Developing the Sport Horse: Common Injuries

Orthopaedic shock waves are used to stimulate cells to regenerate tissue (i.e. tendon,or bone). It also stimulates blood flow to the area, which reduces pain associated with chronic injuries.

Photo: Alexandra Beckstett, The Horse Managing Editor

By Brianne Henderson, BVMS, MRCVS

Every year riders are plagued with limb injuries to their equine partners. Sometimes this is a small blip in the training schedule, other times it spells the end of a competitive season or even a career.

Here, we'll highlight three common injuries and different modalities that can help your horse onto the road to recovery (and a few preventive tips). And, we'll outline different treatments to help manage the injuries discussed in an easy-to-read table.

Suspensory Ligament

The suspensory ligament (SL) is effectively a broad elastic cable that runs from the back of the knee down the back of the canon bone and then branches to cradle the fetlock joint. Its purpose is to suspend the fetlock joint and prevent over extension during loading. Essentially, it works like a spring mechanism to absorb the energy as it stretches and then recoils to lift the fetlock back to its normal position.

Over time, microdamage occurs within the fibres of the ligament and due to the poor blood supply, these microtears are more likely to accumulate than heal. Often this is why we see repetitive strain injuries and/or inflammation in the SL.

The impact of foot balance is critical to the health of the SL. A foot with long toe and low heel places increased strain on structures within the foot (navicular bone), the deep digital flexor tendon (DDFT), and the SL by predisposing to a toe-firs” landing. Instead of allowing a gradual absorption of impact through the structures of the heels and up the limb, this movement creates a snapping action on the DDFT and SL. The long-term effect of foot imbalance is associated with chronic heel pain and also chronic proximal suspensory desmitis. Veterinary treatment options can include shock wave therapy and biologic injections, among other tactics.

Stifle

The stifle is the largest and the most complex synovial joint in the horse's body and, due to its location and structure, it is also the most vulnerable. The stifle is most similar to the human knee.

The stifle consists of two joints:

  • The femoropatellar joint is formed between the femur and the joint surfaces of the patella ("knee cap"). It has multiple ligaments that aid in the support and function of this joint.
  • The femorotibial joint is formed by the back surface of the femur (condyles) and the tibia.

Other important stifle components include:

  • The menisci, which are small wedge shaped “cushions” that lie between the femur and the tibia and provide a shock absorbing function;
  • The collateral ligaments, which lie outside the stifle joints and connect the femur to tibia and femur to patella; and
  • The cruciate ligaments, which lie within the femorotibial joint and stabilize the tibia against the femur

The most common injuries to the stifle in sport horses are related to the soft tissue structures (ligament injuries, cruciate ligament tear, and meniscus damage) and secondary arthritis within the joint. Often, these injuries are the direct result of trauma that results in multiple injuries to one joint. For example, a combined training horse that crashes or has a rotational fall would be at risk of not only a medial meniscus tear but also cartilage damage and collateral (supportive) ligament damage.

Return to full function depends on the severity of damage, but research indicates the percent of horses that completely recover can range from 10% to 50%. Early diagnosis through joint blocks, X ray, and ultrasound will enable a treatment and rehabilitation program to be put in place as soon as possible.

Horses that do not respond to medical management (i.e., stem cell injections, steroid injections) might require surgery to fully understand the extent of the injury as well as reduce the debris floating inside the joint.

Sacroiliac Damage

Dressage and show jumping horses are more commonly affected by sacroiliac (SI) pain and inflammation. Common complaints from riders range from a sudden unwillingness to go forward when ridden to bucking/kicking when ridden. Other riders will grow concerned over reduced impulsion and engagement (worse at canter than trot) or a “stiff-backed” horse. With true SI pain the signs are almost always worse when the horse is being ridden as they are focused on reduced power and suppleness.

Anyone who has suffered from lower back pain understands how debilitating it can be, but what does SI pain mean? Typically SI pain is secondary to another lameness issue in the horse or a result of repetitive strain. Common primary issues would be hind limb lameness and back pain under the saddle (poor saddle fit, kissing spines). These injuries prevent the horse from using their bodies normally and places abnormal stress on the SI joint eventually causing pain.

Proper identification and treatment of primary lameness issues must be the first step in getting a horse on the road to recovery; however, functional exercises play a major role in maintaining the health of the SI joint. The use of carrot stretches, gymnastics, walking over poles, and walking up and down hills all move the SI joints in their full range of motion and stretch the joint and soft tissue associated with the joint. It is restricted range of motion that causes pain/stiffness and eventually abnormalities/injury of the structures within and around the joint.

Treatment options can include carrot stretches, functional exercises, and joint injections. Discuss possible chiropractic treatment with your veterinarian.

Take-Home Message

When faced with a major injury, there are many modern treatments and therapy modalities that can help return your horse to work. However, we must remember that one of the most important factors when healing an injury is “time”. If a horse is pushed back into work without appropriate rest time, they will be at risk of injuring themselves again. Working alongside your veterinarian to ensure an accurate diagnosis and appropriate treatment program is essential to getting your horse on the right road to recovery.

Many of the injuries encountered in athletic horses are the result of repetitive strain/overuse or speed. This highlights the need for cross-training and functional exercises/stretches to be a regular part of a horses’ training in order to reduce the risk of this type of injury. Riders are encouraged to implement carrot stretches and functional exercises into their daily/weekly routine.

Modalities for Treating Common Sport Horse Injuries

What How Why When
Shock Wave Therapy Special crystals are stimulated by an electrical impulse to release a high energy pulse which is focused on a target point (i.e. suspensory ligament branch). Orthopaedic shock waves are used to stimulate cells to regenerate tissue (i.e. tendon,or bone). It also stimulates blood flow to the area, which reduces pain associated with chronic injuries. Shock wave works best in areas where the structure of interest lies against bone (i.e., branches of the suspensory ligament). This aids in focusing the shock waves on the target and reduces the waves dispersed or lost into bulky soft tissue (like muscle).
Biologics (platelet-rich plasma [PRP], stem cells) With PRP, a patient’s blood is spun in a special centrifuge that yields a smaller volume of fluid highly concentrated in platelets and other growth factors which aid in healing. Stem cells are either collected from the patient's bone marrow, fat, or other tissues, or stem cells from a donor horse are used. Tendons and ligaments lack a good blood supply to bring these factors to the site of injury. By injecting a concentrated form directly into the injury site, we give the body what it needs to heal. Commonly used for tears of tendons/ligaments or chronic inflammation of ligaments
Joint Injections Medication--often a combination of steroid and hyaluronic acid (HA)--is injected directly into the joint. Inflammation within a joint causes the joint fluid to become watery and reduces its lubricating effects. By reducing the inflammation (with a steroid) and providing HA (the body’s natural joint lubricant) we can help reduce pain and restore function to inflamed or arthritic joints. Stifle injuries often benefit from this treatment. But regardless of which joint is being treated, caution must be exercised in the frequency of injection. Depending on the injury and if the horse does not improve significantly, further diagnostics and/or arthroscopic surgery should be considered.
Vibration Plates Three-dimensional vibrations stimulate neuromuscular communication, blood and lymphatic flow leading to pain reduction, improved muscle gain and an increase in strength. Increased blood flow and stimulated neuromuscular reactions are common responses to this type of physiotherapy. There are some claims that it could also improve bone density. There is little significant peer-reviewed research regarding the benefits of vibration plates. The primary focus is reducing muscle soreness after work and increasing circulation through the body.
Vibration Plates Three-dimensional vibrations stimulate neuromuscular communication, blood and lymphatic flow leading to pain reduction, improved muscle gain and an increase in strength. Increased blood flow and stimulated neuromuscular reactions are common responses to this type of physiotherapy. There are some claims that it could also improve bone density. There is little significant peer-reviewed research regarding the benefits of vibration plates. The primary focus is reducing muscle soreness after work and increasing circulation through the body.
Chiropractic A chiropractor or veterianrian provides mechanical adjustments to the vertebrae and axial skeleton. This works on the belief that subluxations of the bony column (specifically the vertebrae) impinge upon and irritate the adjacent nerves. Mechanical adjustment corrects the subluxation and allows the nerves to regain normal function. The need for chiropractic adjustments is typically caused by muscle imbalances or gait anomalies, which prevent the horse from moving properly. While chiropractic is a modality for managing athletes (as few of us move perfectly), the primary cause of the issue must also be addressed and corrected.
Functional Exercises/Stretches Examples include carrot stretches, core strengthening and stretching, gymnastics exercises, and backing up. Improves muscle function through stretching and strengthening. Move joints in their full range of motion to help prevent repetitive strain injury. Always! Almost every horse will benefit from these activities. Get proper training on the method and the right exercises prior to starting these on any horse.

 

About the Author

Equine Guelph

Equine Guelph is the horse owners' and caretakers' center at the University of Guelph, supported and overseen by equine industry groups, and dedicated to improving the health and well-being of horses.

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