Morphometric geometric differences between right and left human tali: A cadaveric study of fluctuating asymmetry via systematic measurement and three-dimensional scanning.

Background: Little is known about differences in the size and morphology of the right and left human tali. The present study demonstrates differences between right and left talar morphometric geometric profiles as fluctuating asymmetry in matched pairs of cadaveric specimens.
Methods: In total, 24 tali were collected in this study. All eligible tali were systematically measured with a Vernier caliper and three-dimensional laser scanner, which provided data for further analysis regarding the talar morphometric geometric profiles. Data were calculated to demonstrate differences between the right and left talar profiles using a matched-pair method, including the general size of the talus.
Results: The average talar length was 53.5 mm, the average talar dome height was 31.2 mm, and the average talar body width was 41.3 mm. The average anterior trochlear width, middle trochlear width, posterior trochlear width, and trochlear length were 31.8, 31.2, 28.3, and 30.7 mm, respectively. Eleven matched pairs of intact tali were eligible for the matched-pair study. Paired t-tests showed significant differences in the talar dome height (P = 0.019), middle trochlear width (P = 0.027), and posterior trochlear width (P = 0.016) between the right and left tali. However, there were no significant differences in the surface area or volume between the right and left tali.
Conclusion: Significant differences in the morphometric profile were found between the right and left matched pairs of tali. This basic information indicates that the profile of the contralateral talus may not be used as a single reference to reconstruct or duplicate the talus of interest in certain conditions such as talar prosthesis implantation or customized total ankle replacement.
Competing Interests: Dr. Angthong reports grants from Thammasat University (grant number: ทป2/43/ 2561, year 2018), personal fees from Phoenix Surgical Equipment (Thailand) Co., Ltd, personal fees from Amgen, personal fees from THAI ADK ENGINEERING COMPANY LIMITED, during the conduct of the study; In addition, Dr. Angthong has a patent Manufacture protocol for the artificial total talus (Thailand patent number: 14879) issued. This does not alter our adherence to PLOS ONE policies on sharing data and materials.