No 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.

Adipose-derived stem and regenerative cells (ADRCs), concentrated from autologous fat tissue, have the ability to differentiate into various specific cell types including tenocytes. In this retrospective study, clinical data are presented from 83 horses with 176 suspensory ligament injuries, treated with ADRCs, given a strictly enforced standardized rehabilitation program, and followed up for at least one year after returning to work. Assessment for a successful outcome was return to full work (RFW) at a previous or higher level of performance for one year or more without re-injury. RFW numbers were 84.6% for horses with fore-limb ligament injuries and 82.1% for horses with hind-limb injuries. RFW outcomes were slightly better in cases with proximal suspensory ligament desmitis (86.7%) compared to horses with lesions of the body and branches. The ADRC injection procedure was well tolerated; no treatment-related adverse events, including injection flares, were detected in any of the 83 horses. The demonstrated long term stability of healed lesions strongly supports the therapeutic use of regenerative cells extracted from adipose tissue for treatment of acute and chronic, fore-and hind-limb suspensory ligament injuries in horses of various athletic sport disciplines.