facet_joint_pathology

Table of Contents

Facet Joint Pathology

Facet joints (zygapophyseal joints) are paired synovial joints located between the articular processes of adjacent vertebrae. They are critical for spinal stability and motion but are also a common source of axial pain.

Types of Facet Joint Pathology

Facet Joint Arthropathy (Degenerative)
- Most common type
- Features: cartilage loss, osteophyte formation, joint space narrowing, subchondral sclerosis

Facet Joint Syndrome
- Clinical diagnosis of pain originating from facet joints
- Confirmed by medial branch blocks or intra-articular injections

Facet Joint Effusion
- Fluid in the joint seen on MRI
- Often associated with acute pain

Facet Cyst
- Synovial cysts from degenerated joints
- May cause radiculopathy or spinal stenosis

Facet Joint Hypertrophy
- Bone overgrowth contributing to foraminal or central stenosis

Facet Fracture or Dislocation
- Usually post-traumatic
- Can result in instability or neurologic compromise

Diagnostic Tools

Modality	Role
MRI	Detects joint effusion, inflammation, adjacent edema
CT	Superior for bony changes: sclerosis, osteophytes
SPECT/CT	Detects increased metabolic activity; identifies active pain generators
Medial Branch Block	Diagnostic and therapeutic; confirms facetogenic pain

Imaging Clues (MRI)

T2 hyperintensity within joint (effusion)
Joint irregularity, narrowing
Edema in adjacent bone

Treatment Options

Conservative
- NSAIDs
- Physical therapy
- Postural training

Interventional
- Intra-articular steroid injections
- Medial branch nerve blocks
- Radiofrequency ablation (RFA) of medial branches

Surgical
- Indicated in instability or refractory pain
- Options: joint resection, spinal fusion

Clinical Notes

Pain is typically axial, worsened by extension/rotation
Often no clear correlation with MRI alone
SPECT/CT may reveal metabolically active joints not seen on MRI