JOINTS Flashcards
1
Q
MONOARTHRITIS
Common 5
A
- Septic arthritis—including tuberculosis. Marked juxtaarticular
osteopenia with loss of definition of subchondral bone plate. - Trauma—evidence of fracture or lipohaemarthrosis.
- Osteoarthritis (OA)—marginal osteophytes, subchondral sclerosis
and/or cysts, joint space narrowing. Commonly involves weightbearing joints. - Calcium pyrophosphate deposition disease (CPPD)—
chondrocalcinosis is characteristic; most commonly seen in knee,
wrist, symphysis pubis and intervertebral discs. Arthropathy mimics
OA but has a characteristic distribution: radiocarpal, patellofemoral,
C1/2. Large clustered subchondral cysts are common. - Gout—well-defined juxtaarticular erosions + periarticular soft tissue
mass ± calcification (tophi—highly suggestive). The joint space and
bone density are relatively preserved. Most commonly involves the
hallux MTPJ; other sites include intertarsal, ankle and knee.
2
Q
MONOARTHRITIS Less common
A
- Neuropathic (Charcot) arthropathy—seven Ds: joint degeneration, destruction, dislocation, deformity, debris (loose bodies), distension (effusion) and increased density (subchondral sclerosis). Due to reduced pain sensation and proprioception, most commonly seen in diabetics. The joint involved suggests the underlying cause:
(a) Ankle/foot—diabetes, alcoholism, dysraphism, leprosy,
congenital insensitivity to pain (young patients, multiple
involved joints), amyloidosis, neurosyphilis.
(b) Knee—steroid injection, alcoholism, congenital insensitivity to pain, neurosyphilis.
(c) Hip—alcoholism, steroid injection, neurosyphilis.
(d) Spine—spinal cord injury, diabetes, syrinx (C-spine), neurosyphilis (L-spine).
(e) Shoulder/elbow—syrinx.
(f) Wrist—diabetes, syrinx.
(g) Small joints of hand/feet—diabetes, leprosy, congenital insensitivity to pain. - Avascular necrosis—e.g. in hip. Can mimic OA but changes
mainly involve one side of the joint with relative preservation of
the joint space. - Monoarticular presentation of a usually polyarticular
arthritis - Viral—typically hips in children, a.k.a. ‘transient synovitis’.
- Pigmented villonodular synovitis (PVNS)—well-defined erosions
+ synovial nodules on MRI showing low T2 signal and blooming
on the gradient echo due to haemosiderin. Most cases occur in
the knee; less commonly other large joints. A localized form
limited to Hoffa’s fat pad can also occur. - Synovial osteochondromatosis—multiple intraarticular loose
bodies + calcification. Can be primary (uniform in size) or
secondary (different sizes + coexistent OA)
3
Q
THE MAJOR POLYARTHRITIDES
Synovial
2
A
- Rheumatoid arthritis*—proximal and symmetric distribution,
especially MCPJs and carpus; other sites include feet (especially 5th
MTPJ), knees, ankles, elbows and shoulders. Features include
synovitis, juxtaarticular osteopenia, joint space narrowing,
periarticular erosions, subluxation and ankylosis. - Juvenile idiopathic arthritis*—presents in childhood. Common
joints include hips, knees, ankles, elbows, hands and feet, C-spine.
Features include soft tissue swelling, juxtaarticular osteopenia,
periostitis, epiphyseal overgrowth, joint effusions and subluxation
(e.g. carpus, hip, C1/2). Periarticular erosions, joint space
narrowing and ankylosis are late features
4
Q
THE MAJOR POLYARTHRITIDES
Entheseal
A
- Seronegative spondyloarthropathies—enthesitis + proliferative entheseal erosions with preserved bone density; classically asymmetrical, oligoarticular involvement of peripheral joints.
(a) Psoriatic arthritis—usually asymmetric and distal (especially distal interphalangeal joints). Can present with dactylitis (‘sausage digit’). Occasionally symmetrical, resembling rheumatoid arthritis. Pencil-in-cup appearance and arthritis mutilans in severe disease. Acroosteolysis and interphalangeal joint ankylosis may be seen and are suggestive.
(b) Chronic reactive arthritis—usually seen in young adults, following an STI or gut infection. Similar in appearance to psoriatic arthritis but the hands are typically spared. Commonly involves the feet, SIJs and spine. Calcaneal enthesitis (+ erosions) is suggestive. Dactylitis may also be seen.
(c) Ankylosing spondylitis—typically involves SIJs and the spine.
Other joints include hips, shoulders and knees.
(d) Enteropathic arthritis—associated with IBD. Distribution is
similar to ankylosing spondylitis
5
Q
THE MAJOR POLYARTHRITIDES
Degenerative
2
A
- Osteoarthritis—e.g. hands; involves interphalangeal joints, thumb
carpometacarpal and triscaphoid joints. The erosive form causes
central erosions resulting in a ‘gull-wing’ deformity ± ankylosis. - Neuropathic arthropathy
6
Q
THE MAJOR POLYARTHRITIDES
Depositional
A
- Gout.
- CPPD.
- Haemochromatosis*—resembles CPPD but has a predilection for
the index and middle finger MCPJs with hook-like osteophytes
7
Q
ARTHRITIS WITH OSTEOPENIA
7
A
- Rheumatoid arthritis*—typically polyarticular.
- Septic arthritis—typically monoarticular.
- SLE*—typically causes symmetric osteopenia and joint subluxation
(especially MCPJs) without erosions. - Systemic sclerosis—joint contractures, acroosteolysis and
well-defined soft tissue calcifications (calcinosis). - Reactive arthritis*—juxtaarticular osteopenia in early phase.
- Juvenile idiopathic arthritis*.
- Haemophilic arthropathy—epiphyseal overgrowth, periarticular
erosions, diffuse T2 hypointense synovial thickening + blooming on
gradient echo MRI, due to recurrent haemarthrosis. Males only
8
Q
ARTHRITIS WITH PRESERVATION OF
BONE DENSITY
A
- Osteoarthritis.
- CPPD.
- Gout.
- Seronegative spondyloarthropathies.
- Neuropathic arthropathy.
9
Q
ARTHRITIS WITH PERIOSTEAL REACTION 4
A
- Seronegative spondyloarthropathy—mainly psoriatic arthritis
(hands) and chronic reactive arthritis (feet). Fluffy appearance,
represents entheseal bony proliferation. - Septic arthritis—associated bone destruction and/or abscess.
- Juvenile idiopathic arthritis*—most often seen around
metacarpals/metatarsals. - HIV-associated arthritis—similar to chronic reactive arthritis
10
Q
ARTHRITIS WITH PRESERVED OR WIDENED
JOINT SPACE 6
A
- Any early arthritis.
- Gout.
- Acromegaly*—‘spade-like’ terminal phalanges, enlarged
sesamoids, thickened soft tissues, e.g. heel pad. - SLE*.
- PVNS and primary synovial osteochondromatosis.
- Multicentric reticulohistiocytosis—symmetric erosive arthritis
involving PIPJs and DIPJs + acroosteolysis; mimics psoriatic arthritis
but with nodular soft tissue swelling.
11
Q
ARTHRITIS WITH SOFT TISSUE NODULES
7
A
- Rheumatoid arthritis*—subcutaneous rheumatoid nodules;
typically on extensor surface of the forearm and other pressure
points; more common in seropositive individuals. Intraarticular T2
hypointense rice bodies may also be present (also seen in infection
especially TB). - Gout—tophi: eccentric, lobulated juxtaarticular soft tissue masses,
typically around extensor tendons ± characteristic foci of
calcification. Heterogeneous T2 signal on MRI. - PVNS—synovial nodules that bloom on gradient echo sequences ±
extraarticular extension, e.g. into tendon sheath (giant cell tumour
of tendon sheath). - Synovial chondromatosis—nonossified variant of
osteochondromatosis. T2 hyperintense chondroid nodules on MRI. - Sarcoidosis*—periarticular granulomas causing characteristic
lace-like lytic bone lesions, especially in finger phalanges. - Amyloidosis*—large well-defined erosions + soft tissue swelling.
On MR: low T1/T2 signal thickening of capsule, ligaments and
tendons. Can involve wrists, shoulders, hips or knees; usually
bilateral. History of primary/secondary amyloidosis or dialysis. - Multicentric reticulohistiocytosis—mainly involves hands
12
Q
ARTHRITIS MUTILANS 8
A
Common causes
1. Rheumatoid arthritis.
2. Psoriatic arthritis.
3. Neuropathic arthropathy—diabetes, leprosy or congenital
insensitivity to pain. Leprosy causes distal bone resorption giving a
‘licked candy stick’ appearance.
4. Juvenile idiopathic arthritis.
Less common causes 5. Chronic reactive arthritis*. 6. Gout—typically hallux MTPJ/IPJ. 7. Mixed connective tissue disease—acroosteolysis and sheet-like soft tissue calcification. 8. Multicentric reticulohistiocytosi
13
Q
ACROOSTEOSCLEROSIS
A
- Normal variant—most common in middle-aged women.
- Psoriatic arthritis—ivory phalanx.
- Rheumatoid arthritis*—in association with erosive disease.
- Systemic sclerosis—osteosclerosis may precede or coexist with
osteolysis. - Any cause of sclerotic bone lesion affecting terminal phalanx
14
Q
INTRAARTICULAR LOOSE BODY
4
A
- Trauma—osteochondral or avulsion fracture.
- Synovial osteochondromatosis—more commonly secondary,
due to OA with loose chondral bodies of different sizes ±
calcification. Primary form is rare, due to synovial metaplasia
with multiple uniform loose bodies (no significant OA unless
late in disease). - Osteochondritis dissecans—characteristic age (adolescents) and
location (femoral condyles, capitellum, talar dome). - Neuropathic arthropathy.
15
Q
CALCIFICATION OF ARTICULAR
CARTILAGE (CHONDROCALCINOSIS)
8 (4-4)
A
Common causes
- Osteoarthritis.
- CPPD.
- Hyperparathyroidism*.
- Gout.
Rare causes
- Haemochromatosis*—similar distribution to CPPD.
- Acromegaly*.
- Wilson’s disease.
- Alkaptonuria*
