What are Knock Knees?
As well as the distinctive gait, other symptoms, such as toed-out feet with outward rotation of the cannon and fetlock may be seen in foals with this condition. Conservative treatment through restriction of exercise or surgical growth restriction of the longer bone may be used to correct this condition for your horse.
Horses that receive early treatment for knock knees have less chance of developing complications associated with knock knees. Therefore, if you suspect your young horse may be suffering from knock knees, it is essential that treatment is sought promptly.
Knock knees, also known as carpal valgus, is a term used to describe an orthopedic condition that occurs during growth, due to uneven fetlock bone growth. Named for the distinctive knocking together when the foal runs, this condition occurs when the knee of the horse is positioned to the inside of the horse.
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Symptoms of Knock Knees in Horses
If your horse is suffering from knock knee you may notice that their knees turn in and feet turn out, rather than the legs being straight. Your horse may have a distinctive gait where the knees knock together as they walk or run.
- Knees touch or knock together in walk, trot, or canter
- Knees turn in towards each other
- Feet turn out
Causes of Knock Knees in Horses
This condition is caused due to the uneven growth of the leg bones. As the bones grow unevenly the muscles and other bones may attempt to compensate for this uneven growth, causing further deviations and contortion. Early treatment before the bones fuse is essential for the best outcome.
Diagnosis of Knock Knees in Horses
Your veterinarian will perform a thorough physical examination on your horse. Initially, the veterinarian may assess your horse from a distance to watch their gait and stance. You may be asked to lunge your horse at a walk, trot, and then canter for an evaluation at every stage of movement. The veterinarian will then carefully examine your horse from head to toe, paying close attention to the limbs. Your veterinarian may choose to take radiographs of your horse’s legs to assess the bone maturity and degree of deviation.
Treatment of Knock Knees in Horses
The best treatment program for your horse will be determined based on the age and the severity of the deformation.
Conservative treatment may be recommended for your foal. If your vet recommends this treatment, your foal will require confinement to reduce exercise. Your veterinarian may also recommend that your foal has corrective feet trimming performed to further encourage their legs to straighten.
Your veterinarian will make a small incision on your horse’s leg above the growth plate. This procedure works by lifting the membrane from the bone; this releases the tension on the growth plates and encourages growth. In successful cases, this allows the growth of the leg to catch up with the other. This surgical option is performed under general anesthetic. Due to the risks involved for very young foals your veterinarian may advise surgery is postponed until 2-4 weeks of age. In cases of severe deviation, the benefits of the surgery may outweigh risks of anesthetic and earlier surgery may be recommended.
The aim of this procedure is to restrict growth on the longer side, allowing the shorter side to catch up. This is performed under general anesthetic by making two incisions above and below the growth plate of the longer side, a screw is then inserted into the incision and a wire used to restrict the growth of the plate. In order to ensure correct placement of the screws and wire without damage to the growth plate, your horse will require radiographs. When performed successfully this procedure restricts growth, allowing the shorter side to catch up, however close monitoring should be given to ensure over-correction does not occur. Once the leg is straight your veterinarian will remove the screws and suture the openings. The leg will then be bandaged.
Other options for treatment may include casts or braces, trimming, or wedging of the hooves to encourage leg straightening.
Recovery of Knock Knees in Horses
You should discuss supportive exercise with your veterinarian who will be able to advise the best program to support healing for your horse. A farrier that has experience with knock knees and other orthopedic conditions may also assist in hoof trimming or care that can support leg straightening.
For both surgical options your horse will require proper bandaging. It is essential that the area is kept clean to prevent infection. Bandaging should be secure; however, apply no pressure, as excessive pressure may cause skin ulcers to develop.
If your horse received a transphyseal bridging surgery, they should be carefully monitored and evaluated every 2 - 3 days. Progress photos or videos may be beneficial. Following screw removal, your horse will have sutures to hold the tissue together. These sutures should be removed 7-10 days after surgery to support healing and prevent scarring.