imaging and intervention of sacroiliac joint
TRANSCRIPT
Imaging and intervention of
sacroiliac joint
Dr Ryan Lee Ka Lok
Associate Consultant
Prince of Wales Hospital
Introduction
• 15%-25% of low back pain is related to
sacroiliac joint (SIJ) pain
• SIJ pain is usually under-diagnosed
clinically
Sacroiliac joint
Anterior : Synovial joint
Posterior : ligamentous connection
Ant
Post
Sup
Inf
Sacroiliac joint
Iliac side
AntPost
Sacral side
Ant Post
Imaging modalities
• XR
• USG
• CT
• NM – Bone scan
• MRI
MRI
Oblique coronal Oblique axial
Sagittal planning
Oblique axial
Oblique coronal
True axial
True coronal
SIJ pathology
1. Inflammatory sacroiliitis
2. Infective sacroiliitis
3. Osteoarthrosis
4. Stress reaction/insufficiency fracture
5. Osteitis condensan ilii
6. Others : tumour
Rheumatic
Non-Rheumatic
Sacroiliitis on
imaging Plus
>1 SpA feature
HLA-B27 plus
>2 other SpA featuresor
Sacroiliitis on imaging:• Active(acute) inflammation on MRI highly suggestive of
sacroiliitis associated with SpAor
• Definite radiographic sacroiliitis according to modified New York
criteria
Assessment in SpondyloArthritis international society (ASAS) classification
criteria for axial spondyloarthritis (SpA) 2009
1. Inflammatory sacroiliitis
A. Active (acute) sacroiliitis
• Bone marrow edema (BME)/osteitis
• Capsulitis
• Enthesitis
• Synovitis
Bone marrow edema / osteitis
Bone marrow edema /
Osteitis
T2W STIR
T2W STIR Contrast T1W FS
Contrast T1W FS
? Bone marrow edema / osteitis
T2W STIR Contrast T1W FS
Bone marrow edema/osteitis
At least one signal on
consecutive slice
Bone marrow edema/osteitis
Or more than one signal on single slice
Capsulitis
Posterior capsulitisAnterior capsulitis
Enthesitis
T2W STIR Contrast T1W FS
Enthesitis
Synovitis
B. Definite radiographic sacroiliitis
• According to modified New York Criteria
Subchondral sclerosis
Subchondral periarticular erosion
Periarticular fat deposition
Bony bridges / ankylosis
Grade Radiographic findings
0 Abnormalities are present
1 Suspicious areas are noted
2 Minor erosions
3 Unequivocal abnormalities in the joint
4 Severe change in the joint
Low back pain for at least 3 months improved by exercise and not relieved by rest
Limitation of lumbar spine in sagittal and frontal planes
Reduced chest expansion relative to normal values for age and sex
Bilateral sacroiliitis grades 2-4
Unilateral sacroiliitis grades 3-4
Modified New York criteria for the classification of ankylosing spondylitis
Radiographic
sacroiliitis +
one clinical
symptoms
= AS
Subchondral sclerosis
T1W
Subchondral periarticular
erosion
Pseudo-wideningErosion
Peri-articular fatty infiltration
T1W T2W STIR
T1W
Bony bridges / Ankylosis
Radiograph
Subchondral sclerosis and erosion Ankylosis
Radiographic involvement of sacroiliac joints in different conditions
Bilateral, symmetric Bilateral,
asymmetric
Unilateral
Ankylosing spondylitis
Juvenile
spondyloarthropathy (SpA)
Osteitis condensus ilii
Psoriatic
arthropathy
IBD-associated SpA
Reactive
arthropathy
Undifferentiated
SpA
Infection (including TB)
Malignancy
2. Infective
sacroiliitis
Joint fluid
Iliacus muscle involvement Gluteal muscle involvement
Infective sacroiliitis
Iliacus and gluteal muscle
involvement
Infective sacroiliitis
Abscess
T2W STIR Contrast T1W FS
TB sacroiliitis
Infective or inflammatory sacroiliitis ?
3. Osteoarthritis
Osteoarthritis
4a. Stress reaction
4b. Stress fracture
Honda sign
4c. Insufficiency fracture
4d. Stress related
5. Osteitis
condensans ilii
Osteitis
condensans ilii
Image guided intervention
• CT guided biopsy/aspiration
• CT guided injection
• USG guided injection
• Floroscopic guided injection
CT guided aspiration
Joint fluid
CT guided biopsy
Bone
CT guided pig tail insertion
Needle Guidewire
Dilator Pigtail
CT guided injection
CT guided injection
Ultrasound guided injection
2nd sacral foramen
Floroscopic guided
Take Home Message
• MRI is imaging of choice to diagnosis
different SIJ pathology
• CT is useful for SIJ related diagnostic
and therapeutic intervention
End
Thank You