A definition of Boutonniere Deformity
In Boutonniere deformity the finger is bent down at the middle joint and bent back at the end joint. Usually resulting from an injury, Boutonniere deformity can also develop in inflammatory disorders such as rheumatoid arthritis. Others may be born with a mild boutonniere posture of their fingers. In an injury where the finger is bent forcefully, the tendon tears away from the top of the finger bone. The tear resembles a buttonhole (“Boutonniere” in French) and the tendon cannot straighten the middle joint which remains bent, and all of the force goes to the end of the finger, flipping it back. The PIP Flexion Dynasplint® System can be used for boutonniere treatment because it helps to bend the end joint down and straighten the middle knuckle. In most cases, proper splinting will reduce the need for surgery.
Boutonnière deformity occurs as the result of an injury to the finger tendons, which results in the finger being unable to straighten fully. In Boutonnière deformity, the affected finger appears deformed, with the middle finger joint bent downward and the fingertip joint bent backward.
The fingers comprise a wide range of structures, including bone, tendons, ligaments and other tissues, and a complicated interplay among all of these structures allows the fingers to move in a normal and complete range of motion. Finger movement – particularly flexion, or bending – is facilitated by tendons that run along the sides and tops of the fingers. These tendons alternately contract and stretch to allow the fingers to bend and straighten. Central tendons that run along the top of each finger attach to the middle finger bone. When these tendons become injured, boutonniere deformity can occur.
Most Boutonnière deformities arise as the result of a severe blow to the finger when it is bent, or from a “jamming” motion to the fingertip. Some deformities occur as the result of osteoarthritis or rheumatoid arthritis, and about one-third of all individuals with rheumatoid arthritis have boutonniere deformities.
In other cases, the deformity can occur following an injury that causes a cut in the skin and other tissues of the finger’s top surface, resulting in the tendon becoming torn or detached from the bone. These small openings resemble buttonholes, and provide the genesis for the name “Boutonnière.”
No matter what causes the condition, unless Boutonnière deformity is treated promptly the condition can progress and become permanent, and function can be irretrievably lost.
Boutonnière deformity may become apparent immediately following an injury, or it may develop within one to three weeks following the injury. In every case, the affected finger will be painful and usually swollen, the finger will not be able to be straightened and the fingertip will not be able to be bent.
In addition to a physical examination, x-rays may be ordered to ensure there are no fractures associated with the injury.
Early diagnosis and treatment of boutonniere deformity is essential to regain and retain full range of motion in the injured finger. Both non-surgical and surgical options are available, depending on the type of injury. In general, surgery is reserved for patients
- who have rheumatoid arthritis
- who have displaced bone fragments
- whose tendon has been severed
- when splinting does not work
Following finger surgery, the patient will be asked to wear a splint during recovery. Although surgery can help improve function and reduce or eliminate pain, in most cases, the finger will remain misshapen.
For the vast majority of patients with Boutonnière deformity, non-surgical options are preferred. Splints are the most commonly applied treatment, and are used to straighten the middle finger joint. In most cases, splints will be required from three to six weeks, and may be required to be worn at night even following this period of rehabilitation. Physical therapy/occupational therapy is often recommended in combination with dynamic splinting. Therapy will involve stretching and flexibility exercises to improve the finger’s strength and range of motion. Once the splinting period ends, athletes may be required to wear a protective splint or tape to protect the finger and tendons as they heal. Individuals with arthritis may be given steroid injections or oral medications in addition to splinting.
In all cases, they key to achieving the greatest degree of range of motion and reduction in deformity is to have the finger diagnosed and treated as early as possible.