Tuesday, March 5, 2013

The 5- Finger Hand

The 5- finger hand is a rare anomaly in which there is no thumb, but rather 5 digits in the same plane (i.e., in a row) without a thumb.  That means each digit has three bones (whereas the thumb normally has two bones).  This is important because the normal thumb function is not present because there is no digit where the thumb normally rests.  This means that manipulation of small objects is difficult because the fingers must manipulate the objects, on the side of each digit (scissoring).  Without a thumb the fleshy pulp cannot manipulate the objects.  Also, it is difficult to grasp larger objects because the biggest object is grasped between the fingers (which does have as much space as the thumb/ fingers).  Some children have a "thumb in the plane of the fingers" anomaly which is similar.  However, the difference is that these kids usually have less than 5 digits and have an associated medical problem.  We have shared our experience with this anomaly in the medical literature.  http://www.ncbi.nlm.nih.gov/pubmed/19897326

We consider surgical reconstruction of the 5- finger hand to improve function (and also appearance).  The digit on the thumb side of the hand is shortened and rotated to create the function of a thumb.  Sometime an entire bone can be removed or other times the metacarpal bone in the hand is simply shortened.  Here is an example of a 5- finger hand.

5- finger hand

Another view of 5- finger hand prior to reconstruction

Final view of 5- finger hand

There are a few reports of treatment of the 5- finger hand, most recommending pollicization.  http://www.ncbi.nlm.nih.gov/pubmed/21093346  and http://www.ncbi.nlm.nih.gov/pubmed/5506242

While the considerations are complex, pollicization is one good option for this anomaly.  Here is our pollicization for this patient.  

Pollicization in 5- finger hand

Another view of pollicization in 5- finger hand.  Note, the new thumb is slightly long (based on discussion with family and possible additional surgery later).


  1. At what age do you recommend pollicization?

    1. Julie and Gabriel,
      Thank you for the question. While there is no 'right' age, we typically operate at 18-24 months. Surgery at an earlier age can be done but structures are smaller.

    2. Thank you. And how is the 5-finger hand different from a Triphalangeal thumb?

    3. Great question and I disappointed that I have not made this more clear. Every 5- finger hand has a triphalangeal thumb but not every triphalangeal thumb is a 5- fingered hand. My definition of a 5- finger hand is a hand with 5 digits, each with three phalanges and each in the same plane (ie, no rotation triphalangeal thumb). In contrast, a triphalangeal thumb may be in the normal position of the thumb. Finally, to perhaps confuse matters more, there is the thumb in the plane of the hand. This a normal thumb (ie, 2 phalanges) but aligned with the fingers like the 5- finger hand. Clear as mud, right?

  2. I just had a patient for a nephrostomy who had two five finger hands. In talking with this patient, he stated that he has seen thirty or forty individuals picking produce in the fields with him in California, who have the same congenital anamoly (in people from his area of Mexico.)

    1. Thank you, fascinating. This certain can run in families and ethnic or cultural groups.