Biomechanical Evaluation of Nuchal Ligament in Dogs

Introduction: The nuchal ligament is a fibroelastic structure that dorsally runs through the median cervical region and is divided into two portions, namely, the lamellar and the funicular ones. Because there are no studies addressing the biomechanics of the nuchal ligament, the hypothesis of this paper was: would the resection of the nuchal ligament or a funicular band be possible? Would they work as a donor site for grafts?

Materials and Methods: Nuchal ligament of 30 cadavers of dogs were collected and characterized histologically, by Haematoxylin-Eosin (HE) and Masson's Trichrome (TM) stains; and biomechanically, through testing the ligaments on EMIC Universal Testing Machine—model DL-2000, with load cell of 500 N (load application speed of 100mm/min) and free space between the gripping grips of 20 mm.

Results: The nuchal ligament consists of two thick and parallel bands containing bundles of collagen fibres arranged in a braided pattern, which sometimes intertwine and are distributed longitudinally. Statistical analysis of the biomechanical test showed that the intact ligament group presented greater maximum force (N) than the funicular band Ligament 1 group (p <0.001).

Discussion/Conclusion: Under the tested conditions, the maximum rupture force was significantly greater in the intact ligament than in only one funicular band, which demonstrates that this partial resection (only one band) could represent damage in relation to the biomechanical function of the nuchal ligament. Therefore, even though the ligaments were long enough to be donors for anterior cruciate ligament reconstruction for example, the nuchal ligament would probably not be eligible to be a graft donor site.

Acknowledgement: The authors are grateful to the Sao Paulo Research Foundation (FAPESP, grant 2020/10899–4).

Publication History

Article published online:
26 October 2022