Boutonniere Deformity & Splinting

The boutonniere deformity is a disruption of the normal anatomic alignment provided to the extensor mechanism of the finger involving the central slip. Either traumatic or inflammatory causes of the deformity lead to the finger being in flexion at the proximal interphalangeal joint and in hyperextension at the distal phalangeal joint. The deformity can occur immediately after the injury or take a few weeks to develop. In inflammatory causes of the deformity, there is a progression of the deformity as the synovitis causes elongation.

Traumatic Boutonniere Deformity

• This occurs by laceration or closed rupture to the finger's central slip. A laceration injury occurs when there is direct trauma to the overlying skin and the central slip. A closed rupture typically occurs when there is a forceful trauma to a bent finger, resulting in injury to the central slip.

Synovitis Causing Boutonniere Deformity

• Inflammatory conditions such as rheumatoid arthritis can cause a boutonniere deformity by elongating the central slip because of chronic inflammation of the synovium (synovitis). Approximately one-third of all people with rheumatoid arthritis will develop fingers with boutonniere deformities. Typically, rheumatoid arthritis causing a boutonniere deformity will require surgical correction.

Non-Surgical Treatment

• If the injury to the central slip occurred without an open laceration or chronic inflammatory cause, the finger can be splinted for six weeks. The splint should be made so that the finger remains in extension at the proximal interphalangeal joint. The distal interphalangeal joint should not be immobilized so that it can be actively and passively flexed during treatment. Progress in healing can be seen if the patient is able to actively flex the distal interphalangeal joint with the proximal interphalangeal joint in extension.

  Best results are seen if splinting is prompt and compliance with the splint in extension is maintained. A physician might have the patient see occupational therapy or have the patient do home exercises to improve the finger's strength and flexibility If the patient is involved in athletics or other types of physical activity that increase the risk of trauma to the involved finger, if might be necessary to continue to wear a protective splint or tape the finger for several weeks.

Surgical Treatment

• Most practitioners believe that at least three months of splinting should be tried before surgery, but other indications exist for more emergent surgery. If the boutonniere deformity occurred from a laceration, the central slip is repaired with non-absorbable suture. The finger is then splinted for four to six weeks with the distal interphalangeal joint left free. A large fracture that is displaced might require open reduction and internal fixation.

  Surgery is aimed at typically placing a pin in the joint to place the proximal interphalangeal joint in extension. A tenotomy might be required to assist with attaining proper anatomic alignment of the finger.

  Post-operatively, the finger will require splinting to support the surgical procedure. Typically, the finger will remain in a splint for six weeks or more post-operatively. The splint type will depend upon surgeon preference and what procedures had to be done intra-operatively to restore anatomic alignment.

The Boutonniere Deformity Splint

• The splint is applied to the finger at the proximal interphalangeal joint. The distal phalangeal joint is not immobilized. There are many types of splints that can be purchased or custom designed. Occasionally it is necessary to include the metacarpal phalangeal joint and wrist joints in the splint. If the metacarpal phalangeal joints are to be included in the splint, they are placed in extension to allow for relaxation for the central slip and lateral bands.

  It is important to wear the splint for the recommended length of time according to the physician who is treating the condition. Young patients typically require the full six weeks of splinting, but an elderly patient might only require three weeks. Once the treatment is over, the patient still might need to wear the splint at night to help maintain correction of the deformity.

Warning

• As with any injury or disease, it is recommended to see a physician for definitive treatment as soon as possible. Attempts to self-treat can result in a progressive injury or failure to treat appropriately.