Jelen Vanessa López-Patiño; Julián Guevara Realpe; Francisco Luis Hernández & María Carolina Pustovrh

: Fetal anatomy provides essential information for documenting and understanding human prenatal development and the anatomical bases of congenital anomalies. However, access to human fetal specimens for teaching and research purposes has progressively become more restricted due to ethical, legal and logistical limitations. This has resulted in a significant reduction in the availability of cadaveric material. In this context, traditional educational resources such as two-dimensional atlases and synthetic physical models are inadequate for accurately representing the three-dimensional complexity of fetal morphology. These limitations emphasize the necessity of developing realistic, accessible, and ethically acceptable digital alternatives. The left lower limb of a male fetus at 28 weeks of gestation was prepared using an osteotechnical protocol that included glycerin preservation, controlled heating, soft tissue removal, bleaching and microdissection. This was in order to preserve the delicate fetal ossification centers. A total of 576 high-resolution images were acquired using an iPhone 11 Pro and processed using Specimen Cloner®, an AI-based photogrammetric system developed specifically for this study. The AI algorithm optimized texture detection, segmentation and three-dimensional reconstruction. The resulting model was then exported to the Sketchfab platform for interactive online visualization. The osteotechnical preparation made it possible to clearly identify the osseous, cartilaginous and ligamentous components of the fetal lower limb. The AI-assisted photogrammetric model accurately reproduced the relevant anatomical structures, such as the interosseous membrane, the epiphyses of the femur and tibia, ligament insertions and cartilaginous regions. The digital model preserved the morphology, colour and surface texture of the original, and was made available via a QR code for educational purposes. A high-fidelity fetal skeletal model can be generated using a precise, cost-effective and ethically sound method that integrates photogrammetry and artificial intelligence. This approach is a valuable alternative to the limited availability of fetal cadavers, helps to develop digital anatomy repositories and increases access to high-quality anatomical resources for teaching and biomedical research.

KEY WORDS: Anatomy; Fetus; Lower limb bones; Photogrammetry; Artificial Intelligence.

LÓPEZ-PATIÑO, J. V.; GUEVARA REALPE, J.; HERNÁNDEZ, F. L. & PUSTOVRH, M. C. Development of an artificial intelligence– assisted photogrammetric method for three-dimensional modeling of the human fetal lower limb skeleton. Int. J. Morphol., 44(4):1149- 1156, 2026.