Growth of the Juvenile Talus: A Pilot Study in Age-at-Death Estimation

Learning Objective: After attending this presentation, attendees will understand how measurements of the juvenile talus can be utilized for age-at-death
estimations.

Impact Statement: This presentation will impact the forensic science community by introducing a juvenile age estimation method using measurements
from the talus.

Juvenile growth and its application in age-at-death estimation has been investigated in several regions of the skeleton.1-4 However, there is a paucity of
information relating to growth of the juvenile talus and its utility in juvenile age-at-death estimation. Therefore, the aim of this study was to investigate
talus growth and evaluate the use of measurements of the juvenile talus for age-at-death estimation.

Data was collected from 27 documented tali ranging in age from 2–19 years from the Scheuer Collection.5 The growth of three metrics of the talus
(maximum width of the trochlea, body height, and maximum length of the talus) was assessed using polynomial regression to the fifth order.

Measurements were adapted for juveniles from the adult literature, therefore intra-observer agreement using intraclass correlation coefficient (ICC)
and technical error of measurement (TEM) were calculated.6,7 Inverse regression was used to produce age-at-death estimation equations from metrics
of the talus. The equations were tested on 11 undocumented tali specimens within the Scheuer Collection. The age estimates from the talus were
compared to the age estimates from the diaphyseal length of the tibia.4

Measurements adapted for the juvenile talus demonstrated excellent intra-observer agreement and acceptable relative TEM levels. Growth of the talar
body height and the width of the trochlea could be described as third-order polynomial regression. This regression appeared to demonstrate a period of
rapid growth between 0–4 years old consistent with the infant growth spurt and a pubertal growth spurt after 10 years of age. Growth of the length of
the talus, however, was expressed as a 2nd order polynomial with steady, consistent growth occurring between 2–19 years.

Statistically significant bilateral asymmetry was observed within body height following a Paired Samples T-Test. As a result, pooled and side-specific
age-estimation equations were produced for body height. When the age-at-death estimation equations were tested for group differences using a Related-
Samples Sign test, no statistical differences were observed between median age estimates derived from measurements of the talus and median age
estimates from the diaphyseal length of the tibia. Additionally, statistically significant correlation between talus and tibia estimates were observed
following comparison using Pearson’s Correlation Coefficient and Spearman’s correlation. This preliminarily indicates that the metric analysis of the
talus is a viable option for juvenile age estimation. Further research is required to investigate population specificity and the impact of sex on growth of
the talus.

References:
1. Rissech C, Black S. 2007. Scapular development from the neonatal period to skeletal maturity: A preliminary study. International Journal of
Osteoarchaeology. 17(5), 451–64.
2. Rissech C, Schaefer M, and Malgosa A. 2008. Development of the femur—Implications for age and sex determination. Forensic Science
International. 180(1), 1–9.
3. Rissech C, López-Costas O and Turbón D. 2013. Humeral development from neonatal period to skeletal maturity—application in age and sex
assessment. International Journal of Legal Medicine. 127(1), 201–12.
4. López-Costas O, Rissech C, Trancho G and Turbón D. Postnatal ontogenesis of the tibia. Implications for age and sex estimation. Forensic Science
International. 214(1–3), 207.e1-207.e11.
5. Cunningham C, Scheuer L, Black S. 2016. Developmental Juvenile Osteology 2nd Edition. London: Academic Press.
6. Steele DG. 1976. The estimation of sex on the basis of the talus and calcaneus. American Journal of Physical Anthropology. 45(3), 581–8.
7. Holland TD. 1995. Estimation of Adult Stature from the Calcaneus and Talus. American Journal of Physical Anthropology. 96, 315–320.