Plain Film Diagnosis
of Arthritides
(The Basic Edition)
Jacob Walter, M4
Four main categories of arthritis
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Degenerative
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Inflammatory
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Osteoarthritis (OA)
Secondary – Systemic: hemochromatosis, hemophilia
Seropositive – rheumatoid arthritis (RA)
Seronegative – reactive arthritis, ankylosing spondylitis, psoriatic
arthritis, and enteropathic arthritis (assoc with IBD)
Infectious
Crystal deposition


Calcium pyrophosphate deposition disease (CPPD)
Monosodium urate crystals - Gout
This is not a complete list, but will hopefully get you started
When evaluating arthritis, take into
account…
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Location – bilateral/unilateral, which joint(s)
Which part of the joint is involved, even or
uneven
Demographics – age, gender
Presence of osteophytes, erosions, new bone
formation, subchondral cysts, sclerosis…
Soft tissue swelling
Or, ABCDE’s: Alignment, Bone proliferation,
Cartilage (joint space loss), Density (bone),
Erosions, soft tissues
Degenerative
Osteoarthritis
(OA)
Secondary – Systemic:
hemochromatosis, hemophilia
Degenerative - Osteoarthritis

Characteristics
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Uneven loss of joint space
Osteophyte formation
Normal bone mineralization
Relative absence of
erosions
Subchondral cysts and new
bone formation/sclerosis
Asymmetric distribution,
usually hands, feet, knees
and hips
Not as common in
shoulders, elbows
Associated with changes
d/t age, and mechanical
forces
http://uwmsk.org:8080/EvasMSKTF/
OA cont.

Hand/Wrist



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DIP and PIP involvement,
sparing of MCP
Osteophyte formation with
soft tissue swelling
(Heberdon node at DIP,
Bouchard at PIP)
Usually 1st
metacarpal/trapezium/navic
ular involvement in wrist
Feet

Most commonly 1st MTP
joint
http://podiatryonline.com/
OA cont.
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Knee



Medial joint involvement
more common
Varus deformity of joint,
lateral tibial subluxation
http://uwmsk.org:8080/EvasMSKTF/
Cyst
Hip


Most often superiolateral
joint involvement with loss
of cartilage and osteophyte
formation
Medial sclerosis/new bone
formation in femoral neck
cortex; buttressing
Osteophyte
Buttressing
STATdx
Erosive OA
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
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OA with an inflammatory
component
Same OA distribution, but
may see erosions or
ankylosis
Often postmenopausal
women
http://uwmsk.org:8080/EvasMSKTF/
Degenerative – Systemic
Hemochromatosis
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Abnormal iron deposition
throughout the body,
including articular cartilage
Demonstrates some overlap
with CPPD, Fe inhibits
pyrophosphatase and can
lead to crystal deposition in
cartilage (chondrocalcinosis)
Uniform joint space loss
Bilateral symmetrical
distribution
“Beak-like” osteophytes
Subchondral cysts/sclerosis
Osteoporosis
http://uwmsk.org:8080/EvasMSKTF/
Hemochromatosis cont
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Most often in wrist and
hand, esp. 2nd and 3rd
MCP joints
Flattened metacarpal
heads
Systemic disease may
appear similar to CPPD,
but with more indolent
course and
predominance of
osteophytes
http://uwmsk.org:8080/EvasMSKTF/
Degenerative - Systemic

Hemophilia

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Repetitive hemarthrosis
and intraosseous bleeding
are causative
Overgrown/ballooned
epiphyses
Subchondral cysts
Tissue swelling, evidence
of hemarthrosis
Osteoporosis
Late uniform space loss
Sporadic, asymmetric
distribution
Late osteoarthritis changes
Knee > elbow > ankle >hip
(joints most likely to receive
trauma)
http://uwmsk.org:8080/EvasMSKTF/
Hemophilia cont

Pseudotumors
 Bleeding
in to soft
tissues, subperiosteal,
or intraosseous areas
 May cause some bone
destruction or
periosteal bone
formation
 Do not confuse with
malignancy
http://radiographics.rsnajnls.org/cgi/content/full/23/4/852
Inflammatory
RA
Seronegative

Reactive
Ankylosing Spondylitis
Psoriatic
Enteropathic
Inflammatory – Seropositive
Rheumatoid Arthritis
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Periarticular soft tissue
swelling
Osteoporosis
Uniform joint space loss
Marginal erosions  severe
subchondral erosions
No bone formation (no
osteophytes)
Subluxations
Synovial cysts
Bilateral and symmetric
Generally not present in axial
skeleton, except C-spine
Hands > feet > knees > hips >
C-spine > shoulders > elbows
Erosions, uniform joint spaces
http://uwmsk.org:8080/EvasMSKTF/
RA cont

In hand and wrist, often
involves carpals, MCP joints
and PIP joints

Ulnar subluxation of proximal
phalanges and formation of
swan neck and boutonniere
deformities
 Formation of subcutaneous
rheumatoid nodules

In the foot, erosion of distal
metatarsals, and eventual
radial subluxation of proximal
phalanges

Tarsal joint spaces may also
be heavily involved
http://uwmsk.org:8080/EvasMSKTF/
Effusion
RA cont

Knees affected symmetrically
and bilaterally



Baker’s
cyst
Uniform space loss
Outpouching of synovial cysts
into adjacent bone, or soft
tissue (Baker’s cyst)
Hips affected in 50%
Uniform cartilage loss  axial
or superomedial migration of
femoral head
 Bone erodes on joint side, and
forms on pelvic side leading to
acetabuli protusio (acetabulum
protrudes into pelvis)

STATdx
Erosions and joint space loss
bilaterally, no osteophytes or
sclerosis
RA cont


Shoulder and elbow also show
bilateral, uniform joint space
loss with osteoporosis and
cysts formation
Special consideration: RA
patients are prone to
developing laxity of transverse
ligament between atlas and
odontoid process

Normal distance between the
two on lateral c-spine is 3mm
in adults, 5mm in children
 Increased distance may
indicate need for surgical
fusion to prevent cord
compression during flexion
http://uwmsk.org:8080/EvasMSKTF/
Inflammatory Arthritis –
Seronegative
Associated with HLA-B27
 Negative RH factor
 Axial skeleton often involved

 Sacroiliitis

or spondylitis
Enthesopathy
 Inflammation
of the insertions of
tendons/ligaments
Inflammatory – Seronegative
Reactive Arthritis (Reiter’s)
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Reiter’s included the classic triad of arthritis,
conjunctivitis, and urethritis
Classical model involving chlamydial infection doesn’t
apply to all cases, and Reiter was a WWII war criminal,
so reactive arthritis is now the preferred term
Reactive arthritis may still involve chlamydial infection,
but may also occur after gastroenteritis (Shigella,
Salmonella, Campylobacter, Yersinia, C. defficile)
Likely autoimmune reaction, joints themselves are not
infected
Worldwide has equal prevalence among men and
women
Reactive cont
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Enthesopathy is prominent,
with overlying tissue warmth
and tenderness
Soft tissue swelling (sausage
digits)
Uniform joint space loss
Bilateral, asymmetrical
Often begins with one joint,
don’t confuse with septic
arthritis
Areas of erosion associated
with periosteal reaction, new
bone formation
Most often in feet, ankles,
knees and SI joints
Less in hands, hips, spine
http://uwmsk.org:8080/EvasMSKTF/
Reactive cont
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Very often involves Achilles
tendon insertion, preference
for MTP and 1st IP joint in feet
(vs DIP and PIP in psoriatic)
In SI joint, may be on only one
side or asymmetrically affect
both sides (opposed to
ankylosing spondylitis)
May form large, asymmetric
bony bridges between
vertebrae (similar to psoriatic,
but opposed to ankylosing
spondylitis)
I got tired of bone pics, so here’s
some chlamydia!
http://www.lahey.org/Medical/InfectiousDiseases/ID_Chlamydia.asp
Inflammatory – Seronegative
Ankylosing Spondylitis
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Bilateral, symmetrical
Ankylosis, joint fusion, is
prominent
Before fusion, subchondral
bone formation
Post fusion, generalized
osteoporosis
No cysts or subluxation
Erosions not a prominent
feature, but are present
SI and spine (ascending)
involvement > hips > shoulders
> knees > hands > feet
http://uwmsk.org:8080/EvasMSKTF/
AS cont


Dagger sign,
fused spinous
process
ligaments
Fusion of SI joints is classic
Vertebral bodies initially erode
at corner, reactive sclerosis
occurs below this leading to
squared appearance


Eventually anulus fibrosus and
longitudinal ligaments become
ossified (syndesmophytes)
Discs can become calcified,
along with all ligaments
including those between
spinous processes  bamboo
spine
http://uwmsk.org:8080/EvasMSKTF/
Inflammatory – Seronegative
Psoriatic Arthritis
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Bilateral, asymmetrical
Dramatic joint space loss +/ankylosis (arthritis mutilans)
Bone proliferation, “mouse
ears”
“pencil-in-cup” deformities
Normal mineralization
Sausage digits
Hands > feet > SI > spine
Usually favors DIP and PIP in
hand
SI involvement usually
bilateral, asymmetrical
Large bridging bone formation
in spine, similar to reactive
arthritis
Sausage
digits
http://www.hopkins-arthritis.org/arthritisinfo/psoriatic-arthritis/diagnosis.html
http://uwmsk.org:8080/EvasMSKTF/
http://uwmsk.org:8080/EvasMSKTF/
Inflammatory – Seronegative
Enteropathic Arthritis


20% of patients with inflammatory bowel disease
develop arthritis
Axial disease is very similar to AS with spine and SI joint
involvement
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Peripheral arthritis/arthralgia waxes and wanes with IBD
activity
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Radiographically almost identical to AS
Progresses independently of IBD activity
Oligoarthritis of lower extremities
Erythema nodosum and pyoderma gangrenosa may be
concurrent
Whipple’s disease, pancreatic disease, cirrhosis, and
infection such as Salmonella and Shigella may also be
associated with arthritis
Infectious
Septic arthritis
Septic arthrtitis
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Joint space destruction, both sides, due to release of proteolytic enzymes
Joint effusion
Soft tissue swelling
Osteoporosis
In healthy patients

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IV drug users
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SI joint, sternal, pubic joints
TB
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Knee, hip, and elbow common
N. gonorrhoeae most common cause in young, sexually active patients
Hip, knee, intertarsal joints, spine
TB in vertebral disc space is Pott’s disease
Staph aureus is most common cause, Streptococcus is also common
Gram negatives more common in diabetics
Salmonella in sickle cell patients
Risk factors: Extremes of age, immunocompromised, chronic arthridities,
prosthetic joints, diabetes, and IV drug use
Septic arthritis cont
Uhh, do you see the problem?
http://www.learningradiology.com/images/boneimages1/bonegallerypages/Septic%20arthritis.html
Pott’s
http://www.wheelessonline.com/ortho/tuberculous_spondylitis
Sedona, AZ
(crystals)
Gout
CPPD
Crystals
Gout

Monosodium urate crystal deposition

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May deposite in cartilage to produce an OA like disease, or in
soft tissues (tophaceous gout)
Usually males, postmenopausal females
Tophaceous gout
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Tophi
Relative joint space preservation
Erosive lesions with sclerotic borders, away from joint space,
with overhanging cortex
Normal mineralization
Asymmetrical, polyarticular
May present with acute, monoarticular swelling, pain, and
erythema.
Feet (1st MTP) > ankles > knees > hands > elbows
Gout cont
Erosion with overhanging edge.
Joint space is preserved.
tophus
Crystal in PMN from synovial fluid,
diagnostic for acute gout
Uwmsk.org/residentprojects/gout.html
Crystals
CPPD


Most common crystal arthropathy
Disease spectrum includes:

Deposition in cartilage (chondrocalcinosis), which
may lead to OA like disease or be asymptomatic


Commonly develops in older population
Associated with hyperparathyroidism and hemochromatosis
 Pseudogout
which may present with acute attacks of
arthritic pain similar to gout, although it is more
common in the knees than the 1st MTP

May be indistinguishable from septic arthritis without synovial
fluid analysis
Chondrocalcinosis
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Most common in knee, pubic
symphysis, and wrist
(patients will be affected in at
least one of these areas)
Deposition of crystals in
hyaline and/or fibrous
cartilage
Bilateral
Cysts
Normal mineralization
Subchondral new bone
formation
+/- osteophytes
Knees > hands > hips
Shoulder and elbow involved,
differentiates from OA
wikipedia
Uwmsk.org/residentprojects/
gout.html
Sources
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Bowen, Anne C. Arthritis in Black and White. Philadelphia:
Saunders, 1988
Current Rheumatology Diagnosis & Treatment, Second Edition
John B. Imboden, David B. Hellmann, John H. Stone.
http:/accessmedicine.com
Gay, Spencer B. Woodcock, Richard J Jr. Radiology Recall.
Baltimore: Lippincott, 2000
Pretorius, E. Scott. Solomon, Jeffery A. Radiology Secrets.
Philadelphia: Mosby 2006
Marc Gosselin, M.D., OHSU