In this article we look at the fetlock of a horse and investigate commonly found fetlock injuries, why a horse may develop injuries to their fetlocks and what treatments are available if they do.
Where is the fetlock joint on a horse?
A ‘horses fetlock’ is the name of the joint between the horses cannon bone and the horses pastern bone and is effectively 'the ankle' of a horse.
Fetlocks are found on all four legs of the horse, whether the front or hinds. They are positioned in between the Cannon bones and the Pastern bones.
The fetlock joint itself is a complicated high motion joint which is subjected to extensive force during locomotion, supported by several soft-tissue structures which play a vital role in supporting the horses movement.
At the rear of the fetlock joint are two small bones called the sesamoids, which can often be damaged along with the fetlock joint itself. These run underneath the flexor tendons and strengthened by ligaments running down the horses pastern and cannon bones. These are often referred to as Sesamoid injuries and are slightly different to a fetlock injury.
The horse’s fetlock joint itself has no ligaments or muscles and is in fact more similar to our fingers than our arms, ankles or legs.
An injury to a horses fetlock will often involve the joint itself being damaged or the surrounding soft tissue being effected. In the majority of cases a fetlock injury will occur through a specific trauma and as such will be impossible to predict prior to happening.
Fetlock injuries are a common problem in performance and sports horses often through strains or injuries. When a horse is turning at high speed, jumping or galloping they use their fetlock joints to carry their entire body weight which explains why fetlock injuries are more common in active horses.
Fetlock injury or a fetlock disorder
There are two categories to evaluate if you suspect your horse has a fetlock injury and whether the horse has experienced a specific injury or whether the horse has a fetlock disorder caused over an extended period of time. Establishing this will help you ascertain the best treatment moving forward.
If your horse has slipped, fallen or pulled up lame this would indicate a specific trauma has occurred. If your horse has gradually slowed down and is showing early signs of lameness it is likely to be a degenerative problem.
Injuries to a horses fetlock
There are varying types of fetlock injuries found in horses.
The most commonly reported fetlock injury are specific injuries that do not involve a fracture to the bone but are caused through activity and various ranges of motion.
If an injury has occurred the fetlock joint will often show signs of inflammation (referred to as synovitis or capsulitis) and the supporting ligaments (Suspensory ligament branch and the Distal Sesamoidean Ligaments) can also become inflamed (Sesamoiditis). The horse will show signs of lameness and a significant reduction in their range of motion.
Injuries to a horses fetlocks are commonly seen in high performance sports horses (such as polo, showjumping, eventing and barrel racing horses) and is a condition which involves a strain or tear to the Suspensory Ligament where the ligament fixes to the base of fetlock joint. Many of us refer to this injury as a ‘fetlock sprain’ and will often be hot and painful to touch.
Injuries to the sesamoid bones (the back of the fetlock) are also recognised as a common fetlock injury in jumping and highly active horses and show the same symptoms as a fetlock sprain.
Inflammation to a horses fetlock
Although an early indicator that your horse may have a fetlock injury, in some cases inflammation in a horse fetlock area may not be a cause for concern. Conditions such as 'leg filling' or windgalls can sometimes show inflamed areas around the fetlock which, with careful managing, can be managed without an injury occurring.
Reducing this inflammation can be done using anti-inflammatory medications, cold bandaging and compressing or using advanced magnetic therapy.
Fractures to a horses fetlock
The most severe of fetlock injuries are fractures to the joint. These are more common in highly active and jumping horses and are the worst scenario when discussing fetlock injuries or disorders.
Signs of a fracture in the fetlock area involve sudden, severe weight bearing lameness after work or exercise. There may be significant swelling within the region and intense pain on feeling or bending the fetlock joint.
Another serious condition in the fetlock area are chip fractures where fragments of the fetlock joint break away from the joint creating inflammation and creating damage to the cartilage - this can lead to arthritic pain and further longer term complications.
Chip fractures often occur on the top of the horses long pastern bone and occur when the horse is moving at a high speed due to overextension (hyperextension) of the fetlock joint itself.
Horse fetlock disorders
Repetitive motion of the joint can lead to fetlock disorders and are established over a period of time as opposed to a fetlock injury which occurs with a specific trauma.
Disorders of a horses fetlocks include conditions such as osteoarthritis, osselets, ringbone, sesamoiditis, synovitis, and even windgalls. We take a quick look at each of these conditions:
1. Osteoarthritis of the fetlock joint.
Osteoarthritis in the fetlock joint is a common condition and is a non clinical condition. There are no cures and if left alone without treating can lead to clinical signs such as synovitis, capsulitis, high pain levels and a significant reduction in mobility.
2. Osselets
Osselets are caused by inflammation of the connective tissue that surrounds the cannon bone and the fetlock joint. This inflammatory response can progress to degenerative joint disease so is a well known disorder of the fetlock. The condition is commonly caused by the strain and repeated trauma of training on hard ground.
3. Ringbone
Ringbone is an arthritic condition where the connective tissue surrounding the pastern bone becomes inflamed which leads to the development of spurs or growths. As with other types of arthritis, early signs of ringbone will appear when horses reach middle age.
4. Sesamoiditis
The sesamoid bones in the horses fetlock are kept in position by ligaments. Due to the great stress placed on the fetlock during movement, the sesamoid bones are susceptible to injury strains and pulls. Sesamoiditis is where the sesamoid bones and the tendons they are embedded to become injured and inflamed, usually caused by over use or strain and thus seen more commonly in active horses. They are more commonly found in the front legs.
5. Synovitis
Villonodular synovitis is caused by inflammation of a fibrous cartilage pad found in the upper, front portion of the horses joint capsule which surrounds the fetlock joint. Synovitis issues are caused by repetitive trauma from exercise and due to their location, synovitis is often referred to as a fetlock disorder.
6. Windgalls
Windgalls are soft synovial swellings that form just above and behind the horse’s fetlock joints. Although rarely creating pain or lameness windgalls look worse than they feel and can be an issue with show horses and even high level dressage horses.
Along with fetlocks disorders some horses suffer from what is known as ‘fetlock drop’ which is a genetically inherited condition where the horses connective-tissue abnormally breaks down. This condition, often seen in the hind legs, is incredibly painful and will show the fetlock drop excessively when bearing weight on the joint.
Treating horses fetlock injuries & disorders
Rest and recuperation are vital in treating all fetlock injuries.
The extent of the injury will clearly depend on what period of rest and recuperation are required but in all circumstances a professional examination should be carried out.
Examination of a horse fetlock injury
Initially an examination by a veterinary professional will be carried out.
This examination will initially detect the horses range of movement and any associated lameness. Further diagnosis will often include an ultrasound/x-ray examination.
Treatment to fetlock strains are often diagnosed using ultrasound technology to establish the issue within the soft tissue. Treating these injuries will always involve rest and a strictly controlled exercise regime.
Nerve blocks are sometimes used to establish the exact location of the injury but in many cases your vet will recommend an MRI scan for the most accurate diagnosis.
Be prepared for quite an extensive bill, as diagnosis of injuries within the fetlock area can mount up as the fetlock area is complicated. Thermal imaging is becoming an ever more popular form of diagnosis and can be a lot less money that an MRI scan.
Treating a horses fetlock injury
Initially a bout of anti-inflammatory medication will be administered to provide a reduction in inflammation and reduce the horses pain levels. The horse will be subjected to box rest and prevented from overworking the joint.
Treatment can involve injections into the joint, often using low doses of corticosteroids in combination with hyaluronic acid acting as a joint lubricant. These injections have shown to aid a reduction in the inflammation and associated lameness. New regenerative medicinal methods are now available including stem cell treatment and Plasma therapy (PRP, Platelet Rich Plasma).
Users will routinely bandage their horses legs to provide compression to the leg and prevent over stretching or movement within the joint itself. Other users will use cold therapy to help reduce any internal inflammation.
Treating fetlock fractures
Supporting a horse with chip fractures often involves surgery via arthroscopy and the removal of any loose bone chips. This treatment will require a short term period of rest and recuperation but in most cases will lead to a full recovery.
Simple fractures can sometimes be treated using screws to compress the fracture and restore strength within the joint. Substantial and more sever fractures however carry poor prognosis which will often result in euthanasia.
Using tack to support your horses fetlock injury
With technologies in improving in magnetic therapy and other alternative therapies, many owners now look towards less conventional methods to aid their horses ongoing fetlock care by using a plethora of devices or tack.
Traditional cold-therapy is used by many owners where simply reducing the temperature of the horses legs (within the fetlock area) can lead to a reduction in inflammation. Cold therapies include regular hosing and the use of specifically developed tack products such as ice boots.
Advanced magnetic therapy now provides owners with a long term solution which unlike traditional magnetic therapy creates no heat - this is of significant interest when looking to treat a fetlock injury and can be used both within the recovery stage and as a preventative measure following their recovery.
Conclusion
Fetlock injuries are extremely common and part-and-parcel of working with sports horses. Fetlock disorders are caused by a variety of conditions and are more commonly found with active horses.
Understanding your horse and providing them with adequate ongoing care and protection is a part of working with a sports horse and as fetlock injuries are so common there are now a wide range of solutions to help you through the injury and back to a happy and sound life!
