Treating wounds of the equine distal limbs
"Rapid and accurate recognition of damage to deep structures is mandatory for appropriate case management and a favorable prognosis," says Henry W. Jann, DVM, MS, Dipl. ACVS, at Oklahoma State University's Center for Veterinary Health Sciences.
"Our knowledge of how tendons and ligaments heal is constantly expanding and controversial," Jann says. "We're not really certain of the physio-logical mechanisms that turn tendon healing on and off, but we're learning more every day."Veterinarians know that the healing process is controlled to a large extent by growth factors. To assist healing, practitioners have some new therapies in their armamentarium, including stem-cell and shock-wave therapy.
While it is known that training and exercise help strengthen bones and muscles, just how tendons respond to exercise and the best way to train horses to prevent tendon injury are not well understood. Tendons do get stronger to a certain extent in young horses, but in the mature horse it's hard to get them healed well enough to attain the physical strength required of an equine athlete. With any tendon laceration, the potential for severe hemorrhage is always present because of the proximity of major arteries to the flexor tendons and their relatively superficial location.
"Ligament healing follows essentially the same pattern as tendon healing," Jann notes, "although the intrinsic and extrinsic patterns have not been as clearly defined."
Unlike tendons, ligaments do respond positively to exercise.
"When tendons are compromised, there is an alteration in limb conformation during ambulation or upon weight- bearing," Jann explains. Damage to each of the various tendons, ligaments and joints — superficial deep flexor tendon (SDFT), deep digital flexor tendon (DDFT), metatarsophylangeal or metacarpophylangeal joint (MP), fetlock joint, distal interphalangeal joint (DIP) and coffin joint — has its own specific presentation/appearance. "These changes in conformation are consistent and can be relied upon for categorization of compromise to a specific tendon or tendon group," Jann says.