How is boutonnière deformity diagnosed?
Your healthcare provider will take a complete medical history and do a thorough examination of the affected joint. Your provider will perform an Elson’s test to evaluate your hand injury and see if the central slip is still intact.
Your provider will ask you to curl your fingers around a table edge. Then your provider will press on your middle phalanx (the bone that's between your knuckle and the joint before the tip of your finger) of the affected finger. Your provider will ask you to extend your finger. If they can feel your finger attempting to straighten out, they’ll know that the central slip isn't torn or cut. If you’re not able to extend the finger, they’ll know the central slip isn’t working.
You might need an X-ray if your provider thinks you might have a broken bone.