Instability of the pelvic ring and injury severity can be predictors of death in patients with pelvic ring fractures: a retrospective study.

Abstract

The correlation between fracture type and mortality in patients with pelvic fracture has been previously investigated. The purpose of this study was to determine whether instability of the pelvic ring as assessed by Tile's classification is a predictor of death in patients with pelvic fractures.
The clinical course of consecutive patients with pelvic fractures was retrospectively reviewed. Eighty-seven patients with pelvic ring fractures were included in the study. As potential predictive factors, fracture type according to Tile's classification, and generally used traumatic parameters (injury severity score, revised trauma score, and probability of survival) were analyzed.
The mortality was significantly higher in patients with unstable fracture patterns (P < 0.05). In non-survivors, index values of traumatic parameters were more severe than those in survivors (P < 0.05).
The present study suggests that patients with unstable pelvic fractures have an increased risk of death associated with exacerbated injury severity.

Full text

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ORIGINAL ARTICLE
Instability of the pelvic ring and injury severity can be predictors
of death in patients with pelvic ring fractures: a retrospective
study
Toshiya Tachibana Æ Æ Hideyuki Yokoi Æ Æ
Manabu Kirita Æ Æ Seishiro Marukawa Æ Æ
Shinichi Yoshiya
Received: 20 August 2008/Accepted: 13 March 2009/Published online: 2 April 2009
? Springer-Verlag 2009
Abstract
Background
mortality in patients with pelvic fracture has been previ-
ously investigated. The purpose of this study was to
determine whether instability of the pelvic ring as assessed
by Tile’s classification is a predictor of death in patients
with pelvic fractures.
Materials and methods
The clinical course of consecutive
patients with pelvic fractures was retrospectively reviewed.
Eighty-seven patients with pelvic ring fractures were
included in the study. As potential predictive factors,
fracture type according to Tile’s classification, and gener-
ally used traumatic parameters (injury severity score,
revised trauma score, and probability of survival) were
analyzed.
Results
The mortality was significantly higher in patients
with unstable fracture patterns (P\0.05). In non-survi-
vors, index values of traumatic parameters were more
severe than those in survivors (P\0.05).
Conclusion
The present study suggests that patients with
unstable pelvic fractures have an increased risk of death
associated with exacerbated injury severity.
The correlation between fracture type and
Keywords
Injury severity
Pelvic ring fracture ? Mortality ? Instability ?
Introduction
Pelvic fracture is one of the most challenging fractures for
orthopaedic and trauma surgeons to treat because of the
high mortality and high frequency of the occurrence of
associated injuries. In the assessment of patients with
pelvic fractures, instability of the pelvis ring is thought to
be an important factor affecting the treatment decision. For
unstable pelvic fractures, use of clamps and external fix-
ators are considered to stabilize the pelvic ring so reducing
bleeding.
The correlation between fracture type and mortality in
patients with pelvic fracture has been previously investi-
gated. However, the fracture classification system adopted
in these analyses has varied from study to study, and thus
the prognosis of patients with this injury remains difficult
to predict. Since pelvic ring instability is the key to
determining injury severity, we hypothesized that stability-
based Tile’s fracture type classification might be a useful
predictor of patient mortality [1]. To test this hypothesis,
we assessed the relationship between mortality and fracture
stability using Tile’s classification together with an exam-
ination of injury severity of each patient.
Materials and methods
A retrospective study of pelvic fractures was performed for
consecutive patients admitted to the emergency and critical
care units at our institution between April 2000 and June
2004. Of 136 patients with pelvic fractures, 92 were
diagnosed with pelvic ring fractures, and the remaining 44
with acetabular fractures. Of 92 patients with pelvic ring
fractures, 5 patients with cardio pulmonary arrest on arrival
were excluded, leaving 87 patients as the study population.
T. Tachibana (&) ? H. Yokoi ? S. Yoshiya
Department of Orthopaedic Surgery, Hyogo College
of Medicine, Nishinomiya, Hyogo 663-8501, Japan
e-mail: tachi@hyo-med.ac.jp
M. Kirita ? S. Marukawa
Department of Emergency and Critical Care Medicine, Hyogo
College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
123
J Orthopaed Traumatol (2009) 10:79–82
DOI 10.1007/s10195-009-0050-x

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Fifty-seven patients sustained injuries in road traffic colli-
sions, 24 patients were injured as a results of falls, and the
remaining 6 patients were involved in other accidents.
After initial evaluation and resuscitation, all patients
underwent plain radiography of the pelvis and sonography
in the emergency room followed by the focused assessment
with sonography for trauma (FAST) protocol. For detailed
fracture assessment, all patients underwent plane computed
tomographic (CT) scanning of the pelvis. When the pres-
ence of substantial hematoma was identified, enhanced CT
and angiography were additionally performed after stabi-
lizing the hemodynamics of the patient by fluid. Patients
who had angiographic evidence of extravasation underwent
transcatheter arterial embolization (TAE). The fractures
deemed to be unstable were fixed immediately by external
fixators in the operating room.
For each patient, the fracture type was classified by
univariate analysis using the Tile’s classification, which
divides pelvic ring fractures into types A, B, and C based
on the degree of pelvic instability; type A is stable, type B
has rotational instability, and type C has rotational and
vertical instability. All patients underwent CT scanning,
and fracture type was categorized using plain radiographs
and CT scan images. Especially, vertical instability of the
fracture was assessed by an outlet radiograph and three-
dimensionally reconstructed CT images. Then, patient
mortality was compared between the groups. As additional
indicators of injury severity, injury severity score (ISS: an
anatomic parameter), revised trauma score (RTS: a physi-
ologic parameter) and probability of survival (Ps) were also
evaluated as predictive factors. These parameters were
recorded by physicians immediately after admission of the
patients, and assessment and scoring for each patient were
performed correctly by one senior physician (MK).
In the statistical analysis, v2analysis was performed
with Excel (Microsoft, Redmond, WA, USA), analysis of
variant was performed using StatView (SAS Institute,
Cary, NC, USA), and Logistic regression analysis was
performed using SPSS (SPSS, Chicago, IL, USA). A P
value of\0.05 was considered to indicate significance.
The study conforms to the Declaration of Helsinki and
was approved by the Istitutional Review Board/Ethical
Committee. All the enrolled patients provided informed
consent.
Results
Among the 87 patients included in the study, 70 survived
and 17 died during the subsequent treatment at our
department. There was no significant difference in sex and
age between survivors and non-survivors (Table 1). The
mortality rate in each group with different fracture type
was 3/39 (7.7%), 10/40 (25%), and 4/8 (50%) in types A,
B, and C, respectively (Table 1). Thus, the mortality rate
was significantly higher in patients with unstable fracture
types B and C (P\0.05, Table 1). ISS, RTS, and Ps were
significantly more severe in non-survivors indicating a
close relationship between injury severity and mortality
(Table 1). Logistic regression analysis for potentially
influencing factors on mortality demonstrated that Tile’s
classification, ISS, and RTS significantly affect the survival
rate (Table 2).
Discussion
The mortality of patients with pelvic ring fractures has
been previously described in the literature [2–16]. As
potential predictors of mortality, several factors including
Table 1 Comparison of fracture patterns and trauma scores between
survivors and non-survivors
SurvivorsNon-survivors
Sex
Male468
Female 249
Age39.8 ± 19.150.3 ± 23.1
Tile’s
A 36 3*
B 3010*
C44*
ISS 20.0 ± 8.637.5 ± 8.8*
RTS7.1 ± 0.93.4 ± 1.9*
Ps0.88 ± 0.14 0.30 ± 0.25*
ISS injury severity score, RTS revised trauma score, Ps probability of
survival
* P\0.05
Table 2 Predictive factors of death
Logistic regression analysis
P value Odds ratio 95% CI
LowerUpper
Tile’s0.041*6.8411.086 43.073
Sex0.592
Age 0.119
ISS 0.033* 1.2131.015 1.449
RTS 0.022*0.1730.039 0.775
Ps0.134
ISS injury severity score, RTS revised trauma score, Ps probability of
survival, CI confidence interval
* P\0.05
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fracture type [2–12] injury severity [2, 3, 6, 7, 12, 13] and
hemo-dynamics [14, 15] have been evaluated. Among
those factors, the possible correlation between fracture type
and mortality has remained controversial. One of the
variables that has been most criticized in past studies is the
system for classifying the fracture types.
Eastridge [2] compared the prognosis of patients with
stable pelvic ring fracture patterns and patients with
unstable fractures patterns using Young–Burgess’s classi-
fication which divides fracture patterns based on the energy
direction. They analyzed patients with stable fracture pat-
terns who required on-going resuscitation and who
underwent celiotomy and/or angiography, and showed that
abdominal hemorrhage was responsible for hypotension in
85%, while 25% of the patients died. However, in patients
with unstable fracture patterns, hemorrhage was predomi-
nantly from a pelvic source, as shown by positive
angiograms in 59%; 52% of the patients died. Thus, they
concluded that in patients with unstable fractures patterns,
even in the presence of hemoperitoneum, consideration
should be given to angiography before celiotomy. They
also showed that patients with unstable fracture patterns
had a higher mortality rate than patients with stable frac-
ture patterns. This has been shown in other studies,
adopting Tile’s classification. Shindo et al. [8] reported that
patients with Tile’s type C fractures had a significantly
higher mortality rate than those with stable fracture pat-
terns of type A. In contrast, Hagiwara et al. [3] suggested
that mortality did not correlate with fracture type when
TAE was performed. However, they failed to compare the
mortality rate between patients with and without TEA. In
Key and Conwell’s classification, pelvis stability was not
considered and their study examining the relationship
between mortality and this fracture type failed to show any
significant relationship [7]. No statistical analysis was
presented in other studies, thus the results cannot be con-
sidered conclusive [4, 5, 9–11]. The present study showed a
significant correlation between mortality and fracture type
based on Tile’s classification system which is based on
pelvic stability. Therefore stability of the pelvic ring as
assessed by this system can be a useful indicator in pre-
dicting mortality of patient with pelvic ring fractures.
In the relationship between patient mortality and overall
injury severity, Poole [6] showed that ISS was more severe
in patients with unstable pelvic fractures than in those with
stable fractures, and also more severe in non-survivors than
survivors, indicating a close relationship between injury
severity and mortality. Parreira [7] reported that the out-
come of patients with pelvic fractures due to blunt trauma
correlated with the severity of associated injuries and
physiological derangement on admission. Lunsjo [12]
reported that ISS is the most important predictor in defining
mortality in patients with pelvic fractures. In the present
study, all traumatic parameters (ISS, RTS, and Ps) were
more severe in non-survivors. Moreover, logistic regres-
sion analysis showed that ISS and RTS could be used as
predictive factors of death in patients with pelvic fractures.
Inthe presentstudy,both instability ofthe pelvic ringand
injury severity were correlated with mortality of patients
withpelvicringfractures.Thus,allparametersadoptedinthe
study (Tile’s classification, ISS, RTS) could be regarded as
potent predictive factors for death of the patients. Assess-
ment of the patient condition in various aspects is thought to
be critical in the initial clinical evaluation.
In conclusion, Tile’s classification significantly corre-
lates with mortality, and thus is a useful classification
system for management of patients with pelvic fractures.
Moreover, a close relationship between fracture stability as
assessed by this system and injury severity was also sug-
gested. In the treatment of patients with pelvic fractures,
surgeons should evaluate fracture stability and injury
severity immediately after admission to predict the prog-
nosis and establish the initial treatment plan.
Acknowledgment
editing the manuscript.
We thank Ms. Janina Tubby for her help in
Conflict of interest statement
no competing interests.
The authors declare that they have
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