Facet Joint Arthrosis – Causes, Symptoms, Treatment - Health

Facet joint arthrosis is a pathological process involving the failure of the synovial facet joints.[rx] Degenerative changes begin with cartilage degradation, leading to the formation of erosions and joint space narrowing, and eventually sclerosis of subchondral bone. Risk factors include advanced age, a sagittal orientation of the facet joints, and concomitant intervertebral disk degeneration.[rx]

The lumbar zygapophysial joint, otherwise known as facet joints, is a common generator of lower back pain. The facet joint is formed via the posterolateral articulation connecting the inferior articular process of a given vertebra with the superior articular process of the below adjacent vertebra. The facet joint is a true synovial joint, containing a synovial membrane, hyaline cartilage surfaces, and surrounded by a fibrous joint capsule.[rx] There is a meniscoid structure formed within the intra-articular folds. The facet joint is dually innervated by the medial branches arising from the posterior ramus at the same level and one level above the joint.

The facet joints play an important role in load transmission, assisting in posterior load-bearing, stabilizing the spine in flexion and extension, and restricting excessive axial rotation. Studies before and after facetectomy have shown that the facet joint may support up to 25% of axial compressive forces and 40% to 65% of rotational and shear forces on the lumbar spine.[rx][rx][rx]

Causes of Facet Joint Arthrosis

Facet joint arthrosis is a degenerative syndrome that typically occurs secondary to age, obesity, poor body mechanics, repetitive overuse and microtrauma. Numerous studies have linked facet joint degeneration to degeneration of intervertebral disks, showing that intervertebral disk degeneration likely occurs before facet joint arthrosis.[rx] One explanation for these findings is the increased mechanical changes in the loading of the facet joints following intervertebral disk degeneration. Other studies have demonstrated an increased propensity for facet joint degeneration with a more sagittal orientation of the facet joint.[rx]

Degenerative changes involving the facet joint begin with hyaline cartilage degradation, leading to the formation of erosions and joint space narrowing, and eventually sclerosis of subchondral bone. Studies have shown that over time the posterior capsule of the degenerative joint capsule becomes hypertrophied, with fibrocartilage proliferation and possibly synovial cyst formation. Osteophytes are likely to arise at the attachment sites (entheses) where the fibrocartilage extends beyond the original joint space.[rx] Facet mediated pain occurs secondary to these arthritic changes, as there is rich innervation of the entire joint complex. Other theories behind facet-mediated pain include, but are not limited to, facet intraarticular meniscoid entrapment and synovial impingement.

Symptoms of Facet Joint Arthrosis

Depending on the number of facets affected, the severity of the condition, and the possible involvement of a nearby nerve root, one or more of the following signs and symptoms may occur:

Localized pain – A dull ache is typically present in the lower back.
Referred pain – The pain may be referred to as the buttocks, hips, thighs, or knees, rarely extending below the knee. Pain may also be referred to as the abdomen and/or pelvis. This type of pain is usually caused by facet arthritis and is experienced as a distinct discomfort, typically characterized by a dull ache.
Radiating pain – If a spinal nerve is irritated or compressed at the facet joint (such as from a facet bone spur), a sharp, shooting pain (sciatica) may radiate into the buttock, thigh, leg, and/or foot. Muscle weakness and fatigue may also occur in the affected leg.
Tenderness on palpation – The pain may become more pronounced when the area over the affected facet in the lower back is gently pressed.
Effect of posture and activity – The pain is usually worse in the morning, after long periods of inactivity, after heavy exercise, and/or while rotating or bending the spine backward. Prolonged sitting, such as driving a car, may also worsen the pain. The pain may be relieved while bending forward.
Stiffness – If the lumbar facet pain is due to arthritic conditions, stiffness may be present in the joint, typically felt more in the mornings or after a period of long rest, and is usually relieved after resuming physical activity.
Crepitus – Arthritic changes in the facets may cause a feeling of grinding or grating in the joints upon movement.

Diagnosis of Facet Joint Arthrosis

Patient history – The doctor reviews the patient’s main complaints and asks about the onset of pain; duration and types of signs and symptoms; concomitant medical conditions; and drug and/or surgical history.

Medical exam – The doctor may gently palpate (feel) the lower back to check for tender spots and muscle reflex activity in the legs to rule out possible nerve dysfunction. A medical exam may include some combination of the following tests:

Visual inspection – of the overall posture and skin overlying the affected area
Hands-on inspection – by palpating for tender areas and muscle spasm
Range of motion tests – to check mobility and alignment of the involved joints
Segmental examination – to check each spinal segment for proper motion
Neurological examination – including tests of muscle strength, skin sensation, and reflexes.

If clinical diagnosis of lumbar facet joint pain is suspected, first-line treatment options, such as medication, physical therapy, and spinal manipulation, may be advised. In general, diagnostic imaging and/or injection tests are not needed to treat and help resolve an episode of pain. If the first-line treatments are unsuccessful, then imaging and possibly injections may be recommended.

Treatment of Facet Joint Arthrosis

Nonsurgical Treatments

Several at-home and medical treatments are available to alleviate the pain that originates in the lower back facet joints. Treatments that may be performed at home to relieve lumbar facet pain include:

Applying heat therapy – Heat therapy can help relax the muscles and open up blood vessels to allow blood flow and oxygen to reach the painful tissues, providing nourishment. Using a heat patch or hot water bag in the morning after waking may help ease the morning pain and stiffness. Heat therapy may also be used intermittently throughout the day to keep the tissues relaxed.
Using a cold pack – Cold therapy may be used when the pain is acute or during a pain flare-up, such as after strenuous physical activity. A cold pack constricts the blood vessels, reducing blood flow to the region and numbing the pain.
Supporting the lumbar curve – It is important to maintain the natural spinal alignment by using correct sitting, standing, and/or lying down posture. A good posture helps keep stresses off the facet joints and foster a better healing environment.
Avoiding activities that worsen the pain – In general, activities that include spinal twisting, repeated bending and extending, and sitting for long periods of time must be avoided. Bending the spine backward may cause more strain on the affected joint(s) and must be avoided to prevent further damage.
Staying active – While avoiding certain activities is recommended, it is also necessary to stay active in moderation and avoid complete bed rest, which may decondition the lumbar tissues and increase the pain.
Engaging in low-impact exercises – Following an exercise routine that involves simple, low-impact exercises, such as walking, may be beneficial when done within tolerable limits for short distances. Regular short walks can help avoid pain and stiffness from prolonged inactivity and also improve strength and flexibility in the lower back.
Using a supportive brace – While bracing is not common in treating benign facet pain, a brace may occasionally be used for non-threatening facet instability, such as a subluxation, to help limit spinal motion and promote healing.

Medication

Nonoperative management includes oral medications such as NSAIDs, acetaminophen, and oral steroids during acute flares. Additionally, weight loss and physical therapy have demonstrated successful outcomes. [rx]

Muscle relaxants – and some antidepressants may be prescribed for some types of chronic back pain.
Non-steroidal anti-inflammatory drugs (NSAIDs) – are typically tried first. NSAIDs have been shown to be more effective than placebo, and are usually more effective than paracetamol (acetaminophen).
In severe back pain not relieved by NSAIDs – or acetaminophen, opioids may be used. However, long-term use of opioids has not been proven to be effective at treating back pain. Opioids have not always been shown to be better than placebo for chronic back pain when the risks and benefits are considered.
Skeletal muscle relaxers – may also be used. Their short term use has been shown to be effective in the relief of acute back pain. However, the evidence of this effect has been disputed, and these medications do have negative side-effects.
In people with nerve root pain and acute radiculopathy – there is evidence that a single dose of steroids, such as dexamethasone, may provide pain relief.
Epidural corticosteroid injection – (ESI) is a procedure in which steroid medications are injected into the epidural space. The steroid medications reduce inflammation and thus decrease pain and improve function. ESI has long been used to both diagnose and treat back pain, although recent studies have shown a lack of efficacy in treating low back pain.
Carisoprodol – This muscle relaxant was investigated in two high-quality studies on acute low back pain. The first study compared carisoprodol with diazepam [rx]. Carisoprodol was superior in performance on all the outcome parameters measured. A comparison of carisoprodol with cyclobenzaprine‐hydrochloride in the second study revealed no statistically significant differences between the two treatments [rx].
Chlorzoxazone – This muscle relaxant was compared with tizanidine in one high-quality study in a very small sample of patients with degenerative lumbar disc disease [rx]. No differences were found between the treatments.
Cyclobenzaprine‐hydrochloride – Cyclobenzaprine was compared with diazepam in a low-quality trial on chronic low back pain, but no significant differences between the treatments were identified [rx]. There was also no significant difference between cyclobenzaprine and carisoprodol in one high-quality study on acute low back pain [rx].
Diazepam – In comparison with carisoprodol, diazepam was found to be inferior in performance on muscle spasm, global efficacy, and functional status in a high-quality trial on acute low back pain [rx]. In a very small high-quality trial (30 people) comparing diazepam with tizanidine, there were no differences in pain, functional status, and muscle spasm after seven days [rx].
Tizanidine – This muscle relaxant was compared with chlorzoxazone and diazepam in two very small high quality [rx]. Both trials did not find any differences in pain, functional status, and muscle spasm after 7 days.
Pridinol mesylate – One low-quality trial showed no differences between this muscle relaxant and thiocolchicoside on pain relief and global efficacy.

Surgical Treatment

Indications for surgical intervention include:
- Symptoms refractory to nonoperative modalities (e.g. 3 to 6-month trial)
- Large associated synovial facet cyst correlating with clinical exam and presentation
  - Laminectomy with decompression is the classic first-line treatment for symptomatic, intraspinal synovial cysts
  - The literature also supports the utilization of facetectomy, decompression, and instrumented fusion (as opposed to a simple “lami decompression”)

Minimally invasive techniques

Other management modalities include facet injections, radiofrequency denervation of the medial branch nerves. [rx][rx]

Rehabilitation

Physical therapy – Almost all treatment programs for facet joint disorders involve some type of structured physical therapy and exercise routine, which is formulated by a medical professional with training in musculoskeletal and spinal pain. Physical therapy typically includes a combination of manual therapy, low impact aerobic exercise, strengthening, and stretching. Over time, this treatment is useful in improving and maintaining the stability of the lower back and fostering a healing environment for the tissues. When exercises are performed as directed, long-term pain relief may be experienced.

TENS therapy – TENS therapy involves activating sensory nerve fibers through a tolerable frequency of the electric current. The electric current is delivered through electrodes placed on the skin and attached to a TENS unit. TENS therapy may reduce facet joint pain by the production of endorphins—a hormone secreted by the body that reduces pain. This treatment is usually safe and can be done at home. However, there is limited scientific evidence supporting this treatment. A TENS unit can be purchased online or at a drug store.

Injection therapy – Treatment injections contain numbing medications that work on the nerves around the facet joint, reducing their ability to carry pain signals to the brain. Injections also contain steroids, which decrease the inflammatory reactions in the facet joint, reducing the pain.

Common injection techniques that help target facet joint pain, include:

Facet joint injections – These injections treat pain stemming from a specific facet joint. The injection is typically delivered into the capsule that surrounds the facet.
Medial branch blocks – These nerve block injections deposit medication around the medial branches (pain transmitting branches) of spinal nerves.
Radiofrequency ablation (RFA) – This injection treatment relieves pain by inducing a heat lesion on the pain-transmitting nerve near the facet. The lesion prevents the nerve from sending pain signals to the brain. An RFA is usually considered when an accurate diagnosis of facet joint pain is made through the diagnostic double block injection technique.
Shockwave therapy – helps to break down the scar tissue that can build up around the facet joints, allowing increased blood flow into the area, boosting overall healing and help to improve movement in stiff areas. As movement tends to improve hydration of the joints, shockwave therapy helps the production of joint fluid called synovial fluid, aiming to reduce the wear and tear between the cartilage surfaces of the facet joints.
Spinal remodeling and rehabilitative exercises – can also help by correcting the posture; an incorrect posture can put pressure on certain areas of the spine, which can potentially worsen the condition.

Spinal injections are almost always performed under the guidance of fluoroscopy (live x-ray) or ultrasound. A contrast dye is injected into the tissues to make sure the needle is accurately placed at the suspected site of pain. Medical imaging helps prevent injury and further complications that may be caused by injecting into adjacent structures, such as blood vessels.

Therapeutic injections using fluoroscopic guidance may not be given during pregnancy or when an infection or bleeding disorder is present. A small risk of bleeding, infection, allergic reaction, or permanent nerve or spinal cord damage.

A combination of one or more treatments is usually tried to control the symptoms of facet joint disorders. For the vast majority of patients, a combination of lifestyle changes, medication, physical therapy and exercise, and posture correction will help control the pain. If the pain and/or neurologic signs and symptoms, such as numbness or weakness, continue to progress, a surgical consultation may be recommended.

References

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