A boutonniere deformity or button hole deformity is an injury to a tendon in one of the fingers, resulting in a deformed shape. This usually occurs after an impact to a bent finger.
Boutonniere deformity symptoms
Symptoms include pain at the time of injury with tenderness on top of the middle finger bone which is likely to be swollen. The finger cannot be straightened at the middle joint and the end joint cannot be bent.
A boutonniere deformity usually occurs after a direct impact to the middle finger bone. the middle finger joint may be forcefully flexed, causing a rupture of the extensor tendon. Less frequently, a cut to the upper surface of the finger tip may sever the attachment point of the tendon to the bone. They are also seen in approximately one third of people with rheumatoid arthritis.
Treatment of a boutonniere deformity
If caused by a traumatic injury rest the finger and apply cold therapy to ease bleeding and swelling. Visit a Doctor as soon as possible.
After an examination the doctor can provide a splint to keep the finger straight. This helps the tendon to heal in the correct position. They may also provide anti-inflammatory medication.
Surgery is sometimes performed if the tendon is severed or if there is a fracture present. The tendon may be reattached or a fracture pinned and the finger straightened. It is then put in a splint to allow it to heal. Exercises may be given once the splint is removed to increase strength of the finger extensor muscles.