Radiological Approach to Arthritis : Mnemonic

Mnemonic: ABCDES

Alignment

1. RA: Ulnar and volar subluxation at the MCPJ and boutonniere or swan neck deformities
2. PsA: Multidirectional
3. Absent: CPPD and gout

Bone – mineralization

1. Periarticular osteopenia (hyperemia of inflamed synovium and soft tissues): RA, Septic arthritis, PsA
2. Subchondral sclerosis: OA, Neuropathic arthritis

Bone – production

1. Osteophytes (margins of synovial joint): OA, CPPD (with calcification)
2. Fluffy periostitis: PsA
3. Spondylophytes (horizontal/perpendicular to spine): Spondylosis
4. Syndesmophytes (vertical/parallel to spine): Ankylosing spondylitis
5. Flowing syndesmophytes (atleast 4 vertebra): DISH

Cartilage (Joint space)

1. Asymmetric narrowing: Degenerative diseases (OA, CPPD, EOA)
2. Uniform narrowing: Inflammatory diseases
3. Preserved: Gout

Calcification

1. Periarticular soft tissues: Gout
2. Tendons: HADD (amorphous and globular), CPPD (linear and stippled)
3. Cartilage: CPPD

Distribution

1. OA: 1st CMCJ, STTJ, DIPJ
2. RA: Symmetric and pancarpal, MCPJ, PIPJ
3. PsA: Asymmetric and DIPJ, PIPJ
4. CPPD: 2nd/3rd MCPJ (hooked osteophyte) or SLAC
5. Hemochromatosis: 4th/5th MCPJ (hooked osteophyte and no chondrocalcinosis)

Erosions

1. Marginal erosions (bare area of joint): RA (MCPJ), Psoriatic arthritis (DIP)
2. Subchondral erosions: Erosive osteoarthritis
3. Gullwing deformity (Subchondral erosion + Osteophyte): EOA
4. Pencil-in-cup deformity (marginal erosion + bone proliferation): PsA
5. Periarticular erosions (eccentric where capsules attach): Gout

Soft tissues

1. Symmetric fusiform soft tissue swelling: Inflammatory diseases
2. Asymmetric soft tissue swelling: OA, EOA
3. Lumpy bumpy pattern: Depositional processes (gout, sarcoid, amyloid, neoplasms)

ABCDES of Arthritis of Wrist and Hand

Features	RA	PsA	OA	EOA	CPPD	Gout
Alignment (subluxation)	Ulnar	Multidirection	Lateral	Lateral	None	None
Bone mineralization	Osteopenia	Normal	Normal	Normal	Normal	Normal
Bone production	None	Productive	Reparative	Reparative	Reparative	Overhang
Cartilage (joint narrowing)	Uniform	Uniform	Nonuniform	Nonuniform	Nonuniform	Preserved
Calcification	None	None	None	None	Cartilage	Soft tissue
Distribution	Proximal, bilateral/symmetric	DIP	Typical	Typical	Atypical	Random
Erosions	Marginal	Marginal, Pencil-in-cup	None	Subchondral, Gull-wing	None	Juxta-articular
Soft tissue	Symmetric	Symmetric	Asymmetric	Asymmetric	Asymmetric	Lumpy-bumpy

References and Further Reading:

1. A Systematic Approach to Radiographic Evaluation of Arthritis of the Hand and Wrist. Contemporary Diagnostic Radiology 44(11):p 8, May 31, 2021. | DOI: 10.1097/01.CDR.0000751608.63997.3a
2. The Radiology Assistant : Arthritis