Pencil-in-cup" deformity -fmge march 2012

"Pencil-in-cup" deformity is seen in? (fmge march 2012,aipg 2010)
a.RA
b.OA 
c.Psoriatic arthritis 
d.Sjögren syndrome 


ANS--Psoriatic Arthritis.



The X-ray Changes are similar to rheumatoid but they differ in their distribution, and the formation of pencil in cup deformities along with osteolysis.


1. Asymmetrical distribution of disease
2. Often affects PIP and DIP joints
3. relative absence of peri-articular osteoporosis
4. Erosions seen at the distal interphalangeal joints joints
5. Reduced joint space
6. Pencil in cup deformity (arthritis mutilans with telescoping of the fingers)- this is a result of osteolysis
7. Loss of the terminal tufts of the phalanges (acro-osteolysis)
8. Sacroiliac and spondylitic changes (similar to those of Ank. Spond.)