Synovial hernia as a possible complication of arthroscopic surgery in a horse

A 3-year-old Standardbred gelding was referred for evaluation of a fluctuant swelling that developed over the dorsum of the carpus subsequent to arthroscopic surgery on that carpus. A synovial hernia was diagnosed and surgically repaired. Although complications secondary to arthroscopy are rare, synovial herniation can develop after arthroscopic surgery. The condition must be differentiated from the more common true bursitis or false bursitis that is commonly referred to as a hygroma.