Variations in the Biomechanical Properties of Articular Cartilage of the Midcarpal Joint of Normal Horses

Summary

Carpi from six clinically normal adult horses were used to determine biomechanical properties of equine midcarpal articular cartilage, and compare sites of high and low incidence of osteochondral injury. Test sites were central and dorsal C₃, both facets, central and dorsal distal C_R and Q_I central C₄ and Q_U. An automated indentation apparatus was used to obtain creep behaviour, aggregate modulus (H_A ), Poisson’s ratio (v_S), permeability (k), and cartilage thickness (h) at each site. Results were analyzed using ANOVA and multiple comparisons of means (p<0.05). Results revealed significant variations in HA and h between test sites, and in HA between dorsal and central sites (p = 0.0001). Right cartilage overall was stiffer (p = 0.0006), less permeable (p = 0.0001), and more compressible (p = 0.0001) than left. Topographical variations in biomechanical properties existed, with significant differences between sites of high and low incidence of lesions, and between right and left sides.

An automated indentation apparatus was used to determine and topographically map the biomechanical properties of equine midcarpal articular cartilage, and to compare them at sites predisposed to osteochondral injury with those at rare lesion sites. Results showed topographical variations exist, with significant differences between sites of high and low incidence of lesions, and between right and left sides.

Keywords

Equine - articular cartilage - carpus - biomechanics - cartilage material properties

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