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operative techniques for fibula fixation being developed at
the time.
In 1950, a Danish physician, Niels Lauge-Hansen, fractured cadaveric limbs to describe how foot position and
specific deforming forces resulted in predictable fracture
patterns.30 Based on his dissections, he predicted a sequential order of ligamentous and osseous injury for each fracture type. Lauge-Hansen's classification was based on a
rotational mechanism of injury and described 4 distinct
patterns: supination-external rotation (SER), supinationadduction, pronation-external rotation, and pronationabduction. Subsequent clinical studies have examined the
incidence of these various fracture types and have demonstrated the SER fracture pattern to be the most common.
As such, the SER injury pattern has been most widely
studied in the literature.11,20,27,30,31,39,43,68 For the SER fracture pattern, a rotational sequence of injury focused attention on the medial osseo-ligamentous structures. These
were theoretically the last to be disrupted and accounted
for the final injury destabilizing the mortise. While instability is readily apparent in the case of the SER IV injury
with a medial malleolar fracture, the theory postulated
that comparable instability could result from a multiligamentous injury, in which the lateral malleolus was the
only identifiable fracture. Although its initial utility was
to guide closed reduction during an era of predominantly
nonoperative treatment, the lasting legacy of LaugeHansen's mechanistic theory was to introduce the importance of medial structures for stability.
Despite Lauge-Hansen's work introducing the importance of the medial anatomic structures, Danis's emphasis
on the fibula was subsequently popularized by Weber in
1966.63 Weber classified ankle fractures according to the
level of the fibula fracture in relation to the tibial plafond.
While simplistic, the absence of any discussion of medialsided injury for the purposes of classification implied a
greater importance of the lateral malleolus. Yablon et al67
supported the idea of the lateral malleolus as the chief stabilizer in 1977 when comparing medial versus lateral osteotomies and ligament releases in a cadaveric model. They
concluded that the medial malleolus and deltoid ligament
contributed little to stability while lateral malleolar incompetence led to a marked decrease in ankle stability.67
As operative treatment of ankle fractures increased in the
20th century with the advent of sterile technique, better
operative instrumentation, and x-ray, the Danis-Weber and
Lauge-Hansen classifications became the predominant
means for describing and categorizing ankle fractures.
During this evolution of the concept of ankle stability, an
amalgamation of the 2 classifications and their respective
theorems began to occur. Surgeons recognized that the level
of the fractured fibula typically correlated with ankle instability based on the presence, or absence, of a concomitant
medial-sided injury. In modern usage, the Danis-Weber

Foot & Ankle International 39(7)
classification, which was conceptualized without an understanding of the importance of the deltoid ligament, has been
correlated with the corresponding Lauge-Hansen designation (ie, Weber B and supination external rotation) with an
associated prediction of instability.
The Lauge-Hansen classification has long stood as a seminal work for our understanding of ankle fracture pathomechanics. However, it has faced multiple challenges regarding
its reproducibility, prognostic nature, validity, and usefulness
in guiding treatment.1,15,29,41 As its relevance to modern-day
treatment of ankle fractures has been of question, several
authors have proposed a shift away from descriptive classifications to those rooted in stability-based criteria.46,49 This
concept has led to multiple studies examining means of
assessing stability, establishing criteria for instability, as well
as exploring outcomes of patients with unstable patterns
treated both operatively and nonoperatively.21,26,28,46,49,59,63,68
However, recently published level I studies have demonstrated that the assessment of instability may not be prognostic nor guide decision making.55,65 Accordingly, a management
strategy based on assessment of anatomic alignment of the
mortise (as opposed to stability) has again become increasingly useful. While seemingly straightforward, defining what
constitutes an anatomic mortise has been a challenge and
source of continued investigation.

What Defines an Anatomic Mortise?
Anatomic alignment of the mortise has been demonstrated
in many studies to be important for normal tibiotalar kinematics. From Ramsey and Hamilton's classic cadaveric
study to Lloyd's replication of their original findings, 1 to
2 mm of talar shift has been demonstrated to significantly
alter articular contact.33,54 Traditionally, radiographic
assessment of the medial clear space (MCS), tibiofibular
overlap (TFO), tibiofibular clear space (TFC), and the
talocrural angle have been used to assess the alignment of
the mortise on plain x-rays. Various measurements, defining normal alignment of each parameter, have been
described.* Normal TFO has been defined as values
greater than 10 mm and 1 mm on anteroposterior (AP) and
mortise views, respectively. Normal TFC is less than 6
mm as measured on an AP radiograph as the distance
between the medial fibular cortex and the tibia incisura.
The talocrural angle, measuring approximately 83 degrees,
is an angle subtended by a line parallel to the tibial plafond
and a line connecting the tips of the malleoli, and it is useful for assessing fibular length. Other parameters, such as
the "dime" sign and Shenton's line, have been proposed as
means to assess fibular length albeit with unknown accuracy
and reliability.14,58
*References 3, 5, 12, 13, 19, 26, 46, 50, 55, 59.



Table of Contents for the Digital Edition of Foot & Ankle International - July 2018

Contents
Foot & Ankle International - July 2018 - Intro
Foot & Ankle International - July 2018 - Cover1
Foot & Ankle International - July 2018 - Cover2
Foot & Ankle International - July 2018 - i
Foot & Ankle International - July 2018 - ii
Foot & Ankle International - July 2018 - Contents
Foot & Ankle International - July 2018 - iv
Foot & Ankle International - July 2018 - v
Foot & Ankle International - July 2018 - vi
Foot & Ankle International - July 2018 - vii
Foot & Ankle International - July 2018 - viii
Foot & Ankle International - July 2018 - 1A
Foot & Ankle International - July 2018 - 1B
Foot & Ankle International - July 2018 - ix
Foot & Ankle International - July 2018 - x
Foot & Ankle International - July 2018 - xi
Foot & Ankle International - July 2018 - xii
Foot & Ankle International - July 2018 - 2A
Foot & Ankle International - July 2018 - 2B
Foot & Ankle International - July 2018 - xiii
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Foot & Ankle International - July 2018 - xv
Foot & Ankle International - July 2018 - xvi
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Foot & Ankle International - July 2018 - xxvi
Foot & Ankle International - July 2018 - 3A
Foot & Ankle International - July 2018 - 3B
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Foot & Ankle International - July 2018 - Cover3
Foot & Ankle International - July 2018 - Cover4
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_december2020
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https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_december2019
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_october2019
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https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_july2019
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_june2019
https://www.nxtbook.com/nxtbooks/sage/canadianpharmacistsjournal_05062019
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_april2019
https://www.nxtbook.com/nxtbooks/sage/sri_supplement_201903
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_february2019
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_december2018
https://www.nxtbook.com/nxtbooks/sage/tec_20180810
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_october2018
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_julyaugust2018
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https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_june2018
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_april2018
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https://www.nxtbook.com/nxtbooks/sage/slas_discovery_201712
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_february2018
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_december2017
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_november2017
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_october2017
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_september2017
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_julyaugust2017
https://www.nxtbook.com/nxtbooks/sage/fai_supplement_201709
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_june2017
https://www.nxtbook.com/nxtbooks/sage/hospitalpharmacy_may2017
https://www.nxtbook.com/nxtbooks/sage/fai_201706
https://www.nxtbook.com/nxtbooks/sage/fai_201607
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