A boutonniere deformity or buttonhole 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. Here we explain the causes, symptoms, and treatments of Boutonniere deformity.
Boutonniere deformity symptoms
- Symptoms include pain at the time of injury.
- 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.
Causes

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 fingertip 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

Consultant wrist and hand surgeon Mr. Elliot Sorene explains Boutonniere Deformity.
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 the strength of the finger extensor muscles.