Seronegative spondyloarthropathies

radiology

1. SERONEGATIVE SPONDYLO
ARTHROPATHIES

2. 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. Five subgroups of spondyloarthritis:
Ankylosing spondylitis
Psoriatic arthritis
Reactive arthritis (Reiter syndrome)
Enteropathic arthritis (i.e. extra-intestinal
manifestation of IBD)
Undifferentiated spondyloarthritis

4. Case 1. 27 yr old male with low backache

5. Ankylosing spondylitis (AS) is a chronic, multisystem
inflammatory disorder involving primarily the
sacroiliac (SI) joints and the axial skeleton.
ANKYLOSING SPONDYLITIS

6. 96% of patients are HLA-B27 positive .
Men:women 3:1
Age of onset typically between 20 and 40 years.
More commonly involves the axial skeleton,
although peripheral joints may also be affected.
ANKYLOSING SPONDYLITIS

7. Signs and symptoms:
Insidious onset of low back pain - The most
common symptom
Fatigue-- 2
nd
most common symptom.
Presence of symptoms for more than 3 months.
Symptoms worse in the morning or with inactivity.

8. Extra-articular manifestations of AS can include the
following:
Uveitis
Cardiovascular disease
Pulmonary disease
Renal disease
Neurologic disease
Gastrointestinal (GI) disease

9. RADIOLOGIC FINDINGS:
The diagnosis of AS is generally made by
combining the clinical criteria of inflammatory back
pain and enthesitis or arthritis with radiologic
findings.

10. Plain Radiography:
Sacroiliac involvement is typically bilateral and
symmetric.
Spine involvement is often centered at the
thoracolumbar or lumbosacral junction.

11. Spine involvement is characterized by
osteitis,
 syndesmophyte formation,
facet inflammation, and eventual
facet joint and vertebral body fusion.

12. Initially, there is indistinctness and discontinuity of
the thin white subchondral bone plate.
Progresses to gross bone erosions.
adjacent bone is often sclerotic and joint space
narrowing and bone fusion eventually occur.

14. “Squaring of the vertebral bodies”
 One of the early radiographic signs of enthesitis.
caused by erosions of the superior and inferior
margins of vertebral bodies, resulting in loss of the
normal concave contour of the anterior surface.

15. “Shiny corner sign (Romanus lesion)”
The inflammatory lesions at vertebral entheses may
result in sclerosis of the superior and inferior margins
of the vertebral bodies.

17. “ Bamboo spine” 
Thin and slender syndesmophytes are generally
evident, representing ossification of the outer layer
of the annulus fibrosis.
On AP lumbar spine radiographs the
syndesmophytes thicken,become continuous giving
knobbly appearance.

19. “Dagger sign”
On AP radiographs of the lumbar spine Ossification
of the posterior interspinous ligaments produces a
dense radiopaque line.

21. “Trolley-track sign”
The combination of the fused facets and
ossification of the interspinous ligaments.

23. Facet joint inflammation leads to indistinctness
and narrowing of the involved joint progressing to
fusion.
Disk calcification may also occur, possibly due to
relative immobilization of the vertebral column.

24. “Andersson lesion”
Localised destructive lesion of vertebral end plates
with disc narrowing and marked reactive sclerosis.

25.  Hip involvement is usually bilateral in distribution.
Uniform joint space loss
acetabular protrusion,
subchondral cysts, and
a rim of osteophytes about the femoral neck.

27. Bone erosions and remodelling in the antero
lateral aspect of the humerus produce a
“hatchet” appearance.

29. Computer Tomography:
may be useful in selected patients with normal or
equivocal findings on sacroiliac joint radiographs.
joint erosions, subchondral sclerosis, and bony
ankylosis are better visualised on CT.
supplements scintigraphy in evaluating areas of
increased uptake.

30. superior to radiographs and MRI in demonstrating
injuries.
imaging modality of choice in patients with
advanced disease having suspicion of spine
fracture.

33. MRI
when radiographs are normal or equivocal, MRI
can be useful in the diagnosis of sacroiliitis by
showing joint fluid and marrow edema.

34. MRI
superior to CT in detection of cartilage, bone
erosions, and subchondral bone changes.
useful in follow up of active disease.
synovial enhancement on MR correlates with
disease activity measured by inflammatory
mediators.

35. enhancement of the interspinuous ligaments is
indicative of an enthesitis.
Decreased T1,increased T2 signal & enhancement
on post contrast sequences correlate with edema
or vascularized fibrous tissue.

38. Sagittal T1, T2 fat-sat & contrast-enhanced T1 images of the
lumbar spine show signal alterations in anterosuperior corner of L4
and L5 vertebrae.
Axial T2-fat-sat MR image passing through L5 body confirms the
corner lesion & the corresponding axial CT scan demonstrates the
corner erosion of vertebral endplate surrounded by
spongiosclerosis.

39. BONE SCAN
may be helpful in selected patients with normal or
equivocal findings.
quantitative analysis is more useful.
ratios of SI joint to sacral uptake of 1.4:1 or higher is
abnormal.

40. Case 2. 20 yr old female with red scaly rash.

41. 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.
Psoriatic arthritis

42. The hallmarks of psoriatic arthritis are signs of
inflammatory arthritis combined with
 bone proliferation,
periostitis,
enthesitis.
RADIOLOGIC FINDINGS

43. In the hands, wrists, and feet, a distal distribution is
characteristic.
 Findings may be bilateral or unilateral and
symmetric or asymmetric.

44. “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.

47. “Pencil and cup”
 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.

48. Pencil and cup

49. “Ivory phalanx”
Involvement of the distal phalanges (especially in
the first digit) in the foot with sclerosis, enthesitis,
periostitis, and soft-tissue swelling.

51. Periostitis
It 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.

52. Sacroiliac joint involvement is usually bilateral,
either symmetric or asymmetric in distribution.
SI joints will show signs of inflammation with an
indistinct subchondral bone plate or osseous
erosions,
joint space irregularity & mild widening,
eventual joint space narrowing & fusion.

53.  The thoracolumbar spine may show large
comma-shaped paravertebral ossifications.
The facet joints are relatively spared, and there is
absence of vertebral body squaring.
Other sites of joint involvement include the knees ,
elbows, ankles, and joints about the shoulders.

55. Case 3. 30 yr old male with symptoms of urethritis.

56.  Also called Reiter’s syndrome, is a sterile
inflammatory arthritis.
follows enteric or urogenital infection.
 Associated with urethritis and conjunctivitis.
 80% seropositive for the HLA-B27 antigen.
most common in young men aged 25–35 years.
REACTIVE ARTHRITIS

57.  The features allowing differentiation between
reactive arthritis and psoriatic arthritis relate to

clinical history,
patient sex and age, and
distribution of joint involvement.

58. Radiographic features:
In appendicular skeleton distribution may be
unilateral or bilateral and symmetric or asymmetric.
Affects feet more commonly than hand and also in
more severe form.

59. Findings seen in the hands, wrists, and feet include

joint inflammation,

bone proliferation,
periostitis, and
enthesitis,

60. 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.

61. 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.

63. Erosions & bony proliferation of the 1
st
to 4
th
MTP J with subluxation.
Fluffy bony proliferation along the medial malleolus, navicular &
sesamoid bones of the 1
st
metatarsal head.
Ill-defined plantar calcaneal enthesophytes, periosteal reaction
along the posterior aspect of the distal tibia , retrocalcaneal bursitis &
thickening of the Achilles tendon ,& erosions at the subjacent
calcaneus.

65. THANK YOU