Abstract
The rupture of the central slip of the extensor tendon of the finger causes a deformity, characterized by flexion at the proximal interphalangeal (PIP) joint and hyperextension at the distal interphalangeal joint (the boutonnière deformity). Various treatments are used in this condition, including conservative and operative methods, however, there is no standard treatment guideline. The idea the relative motion flexion splint method is based on an importance of keeping the metacarpo-phalangeal joint of the involved finger relatively flexed compared with these joints of the adjacent fingers. This is done with a relative motion flexion splint. Flexion in the metacarpo-phalangeal joint allows the lateral slips of the extrinsic extensor tendon to pull the lateral bands dorsal to the axis of the PIP joint. It allows also the relaxation of the intrinsic muscles and the lateral bands so they can migrate dorsal to the axis of the joint. This article presents the method and provides literature review about outcomes of treatment of the condition.