Seronegative spondyloarthropathies in Radiology

2. INTRODUCTION
Seronegative spondyloarthropathies
are a group of musculoskeletal
syndromes linked by common clinical
features and common
immunopathologic mechanisms.
Negative to rheumatoid factor and
mostly involve the axial skeleton.
Most have positivity to the HLAB27
gene.

3. CLASSIFICATION
Ankylosing spondylitis
 Psoriatic arthritis
 Reactive arthritis
(Reiter syndrome)
 Enteropathic arthritis
(i.e. extra-intestinal
manifestation of IBD)

4. ANKYLOSING SPONDYLITIS
 Ankylosing spondylitis (also known as Bechterew
disease and Marie Strümpell disease) is a
spondyloarthropathy, which, as the name suggests,
results in fusion (ankylosis) of the spine and
sacroiliac (SI) joints, although involvement is also
seen in large and small joints.
 There is a male predilection of 3:1 and it usually
manifests in young adults
 The axial skeleton is predominantly affected,
although in ~20% of cases the peripheral joints are
also involved.

5. IMAGING
Sacroiliitis is usually the first
manifestation and is symmetrical and
bilateral
 The sacroiliac (SI) joints first widen before
they narrow
 Subchondral erosions, sclerosis and
proliferation on the iliac side of the SI joints
 At end-stage, the SI joint may be seen as a
thin line.

6. IMAGING(CONTINUED)
 Spine - early spondylitis is characterized by small
erosions at the corners of vertebral bodies with reactive
sclerosis: Romanus lesions of the spine (shiny corner
sign)
 Vertebral body squaring
 Diffuse syndesmophytic ankylosis can give a "bamboo
spine" appearance
 Interspinous ligament ossification can give a "dagger
spine" appearance on frontal radiographs
 Ossification of spinal ligaments, joints and discs (with
fatty marrow within the ossified disc, best seen on MRI)
 Apophyseal and costovertebral arthritis and ankylosis

7. OTHER FINDINGS
There can be bridging or fusion of the pubic
symphysis.
Knees demonstrate uniform joint space
narrowing with bony proliferation.
Hands are generally involved asymmetrically,
with smaller, shallower erosions and marginal
periostitis.
Shoulder joint involvement is not uncommon
and demonstrates a large erosion of the
anterolateral aspect of the humeral head,
producing a 'hatchet' deformity.

8. RADIOGRAPH OF THE SACRO-ILIAC JOINT
SHOWING FUSION OF THE JOINT IN A CASE OF
ANKYLOSING SPONDYLOARTHROPATHY

11. BAMBOO SPINE

12. DAGGER SIGN-DENSE LINE CAUSED BY
OSSIFICATION OF SUPRASPINOUS AND
INTERSPINOUS LIGAMENTS IN ANKYLOSING
SPONDYLITIS

15. PSORIATIC ARTHRITIS
Etiology is considered to be a
combination of environmental and
hereditary factors.
 60% of patients being HLA-B27
positive. Approx. 10%–15% of patients
with skin manifestations of psoriasis will
develop psoriatic arthritis.
Usually such manifestations will
precede the development of arthritis.

16. RADIOLOGIC FINDINGS
 The hallmarks of psoriatic arthritis are signs of
inflammatory arthritis combined with bone
proliferation, periostitis and enthesitis.
 In the hands, wrists, and feet, a distal distribution is
characteristic. Findings may be bilateral or
unilateral and symmetric or asymmetric.
 “Sausage digit” Diffuse fusiform swelling of a digit
due to involvement of several joints in a single digit.
 “Fuzzy” appearance or “whiskering” Bone
proliferation produces an irregular and indistinct
appearance to the marginal bone about the involved
joint.

17. RADIOLOGIC FINDINGS
(CONTINUED...)
 The erosions can cause a "pencil in cup" deformity
where one articular surface is eroded creating a
pointed appearance; the other articulating bone
becomes concave, resembling an upside down cup.
 “Ivory phalanx” Involvement of the distal phalanges
(especially in the first digit) in the foot with sclerosis,
enthesitis, periostitis, and soft-tissue swelling.
 Periostitis may appear as a thin periosteal layer of
new bone adjacent to the cortex, a thick irregular
layer, or irregular thickening of the cortex itself.
Joint subluxation may also be present.

18. PSORIATIC ARTHRITIS
Radiograph (PA) Hand.
Note the asymmetrical but predominantly distal
distribution. Prominent periarticular swelling (S),
uniform loss of joint space (J), marginal erosions (E),
and fluffy periostitis (P) complete the radiologic picture.

19. PENCIL IN A CUP DEFORMITY IN
PSOARIATIC ARTHRITIS

20. IVORY PHALANX IN THE GREAT TOE IN A
CASE OF PSOARIATIC ARTHRITIS

21. DIFFERENCE BETWEEN NORMAL AND
PSORIATIC ARTHRITIS IN HIP JOINT

22. REACTIVE ARTHRITIS
Also called Reiter’s syndrome, is a sterile
inflammatory arthritis. It follows enteric or
urogenital infection.
 Associated with urethritis and
conjunctivitis.80% positive for the HLA-
B27 antigen.
It is most common in young men aged 25–
35 years.
The features allowing differentiation
between reactive arthritis and psoriatic
arthritis relate to clinical history, patient
sex and age, and distribution of joint
involvement.

23. RADIOGRAPHIC FEATURES
 In appendicular skeleton, distribution may be
unilateral or bilateral and symmetric or
asymmetric. Affects feet more commonly than
hands and also in more severe form.
 Findings seen in the hands, wrists, and feet include
joint inflammation, bone proliferation, periostitis,
and enthesitis,
 Calcaneal enthesitis and spur formation occurs in
35-40%. Sausage digit and pencil-and-cup
deformities may also occur. In the feet, an ivory
phalanx may be seen.

24. RADIOGRAPHIC
FEATURES(CONTINUED…)
Axial involvement may also occur, leading to
bilateral symmetric or asymmetric sacroiliitis.
Large, comma-shaped, paravertebral
ossification may also be seen. Other peripheral
joints are less commonly involved.
Erosions & bony proliferation of the 1st to 4th
MTP Joints with subluxation. Fluffy bony
proliferation along the medial malleolus,
navicular & sesamoid bones of the 1st
metatarsal head.

25. EROSIONS AND BONE FORMATION AT THE
POSTERIOR CALCANEUS IN A CASE OF REACTIVE
ARTHRITIS

26. THE RADIOGRAPH SHOWS A PERIOSTEAL REACTION AT THE
PLANTAR FASCIA INSERTION (BLACK ARROW) AND EARLY
EROSION AT THE ACHILLES TENDON INSERTION
(WHITE ARROW) ON THE CALCANEUS

27. X RAY FOOT SHOWING THIN LAYER OF PERIOSTEAL
NEW BONE AT THE PHALANGEAL BASE AT 3RD
METATARSOPHALENGEAL JOINT AND DIMINISHED
DENSITY IN METATARSAL HEAD (ARROWHEAD)

29. ENTEROPATHIC ARTHRITIS
(EA)
 is a form of chronic, inflammatory arthritis
associated with the occurrence of an inflammatory
bowel disease (IBD), in approximately 20% of
patients of IBD .
 A least three forms of joint abnormalities are
recognised in patients with inflammatory bowel
diseases according to location :
 peripheral joint arthritis
 sacroiliitis
 spondylitis identical to Ankylosing spondylitis

30. LEAD PIPE APPEARANCE OF THE COLON (RED ARROWS).
ANKYLOSIS OF THE LEFT SACROILIAC JOINT AND
PARTIAL ANKYLOSIS ON THE RIGHT (YELLOW ARROW).

31. CT SCAN SHOWING BILATERAL SACROILIAC
JOINT ANKYLOSIS DUE TO ENTEROPATHIC
ARTHRITIS