title: In vitro mechanical properties and failure mode of the equine (pony) cranial cruciate ligament.
abstract: In vitro failure modes and mechanical properties of the equine cranial cruciate ligament (CCL) were evaluated in 15 stifle joints from 10 ponies. Ponies were from 3 to 25 years of age and weighed from 122 to 208 kg. Femur-CCL-tibia specimens were mounted in 48 degrees of flexion, distracted until a 500-g tensile preload was achieved, and then tested by tensile loading to failure. Specimens failed by complete midsubstance CCL rupture (n = 9), combined tibial insertion avulsion fracture and midsubstance CCL rupture (n = 4), and combined femoral origin avulsion fracture and midsubstance CCL rupture (n = 2). No significant differences were found between CCL mechanical properties and failure mode or body weight. Femur-CCL-tibia maximum tensile loads ranged from 1,945 to 4,326 N (median, 2,914 N). Mean maximum tensile load (N) per kilogram of body weight was 17.98 N/kg (median, 17.55 N/kg). These pony specimens had stiffer cranial cruciate ligaments (median, 320.2 N/mm) with a higher elastic modulus (median, 321.7 MPa) than has been reported for other species. Significant decreases in linear tensile load (P = .0292), maximum tensile load (P = .0493), and increases in strain to maximum load (P = .0463) were found in the specimens from 20- to 25-year-old ponies when compared with those from 3- to 10-year-old ponies.
authors.affiliation: Department of Clinical Studies, New Bolton Center, University of Pennsylvania, School of Veterinary Medicine, Kennett Square.
authors.forename: F R
authors.initials: FR
authors.lastname: Rich
authors.forename: R R
authors.initials: RR
authors.lastname: Glisson
mesh_terms: D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000502:physiology; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005269:Femur; D006736:Horses / Q000293:injuries* / Q000502:physiology; D012044:Regression Analysis; D012421:Rupture / Q000662:veterinary; D013045:Species Specificity; D013977:Tibia