Mechanical response of ankle ligaments at low loads

Bulter, Adam M.; Walsh, William R.

Affiliations

¹Orthopaedic and Surgical Research Laboratories, Division of Surgery, University of New South Wales, Prince of Wales Hospital, Randwick, NSW, Australia

²Graduate School for Biomedical Engineering, University of New South Wales

³Division of Surgery, Sydney Children's Hospital, Randwick, NSW, Australia

Abstract

Background: The aim of this study was to examine the mechanical behavior of human ankle ligaments at low forces. Predominantly, ankle ligaments have been studied under the auspices of ligament injury. While the mechanical properties of a ligament when tested to failure provide a basis for comparisons, the loads and displacement do not reflect normal physiologic loading.

Methods: Eight fresh-frozen ankles (mean age 65) were dissected to expose the ligaments surrounding the talocrural joint. Eight ankle ligaments were studied and included: medially-anterior tibiotalar (ATTL), posterior tibiotalar (PTTL), tibiocalcaneal (TCL); laterally-anterior tibiofibular (ATiFL), posterior tibiofibular (PTiFL), anterior talofibular (ATFL), posterior talofibular (PTFL), and calcaneofibular (CFL). Stress relaxation tests were carried out at 30% and 10% strain. The peak load and area under the curve were assessed for all experiments.

Results: Significant differences were found for the average peak loads of the elastic response between 30% and 10% strain for each ligament (p < .05). At 10% strain the relationship between the ligaments on the medial and lateral side revealed a Pearson R value of .991 (p = .087). No significant difference was found between the strain energies of the various ligaments (p < .05). The anterior talofibular ligament was found to possess similar relaxation results to the medial ligaments. The calcaneofibular ligament relaxed up to 10% more compared to the anterior talofibular for the same relaxation period. The mechanical testing was performed in uniaxial tension and did not consider off-axis loading that may occur in vivo during ankle motion.

Conclusions: The stress relaxation experiments revealed all ligaments to relax even when loaded to less than 5 N, reflecting the viscoelastic nature of ligaments. The stress relaxation results show that the anterior talofibular ligament does not relax to the same extent as the other lateral ligaments. Examining the properties of human ankle ligaments at low loads has revealed some new findings.

Clinical Relevance: This study highlights the need to understand the synergistic effects of the ligaments. This is important for reconstruction and arthroplasty procedures.

Links

DOI: 10.1177/107110070402500103

PubMed: 14768958

WoS: 000188666900003

Cited Works (8)

Year	Entry
1998	Bahr R, Pena F, Shine J, Lew WD, Engebretsen L. Ligament force and joint motion in the intact ankle: a cadaveric study. Knee Surg Sports Traumatol Arthrosc. 1998;6(2):115-121.
1990	Nigg BM, Skarvan G, Frank CB, Yeadon MR. Elongation and forces of ankle ligaments in a physiological range of motion. Foot Ankle. August 1990;11(1):30-40.
2000	Funk JR, Hall GW, Crandall JR, Pilkey WD. Linear and quasi-linear viscoelastic characterization of ankle ligaments. J Biomech Eng. February 2000;122(1):15-22.
1998	Milner CE, Soames RW. Anatomy of the collateral ligaments of the human ankle joint. Foot Ankle Int. 1998;19(11):757-760.
1985	Attarian DE, McCrackin HJ, DeVito DP, McElhaney JH, Garrett WE Jr. Biomechanical characteristics of human ankle ligaments. Foot Ankle. 1985;6(2):54-58.
2000	Leardini A, O'Connor JJ, Catani F, Giannini S. The role of the passive structures in the mobility and stability of the human ankle joint: a literature review. Foot Ankle Int. 2000;21(7):602-615.
1988	Siegler S, Block J, Schenck CD. The mechanical characteristics of the collateral ligaments of the human ankle joint. Foot Ankle. April 1988;8(5):234-242.
1990	Colville MR, Marder RA, Boyle JJ, Zarins B. Strain measurement in lateral ankle ligaments. Am J Sports Med. March 1990;18(2):196-200.

Cited By (5)

Year	Entry
2014	Forestiero A, Carniel EL, Natali AN. Biomechanical behaviour of ankle ligaments: constitutive formulation and numerical modelling. Comput Methods Biomech Biomed Eng. March 12, 2014;17(4):395-404.
2010	Wei F, Villwock MR, Meyer EG, Powell JW, Haut RC. A biomechanical investigation of ankle injury under excessive external foot rotation in the human cadaver. J Biomech Eng. September 2010;132(9):091001.
2009	Villwock MR. Rotational Traction At the American Football Shoe-Surface Interface and Its Application to Ankle Injury [Master's thesis]. East Lansing, MI: Michigan State University; September 2009.
2012	Wei F. Biomechanical Investigations and Computational Modeling of the Human Ankle [PhD thesis]. East Lansing, MI: Michigan State University; 2012.
2019	Berardo-Cates A. Development of Methods for Characterizing Ankle Ligament Viscoelastic Properties [Master's thesis]. University of Washington; 2019.