Pollicization of Thumb

Pollicization is a reconstructive surgical procedure in which another finger—most commonly the index finger—is transformed into a functioning thumb. The thumb is essential for hand function, accounting for nearly 40% of the hand’s ability to grip, pinch, and manipulate objects. When the thumb is absent or severely underdeveloped due to congenital conditions, trauma, or disease, pollicization provides a way to restore hand function by repositioning and reshaping another digit to act as a thumb.

Pediatric Hand Surgery

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Importance of the Thumb

The thumb plays a unique role in human hand function:

Indications for Pollicization

Pollicization is usually performed when the native thumb is absent or non-functional. Indications include:

Congenital absence or hypoplasia: Seen in conditions such as radial longitudinal deficiency or isolated thumb aplasia.
Traumatic loss: Severe injury or amputation where thumb reconstruction with other techniques (like toe-to-hand transfer) is not feasible.
Tumor resection or disease: Rarely, when the thumb is removed due to cancer or severe infection.

Principles of the Procedure

The concept of pollicization involves moving the index finger to the position of the thumb while preserving its blood supply, nerves, tendons, and joints. The procedure does not merely transfer the finger but reconfigures it to look and act like a thumb.

Rotation and Transposition – The index finger is rotated and moved laterally to the position of the thumb.
Shortening – The transferred digit is shortened to achieve proper thumb length relative to the other fingers.
Rebalancing of Tendons and Muscles – Flexor and extensor tendons are re-routed to provide balanced motion.
Joint Realignment – The metacarpophalangeal joint of the index finger becomes the new carpometacarpal (CMC) joint of the thumb, allowing opposition and abduction.
Preservation of Sensation – Nerves are carefully preserved and adjusted to provide protective and functional sensation in the new thumb.

Surgical Technique (Simplified Overview)

The surgeon designs a skin incision to allow adequate mobilization of the index finger while preserving blood supply and nerves.
The index finger is carefully freed, keeping the digital arteries and nerves intact.
The digit is rotated and repositioned at the base of the hand where the thumb should be.
Flexor and extensor tendons are adjusted to provide appropriate movement—flexion, extension, and opposition.
The new thumb is stabilized in its position using sutures or wires, ensuring correct alignment.
The skin is closed, and a dressing or splint is applied to protect the reconstruction.

Recovery and Rehabilitation

Hospital Stay: Usually a few days, depending on age and healing.
Immobilization: A splint or cast is applied for several weeks to protect the new thumb.
Therapy: Occupational and physical therapy are critical for teaching the child or adult how to use the reconstructed thumb effectively.
Adaptation: In children, adaptation is rapid, and the brain quickly learns to integrate the new thumb into function. Adults may require longer rehabilitation.

Risks and Complications

Vascular compromise leading to poor circulation in the transferred digit.
Stiffness or limited range of motion.
Weakness in pinch strength compared to a natural thumb.
Growth differences in children, as the new thumb may not grow proportionally.
Aesthetic concerns about appearance.

Prognosis and Long-Term Significance

Pollicization dramatically improves hand function and quality of life. Children who undergo surgery early often achieve near-normal function and appearance, integrating the reconstructed thumb seamlessly into daily tasks. Adults may face longer rehabilitation but also benefit significantly in terms of independence and dexterity.

Beyond its functional impact, pollicization has a profound psychological and social benefit, especially for children, by improving confidence, social interaction, and participation in activities.

Conclusion

Pollicization of the thumb is a remarkable reconstructive surgery that transforms an existing finger into a fully functional thumb. By restoring opposition, grip, and dexterity, it allows patients—particularly children with congenital absence—to live more independent, active lives. With advances in surgical technique and rehabilitation, outcomes are consistently excellent, making pollicization one of the most valuable procedures in hand reconstruction.

Explore more:

Toe to Thumb Transfer