When a horse is lame, computed and digital radiographs (X rays) have, for years, allowed veterinarians to easily visualize bone and joint problems that aren't always visible to the naked eye. But when dealing with abnormalities on joint surfaces, it now appears that ultrasonographic imaging could be the tool of choice, according to one researcher team that completed a study recently comparing the accuracy of ultrasound and radiography in detecting articular lesions.

A team led by Antje Hinz, DVM, formerly a practitioner at Chino Valley Equine Hospital in Chino Hills, Calif., reviewed records of 432 lesions in 254 joints on 137 horses. The researchers selected the study horses after reviewing surgical records of horses that had diagnostic or therapeutic arthroscopy (during which the veterinarian uses a tubular instrument to examine and carry out surgical procedures within a joint) of any joint between November 2003 and December 2006 at the Chino Valley Equine Hospital. 

Lesions identified included everything from bone fragments and degenerative joint disease (arthritis) to the joint disorder osteochondrosis dissecans. Nearly 83% of the lesions were identified via ultrasonography while only 62.2% of the lesions were identified using radiography.

Hinz noted that in 62 instances, ultrasonographic and radiographic findings correlated but surgical findings did not. In 27 of these, ultrasonography and radiography both had false positive findings