Joint Injections

Long term comfort and relief from arthritis and enhancement of your horse’s performance can be achieved through joint injections.

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Joint injections can be discussed in two separate sections. First, high motion joints, or those that must have full range of movement to allow normal athletic function. Second, low motion joints, or those that may not necessarily be required to move to allow normal athletic function.

An example of a high motion joints would be the ankle or fetlock. These joints include ALL of the leg joints in the body EXCEPT the pastern joints AND most importantly, the lower two joints of the hocks.

The most important, and commonly treated, lower motion joints are these two lower joints in the hock. As we will discuss here, the treatments for these two different types of joints may be radically different.

High motion joints require lots of TLC... 

Low motion joints, such as the lower hock joints, may be treated with long term pain killers (anti-inflammatories) without the worries that long term damage to the joint will occur...

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The Myth of Hock Injections Unveiled
(or “Be careful what you ask, the answer may not be short...”)

Sport horses are frequently afflicted with degenerative conditions (arthritis) due to the nature of the performance demands we place on them. One of the most common areas this occurs is the lower two hock joints. The hock is a complex of four different joints. In humans it is akin to our ankle. Within this group is the upper most joint where all of the motion of the hock is seen and then three corresponding low motion joints beneath. Fortunately, the upper, high motion joint (tibiotarsal joint) is rarely afflicted with significant degeneration from work. Similarly, the upper most low motion joint (which communicates with the tibiotarsal joint) also is rarely afflicted. For the purposes of this discussion we are singling out the two lowest joints of the hock as the lower motion joints. Arthritis of these lower two joints is so common it has been termed “bone spavin” as a common name for discussing the condition.

The lower motion joints of the hock are unique in that they are a major origin of subclinical performance issues (commonly sore back syndromes and poor movement and push from behind), yet are not essential for movement of the hock. For this reason they can be viewed in a radically different manner than other joints within the horse. In fact, if these joints were to magically be removed from your horse, they would maintain their full athletic scope and ability without the downside of persistent, low grade discomfort which often accompanies arthritic change. 

For this reason, long term comfort of the horse and relief from the arthritis is the primary goal of lower hock joint treatment, NOT continued motion and flexibility of these low motion areas. This is a very important concept to grasp as joint comfort and treatment for joint function are not necessarily the same. Granted, high motion joint treatments such as Adequan, Legend (intravenous hyaluronic acid), intra-articular hyaluronic acid (HA) and low dose, short acting steroids do play some role in creating comfort. However, all of these drugs are aimed primarily at restoration of a more “normal” joint environment. The primary goal being preservation and regeneration of healthy cartilage. In lower hock joints we often take a different approach. As these joints are not necessary from athletic performance, their more reliable comfort becomes the primary goal somewhat at the expense of the cartilage involved. For this purpose, long acting steroids (the most potent anti-inflammatory available) are used.

As we now know these joints do not play any significant role in the motion of the horse, thus the worst case scenario from such treatment (i.e. continued, progressive joint deterioration and possible increased arthritis production which may be enhanced by steroid injections) may only result in joint fusion. If this were to occur in a high motion joint pasture retirement, at best, would result. In the lower hock joints, however, this results in a pain free performance horse which no longer requires periodic joint injections.

Interestingly enough, recent research has down played the significance of long acting steroids in the progression of arthritis in joints (steroid arthropathy). The newest theories support the progressive degeneration regardless of therapies used. Our own clinical experience would somewhat support this as well as many horses appear to progress an fuse despite numerous injections while others apparently never fuse through their entire career even with frequent injections. In other words, the horse is going to do what the horse is going to do. If you have a performance horse and you feel there may be some subtle hind end or back soreness issues, consider looking first at their hocks...

One final note. Starting down the pathway of “joint maintenance” and semi-routine injections DOES NOT mean the horse will desire or require continued injections for the remainder of their life (not even their performance life for that matter...). In fact, many horses once on the decline of their careers will move to lesser levels of performance where these types of conditions may not affect their comfort.

The bottom line: Have your horse evaluated if you believe hind end performance or comfort issues are of concern. This is especially true in muscle soreness over the croup is clinically apparent. Lower hocks are by far the most common cause of many of these issues and should be considered a routine maintenance condition for many performance horses.