Manjatika, Arthur Tsalani2025-10-222024Manjatika, Arthur Tsalani . (2024). Examination of the metatarsal diaphyseal nutrient foramina: Implications for forensic analysis and morpho-functional adaptations in 19th and 20th century individuals [PHD thesis, University of the Witwatersrand, Johannesburg]. WIReDSpace. https://hdl.handle.net/10539/47177https://hdl.handle.net/10539/47177A research report submitted in fulfillment of the requirements for the Doctor of Philosophy, in the Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, 2024Metatarsal fractures occurring at the nutrient foramen (NF) level are debilitating and result in poor healing patterns due to disturbed blood flow. Variations in the topographical anatomy of the NF, which may be population-specific, make it challenging to understand its role in fracture development. The area around the NF is considered weak as the nutrient canal may reduce the structural integrity of the bone, predisposing the bone to a high risk of fracture development. However, there are no previous studies that examined the trabecular microarchitecture around the metatarsal diaphyseal NF to determine its fragility. In forensic settings, the NF of upper and lower limb long bones aids in the sex estimation of unknown individuals. However, the usefulness of the measurements around the metatarsal diaphyseal NF is unknown. This study aimed to examine the topography, morphometry and trabecular microarchitecture around the NF in 19th and 20th century South African populations. The study utilised 4284 dry cadaveric metatarsal bones (first to fifth, from the left and right sides) of South African populations, including South African Africans (SAA), South Africans of Mixed Ancestry (SAMA) and South Africans of European descent (SAED) that are housed in the Raymond A. Dart Collection of Modern Human Skeletons housed in the School of Anatomical Sciences, University of the Witwatersrand. The metatarsals were obtained from 438 individuals aged between 18 and 65 years (mean age 46.78 ± 13.29 years). The metatarsal bones were examined for topographical variations (i.e. location, position, number, size) of the NF. For sex estimation, five dimensions around the region of the NF (total length of the bone, distance from the proximal end to NF, circumference at the level of the NF, and mediolateral and dorsoplantar diameters at the level of the NF) were measured from 876 metatarsals from 186 individuals of the SAED, 995 metatarsal bones from 200 individuals of SAA, and 248 metatarsal bones from 51 individuals of the SAMA population. The direct and stepwise discriminant function (DFA) analysis and logistic regression (LRA) analysis were then used to generate functions for sex estimation from these measurements. For the analysis of age-related trabecular microarchitecture changes among the three modern populations (20th century) of South Africa, 88 metatarsal bones from 44 first and 44 fifth metatarsal bones were utilised. The age range for the specimens was 0-40 years. The bones were scanned using μCT to examine the trabecular microarchitectural parameters including bone surface volume (BS/BV), bone volume fraction (BV/TV), trabecular number (TbN), trabecular spacing (TbSp), trabecular thickness (TbTh), and local bone density for trabecular bone strength. Finally, 32 first and 32 fifth metatarsal bones were selected from SAA individuals from the age-matched (18-65 years) 19th and 20th century populations in order to determine secular changes in the trabecular microarchitectural parameters using μCT. Topographically, the NF was observed in 99.4% of all the metatarsal bones. Most (84.5%) of the metatarsals had a single NF. The highest number of NF observed on a single bone was 5. The NF were primarily (97.4%) located in the middle third of the metatarsal bones. The position of the NF exhibited variations depending on the bone. The first metatarsal bones had predominantly dominant-sized NF, while the second, third, fourth and fifth metatarsal bones had predominantly small-sized NF. Overall, there were no significant population topographical variations of the NF (P>0.05). Morphometrically, the dimensions around the NF exhibited sexual dimorphism in all populations. In the SAED, the classification accuracies for multivariable DFA and LRA ranged from 83.1-88.7%. In the SAA, the classification accuracies for multivariable DFA and LRA ranged from 75-80.5%. In the SAMA, the classification accuracies for multivariable DFA and LRA ranged from 75-83.7%. The BV/TV and TbTh showed higher values, and the BS/BV, TbN and TbSp showed lower values around the NF than at the proximal and distal diaphyses in all population groups (P<0.001). In the 20th century SAA, SAED and SAMA, the BV/TV and TbTh were highest, and the BS/BV, TbSp, and TbN were lowest in the 21-30 years group. In the 19th and 20th century SAA, the BS/BV, TbSp and TbN gradually increased while the BV/TV and TbTh gradually decreased from 18-29 to 50-65 years. Overall, there were no significant population differences in the trabecular microarchitecture between 19th and 20th century SAA individuals or across the 20th century SAA, SAED and SAMA. The present study found that the topographical anatomy of the metatarsal diaphyseal NF exhibits no significant population variations. The measurements around the metatarsal NF are sexually dimorphic. The DFA and LRA functions yielded high classification accuracies for sex estimation appropriate for forensic use in the SAED, but the functions can be cautiously applied in the SAA and SAMA for estimating sex in forensic and archeological settings due to low discriminatory power. The study demonstrated that the region around the metatarsal diaphyseal NF exhibits high BV/TV, TbTh, but low BS/BV, TbN and TbSp indicating high trabecular bone quality in the NF region compared to other parts of the metatarsal diaphysis across all age groups and the different populations examined. The study also demonstrated that there are no significant secular trabecular microarchitecture changes between 19th and 20th century individuals. Comprehensive knowledge of the NF is essential to understanding fracture development and repair patterns clinically and for use in estimating sex in forensic settings.en© 2024 University of the Witwatersrand, Johannesburg. All rights reserved. The copyright in this work vests in the University of the Witwatersrand, Johannesburg. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of University of the Witwatersrand, Johannesburg.UCTDDiaphyseal nutrient foraminaMetatarsal bonesSex estimationSouth African populationsTopographyTrabecular microarchitectureThesisUniversity of the Witwatersrand, JohannesburgSDG-3: Good health and well-being