Carolyn E. Arnold, DVM, of the University of Pennsylvania’s New Bolton Center said stifle trauma can be a common cause of lameness in the horse, in her presentation given at the recent American Association of Equine Practitioners convention. Fractures of the tibial tuberosity often occur as a result of direct trauma, such as hitting the stifle on a fence while jumping, or as an avulsion injury (the tearing away of part of the structure) caused by slipping on ice. When a fracture is involved, surgery is a repair option, but, Arnold said, there are some inherent risks, especially during recovery from anesthesia.

The purpose of her study was to determine whether conservative treatment involving stall rest would be successful as surgery. As part of her study, she examined the records of 15 horses admitted to New Bolton Center and treated conservatively for tibial tuberosity fracture. A follow-up survey revealed that 10 of the 15 horses had recovered and were performing at a previous or higher athletic level at an average of 52 months after the injury.

Three of the 15 never returned to athletic capability due to protracted lameness. The other two horses in the group developed patellar desmitis.

In conclusion Arnold said, "The mortality rate associated with internal fixation (surgery) is as high as 50%. Implant failure and catastrophic fracture of the tibia were cited as the cause for failure