Pollicization is a surgical procedure to substitute an absent or deficient thumb with a working finger, usually the index finger.
The functioning of the hand is highly dependent on the thumb as it helps perform functions such as grasping and pinching. The movements of the thumb, are critical in performing all activities of daily living.
The goal of pollicization is to provide a thumb that is functional and aesthetically pleasing.
Pollicization is indicated in children who are born without a thumb (aplasia) or have a poorly developed non-functional thumb (severe hypoplasia).
Thumb function may be lost in cases of:
congenital mirror hand (a hand with multiple fingers and no thumb)
Abnormally large thumb with poor function (macrodactyly)
Traumatic loss of the whole thumb including the Carpometacarpal joint (the joint at the base of the thumb).
For congenital deformities pollicization is best performed in toddlers who are developing and adapting their motor functions, especially those who consistently use their index finger to perform the functions of a thumb. Therefore, the ideal age to perform this operation is about one year.
Pollicization surgery is performed with your child under general anesthesia. A tourniquet is applied to minimize blood loss.
Your surgeon makes a skin incision to allow easy repositioning of the index finger and adequate web space between the new thumb and the next finger.
The nerves and blood vessels supplying the index and middle finger are separated so that there will not be any tension while rotating and repositioning the finger.
The tendons and muscles of the index finger are released to form the tendons and muscles of the new thumb.
Once the supportive structures are released, the growth plate of the metacarpal is cut and the growth plate is completely destroyed so that it does not have any future potential for growth. This is done to ensure that the reconstructed thumb does not grow too long.
The height of the index finger is then shortened by resection of the metacarpal bone to create an overall thumb-like appearance of the finger. However, the base of the metacarpal bone may be retained if the phalanges are relatively short.
The finger is then repositioned in the desired position and secured with steel wires and sutures.
The new tendons are stitched in full tension.
The skin is then closed with absorbable sutures and any extra skin is trimmed.
The palm is then dressed and placed in a cast.
Following surgery, your child will have regular follow-up visits with the surgeon to examine the new thumb. You may be referred to an occupational therapist who will teach your child stretching exercises and finger activities so that within a period of 12 weeks the finger will function like a thumb.
Advantages & Disadvantages.
The main advantage of pollicization is the restoration of thumb function and sensation which helps significantly in performing independent activities of daily living.
Risks and Complications.
As with all surgeries, pollicization surgery may be associated with certain risks and complications such as:
Arterial inflow compromise (faulty blood supply), leading to a non-viable finger
Necrosis (tissue death)
Scar contracture (tightening of the skin)
Stiffness: The functional state of the new thumb following this operation is directly related to the functional dexterity of the finger which is transferred to create the thumb. Some children have very stiff fingers that do not move very well, however even a relatively stiff thumb is much more useful than no thumb.
Pollicization is a corrective surgery for congenital hand disorders characterized by a missing or poorly developed and functioning thumb. The surgery involves repositioning the index finger to function as a thumb. This complex surgery, performed by a skilled surgeon can successfully restore the opposable function and abduction and adduction movements of the thumb, which are critical in performing activities of daily living.