Spondyloarthropathies: Approach in wrists

Wrist is not a single joint. For the purpose of Arthropathies, the wrist can be divided into following compartments:
1. Inferior radioulnar joint
2. Radiocarpal joint
3. Midcarpal joint
4. Pisiform-triquetral joint
5. Carpometacarpal joint
6. 1st CMCJ

Initial coimpratments: radiocarpal, radioulnar, pisiform-triquetral
Eventually pancompartmental
Major damage occurs in distal ulna

Midcarpal and common carpometacarpal compartments are predominalty involved with distal carpal migration
Eventual fusion of carpal bones and base of 2-5 metacarpals
relative sparing of the 1st CMCJ and radiocarpal joint

OA and erosive OA:
1st CMCJ with radial subluxation and trepizioscaphoid joints

Mimics OA
Radiocarpal joint is predominantly involved with narrowing of the joint space
Also midcarpal
Check lunotriquetral joint for chondrocalcinosis. This is more sensitive than TFCC for chondrocalcinosis
Radial erosions
Decrease in lunate-capitate space
Increase in scapholunate space
Destruction of trapezio-scaphoid joint

Predominant involvement of common carpometacarpal joints with erosions at the bases of metacarpals
CMCj may also be involved

Septic arthritis:
Never forget this in the differentials
Diffuse pancompartmental

Arthropathy in 1st CMCj with subluxation and calcification

Collapse of scapholunate space

Resnick et al, Bone and joint imaging, 3rd edition, Elsevier Saunders publications