Common arthropathies involving the hand may be categorized into one of the following:
- Degenerative (osteoarthritis, post traumatic)
- Inflammatory (rheumatoid, seronegative spondyloarthropathy, and JIA)
- Crystaline arthropathy (CPPD and gout)
One of the most important distinguishing factors between osteoarthritis, rheumatoid arthritis, and CPPD arthropathy is distribution of findings.
Osteoarthritis:
- Asymmetric joint space narrowing
- Marginal osteophytes
- Subchondral cystic change
- Subchondral sclerosis
Erosive osteoarthritis:
- Central, gull-wing erosions, usually involving DIP
Rheumatoid arthritis:
- Soft tissue swelling
- Periarticular osteopenia
- Periarticular erosions
- Diffuse/symmetric joint space narrowing
- Joint subluxations and ankylosis (if advanced)
CPPD arthropathy:
- Joint space narrowing
- Calcium deposition
- Subchondral cysts
- 2nd and 3rd metacarpal hook shaped osteophytes
- SLAC wrist related to deposition in the scapholunate ligament and subsequent ligament insufficiency
Gout:
- Sharply marginated, juxta-articular erosions with overhanging margins
- Nodular, soft-tissue swelling/mineralization (tophi)
Psoriatic arthritis:
- Diffuse soft tissue swelling resulting in “sausage digit”
- Mixed erosive and productive changes involving DIPs
- Periostitis/fluffy periosteal reaction/ “whiskering periostitis”
- Pencil-in-cup erosions
- Arthritis mutalans (if severe)
Arthritis search pattern can by driven ABCDES characteristics which categorizes distinguishing factors between degenerative, inflammatory, and crystaline arthropathies:
- Alignment: +/- subluxations/dislocation
- Bone mineral density: +/- diffuse or periarticular osteopenia
- Bone creation: +/- osteophytes, +/- periosteal reaction, +/- ankylosis
- Calcification: +/- chondrocalcinosis, +/- soft tissue calcification
- Cartilage space: asymmetric or symmetric narrowing
- Distribution: PIP/DIP/CMC (OA), MCP/PIP/intercarpal (RA), MCP with osteophytes (CPPD or hemochromatosis)
- Erosions: periarticular erosions (RA), gullwing erosions (erosive osteoarthritis), pencil in cup erosions (psoriatic arthritis), juxta-articular erosions with overhanging margins (gout)
- Soft-tissues: symmetric swelling (inflammatory), nodular swelling (gout), asymmetric swelling (OA)
Example report negative for arthritis
FINDINGS:
- No acute fracture or dislocation. Joint spaces are preserved. No osseous erosions. No periosteal reaction.
IMPRESSION:
- No findings of inflammatory arthritis. No erosions.