A panel of three veterinarians addressed the topic of stifle treatment at the Western Performance Horse Forum held in Nampa, Idaho, on Feb. 15-17, 2007. Those veterinarians were: Robert Schneider, DVM, MS, equine orthopedic surgeon at Washington State University; Van Snow, DVM, from Santa Ynez, Calif.; and Chris Ray, DVM, MS, Dipl. ACVS, of Weatherford, Texas. Due to the varied nature of stifle injury, each syndrome was addressed separately.

Depending on the location and degree of associated clinical signs, treatment for stifle OCD relies on several options:


Rest with light exercise, such as hand walking, is one treatment option for stifle OCD.

  • Intramuscular Adequan injections at an early age to improve cartilage development;
  • Injection of anti-inflammatory medications such as hyaluronic acid and corticosteroids directly into the joint;
  • Rest with light, but controlled exercise; or
  • Arthroscopic surgery to remove a cyst or cartilage flap if none of the above treatments provide resolution.

The use of bone marrow or Interleukin-1 receptor antagonist protein (IRAP) was also suggested as possible treatment options.

For upward fixation of the patella or delayed patellar release, the best treatment relies on turnout 24/7, conditioning, and specific exercises to develop muscle strength in the hindquarters. Foot problems must be corrected to improve biomechanics to avoid stifle locking. Injection of counter irritants into the offending ligament is an effective therapy. A similar strategy uses a stabbing procedure to scar the proximal medial patellar ligament to tighten it up so the patella cannot catch on it. Conjugated estrogen therapy was reported to work only about half the time.

Another historically popular technique was desmotomy (cutting) the medial patellar ligament. Schneider stressed that if the ligament was cut, the horse must be in a rehabilitation program at least six months; if kept in regular exercise, there is a high probability of fragmentation of the patella with associated osteoarthritis.

Treatment of a middle patellar ligament injury is difficult to resolve with rest alone. Three months of rest followed by two months of rehabilitation on an Aquatred (a treadmill immersed in water) is recommended. Snow has also seen good results using injection of fat-derived stem cells.

Treatment of meniscal damage relies on extended rest and injection with IRAP or stem cells. A human with a meniscal tear should be non-weight-bearing for 60 days, and this is clearly not possible with horses. Surgery is not usually very successful.

A horse with a collateral ligament injury needs rest and a slow, progressive rehabilitation. Despite careful rehab, most horses have their level of activity limited by this injury. Stem cell therapy might be something to try, but do not yield return to high performance.

Osteoarthritis due to cartilage trauma is best treated initially with intra-articular (IA) anti-inflammatory medications such as hyaluronic acid and corticosteroids. If the horse quickly relapses or fails to respond, the stifle should be scoped. Those that respond best to surgical debridement, lavage, intra-articular anti-inflammatory medication, and post-surgical rest are those without full-thickness cartilage defects. Rehabilitation is designed around the type and extent of injury.

A non-complicated, non-displaced patellar fracture can heal with a fibrous or bony union and yield a sound horse. In other cases, chips are best removed with arthroscopic surgery. Stall rest for three months and non-steroidal anti-inflammatory drugs might improve the outcome.

The panel discussed using fat-derived stem cells on tendons and ligaments to improve healing. Schneider says this form of therapy needs a scientific model and controlled studies to determine if it is a viable treatment alternative since there are variable results at this time. Depending on the type of injury involved, shock wave therapy might be useful to desensitize the pain and return the structure to function.

Rehabilitation programs must take into account the surface on which a horse is going to perform. An Aquatred or regular treadmill is useful, but preparation of the horse also requires simulating or using a natural surface. Just as bone can be trained to improve its strength, tendon and ligament insertions can be similarly adapted. It should be noted that an arena horse might encounter different depths and textures of the surface, all of which create different forces on the limb. An owner must be aware that if only the medical portion of treatment is applied without proper rehab, then one cannot expect results. Providing tissues a controlled environment for healing and keeping muscles strong are imperative to achieving success in stifle injuries.

For more from the Western Performance Horse Forum click here.

About the Author

Nancy S. Loving, DVM

Nancy S. Loving, DVM, owns Loving Equine Clinic in Boulder, Colorado, and has a special interest in managing the care of sport horses. Her book, All Horse Systems Go, is a comprehensive veterinary care and conditioning resource in full color that covers all facets of horse care. She has also authored the books Go the Distance as a resource for endurance horse owners, Conformation and Performance, and First Aid for Horse and Rider in addition to many veterinary articles for both horse owner and professional audiences.

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