Facet joints connect vertebrae between the different sections of your spine. Wherever they become damaged or inflamed, they can cause back pain with or without referred pain into the limbs. A facet joint has articular cartilage, which can be damaged by injury and other processes. In this way, facet joint injuries most commonly occur in association with trauma, particularly falls and car accidents.
The lumbar spine vertebrae are joined at either side by a disc, and the arches of the vertebrae are joined by facet joints on each side. The lowest two facet joints, are the most common source of facet joint pain. They can produce back, leg and buttock pain which can travel down the leg as far as the foot. In the lumbar spine, the facet joint can also become painful if it is required to take more of the body’s load. This will generally occur if the disc has degenerated or is overloaded. For this reason, the elderly and those who are overweight generally suffer from facet joint pain more often.
The cervical spine consists vertebrae that connect the head with the neck. The facet joints associated with the cervical spine are very different from the other joints in the spine; they are less accessible, and have quite different nerve supplies to all the other facet joints. Pain resulting from cervical spine facet joints is most commonly felt in the neck and shoulders and can include headaches.
It’s very important to know that diagnosis cannot be made by a clinician without the resources to conduct special tests. Symptoms such as pain when sitting or rising from a sitting position can occur due to other structures, such as the disc, and don’t necessarily denote facet joint issues.
Diagnosis is complicated because x-rays, CT scans, bone scans and MRIs cannot establish whether or not a facet joint is the source of pain. The only test that provides some certainty involves the use of an x-ray controlled injection of anaesthetic either into the joint itself or onto the nerve supply of the joint. Whether or not this injection is effective can indicate whether the pain is facet joint related or not. Yet, this is only effective if your pain is consistent. If your pain has the tendency to subside by itself, the injection can create a ‘false positive’ result.
The pain sometimes goes down my leg – how does that come from the back?
Facet joint pain can present as an acute attack, or, in more chronic cases, can build up over time. The pain associated with the acute attacks will generally dissappear quickly. However, those with more chronic facet joint pain may continue to experience pain over an extended period. It is not always possible for your doctor to confidently predict what will happen in the long term. However, history suggests that in most cases total recovery is possible.
Facet joints are notoriously difficult to prevent. However, evidence and common sense suggest the following to be good practice:
Once I have had a facet joint injury will it always be a problem?
Not necessarily. Facet joint pain can fully resolve and heal. However, once you have had a first attack of low back pain, your body changes the way it supports the spine. You may then be more susceptible to other types of low back pain. This is due to the fact that your body has lost its protective mechanisms for the spine. Physical therapists can train you to rehabilitate your muscular system to protect your spine.
Do I need to get a scan to show my facet joint injury?
X-rays and CT Scans may be useful for facet joint. However, the majority of facet joint injuries resolve quickly without the need for scans. In an acute situation, a diagnosis is made purely on clinical presentation. However, in the chronic situation, more involved tests are required to make the diagnosis. The decision to have scans is one that you and your general practitioner and/or specialist will make, depending upon circumstance. The use of SPECT nuclear medicine scans and MRI for facet joint pain is over-rated because of the high false-positive rates (i.e. an abnormality is seen but it is not the cause of the problem).
Should I use medication?
If you present with acute pain, your doctor may wish to organise some medication to alleviate the pain, inflammation and/or muscle spasm. These can be required for up to a week. If pain persists past that, a review of the diagnosis and medication may be required. Your doctor should be involved in any decision regarding the use of medication as it will vary depending upon individual circumstances.
Is there any proven treatment?
The only treatment proven to work for facet joint pain is radiofrequency heat lesioning of the nerve supply to the joint. Unlike the hip, knee and shoulder joints, there is so far no joint replacement available. Regenerative therapies may play a role, but these have yet to be tested.