Facet Joint Arthropathy
Facet joint arthropathy is a degenerative condition affecting the zygapophyseal (facet) joints of the spine, often contributing to chronic axial pain, especially in the cervical and lumbar regions.
Pathophysiology
Facet joints are synovial joints prone to wear and tear due to repetitive mechanical stress and age-related degeneration. Arthropathy involves:
- Cartilage degeneration
- Subchondral bone sclerosis
- Osteophyte formation
- Joint space narrowing
- Synovial inflammation
These changes lead to nociceptive pain from the richly innervated joint capsule and surrounding structures.
Clinical Presentation
- Axial pain (neck or low back)
- Worse with extension, rotation, prolonged standing
- May mimic radiculopathy but without dermatomal distribution
- Pain often improves with flexion or sitting
Diagnosis
Clinical Exam
- Localized paraspinal tenderness
- Pain reproduced with extension/rotation
Imaging
| Modality | Findings |
|---|---|
| MRI | Joint effusion, osteoarthritis signs, adjacent edema |
| CT | Bone detail: osteophytes, sclerosis, hypertrophy |
| SPECT/CT | Identifies metabolically active (painful) joints |
Diagnostic Injections
- Medial branch block (MBB) – anesthetic near the medial branch nerves
- Intra-articular injection – direct steroid/anesthetic into the facet joint
- Positive response supports diagnosis
Management
Conservative
- NSAIDs
- Physical therapy (core strengthening, posture)
- Activity modification
Interventional
- MBB (diagnostic and therapeutic)
- Intra-articular steroid injection
- Radiofrequency ablation (RFA) – long-lasting denervation of medial branches
Surgical
- Rarely needed
- Consider facet resection or spinal fusion in unstable or refractory cases
Key Points
- Common source of axial spinal pain in adults
- Often underdiagnosed; imaging alone may be insufficient
- SPECT/CT can identify active facet joint involvement
- RFA provides long-term relief in selected patients