Boutonnièredeformiteit

Boutonnièredeformiteit is a condition affecting the finger, characterized by a flexion deformity at the proximal interphalangeal (PIP) joint and hyperextension at the distal interphalangeal (DIP) joint. This results in a characteristic appearance resembling a buttonhole, hence the name. The deformity typically arises from an injury to the central slip of the extensor mechanism, which runs along the top of the finger. This central slip is responsible for straightening the PIP joint. When it is damaged, the PIP joint tends to flex, and the forces that would normally extend it are transmitted to the lateral bands of the extensor mechanism, causing the DIP joint to hyperextend.

Common causes of boutonnièredeformiteit include direct trauma to the PIP joint, such as a forceful blow or a jammed finger, and closed injuries where the finger is bent backward. Rheumatoid arthritis is another significant cause, as the inflammatory process can erode or rupture the central slip. Repeated minor trauma can also lead to the development of the deformity over time.

The presentation varies depending on the severity and stage of the injury. Initially, there may be pain, swelling, and difficulty straightening the finger. As the deformity progresses, the PIP joint becomes fixed in flexion, and the DIP joint adopts a hyperextended position. The ability to grip and perform fine motor tasks can be significantly impaired. Diagnosis is usually made based on the clinical appearance and a history of trauma or underlying condition. X-rays may be used to assess for fractures or signs of arthritis. Treatment options depend on the cause, duration, and severity of the deformity. Conservative management, including splinting and physical therapy, may be effective in acute cases to prevent the development of the fixed deformity. For established deformities, especially those causing significant functional impairment, surgical intervention may be considered to reconstruct the extensor mechanism or improve joint alignment.