures . Excluded from this case series were two patients
with duckbill fractures without articular involvement who were
treated with compression screws. Patient characteristics and
fracture types are outlined in Table 1. The mean age of the patients
was 48 years (±19.5; range 13-71) and mean body mass index was
23.8 (±4.1, range 17.6-32.8). Ten of the fourteen fractures resulted
from high energy trauma.
Ideal positioning for this type of operation is lateral with
application of a high tourniquet. Perioperative use of an additional
femoral catheter decreases the need for pain medication during
the first few postoperative days. Surgical preparation included
marking the anatomy on the skin, including the expected course
of the sural nerve (Figure 1). A 5-cm incision started from the
tip of the lateral malleolus to the center of the calcaneocuboid
joint. The peroneal tendons were retained distally in order to
enter the sinus area proximally. If the calcaneocuboid joint was
involved, the fascia of the short extensor muscle was split at its
origin and dissected to expose the joint and fracture margins. This
previous step is not necessary for fractures that do not involve
the anterior process. Therefore, the skin incision can be shorter.
During soft tissue dissection, we used blunt skin retractors to
reduce diminution of local blood supply. To reach the subtalar
joint, dissection of the sinus fat pad was performed. At this point,
full exposure to the calcaneocuboid and subtalar joint, as well as
the posterior facet, was achieved.
For plate insertion, distal dissection to the calcaneus body was
often necessary and was done only fasciocutaneously. Caution was
taken not to dissect too extensively since it has been associated
with a higher risk of soft tissue complications. Although a variety
of different plates are available for osteosynthesis of calcaneal
fractures, we have found that the 1/3-tube plates (Synthes®,
West Chester, PA, USA) reliably fix the reduced joint fragments to
the calcaneal body. Anatomic calcaneal plates are larger and more
difficult to insert through a small approach. Furthermore, the
calcaneal plate covers more of the corpus, which requires a larger
dissection for plate insertion. In patients with poor bone quality,
we used the calcaneus plate 3.5mm (Synthes®, West Chester,
PA, USA). Examples of each implant, including the postoperative
radiological results, are illustrated in Figure 2.
After finishing the fasciocutaneous dissection for plate
insertion, the AO-Distractor (Synthes®, West Chester, PA, USA)
was applied to restore the Bohler’s angle and to assess anatomical
reduction of the depressed joint fragments (Figure 1). A Schanz
screw was inserted into the calcaneal tuberosity. The insertion
point was carefully selected and evaluated under fluoroscopy
to avoid inserting the screw into the fracture line. The second
5mm pin was inserted bi-cortically into the distal tibia shaft.
The distractor was then fixed by connecting the two pins. When
distraction has been performed, the subtalar joint might also
needed to be reconstructed. To avoid overcorrection, the subtalar
joint was fully exposed before restoring the Bohler’s angle. In our
experience, distraction can be done under fluoroscopy. It not only
restores angulation but also reduces fragments by ligamen to axis,
especially of the tuberosity.
All patients underwent non-weightbearing postoperative care
for 3 months. During this time, physiotherapy with ankle joint
movement and drop-foot prophylaxis was performed. Further
wound care and stitch removal following discharge from the
hospital was conducted by the patient’s primary care physician.
Clinical and radiological follow-up visits (6, 12, and 36 weeks)
included assessments with the American Orthopedics Foot and
Ankle Society (AOFAS) scale and the modified ROWE Score.
Changes in the Bohler’s angle and intraarticular steps >2 mm
were assessed by an independent radiologist. Additional longterm
assessments (AOFAS and ROWE scores) were done at least
one year postoperatively.
Most fractures were Sanders Type 4 (n=9). In addition, we
treated two fractures (Sanders Type 2B), two Sanders Type 3BC
and one Sanders 3AB fracture. In this case series, anatomical
reduction of the subtalar joint and standard Bohler’s angle
(normal range: 20-40 degrees) was possible in 10 (71%)
cases. At the follow-up visits, a loss of Bohler’s angle of greater
than 5 degrees was detected in one patient (Case 2). The mean
postoperative Bohler’s angle was 27.5 degrees (±7.4, range 15-
40) and decreased to 25.7 degrees (±7.5, range 14- 37). The mean
postoperative tibialcalcaneal angle was 39 degrees (±6.4, range 25- 50; normal range: 30-50). A displacement in the subtalar joint
greater than 2 mm occurred in only one patient (Case 13). Fracture
healing occurred in all cases. There were no notable differences
between the 1/3-tube plate group and patients with calcaneal
plate fixation techniques. Patient outcomes are presented in Table
The mean time to operation was 7 days (±2.8, range 3-12),
and the mean operation time was 57 minutes (±13.8, range
25-95). Surgery was performed three days after trauma in the
youngest patient in our cohort (case 1). The mean hospitalization
time was 15 days (±5.5, range 7-28). At annual follow-up visits,
the mean AOFAS score was 85 (±10.5, range 68-100) and modified
Rowe Score was 86 (±12, range 65-100). Due to localized pain
and swelling, implants were removed in two cases after complete
fracture consolidation (7 and 13 months after initial surgery).
Therapeutic options for displaced intra-articular calcaneal
fractures continue to be debated in the literature [24,25]
although most cases are eventually treated operatively. The
functional outcome and patient satisfaction levels are reportedly
better after surgery than non-operative therapy, particularly for
younger patients . Anatomic or near-anatomic reconstruction
and restoration of the physiological calcaneal angulation play
important roles in improved clinical results. When osteosynthesis
is needed, the extended L-shaped lateral approach is often
used [5,12-14]. This approach allows for good exposure of the
corpus fragments. However, visualization of the subtalar and
calcaneocuboid joint is often insufficient or associated with a
large fasciocutaneous flap. Soft tissue necrosis, wound infections
and bone necrosis due to lateral devascularization are common
. A variety of published reports describe minimally invasive
techniques aimed at reducing damage to the blood supply, [10,27-
29] but these methods are also limited by insufficient exposition
for anatomical reduction of the subtalar joint.
The sinus tarsi approach, which has been used in several studies,
attempts to address the disadvantages of the L-shaped extended
lateral approach [17,30-33]. Clinical results were comparable to
those of the extended L-shaped approach but with less soft tissue
complications [17,34,35]. Anatomic calcaneal plates are widely
used, even with the less invasive sinus tarsi approach, and studies
report good radiological and clinical outcomes. Due to the larger
size of the anatomical plate, the approach must be enlarged and
the periost dissected widely to ensure amble space for the plate.
Based on our experience, smaller dissections are needed to insert
tubular plates and blood supply damage can be minimized. With a
minimally invasive approach, restoration of the Bohler angle may
be easily performed using the AO distractor without access to
the corpus of the calcaneus. Furthermore, findings from this case
series indicate that the clinical and radiological outcomes do not
differ from those following insertion of a calcaneal plate.
There are conflicting results in the medical literature about
the effects of the length of time to surgery. In our case series,
there was an average delay of 7 days, with a relatively wide
range from 3 to 12 days. Kwon et al.  found increased wound
complication rates in their cohort of patients who underwent
sinus tarsi or percutaneous approach when the time span was
greater than 7 days. The wound complication rate increased from
2% (0-7 days) to 8% (8-14 days). In the group with the extensile
lateral approach, the rate did not change significantly in terms
of the time to surgery (0-7 days 34%, 8-14 days 28%). However,
the wound complication rate for the extensile lateral approach
was significantly higher than the rate following the sinus tarsi
approach. Nevertheless, a delay of surgery is associated with an
increased amount of soft tissue swelling, which could have an
influence on the development of complications.
A retrospective study of 65 calcaneal fractures conducted by
Zhou et al.  showed a significantly lower wound necrosis rate
in 28 fractures treated with a sinus tarsi approach and medial
distraction. They used screws or micro plates for fixation. In the
group undergoing a sinus tarsi approach, there was only one case
of wound necrosis (4%) compared to two superficial infections
(7%) and three cases of partial flap necrosis (11%) in the extended
lateral approach group. In a prospective, randomized multicenter
study, Basile et al.  compared the extended lateral approach
with the sinus tarsi approach and distraction with a Schanz screw
in the posterior tuberosity. Only one case of wound necrosis was
found in the extended lateral approach group (7.9%), which was
not statistically significant. They found no significant differences
in the quality of reduction or the Bohler`s angle. Scott et al. 
investigated radiological outcomes after reduction with a sinus
tarsi approach in 39 displaced calcaneal fractures. The mean
Bohler`s angle improved from 7.7 to 25.5 degrees, without
relevant articular step-off. There was one deep wound infection
and two cases of superficial wound dehiscence at the posterior
apex wound. There were no complications at the incision site.
Park et al.  retrospectively reviewed 47 cases of calcaneal
fractures treated with sinus tarsi approach and percutaneous
screw fixation. They combined allogenous cancellous bone chips
and a demineralized bone matrix to support the restored joint
line. Sanders IV fractures were excluded from the study due to
the difficulty of achieving the amount of visualization needed for
the open reduction. They found 3 minor soft tissue complications,
but no cases required revision. In their case series, the mean
restoration of the Bohler’s angle was 71.6%.
Wang et al.  treated 18 patients with calcaneal fractures
(14 Sanders Type II and 4 Sanders Type III) by using the sinus tarsi
approach and a custom designed combined plate. The titanium
plate has two mutually independent fixed arms and includes up
to 6 locking screws. It was developed to create triangular support of the calcaneus using locking screws and to avoid extensive soft
tissue damage. No wound healing problems occurred in their
We also believe that the standard calcaneal locking plates
require extensive space and too often result in soft tissue damage
for placement, even when using the minimally invasive sinus
tarsi approach. It is our opinion that a locking screw system is
not necessary. With the Bohler’s angle and the calcaneal joint
line restored, a simple 1/3 tube plate and conventional screws
provide sufficient stability. In our case series, the postoperative
Bohler’s angle loss was small, which was comparable to findings
from studies with calcaneal locking plates. Given that the number
of patients in our case series was limited due to the low incidence
of these fracture types, we recommend further investigations into
the effectiveness of these approaches in combination with various
In our case series, the sinus tarsi approach in combination
with external distraction was a safe surgical procedure for the
treatment of calcaneal fractures. It provided good visibility of
the joint, and achieved restoration of the Bohler’s angle and
the talonavicular joint surface. Moreover, there were no wound
healing disorders. We believe the use of a calcaneal plate is not
necessary in patients with normal bone quality and a short tubular
plate is sufficient for joint restoration. Despite the limited number
of cases in this series, we recommend further investigations and
use of this procedure, particularly for those surgeons who prefer
minimally invasive solutions.