What is it?
The sacroiliac (SI) joint is a part of the horses back where the sacrum (part of the spine) and ilium (part of the pelvis) unite. The joint is stabilised by three sets of ligaments on each side; the dorsal, ventral and the interosseous ligament.
There is minimal movement available at this joint, but it is crucial for transferring forces from the hindlimbs to the vertebral column, and through the body. When the SI joint is injured or painful, there is often a 'disconnection' from the hindlimbs felt when ridden, and you may find that the horse will refuse to work or jump, or shows extreme adverse behaviours when asked to perform activities that engage the hind end.
What are the signs?
When the SI joint is painful, behavioural signs are often first to manifest before others. General 'grumpy' or 'depressed' behaviours when handling can arise which weren't present previously.
Ridden work can also deteriorate with new, potentially dangerous behaviours occurring. Typical signs include a lack of impulsion from the hind, reluctance to move forward, bunny hopping, bucking, rearing, reluctant to work correctly on the bit, disunited canter and any evasion behaviours may be noticed. Jumping and collection work will be particularly painful due to the increased hindlimb engagement and thus, stressing the SI joint. When walking or trotting up, you may also notice that your horse is no longer fully tracking up.
Your horses shape may also change. Postural changes to the back, such as a hunters bump (shown above), may develop over time with continued SI dysfunction. This is where the muscles surrounding the SI area may atrophy (muscle mass loss) due to a lack of proper engagement from the hind. This will only continue to deteriorate.
What causes an injury to the SI area?
SI dysfunction may be a result of a primary injury caused by direct trauma to the area. I.e a fall that causes an injury to the ligaments, or the actual joint(s) itself, or fracture to the pelvis.
SI dysfunction can also develop secondary to another pathology. This is common in cases of hindlimb lameness such as suspensory ligament and tendon injuries, and hock issues.
Horses may also develop SI problems as a result of ongoing demanding activities that put increased mechanical stress through the joint. For example, dressage and show jumping place increased strain through the SI area, however, SI dysfunction has the potential to arise in all disciplines and work loads.
How is SI dysfunction treated?
Your vet and physiotherapist will work together to identify, treat and prevent sacroiliac dysfunction from reoccurring. A thorough physiotherapeutic assessment can identify pain on dynamic assessment, SI manipulation, along with other 'tell-tell' signs and common compensatory patterns. Your vet may use diagnostic imaging, such as diagnostic ultrasound, to confirm and diagnose SI dysfunction.
Treatment may include steroid injections to the SI area if required, but SI dysfunction can be managed alternatively through a course of physiotherapy treatments. Pulsed electromagnetic field therapy is the only electrotherapy that can penetrate to the SI area in a horse. This will treat the damaged tissue at a cellular level, whilst other modalities can be used to treat the compensatory pain and muscle spasm.
Prognosis is largely dependant on the severity of the injury, and at what stage the dysfunction is identified.
At Berkshire Vet Rehab, we have successfully treated a number of horses with physiotherapy treatment that have presented with sacroiliac issues / pain, either alongside veterinary treatment, or as a stand-alone treatment. These horses have gone back to successful ridden life including jumping with no clinical signs of SI pain returning. Dedication to a rehab plan is crucial to success in these cases.
If you think your horse is presenting with any signs of sacroiliac dysfunction or pain, or would like to discuss your horse in general, then please do not hesitate to contact me here.
Berkshire Vet Rehab provides fully insured mobile veterinary physiotherapy services to dogs, horses and more. Services cover 15 mile radius from RG4, South East England including Berkshire, Hampshire, Surrey, Oxfordshire and more on request (additional fuel charge applicable).