Small Thumb

Early Outcome for Pollicization (creation of a thumb)

Pollicization is the name of the surgery which entails the creation of a new thumb, a “Pollex” (Latin for thumb).  For those of us who regularly care for children born with anomalies of the upper extremity, this is perhaps our favorite because it dramatically helps both appearance and function.  I have previously blogged about pollicization several times as summarized in this Post.  There is some good information on the Internet about pollicization.  My friends at the Texas Scottish Rite Hospital have a wonderful set of videos on pollicization.  The following is a trailer from their work with some very good information:

One of the interesting questions that we face as surgeons is regarding the timing of this surgery.  We want it to be early enough so that the child learns to incorporate the thumb into daily activities as soon as possible.  There is some thought that the surgery should be done very early (1 year of age) so that the brain is reprogrammed to understand that the index finger is now the thumb.  It is my personal belief that the brain has an understanding of the index finger as the most radial (or thumb sided digit) and so pushing for earlier surgery is not necessary.  The child will learn to best incorporate the thumb and it will become consciously and subconsciously clear that the new thumb will help the child function.   
Others wonder whether waiting until an older age might be helpful.  As the hand doubles in size between birth and 2 years of age and then nearly doubles again at maturity, a larger hand will be easier to address surgically.  And a larger hand will be safer to address as the key anatomical structures are bigger.  All of this is true but with surgical experience, the “risks” of surgery in the younger child are very manageable.  An older child, it is argued, will also better participate with therapy.  This is also true but, thankfully, not a great deal of therapy is needed as the thumb usually works well for the child and time/ play activities are usually the keys to a successful functional outcome.
I personally take what I consider is the middle ground an like to perform the pollicization between 18-24 months of age.  I feel that it is the best balance between the benefit of an early surgery (incorporation of the new thumb into life) and a later surgery (larger size and the child may be easier to work with after surgery).  
Here are a few pictures of a child we treated recently.  

Hand with absent thumb before surgery

Palm view of hand with absent thumb before surgery

We performed surgery to create the thumb using the index finger- the pollicization procedure.

After pollicization surgery.  Note the index finger has been reconstructed into a thumb.

After pollicization surgery.

Here is the child only 6 weeks after surgery.  Note that the child is using the thumb but not quite “normally.”  He tends to use the two fingers first with the thumb as an assist.  Dad has noticed that he is progressively using the thumb more and more.  It will be fun to watch him learn to incorporate the thumb into all activities- his use pattern will change during the next 3-6 months.  It is tough to video kids this young, maybe on his next visit I can obtain and then share.

Early after pollicization, using the thumb to help the next to finges.

Early after pollicization, using the thumb to help the next to fingers.
Another picture 6- weeks after pollicization.  He is using his left hand but differently from his normal right hand.  This will change over time.

Charles A. Goldfarb, MD
My Bio at Washington University
congenitalhand@wudosis.wustl.edu

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