<prompt> Boutonniere deformity involves -Flexion at PIP and DIP jointExtention at PIP and DIP jointFlexion at PIP and Extention at DIP jointExtention at PIP and Flexion at DIP joint  <response>: Ans. is c i.e., Flexion at PIP and Extention at DIP joint Important hand deformities of hand in RA Boutonniere deformity: Flexion contracture of PIP joint and extension of DIP joint. Swan neck deformity: Hyperextension of PIP joint and flexion at DIP joint. Z-deformity: Radial deviation of wrist with ulnar deviation of fingers. Hyperextension of 1st interphalangeal joint and flexion of MP joint. 