Compensatory load redistribution in naturally occurring osteoarthritis of the elbow joint and induced weight-bearing lameness of the forelimbs compared with clinically sound dogs.

The current study investigated the compensatory load redistribution due to osteoarthritis of the elbow joint using ground reaction forces of all four legs, simultaneously measured on a treadmill with integrated force plates. Three groups of dogs were used: the first group was clinically sound; the second group suffered from a naturally occurring osteoarthritis of the elbow joint, and a reversible lameness was induced in the third group. The naturally occurring osteoarthritis resulted in a compensatory gait pattern to reduce the stress on the affected limb. The load was reduced on the lame limb and increased on the contralateral hindlimb. The symmetry index indicated a weight-shift to the contralateral forelimb and diagonal hindlimb, which resulted in a more balanced weight distribution than in normal dogs. Dogs with induced lameness showed comparable but less pronounced alterations. These results suggested that forelimb lameness could lead to overload on non-affected extremities and the vertebral spine.