# Imaging Studies of the Stifle Joint in Puma concolor (Linnaeus, 1771)

## TL;DR

This study uses various imaging techniques to examine the stifle joint in pumas, revealing structural details important for understanding their anatomy and potential health issues.

## Contribution

The study provides the first detailed imaging analysis of puma stifle joints using multiple modalities, including ultra-high-field MRI.

## Key findings

- Digital radiography, CT, and MRI each revealed different aspects of the puma stifle joint anatomy.
- Meniscal mineralization was detected in four pumas using all imaging methods.
- Ultra-high-field MRI (7 Tesla) provided the most precise visualization of cruciate ligaments and menisci.

## Abstract

Pumas are known for their agility and can jump to heights exceeding 5 m. The stifle joint is considered a complex joint, both anatomically and functionally. Although the stifle joint of wild felines shares several characteristics observed in domestic cats, other characteristics are specific to each species. Therefore, this study aimed to evaluate the stifle joints of pumas (Puma concolor) using digital radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Imaging methods complemented each other in assessing the components of the puma’s stifle joint, as certain structures like the cruciate ligaments and meniscus were not visible on plain radiographs. The meniscus and cruciate ligaments were visualized on CT and MRI, but ultra-high-field MRI (7 Tesla) allowed these structures to be observed with precision. In the stifle joints where meniscal mineralization was present, identified in three adults and one young animal, it was detected across all imaging modalities.

Although the stifle joint of wild felines shares several characteristics observed in domestic cats, other characteristics are specific to each species. This study aimed to evaluate the stifle joints of eight Puma concolor, including two young and six adults, through different imaging examinations. All stifles were assessed using radiographs and computed tomography (CT). Magnetic resonance imaging (MRI) was performed on the stifles of one animal using 7 Tesla equipment. In all imaging modalities, the four sesamoid bones were detected. Meniscal mineralization was identified in the stifles of three adult animals and one young animal. The cruciate ligaments and menisci were identified on CT, with MRI providing better visualization. The mean values of CT measurements (cm2) in the sagittal section included patella (2.475), medial fabella (0.481), lateral fabella (0.772), popliteal sesamoid (0.222), and medial meniscus (0.051). No differences were found in HU values between the central trabecular bone of the patella and popliteal sesamoid, the cortical bone of the patella and lateral and medial fabellas, or the cortical bone of the patella and popliteal sesamoid. In conclusion, the descriptions of the stifle of Puma concolor from the different imaging methods contribute to understanding the species and can serve as a basis for identifying alterations.