Swan Neck Deformity – Finger Deformity

The fingers consist of three bones known as phalanges, divided by two joints: the distal interphalangeal (DIP) joints near the fingertips and the proximal interphalangeal (PIP) joints located in the middle section.

Extensor tendons connect to the phalanges, enabling finger extension. Ligaments join the bones together, while the volar plate—a robust fibrous structure on the palm side of the PIP joint—prevents hyperextension of this joint.

A swan neck deformity occurs when the volar plate is torn, weakened, or overstretched. This compromise leads to excessive backward bending (hyperextension) of the PIP joint and subsequent inward bending (flexion) of the DIP joint, resulting in the characteristic crooked appearance.

The most frequent cause is chronic inflammation due to rheumatoid arthritis. Other factors, such as trauma or neurological disorders like cerebral palsy, stroke, Parkinson's disease, and traumatic brain injuries, can also contribute to muscle tightening that stretches the volar plate.

Individuals with a swan neck deformity may experience pain and swelling in their finger joints. The PIP joint will hyperextend, while the DIP joint flexes toward the palm. If the deformity is rigid, it may significantly impact finger function, leading to a visibly crooked finger.

A physician can diagnose a swan neck deformity through a physical examination of the hand. X-rays may be ordered to assess joint alignment and damage, as well as to rule out fractures.

Non-surgical treatments such as splinting and hand therapy may be effective, especially for flexible finger joints. A hand therapist will guide you through exercises designed to stretch and strengthen the joints, enhancing functionality. Treatment with a splint typically lasts for a minimum of six weeks.

In cases where non-surgical methods are insufficient, surgical options may be necessary to reconstruct the supporting skin, tendons, and ligaments of the PIP joint. If the PIP joint is severely damaged, an artificial joint may be implanted to restore movement in a procedure known as arthroplasty. Alternatively, surgical fusion of the bones may be performed to limit movement. Post-surgery, splinting and rehabilitation through hand therapy are essential for recovery.

In cases where non-surgical methods are insufficient, surgical options may be necessary to reconstruct the supporting skin, tendons, and ligaments of the PIP joint. If the PIP joint is severely damaged, an artificial joint may be implanted to restore movement in a procedure known as arthroplasty. Alternatively, surgical fusion of the bones may be performed to limit movement. Post-surgery, splinting and rehabilitation through hand therapy are essential for recovery.