Arthritis Flashcards
1
Q
Osteoarthritis generalities
A
- OA involves the entire joint (bone, ligaments, menisci, joint capsule, synovium and musculature).
- Affects weight-bearing joints and hands in a specific distribution.
- Abnormal locations: shoulder, elbow and ankle –> Suspect trauma or arthitis.
2
Q
Osteoarthritis Rx / CT findings (5)
A
- Osteophytes.
- Subchondral cystic changes.
- Sclerosis of subcondral bone.
- Lack of periarticular osteopenia.
- Lack of Erosions
3
Q
Osteoarthritis MRI findings (4)
A
- Osteophytes.
- Subchondral cystic change.
- Subchondral edema.
- Synovitis.
4
Q
Osteoarthritis of the hand (Locations)
A
- Distal interphalangeal joints (Heberden nodules).
- Proximal interphalangeal joints (Bouchard nodules).
- First carpometacarpal joint.
5
Q
Erosive osteoarthritis of the hand - Generalities
A
- Eldery females.
- Combines clinical findings of AR and imaging features of OA.
- Erosions are present (limited to the hand, commonly DIP).
- Gull-wing appearance of the DIP.
6
Q
Osteoarthritis other locations (Shoulder, foot and knee)
A
- Shoulder: Glenohumeral joint narrowing (Grashey view RX - AP 40° external rotation).
- Foot: 1° MTP –> Hallux rigidus. Also affects the talonavicular joint –> Dorsal beaking.
- Knee: Asymmetrical involvement of the medial tibiofemoral compartment.
7
Q
Osteoarthritis of the hip
A
- Characteristic superolateral space narrowing.
- Less commonly medial or axial concentric cartilage space loss.
- Axial narrowing without osteophytes: Typical of AR.
8
Q
Degenerative changes in the spine
A
- OA affects: Zygapophyseal, atlantoaxial, uncovertebral , costovertebral and sacroiliac joints.
- OA Doesn’t affect the disc-endplates.
- Vaccuum phenomenon is pathognomonic for degenerative change.
9
Q
Kümmell disease
A
Gas in a vertebral body compression fracture representing osteonecrosis.
10
Q
Diffuse idiophatic skeletal hyperostosis (DISH). Generalities
A
- Defined as flowing bridging anterior osteophytes spanning at least 4 vertebral levels.
- May be associated with ossification of the posterior longitudinal ligament, which may cause spinal stenosis.
11
Q
Rheumatoid arthritis generalities
A
- Symmetrical joint pain, swelling and morning stiffness.
- Rheumatoid factor is typically positive.
- Affects (in order): Hands, wrists and feet. Advanced cases: cervical spine, knees, shoulders and hips.
- Erosions are the imaging and pathologic hallmarks of AR.
12
Q
Rheumatoid Artrhitis RX and CT findings (5)
A
- Marginal erosions.
- Soft-tissue swelling.
- Diffuse, symmetric joint space narrowing.
- Periarticular osteopenia.
- Joint subluxations.
13
Q
Rheumatoid Artrhitis MRI findings (4)
A
- Marginal erosions.
- Synovitis.
- Subchondral edema.
- Joint subluxations.
14
Q
Rheumatoid Artrhitis in the hand
A
- Affects PIP, MCP and the carpal articulations (DIPs are usually spared).
- Erosions: radial aspect of 2° 3° metacarpal heads, the radial and ulnar aspects of the bases of proximal phalanges and the ulnar styloid.
- Common subluxations: Bouttoniere deformity (PIP flexion and DIP hyperextension), Swan neck deformity (PIP hyperextension and DIP flexion), ulnar subluxation of the fingers at MCP.
- Late-stage AR may produce ankylosis.
15
Q
Rheumatoid arthritis in the feet and hip
A
- Affects MTF joints and the talocalcaneonavicular joint.
- Axial migration of the femoral head.
- Protrusio deformity in severe cases.
16
Q
Protrusio deformity definition
A
- > 3 mm medial deviation of the femoral head beyond the ilioischial line (males).
- > 5 mm deviation (females).
17
Q
Reumathoid arthritis in the knee
A
- All three joint spaces may be affected (medial and lateral tibiofemoral and patellofemoral).
- Erosions are not a prominent manifestation on the knee.
18
Q
Reumathoid arthritis in the spine
A
- 70% of patients are affected.
- Subluxation of multiple levels, osteopenia, erosions of the odontoid, facet joints, vertebral endplates and spinous processes.
- Unlike OA there is no bone production.
- Atlanto-axial C1-C2 subluxation: anterior, vertical and posterior.
19
Q
Atlanto-axial subluxations types (3)
A
- Anterior: By laxity of the transverse ligament. Atlanto-dental interval >2.5 mm in adults and >5 mm in children.
- Vertical: Atlantoaxial impaction, protrusion of the odontoid through the foramen magnum.
- Posterior: Due to odontoid erosion or fracture.
20
Q
Seronegative spondyloarthropaties generalities
A
- 4 types: Ankylosing spondilitis, psoriatic arhtritis, reactive arthritis and IBD associated arthropathy.
- Negative rheumatoid factor.
- Usually HLA-B27 positive.
21
Q
Seronegative spondyloarthropaties sacroiliitis
A
- Only the inferior aspect of the SI joint is affected.
- Erosions first involve the iliac aspect of the SI joint.
- Symmetric: IBD and ankylosing spondylitis.
- Assimetric: Psoriatic arthritis and reactive arthropathy.
22
Q
Ankylosing spondylitis generalities
A
- Young men with HLA B27.
- Can be associated with: pulmonary fibrosis, aortitis and cardiac conduction defects.
- Earliest findings: Symmetric erosions, widening and sclerosis of the sacroiliac joints.
- May produce an Andresson lesion.
23
Q
Andersson lesions
A
Pseudoarthrosis occuring in a completely ankylosed spine
24
Q
Ankylosing spondylitis findings in the spine
A
- Romanus and shiny corner lesions.
- Delicate syndesmophites and bamboo spine.
- Dagger sign.
- Squaring of the vertebral body.
- Cervical fusion.
25
Q
Psoriatic arthritis generalities
A
- Most commonly affect the hands.
- Mineralization is preserved.
- Asymmetric sacroiliitis.
- Patterns: Oligoarthritis, polyarthritis, spondiloarthropathy (bulky asymmetric brindging) and arthritis mutilans.
26
Q
Reactive arthropathy (Reiter disease)
A
- Inflammatory arthritis sequela of infectious diarrhea, urethritis or cervicitis.
- Asymmetrical sacroiliitis.
- Predominantly affects the feet
- Findings: diffuse soft-tissue swelling, joint space loss, agressive marginal erosions, juxta-articular osteopenia.
- Calcaneus is affected with proliferative changes, erosions, enthesophytes, fluffly periosteal reaction.
- Secondary Achilles tendinitis.
- Hands: Interphalangeal joints, MTP with erosions and diaphyseal periostitis.
- Coarse bony bridging of the spine (similar to psoriatic arthritis).
27
Q
Systemic lupus erythematosus arthopathy
A
- Affects 90% of SLE patients.
- Reducible subluxations of the MCP and PIP.
- Subluxations become apparent in the Norgaar or oblique views.
28
Q
Jaccoud arthropathy
A
- Secondary to recurrent rheumatic fever.
- Identical to SLE arthropathy sharing the same type III hypersensivity mechanism.
29
Q
Scleroderma
A
- Systemic collagen vascular disease, deposit of collagen in the skin and soft tissues.
- Acro-osteolysis is characteristic.
- Dystrophic soft-tissue and periarticular calcifications are common.
30
Q
Acro-osteolysis differential diagnosis (8)
A
- Collagen vascular diseases (Schleroderma and Raynaud’s).
- Neuropathy.
- PVC exposure.
- Thermal injury (burn of frostbite).
- Hyperparathyroidism.
- Hjdu-Cheney.
- Psoriasis.
- Pyknodysostosis.
31
Q
Crystal arthropathies generalities
A
- Arthritis caused by intra-articular deposition of various crystals.
- Two most common: Calcium pyrophosphate crystal arthritis and gout.
- Calcium hydroxyapatite causes tendinopathy and much less common arthritis.
32
Q
Calcium pyrophosphate arthritis
A
- Microsopically romboid crystals are positively birefrigent.
- Causes: Idiopathic, hemochromatosis, hyperparathyroidism and hypophosphatasia.
- Acute phase: May mimic septic arthritis.
- Chronic phase: May mimic OA, gout, AR.
- Hallmark: Chondrocalcinosis (Calcification of hyaline (articular) or fibro (meniscal/labral) cartilage.
- CT RX: Thin lineal calcifications of the articular cartilage.
- Wrist: Affects the triangular fibrocartilage complex, advanced disease may lead to scapholunate advanced collapse.
- Knee: Patellofemoral compartment is affected first, but all three compartments may be involved.
- Hand: Involvement of 2°-3° MCP joints, producing Hook-like osteophytes.
33
Q
Gout arthropathy
A
- Deposition of sodium urate crystals in the joints.
- Excess uric acid may be due under-excretion (more common, caused by renal insufficiency) or overproduction (rare, seen in younger patients).
- Microscopically: needle-like crystals with neutrophils and negatively berefrigent.
- The great toe is most commonly affected.
- RX: Sharply marginated erosions with overhanging margins.
- ECO: Double contour sign.
- Tophaceous gout: Deposition of urate crystals, inflammatory cells and foreign body giant cells in the soft tissues (joint, tendons, ligament, bursae, etc.).
- Dual energy CT is excellent for identifying urate and CPP crystals.
34
Q
Calcic hydroxyapatite
A
- Calcific tendinitis, crystals are deposited in degenerating or hypoxic tendons, triggering a inflammatory response.
- Commonly seen in DM.
- Mineralization appears amorphous or globular, there cannot be any cortication or internal trabeculation.
- May erode through tendons and cause adjacent calcific bursitis.
- Rarely it can erode bone.
- Shoulder is by far the most common site for calcific tendinopathy, supraspinatus tendon the most affected.
- Also: tendons of the hip, including gluteal and rectus tendons.
- Wrist: Flexor carpi ulnaris tendon.
- Neck: Longus colli muscle.
- Very rare Milwaukee shoulder (rapid destruction of the rotator cuff and the glenohumeral joint).
- MR low signal intensity on all sequences, with surrounding edema/inflammatory changes.
- US: Globular hyperechoic shadowing foci.
35
Q
Hemochromatosis arthropathy
A
- Affects 50% of patients with hemochromatosis.
- Deposition of iron and calcium pyrophosphate dihydrate crystals.
- Affects MCP joints, produces hook-like osteophytes at the metacarpal heads.
- DD: CPPD identical but affects only the 2° and 3° MCP. Acromegaly.
36
Q
Acromegaly arthropaty
A
- Excess growth hormone.
- Causes arthropathy due to enlargement of the articular cartilage and subsequent degeneration.
- Joint spaces are widened
- Later stages secondary OA occurs with cartilage space narrowing.
- In the hand, beak-like osteophytes of the metacarpal heads and spade like enlargement of the terminal tufts are characteristic.
37
Q
Amyloid arthropathy
A
- Rare non-inflammatory arthropathy due to infiltration of bones, joints and soft-tissues by beta-pleated sheets of aminoacids.
- Primary: Monoclonal plasma cell dysplasia.
- Secondary: Chronic underlying inflammation or infection, accumulation of B2-microglobulin in patients with chronic HD.
- Shoulder pad sign.
- Findings are non specific, but might resemble AR.
38
Q
Ochronosis
A
- Connective tissue manifestation of alkaptonuria.
- Defect in homogentisic acid oxidase, causing homogentisic acid polymerates to accumulate in visceral organs, joints and intervertebral disks.
- Causes: Intervetebral disc calcifications at every level, with accompanying disc space narrowing.
39
Q
Sarcoidosis
A
- Multisystemic granulomatous disease.
- Affects: Lungs, adenopathies and parenchymal disease.
- Body manifestations are rare, might produce lace-like lytic lesions in the middle or distal phalanges.
- Might produce acute or chronic polyarthritis, suspect in ankle involvement, especially if bilateral or associated with erythema nodosum.
40
Q
Multicentric reticulohistiocytosis
A
- Rare disease.
- Lipid-laden marophages are deposited in soft-tissues and periarticular tendons, forming skin nodules with erosions and schlerotic margins.
- Well defined erosions of DIP symmetrically.
- Joint destruction may be rapid and progressive, producing arthritis mutilans appearance.
41
Q
Hemophilic arthropathy
A
- X-linked inherited disorder of either factor VIII (Hemophilia A) or IX (Hemophilia B) deficiency, causing recurrent bleeding.
- Affects knees, elbows and ankles.
- Recurrent hemarthrosis results in synovial hyperemia and hyperthrophy, may cause epiphyseal enlargement and early fusion.
- Knee: Widened intercondylar notch, metaphyseal flaring and uniform joint space narrowing.
- Elbow: Enlargement of the radial head and trochlear notch with uniform joint space narrowing.
- Secondary arthritis may lead to marked joint space narrowing.
- Pseudotumor of hemophilia: benign lesion caused by recurrent intraosseous or subperiosteal bleeding.
42
Q
Juvenile idiophatic arthritis
A
- Affects children <16 years old.
- Monoarticular or pauciarticular (most common) on knees, ankles , elbows or wrists. Or polyarticular.
- Still disease: Systemic disorder in <5 years old with fever, rash, adenopathy, pericarditis and arthralgias.
- RX or CT findings: abnormal bone length or morphology, premature skeletal maturation and physeal fusion.
- Hand: Brachydactyly.
- Knee: Widened intercondylar notch, metaphyseal flaring and uniform joint space narrowing.
- Elbow: Enlargement of the radial head and trochlear notch with uniform joint space narrowing.
- Hips: Symmetrical cartilage space narrowing, protrusio deformity and gracile appearance of the femoral shaft.
- Ankylosis in the wrist, zygapophyseal joints of cervical spine.
43
Q
Neuropathic arthropathy (Charcot joint)
A
- Destructive form of arthritis caused by neurosensory defect.
- Painless, swollen joint.
- Causes: Diabetes, syringomyelia, alcohol, amyloid, spinal tumors, syphilis or leprosy.
- Hypertrophic (more common): Anarchy in a joint, destruction, dislocation, debris, disorganization and no demineralization.
- Artrophic: Humeral head resoption with a sharp surgical-like margin.
- 6 D: density change, destruction, debris, distension, disorganisation and dislocation.
