Nov 16, 2018University of Barcelona researchers discover new ankle ligament
Researchers at the University of Barcelona have discovered a new ligament in the lateral side of the ankle, which could help explain chronic pain after an ankle sprain. This new anatomic structure is described as the lateral fibulotalocalcaneal ligament complex (LFTCL). Published in the scientific journal Knee Surgery, Sports Traumatology, Arthroscopy, the finding is changing the understanding of the ankle.
According to a release from UB, it was thought that there were only two ligament complexes in the ankle before this research: the lateral collateral ligament and the medial or deltoid collateral ligament. By analyzing fibers that link two of the lateral collateral ligament compounds, researchers were able to describe the new anatomic structure. Significantly, a part of this structure was described as intra-articular.
Ankle lateral ligaments are an area of the body that receive a lot of injuries, especially due to ankle sprains. It’s often puzzled medical professionals why these injuries can lead to chronic pain and make the area more susceptible to re-injury, but this new finding has provided an important missing piece of that puzzle.
“This lack of explanation was the key to change the way to tackle ligament dissection in the dissection room and we saw linking fibers between ligaments were usually removed because they were not associated with the ligament,” said Miquel Dalmau Pastor, PhD, PT, DPM, researcher and Associate Professor from the Human Embryology and Anatomy Unit in UB’s Department of Pathology and Experimental Therapeutics.
According to the study, these fibers link the inferior fascicle (set of ligamentous fibers) in the anterior talofibular ligament and the calcaneofibular ligament, two out of the three components in the lateral collateral ligament.
“This connection was never described, and contrary to what was thought, it suggests that both ligaments are a functional unit. That is, we could consider these two connected ligaments as an anatomic structure we call lateral fibulotalocalcaneal ligament complex,” said Dalmau Pastor.
Other clinical publications had previously shown positive results from isolated repairs of the anterior talofibular ligament in cases of injuries to the anterior talofibular ligament and calcaneofibular ligament. To the team at UB, these findings suggested that there must be something connecting the different ligaments for these repairs to work.
“These publications made us think that perhaps the calcaneofibular ligament could be repaired by repairing the anterior talofibular ligament, and this could only happen if there was some kind of connection between ligaments,” says Dr. Jordi Vega, an Associate Professor at UB, who also worked on the study.
Discovering that part of the anterior talofibular ligament is an intra-articular structure could have a major impact on how ankle injuries are treated in the future.
“These findings suggest the behaviour after an injury will be similar to the other intra-articular ligaments, such as the twill, which are not able to cicatrize, and this makes the joint to remain unstable and in many cases it requires a surgical operation,” said Dalmau Pastor.
The results from the study also help explain why pain often remains after an ankle sprain appears to have healed.
“Since the intra-articular ligament does not cicatrize, the instability of the joint produces pain so these patients are likely to suffer from another sprain and develop other injuries in the ankle,” explained Francesc Malagelada, another researcher on the UB team.