Soft Tissue Injuries
There are many ligaments in the horse’s body. The most common ligament that can sustain an injury is the suspensory ligament. A major component of the horse’s suspensory apparatus, this ligament in the forelimb courses from the back of the knee to the fetlock joint. In the hindlimb the suspensory ligament runs from the lower part of the hock to the fetlock joint. Injuries to this ligament can be anywhere along its length. The more common injuries are seen either at its origin (proximal suspensory) or in the branches where the suspensory inserts onto the sesamoid bones. As with most injuries in the horse, they can vary greatly in severity and thus the treatment will be determined by this severity.
Tendons, by definition, connect muscle to bone. There are many in the horse. The most commonly injured tendon is the superficial digital flexor tendon (SDFT). When a horse is said to have a “bowed tendon” the SDFT is the structure that has been injured. Less commonly the deep digital flexor tendon (DDFT) can be injured. Both are significant injuries in the horse and although they may not always cause obvious lameness at the time, they can have a major effect on the integrity of the horse’s limb support. Horses can often return to racing after tendon injuries but they can take a long time to rehabilitate and commonly reoccur.
Long Bone Fractures
Although long bone fractures in horses can be difficult, at times, to treat successfully, many have a good prognosis not only for life but for return to racing. One of the most common long bone fractures that a race horse may sustain is called a condylar fracture. These fractures can commonly be treated with surgical lag screw fixation and many return to racing at a similar level of competition. There have been many advances in the treatment of long bone fractures over the last few decades and more advances will develop in the years to come.
Bucked shins are pathological manifestations of normal adaptive changes to the cannon bone that take place during normal training exercise. It is important to note that bucked shins aren’t necessarily a result of improper training. The cannon bones of horses remodel in response to the training stresses that are placed upon them. In some instances this remodeling, that is meant to strengthen the bone, can become overwhelmed. Lameness and/or soreness to the front of the cannon bone can occur. Treatment and rehabilitation times can vary greatly depending on the extent of the injury and the preferred treatment method of the veterinarian.
Bone chips or osteochondral fragments are relatively small fractures within a horse’s joints. They are called “osteochondral” as they are normally composed of both cartilage and bone. These fragments can be very small at times but the size often doesn’t matter. What matters is the amount of debris within the joint and the degree of inflammation that it may cause. Chips are most common in the front fetlocks and knees of horses but can occur in all joints. Treatment of chip fragments will be dictated by the amount of lameness and inflammation that they may cause.
Although there are different types of sesamoid bones in the horse, the ones typically discussed are the small bones at the back of the front and rear ankles. These bones act as a lever and have attachments to the suspensory ligaments of the front and rear limbs. The most common acute injury to a sesamoid bone is a fracture. These can vary greatly in severity and thus the treatment will be determined by the degree of injury to the sesamoid bone.
Often joint injury is limited to the joint capsule. Terms that may be used for this are synovitis or capsulitis. These injuries are typically less in severity than ones that involve chips or fractures. Commonly the treatments are less extensive as well. Normally these treatments are restricted to intra-articular injections or physical therapy.