Arthritis pdf - Dr.Kareem

MSK Series

Tikrit University
College of Medicine
Department of Radiology

Arthritis

Affect bones on both sides of the joint space
due to cartilage destructing evident on
radiographs by joint space narrowing.

Approach to an Image



Soft tissues

: effusions, calcification, masses



Mineralization

: diffuse demineralization, periarticular

demineralization



Joint space

narrowing and subchondral bone sclerosis,

intraarticular bodies, ankylosis



Erosions

: central (articular surface), marginal (bare area),

periarticular.



Proliferation

: osteophytes, periostitis



Deformity

: varus/valgus, flexion/extension, subluxation,

dislocation, collapse



Distribution

: monoarticular, pauciarticular, polyarticular,

symmetric/asymmetric

Arthritis can be divided into:

• Degenerative (osteoarthritis)

– Primary : idiopathic, seen in aging
– Secondary: arthritis in adult 2

to - e.g. trauma

– Neuropathic -

Charcot join

• Inflammatory:

• Crystal deposition:

– Gout
– Calcium pyrophosphate deposition (CPPD)

• Hematologic

(hemophilia)

• Septic

(due to joint infection)

• RF blood test is positive, include:

• RA
• Lupus
• Scleroderma
• Others

Sero +ve

• RF blood test is Negative. Usually +ve HLA-B27

• Ankylosing spondylitis
• Psoriatic arthritis
• Reiter's syndrome
• Enteropathic arthritis (with IBD)

Sero -ve

Osteoarthritis (OA)

• Also called osteoarthrosis or degenerative

joint disease (DJD).

• OA is the result of articular cartilage breakdown from

local mechanical factors.

• OA typically occurs in

weight-bearing joints

and the

hands .

• Commonly seen in

Knee

Hip

joints

• When radiographic findings of OA are seen in

younger patients

or in

unusual locations

such as the

(shoulder, elbow, or ankle) usually its

secondary OA

due to

trauma

or other condition

The radiographic features of OA

• A

symmetrical joint space narrowing -

dependent

part of the joint

(

medial in Knee & supero lateral in Hip

)

• Subchondral Sclerosis, loss of hyaline cartilage

and reactive remodeling.

• Subchondral cystic change – Geode

- due to

herniation of joint fluid into bone through a cartilage defect.

• Osteophytosis.

• Lack of periarticular osteopenia (

vs RA

OA of the knee joint

• There are three joint compartments in the knee:

– The medial and lateral tibiofemoral compartments
– The patellofemoral compartment.

• The typical pattern for OA of the knee is

asymmetrical

involvement of the medial

tibiofemoral

compartment.

• Severe

osteoarthritis can involve all three compartments.

• The degree of joint space narrowing reflects the severity

of OA.

Best assessed on standing weight-bearing views

• Bilateral

involvement of the knees is

typical

• Tends to be bilateral - Similar to the knee.

• Typical features of OA in general including:

– joint space narrowing
– Osteophytosis
– subchondral cystic change
– Sclerosis

• Plus hip OA features including:

– migration of the femoral head in a

supero-lateral

direction. Less commonly, medial migrating

– axial

migration is seen more commonly in

inflammatory arthritis

OA of the Hip joint

• RA is an autoimmune disorder targeting the

synovium.

• Rheumatoid factor

(RF) is typically +ve

, not

specific (RF is an antibody).

• RA clinically presents with

symmetrical

joint

pain

swelling

, and

morning stiffness

• RA first affects the small joints in the hands and

wrists. .

• In more

advanced

cases, RA affects the cervical

spine, knees, shoulders, and hips

Rheumatoid Arthritis (RA)

• Marginal erosions

which first occur at the intra-capsular

articular margins in the:

“bare area”

The bare area is a region of exposed bone just within the joint

capsule that is not covered by thick cartilage.

• Soft tissue swelling.

• Diffuse, symmetrical joint space narrowing.

• Peri-articular osteopenia.

• Joint subluxation.

Radiographic features of RA

Marginal erosion

Erosions

Soft tissue
swelling

• The

hands

are commonly affected

in patients with RA.

• The earliest radiographic changes

of RA are

soft tissue swelling

and

peri articular osteopenia

due to

synovitis and hyperemia.

• Typical joints involved are the

MCPs

PIPs

, and the carpal

articulations.

The DIPs are usually

spared.

Rheumatoid arthritis in the hand and wrist

• Joint subluxatins

are present in more advanced

disease, which typically are not reducible and lead to

several common deformities, including:

– Boutonnière deformity

(PIP flexion and DIP

hyperextension).

– Swan neck deformity

(PIP hyperextension and DIP

flexion).

– Ulnar deviation

Atlantoaxial
subluxation in RA

Always a concern in
patient with
longstanding RA
and neck pain or
cervical neurological
symptoms

Order a view of the atlantoaxial articulation through an open mouth
to fully assess. This shows lateral atlantoaxial subluxation of the
odontoid process with respect to the lateral masses of the atlas.

Charcot joint

• also known as a

neuropathic joint

refers to a

progressive degenerative / destructive joint
disorder in patients with

abnormal pain

sensation

Charcot joint

Causes of a Charcot joint

• can be remembered as they (all) start with the

letter

Mnemonic

– sugar (

diabetes

)

– syphilis

– steroid use

– syringomyelia

– spinal cord injury

– spina bifida

– scleroderma
– (leprosy)

Radiographic findings

• 6

Ds of Charcot joint

Mnemonic

– increased

ensity (subchondral sclerosis)

– d

estruction

– d

ebris (intra-articular loose bodies)

– d

islocation

– d

istention

– d

isorganization

↑d

ensity

estruction

ebris

islocation

istention

isorganization

↑d

ensity

estruction

ebris

islocation

istention

isorganization

↑d

ensity

estruction

ebris

islocation

istention

isorganization

Psoriatic Arthritis



Characterized by

erosions

and

bony

proliferations

 RA does not typically have new bone formation



Asymmetric

distribution



Soft tissue findings:

fusiform

soft tissue

swelling around the joints; can progress so the
whole digit is swollen (

sausage digit

)



Marginal

erosions also often show fluffy

periostitis from new bone formation

Psoriatic Arthritis

• Deformities

– Pencil and cup – end

– Complete destruction of bone (

arthritis mutilans

)

Pencil-in-cup deformity

• Pencil-in-cup deformity is the

description given to one of the
appearances on plain radiograph
in

psoriatic arthritis

• The appearance results from

periarticular erosions and bone
resorption

giving the appearance of

a pencil in a cup.

Pencil-in-cup deformity

Psoriatic hands

Erosive changes
at the DIPs and
PIPs

Sparing of MCPs
and wrists

Arthritis mutilans

Pencil and cup deformity

Pencilling

Psoriatic Arthritis

• Spine

– Asymmetric sacroiliitis
– Asymmetrical syndesmophytes (bony bridges

between vertebrae)

Asymmetric
sacroiliitis
with left sided
erosions and
sclerosis

Non-marginal syndesmophytes
typical of psoriatic arthritis

Ankylosing Spondylitis

• Changes begin at SI joints and lumbosacral

junction, then typically move up the spine

• SI joints:

– Initially subchondral

sclerosis

– Erosions occur first at

iliac side

, which has thinner

cartilage

– Remember that the synovial part of the SI joint is

the anterior,

inferior

portion

– Reactive sclerosis with eventual

fusion

Ankylosing Spondylitis

• Spine

– Early changes include squaring of the anterior

vertebral body

– Enthesitis

and sclerosis

– Progressive mineralization form osseous

bridging

syndesmophytes

– Ossification of the interspinous ligaments

Erosions and sclerosis on iliac side

Bilateral sacroiliitis with
erosions, bony sclerosis and
joint width abnormalities

Bilateral sacroiliitis, definite
erosions, severe juxta-
articular bony sclerosis and
blurring of the joint

Advanced AS

Fused sacroiliac
joints

Ankylosis of the
lower lumbar
spine (bamboo
spine)

Gout

• Erosions and masses, especially in the peripheral

joints

• Masses may be dense, due to crystals or

associated calcification

• Erosions are juxtaarticular from adjacent soft

tissue tophi or intraosseous crystal deposition

– Appear rounded with a well circumscribed sclerotic

margin

• Deformity occurs early
• Olecranon and prepatellar bursitis may calcify

Gouty changes in the big
toe

Erosions due to tophi

Olecranon
bursitis with
erosions due to
gout

Large, destructive tophus of first MTP

Pseudogout (CPPD)

• Usually manifests as OA in an

unusual

distribution

• Prominent osteophytes
• Soft-tissue calcification in the joint capsule,

synovium, bursa, tendons, ligaments,
periarticular soft tissues

• Chondrocalcinosis

(cartilage calcification)

• No erosions

• Subchondral cysts are prominent

• No periosteal reaction or new bone formation

Chondrocalcinosis

Multiple cysts

Chondrocalcinosis of the
triangular ligament

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