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ARTHRITIS
- Disease that affects bones on both sides ofthe joint space and Narrows the space in
between them
Classification
Hypertrophic Hallmarks
Bone production Sclerosis
Infectious Hallmark
Destruction of articularcortex
Erosive Hallmark
ErosionsHypertrophic Arthritis (Osteoarthritis)
Degenerative arthritis Charcot arthropathy x-ray changes :
- Sclerosis- Osteophyte formation- Decreased joint space
Hypertrophic Arthritis Classification
Degenerative arthritis Charcot arthropathy
Charcots Arthropathy
General Disturbance in sensation leads to multiple
microfractures
Pain sensation intact from muscles and softtissue
Causes Shoulders syrinx, spinal tumor Hips tertiary syphilis, diabetes Feet diabetes Charcot arthropathy is a
progressivemusculoskeletal
condition characterized byjoint
dislocation,fracturesand
deformities. It results in
progressive destruction ofbone
andsoft tissueof weight-bearing
joints, most commonly in thefoot
andankle. It is most commonly
due todiabetes.
Findings
X-ray findings Fractures
Soft tissue swelling Destruction and/or dislocation of
joint
Sclerosis Osteophytosis
Infectious Arthritis More common in adult
Usually from local trauma-surgeryor accident
Children may can be affected withosteomyelitis
Destruction of articular cartilage & cortex Tends to affect one joint (DDx from gout)
Infectious ArthritisCauses
Usually staph - early destruction ofarticular cortex
Rapid course (unlike mostarthritides)
TB spreads via bloodstream from lung More protracted course In children, spine most common; in
adults, knee
Severe osteoporosis Healing with ankylosis common in both
(ankylosis - Stiffness or, more often, fusion of a joint)
Septic Arthritis
- A plain X-ray is not so useful to diagnose theearly stages of septic arthritis.
- However, it may be a useful test to rule outother medical conditions that share similar
symptoms with septic arthritis.
- Septic arthritis usually has to go untreatedfor at least two weeks before the damage it
causes can be detected on an x-ray.
- X-ray finding: Destruction of articularcartilage & cortex
- A scan of the joint may help to confirm thediagnosis.
Radiographic Findings y of TB of the Bones (Other
than the Vertebral Column)
1. bony rarefaction- at first merely show asosteoporosis, ie. Loss of trabecular pattern
and reactive hyperemia, decalcification
2. bony destuction- is present in epiphysis andmetaphysis and the cortex outline of the
articular surface is lost
3. heavy overcalcification ring calcificationmay be seen with abscess
http://en.wikipedia.org/wiki/Progressive_illnesshttp://en.wikipedia.org/wiki/Musculoskeletalhttp://en.wikipedia.org/wiki/Musculoskeletalhttp://en.wikipedia.org/wiki/Musculoskeletalhttp://en.wikipedia.org/wiki/Jointhttp://en.wikipedia.org/wiki/Jointhttp://en.wikipedia.org/wiki/Jointhttp://en.wikipedia.org/wiki/Dislocationhttp://en.wikipedia.org/wiki/Dislocationhttp://en.wikipedia.org/wiki/Fractureshttp://en.wikipedia.org/wiki/Fractureshttp://en.wikipedia.org/wiki/Fractureshttp://en.wikipedia.org/wiki/Deformitieshttp://en.wikipedia.org/wiki/Deformitieshttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Soft_tissuehttp://en.wikipedia.org/wiki/Soft_tissuehttp://en.wikipedia.org/wiki/Soft_tissuehttp://en.wikipedia.org/wiki/Foothttp://en.wikipedia.org/wiki/Foothttp://en.wikipedia.org/wiki/Foothttp://en.wikipedia.org/wiki/Anklehttp://en.wikipedia.org/wiki/Anklehttp://en.wikipedia.org/wiki/Anklehttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Anklehttp://en.wikipedia.org/wiki/Foothttp://en.wikipedia.org/wiki/Soft_tissuehttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Deformitieshttp://en.wikipedia.org/wiki/Fractureshttp://en.wikipedia.org/wiki/Dislocationhttp://en.wikipedia.org/wiki/Jointhttp://en.wikipedia.org/wiki/Musculoskeletalhttp://en.wikipedia.org/wiki/Progressive_illness7/28/2019 ARTHRITIS.docx
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- Juxta-articular erosionso Sharply marginated with sclerotic
rims
o Overhanging edges (rat-bites)- No joint space narrowing until later- Little or no osteoporosis- Soft tissue swelling- Tophi rarely calcified
Gout: Bony erosions are typically punched out with
sclerotic margins and overhanging edges "rat bite
erosions".
Erosive osteoarthritis is typically bilateral and
symmetrical, and it occurs in the interphalangeal,
particularly distal interphalangeal, joints of the
hands. The disease most commonly occurs in
postmenopausal women, and it may be hereditary.
The erosions are centrally located in contrast to the
marginal erosions in rheumatoid arthritis. Joints
assume a gull-wing configuration, with central
erosions flanked by raised lips of bone.
Rheumatoid Variants
Psoriatic Arthritis Ankylosing Spondylitis
Psoriatic Arthritis
Almost always accompanies skindisease, especially nail changes
Involves DIP joints of hands > feet Cup-in-pencil deformity
Resorption of terminal phalanges No osteoporosis
Psoriatic Arthritis X-ray Findings
Psoriatic arthritis patients often haveosteolysisloss of boneon their x-rays.
The pencil-in-cup deformity at the DIP jointis classic for psoriatic arthritis.
Other x-ray findings seen in psoriatic arthritis
include:
swelling of non-bony structures, joint space narrowing joint erosions and/or spontaneous joint fusions.
These findings can also occur with:
erosive osteoarthritis and rheumatoid arthritis as well
Sausage finger with swelling of middle joint (PIP)
X-ray of the hand with diffuse fusiform soft-tissue swelling of the entire 3rd digit. This
sign refers to fusiform soft-tissue swelling
involving an entire, single digit within the
hand. The appearance of a sausage digit
(cocktail sausage) is classically associated
with the single x-ray pattern of involvement
seen in some patients with psoriatic
arthritis, and may be the initial
manifestation of the disease.
Ankylosing Spondylitis
Ankylosing spondylitis (AS) refers toinflammation of the joints in the spine.
AS is also known as rheumatoid spondylitisor Marie-Strmpells disease (among other
names).
Squaring of vertebral bodies Bamboo-spine from continuous
syndesmophytes
Peripheral large joint erosive arthritisImaging of Infectious Arthritis
- Conventional Radiography- Arthrography- Ultrasound- Nuclear Medicine Studies- CT- MRI
Arthrography
Used only in conjunction with jointaspiration
Joint aspiration is the most effectiveprocedure for diagnosis of infectiousarthritis
- Provides synovial fluid fordiagnosis
- Relieves joint pressure cause byaccumulation of fluid/ pus
Injection of contrast into the joint confirmsneedle placement
Radiographs obtained after contrast mayreveal:
- Destruction of the articularcartilage
- Hypertrophic alterations to thesynovium
Irregular or contracted joint capsule inchronic infection
Ultrasound for Infectious Arthritis
Alone, US is unable to confirm the diagnosisof septic arthritis
However, US is a very sensitive modality fordemonstrating joint effusion
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May be effective in guiding needleaspiration of joint
Nuclear Medicine Studies for Infectious Arthritis
Most rapid method for determination ofthe site and distribution of joint infection
Scintigraphy studies are sensitive indicatorsof altered osteoblastic activity Limited by:
Poor specificity Inability to accurately delineate
complex anatomy
Local disturbances in vascularperfusion, clearance rate,
permeability and chemical binding
3- or 4- phase bone scan with T99m MDP isthe most commonly used nuc med study
Bone Scan for Infectious Arthritis
3-phase T99 MDP Bone Scan findings Increased blood flow adjacent to
the joint
Prominent activity on blood poolimages on both sides of the
affected area
A fourth phase (delayed 24 hour imaging)shows:
Diminution of activity This is in contrast to osteomyelitis
which invariably has increased
activity on delayed images
CT for Infectious Arthritis
Not standard for evaluation of jointinfections but can be used to guide complex
joint aspirations
When used, CT findings include: Water density fluid in the joint
space and associated irregularity
and narrowing of the joint
Soft tissue swelling Articular erosion and subchondral
bone destruction
Effective in dx early infectious arthritis: Synovial thickening Small joint effusion
Can identify air bubbles in infections causedby gas forming organisms
Caution b/c air bubbles can alsorepresent a degenerative process
in SI and facet joints and are also
common after hip dislocation
MRI for Infectious Arthritis
Not commonly used for imaging suspectedseptic arthritis as dx can readily be
confirmed with less expensive modalities
Advantages: Extremely sensitive for detection
of infectiousarthritis
More specific for infectiousarthritis than
conventional
radiography or
CT
Can provide images in any place Disadvantages
Expensive Not needed to establish diagnosis
MR Findings in Infectious Arthritis
Early Stages of Infection: T2 images reveal distention of joint
capsule by
nonspecific high-
intensity fluid
Later Stages of Infection: Can detect joint effusion, cartilage
destruction, narrowing of joint and
cellulitis around joint
MRI can readily detect extension of theinfectious process into adjacent bone
marrow and the transition to
osteomyelitis T2 images reveal infected fluid and
blood in the joint of inhomogeneous
intermediate signal intensity
T2 images also reveal an area of signalhyperintensity in the soft tissue around
the affected joint
Infectious Arthritis Summary
Conventional radiography and jointaspiration are the mainstays of infectious
arthritis diagnosis
Arthrography and less commonly CT orUltrasound may play a role in guiding joint
aspiration
MRI has little role in the dx of infectionarthritis but may be used to evaluate for
complications, particularly osteomyelitis