lumbar facet joint degenerative arthropathy

Introduction

lumbar facet joint degenerative arthropathy is a common cause of low back pain increasing in prevalence with age
these joints support 20% of the upper body weight and thus tend to degenerate earlier than other joints leading to chronic low back pain which worsens as you age
facet joint pain accounts for up to half of all older adult chronic low back pains

lumbar disc disease - reduction in disc height results in increased weights placed upon the facet joints and increasing wear
overuse injury - repetitive twisting
poor posture
obesity
in addition the facet joints can be involved in other arthritic conditions such as ankylosing spondylitis (AS), rheumatoid arthritis, psoriasis, spondyloarthropathies

midline lumbar back pain which may radiate to buttocks, groin and/or thighs but not below knees (this would suggest sciatica)
often worse in the morning with morning stiffness or stiffness after rest
pain usually worse during spinal extension (bending backward) or twisting, and often improves when leaning forward
may have focal tenderness
may cause narrowing of neural foramina outlets causing sciatica and may cause spinal stenosis

CT scan or MRI
medial branch block (MBB):
- diagnostic local anaesthetic injection to temporarily block the medial branch nerve may confirm source of pain

patient should expect that the pain is likely to gradually get worse over time and the degeneration cannot be reversed with current therapies
usually conservative
- simple analgesics
- non-steroidal anti-inflammatory drugs (NSAIDs)
- consider neuropathic pain modulators such as tricyclics
- reduce load on facet joints:
  - avoid slouching or over-extending the back
  - weight reduction if obese
  - strengthen core muscles
  - posture aids / supportive chairs
steroid injections may help in short term
medial branch nerve destruction:
- usually indicated only if MBB provides substantial pain relief
- may require multiple vertebral levels
- radiofrequency ablation of nerves may provide “window” of pain relief of 6 to 18 months
  - minimally invasive
  - the period of relative pain relief should be utilised as a time to build muscle strength to reduce risk of recurrence:
    - intensive physical therapy to strengthen muscles - particularly core muscles, hip mobility, and posterior chain strengthening
    - low impact exercise such as walking or swimming
    - weight loss if abdominal obesity
- cryotherapy to freeze the facet nerves
- chemical neurolysis to destroy the nerves
surgical
- usually is a last resort
- will result in reduced mobility which may in itself cause ongoing pains
- has mixed results for pure facet joint pain
- may be indicated for those with structural instability or severe deformity
- eg. spinal fusion or laminectomy