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
5. ANKYLOSING SPONDYLITIS
Ankylosing spondylitis (AS) is a chronic, multisystem
inflammatory disorder involving primarily the
sacroiliac (SI) joints and the axial skeleton.
6. ANKYLOSING SPONDYLITIS
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.
7. Signs and symptoms:
Insidious onset of low back pain - The most
common symptom
Fatigue-- 2nd 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.
13.
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.
16.
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.
18.
19. “Dagger sign”
On AP radiographs of the lumbar spine Ossification
of the posterior interspinous ligaments produces a
dense radiopaque line.
20.
21. “Trolley-track sign”
The combination of the fused facets and
ossification of the interspinous ligaments.
22.
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.
26.
27. Bone erosions and remodelling in the antero
lateral aspect of the humerus produce a
“hatchet” appearance.
28.
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.
31.
32.
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.
36.
37.
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.
41. 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.
42. RADIOLOGIC FINDINGS
The hallmarks of psoriatic arthritis are signs of
inflammatory arthritis combined with
bone proliferation,
periostitis,
enthesitis.
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.
45.
46.
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.
49. “Ivory phalanx”
Involvement of the distal phalanges (especially in
the first digit) in the foot with sclerosis, enthesitis,
periostitis, and soft-tissue swelling.
50.
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.
54.
55. Case 3. 30 yr old male with symptoms of urethritis.
56. REACTIVE ARTHRITIS
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.
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.
62.
63. Erosions & bony proliferation of the 1st to 4th MTP J with subluxation.
Fluffy bony proliferation along the medial malleolus, navicular &
sesamoid bones of the 1st 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.
Stiffness of the spine and kyphosis resulting in a stooped posture are characteristic of advanced-stage AS.
Constitutional and organ-specific extra-articular manifestations.
Ankylosing spondylitis. Lateral lumbar spine radiograph shows squaring of anterior magins of vertebrae with a shiny sclerotic inferior end—shiny corner sign.
Ankylosing spondylitis. Anteroposterior pelvis radiograph shows bilateral diffuse joint space narrowing and bone erosions of each hip joint (arrowheads), with sacroiliac joint fusion (arrows).
Bilateral sacroiliitis. Axial CT scan shows erosions and iliac side subchondral sclerosis of both sacroiliac joints.
Psoriatic arthritis. Posteroanterior finger radiograph shows narrowing of distal interphalangeal joint.bone proliferation and periostitis throughout phalanges with partial incorporation of new bone into the cortex & soft-tissue swelling of entire digit
Psoriatic arthritis. Posteroanterior finger radiograph shows marginal bone erosions with adjacent irregular bone proliferation.
Psoriatic arthritis. Anteroposterior radiograph and bone proliferation of distal phalanx (ivory phalanx) of the first digit, with soft-tissue swelling. shows increased density
comma-shaped paravertebral ossifications
Reactive arthritis. Lateral radiograph of calcaneus shows bone sclerosis and irregular inflammatory enthesopathy (arrow)
Reactive arthritis. Anteroposterior radiograph of big toe shows bone sclerosis, marginal bone erosions, and bone proliferation about interphalangeal joint and distal phalanx, with soft-tissue swelling.