Facet joint tropism

Case contributed by Dr Heba Mohamed


Low back pain

Patient Data

Age: 35 years
Gender: Male
Modality: CT

Abnormal orientation of L5-S1 right Facet joint with the joint has a more sagittal orientation (almost parallel) if compared to the left one. Right facet joint grade II facet arthropathy is noted as well.

Annotated image with the reference plane at the posterior edge of the vertebral body. The sagittal plane along the spinous process, Right angle to the reference plane.  Right facet orientation is defined with the brown line and left facet joint orientation id defined with the pink one.


Case Discussion

Facet orientation is the angle that lies between both transverse and sagittal planes. Facet joint tropism may easily predispose to facet joint arthropathy.

Grading of facet joint arthropathy:

  • Grade I (Normal): Normal joint space.
  • Grade II (Mild): narrowed joint space 1–2 mm. Small osteophytes, No sclerosis, subchondral erosions or subchondral cysts. No air within the joint space.
  • Grade III (Moderate): narrow joint space ≤1 mm); moderate osteophytes. Mild subchondral erosion with subchondral cystic changes. Moderate air within the joint space is seen.
  • Grade IV (Severe): joint space is no longer see. Marked osteophytes with severe subchondral erosions and cystic changes.
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Case Information

rID: 52399
Case created: 6th Apr 2017
Last edited: 11th Apr 2017
System: Spine
Inclusion in quiz mode: Excluded

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