Small Thumb Video

Untreated Adult Hypoplastic (Small) Thumb

On occasion, an adult comes to my clinic for evaluation of one issue and a previously unrecognized issue is identified.  This type of presentation can come in different varieties and, due to my particular practice type, often we find a birth anomaly that has not been recognized or treated.  This patient is one very interesting example.  She has a left hypoplastic thumb.  There is an appearance difference and a functional difference yet it has not caused major problems for her.  Her right thumb and hand are dominant and the left hand and thumb are used for assist (as we all function).  Her thumb is weaker and more lax and has decreased motion.  But none of these problems were completely troubling to her and she certainly is not interested in treatment at this point. 

From the hand surgeon perspective, she has a classic small thumb on the right (technically a hypoplastic thumb– Type IIIA).  It is thin (and seems long but that is really only because it is thin).  She has small muscles at the base of the thumb (thenar muscles), a decreased web space (between the index and thumb), laxity at her MCP joint, and decreased thumb motion.  In other words, she checks all the boxes for a classic hypoplastic thumb.

These videos demonstrate many of these classic findings for hypoplastic thumb and hopefully are helpful to better demonstrate the limitations of her left thumb.  While I see many children with this condition, it is a little bit more tricky to capture the presentation on video!

Charles A. Goldfarb, MD              

My Bio at Washington University     

Please CLICK HERE to support our research.  
Designate my name.  Thank you!


    1. How was life with it on two hands? I have it on one hand, but my kid has it on both. Is it debilitating for you?

      1. Agree that when both are involved, the challenge is greater. Clearly, when only one hand is involved, it is easier to compensate with the ‘normal’ hand. With both involved, issues are magnified and reconstructive surgery becomes even more impactful.

    2. I have this on my right hand. I am right-handed, but I do things with my left a lot. I text with the left thumb and I deal playing cards with my left hand and other things that I don’t think about it.

  1. Thank you for this, my hands are exactly like hers. I never knew what it was exactly but I have it on my right hand thumb and i’m right handed. Could this be fixed with surgery and how long is recovery?

    1. Steven,

      Thank you for sharing. Surgery on adults for hypoplastic thumb is not commonly performed for a few reasons. First, surgery is usually done in childhood. And second, you have likely learned to adapt. However, on occasion, surgery can be helpful and improve function. Ideally, you can seek care with a hand surgeon who cares for adults and children.

Leave a Reply

Your email address will not be published. Required fields are marked *