Extra Digits (radial polydactyly) Rare Conditions

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. 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.)

  3. I was born with 2 5 fingered hands and extra sets of bones in my big toes. I’m 70 years old and it was not hereditary. When I was going thru surgeries which started 68 or 69 years ago, it was all experimental. My hands have never affected the use of them. I have always been able to do whatever I’ve needed to do. About the only thing I haven’t been able to do is snap my fingers but that’s ok.
    The reason I am writing this is to give people courage and let them know that they can live a very normal life.

  4. I have 2 triphalangeal thumbs. So does my dad, my uncle, my grandpa and my grandfather’s sister. Having triphalangeal thumbs I think gives me more of an advantage than disadvantages.

    1. Arielle,

      Thank you for sharing. Your family’s experience is common as triphalangeal thumbs are strongly genetic. Some of the best studies have come from Rotterdam in The Netherlands with a large number of affected families.

      I am glad you feel that the triphalangeal thumbs offer advantages. I typically hear more regarding challenges with the extra bone.

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