Boutonniere deformity commonly occurs due to an injury of the central slip of the extensor tendon. Often when the patient presents to us they may have sat in this position for a couple of weeks, and thus started to develop a FFD meaning that they are starting to tighten up in that flexed position.
Boutonniere deformities can be brought on by an acute trauma (laceration or traumatic avulsion) or due to RA (up to 50% of patients with RA develop boutonniere deformity in at least one digit).
A way of testing for a boutonniere (prior to the development of a FFD) is to do the Elson’s test – used to isolate and therefore assess the action of the central slip.
Conservative treatment – once the finger is passively correctable into full extension, then the patient is put into a cylindrical splint for approximately 5 weeks.
Surgery – necessary for failed conservative cases or more chronic conditions and of course if there is an open laceration. This involves centralising the lateral bands which are subluxed volarly, repairing the central slip.