This document discusses differentiating between perimortem (around the time of death) and postmortem (after death) fractures in bones. Antemortem fractures occur before death and show signs of healing. Perimortem fractures do not show healing as death occurred at the same time as injury. Postmortem fractures can result from various post-death factors like scavenging or environmental effects. A blind study of 210 known fractures by two anthropologists found error rates of 22.2% for perimortem and 10.4% for postmortem determinations, showing the difficulty of reliable identification due to postmortem changes mimicking perimortem features. Current criteria cannot definitively differentiate peri-

1. Differentiating Perimortem1
Running Head: PERI AND POSTMORTEM FRACTURES
Differentiating Perimortem and Postmortem Fractures
Michael Schuster
State University of New York College at Oswego
Forensic Science
Professor Fuller
December 7, 2014

2. Differentiating Perimortem 2
Abstract
In this essay I will be focusing on the presence of deformities as a result of antemortem,
perimortem and postmortem injuries and the trouble in correctly identifying them as such.
Although each period of fracture has key characteristics that indicate a particular fracture as so,
forensic anthropologists still cannot reliably confirm an injury to have occurred before or after
the time of death.

3. Differentiating Perimortem 3
Differentiating Perimortem and Postmortem Fractures
A homicide victim has been uncovered with signs of severe decomposition, requiring the
need for forensic anthropology. Their purpose is to determine gender, age, ancestry, presence of
deformities, time of death, and general cause of death. In this essay I will be focusing on the
presence of deformities as a result of antemortem, perimortem and postmortem injuries and the
trouble in correctly identifying them as such. Each period of injuries are distinguished through
common characteristics regarding how brittle the bones are at the fracture site, the smoothness of
the fracture, bone elasticity and types of fractures present to name a few. Antemortem,
perimortem and postmortem injuries to bone structure can be summarized as follows:
Fractures that are antemortem are those that have occurred prior to death. Such fractures
are often found to be a little flexible and have irregular breaks. A fracture can be determined to
be ante-mortem by the presence of cell growth around the fracture site, indicating signs of
healing. The healing process occurs in three stages the first being the inflammatory stage.
During the inflation stage, a clot forms within the tissue within hours of onset. Inflammatory
cells (macrophages, monocytes, lymphocytes, and polymorph nuclear cells) and fibroblasts
infiltrate the bone under prostaglandin mediation. This results in the formation of granulation
tissue, ingrowth of vascular tissue, and migration of mesenchymal cells. (Kalfas, 2001). The
second is the repair stage, in which a scab like structure forms over the fracture site. Over time
the scab will ossify and fill in fragmented areas in the bone. This process can take weeks before
moving into the remodeling stage. During the remodeling stage, bone formation shifts from areas
under less stress to areas of higher stress. Unlike antemortem fractures, perimortem fractures do
not show signs of healing. This is because death has occurred at the same time span as the injury.

4. Differentiating Perimortem 4
Fractures that are termed post-mortem are those that have occurred after death. Such
fractures may be the result of dismemberment, scavengers, burial, decay, the body’s
environmental surroundings, etc. (topics of taphonomy). From the view of the forensic
investigator, there are at least three events in taphonomic time: (1) the time of death; (2) the time
of deposition in the recovery location; and (3) the time of recovery. (Haglund & Sorg, 2000).
The fractures that occur during this time frame can prove if a person attempted to cover up the
homicide or if the death may have been accidental. Also as the post-mortem interval expands,
bones lose moisture and fresh marrow making them brittle. In accordance with Wheatley, fresh
marrow "greatly increases the ability to absorb stress" (As cited by Wright, 2009). In contrast to
dry bone, fresh bone does not behave in a brittle or inflexible manner, but is instead visoelastic
(flowable and deformable) and ductile, capable of withstanding great amounts of pressure and
deformation before failure (Wright, 2009). It should also be noted that post-mortem fractures
tend to shatter under force. The fracture site will also possess a crumbled appearance,
accompanied by discoloration in contrast to the surrounding bone.
Despite knowing the characteristics of ante-mortem, perimortem and postmortem
fractures, there remains a high percent error when classifying fractures as such. As Cappella et al
note numerous studies have demonstrated that environmental factors can hinder the characteristic
features of bone injuries. In accordance with Ubelaker, they further mention that for example
“weathering cracks can resemble blunt force trauma, showing that bone macroscopic changes in
aquatic environments can severely change and hinder important indicators of perimortem trauma
by rounding off the fractured edges” (Cappella et al, 2014). This symbolizes a problem with
anthropological examination of remains, in the sense that the current means of classification

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between injuries inflicted during the perimortem interval and postmortem interval is at times
incapable of differentiating the two.
To test this theory Capella et al conducted a blind test on 210 fractures of known origin.
The test consisted of two forensic anthropologists, four skeletons containing 210 fractures. All
four skeletons had been buried for 20 years, buried at the same time frame and in the same
cemetery (Cimitero Maggiore in Milano) and were also exhumed and reburied twice in 15 years,
by means of heavy vehicles until complete skeletonization. Of the four specimens three had died
from traumatic deaths, while one died from natural causes. Each specimen had a separate
autopsy report, which documented all fractures detected by means of visualization, palpation and
the dissection of soft tissues. All perimortem fractures and some postmortem fractures (ribs were
too damaged and were excluded) were given to the two experienced forensic anthropologists.
The 1st of which had 10 years of experience and the 2nd 4 years of experience. Table 1 below
lists the number of fracture by type and the specimens cause of death.
Table 1: Data concerning the four skeletons in analysis
Case Cause of death
1 Pedestrian hit by
truck
8 36
2 Pedestrian hit by tram 11 51
3 Pedestrian hit by car 8 50
4 Congestive cardiac
failure
0 46
total 27 183
After a 6 month break the test was reconducted using the same specimens by the same
forensic anthropologists as shown in table 2The results of this test showed a 22.2% error and a
10.4% error when identifying perimortem and postmortem fractures respectively.
Table 2: Average values of blind test
Evaluation Observer Average T1, % Average T2, %
Perimortem correct Observer A 63 59.3

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Observer B 81.5 70.4
Postmortem correct Observer A
Observer B
83.6
84.1
56.2
85.2
Perimortem wrong Observer A
Observer B
37
18.5
14.8
18.5
Postmortem wrong Observer A
Observer B
14.8
11.5
9.8
5.5
Dubious on
perimortem
Observer A
Observer B
/
/
25.9
11.1
Dubious on
postmortem
Observer A
Observer B
1.6
4.4
34
9.3
In conclusion and as supported by Capella et al’s blind test demonstrated there is
significant difficulty in establishing peri and postmortem fractures and that their determination is
subject to observer dependency. The high percent error does not reflect inadequate training of the
observers, but shows how postmortem factors can result in the mimicking of the characteristic
breaking found in perimortem fractures. Given current identification practices and human error,
the current criteria for differentiating peri and postmortem fractures has proven to be unreliable.

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References
All Things AAFS! (n.d.). Retrieved December 6, 2014, from
http://allthingsaafs.com/tag/perimortem-and-postmortem-trauma/
Capella, A., Amadasi, A., Castoldi, E., Mazzarelli, D., Gaudio, D., & Cattaneo, C. (2014). The
Difficult Task of Assessing Perimortem and Postmortem Fractures on the Skeleton: A
Blind Text on 210 Fractures of Known Origin. Journal of Forensic Sciences, 59(6).
Retrieved December 5, 2014, from Wiley Online Library.
Iain H. Kalfas, MD, FACS Department of Neurosurgery, Section of Spinal Surgery, Cleveland
Clinic Foundation, Cleveland, OhioNeurosurg Focus. 2001;10(4)
Haglund, W., & Sorg, M. (2002). Advances in forensic taphonomy: Method, theory, and
archaeological perspectives. Boca Raton, Fla.: CRC Press.
Smith, A.C. 2010. Distinguishing Between Antemortem, Perimortem, and Postmortem
Trauma.Academia.edu.
Ubelaker DH. Perimortem and postmortem modification of human bone. Lessons from forensic
anthropology. Antropologie 1991;29:171–4.
Wheatley, B. P. (2008). Perimortem or postmortem bone fractures? An experimental study of
fracture patterns in deer femora. Journal of Forensic Sciences, 53(1), 69-72.
Wright, C. (2009). Perimortem and postmortem fracture patterns in deer femora. Tuscaloosa,
Ala.: [University of Alabama Libraries]