Forearm deformity Ulnar Deficiency

Ulnar deficiency, considerations for surgery

I have previously written several times about ulnar deficiency.  I would like to provide some additional thoughts on function, limitations, and possible ways that a surgeon can help.  First, I want to state again that most kids with ulnar deficiency do not need surgery.  Function is typically good although there can be some notable limitations.

This first child functions well with her ulnar deficiency.  No doubt.  And surgery is not always appropriate.  However, I think it is my job to consider options to help her function better.  I explain some of these below.

Excellent shoulder function in ulnar deficiency
Ulnar deficiency.  Note short arm

Side view of ulnar deficiency

These pictures demonstrate that the shortness of the arm can be an issue.  Obviously, the affected arm moves well but you can imagine that 2- handed activities can be a challenge.  The following x-ray demonstrate that the radius is fused to the humerus and there is a short ulna.

Ulnar deficiency with radiohumerus synostosis.

Very rarely, if there is a well developed proximal ulna (in this case the ulna is really small), the surgeon can try to separate the humerus and the radius to allow some (although limited) elbow motion.  This has been an option only a few times despite many cases at our hospital.  If this is an option, it is done at a young age.  Another option is to lengthen the radius (or humerus) to make the arm longer.  This is not a procedure I will offer commonly in these children but it can be considered.

Ulnar deficiency hand to mouth
Ulnar deficiency resting position

Ulnar deficiency, hand on side

Other thoughts.  First, the hand appears to rest on the flank.  More bluntly, the hand/ arm can appear to be on backwards.  However, as the pictures demonstrate, the shoulder works great and the child can put her arm wherever she wants or needs to.  So, we can cut and rotate the forearm bone to make the position of the arm look better, it doesn’t usually help function in ulnar deficiency and so we rarely perform this surgery.

The most common surgery in children with ulnar deficiency is hand surgery.  These surgeries typically address angulation, syndactyly-, or positioning of the digits.   The child pictured above had 3 fingers but only 2 metacarpals (the hand bones on which the fingers rest).  It will be difficult for a surgery to improve her function but rotating one of the digits into more of a thumb position might be helpful and will be considered as she gets older.
This is a different child with a syndactyly of the two digits in ulnar deficiency.  Separation of the digits will make a big functional difference for the child.

Ulnar deficiency and 2 fingered hand with syndactyly
Palm view of syndactyly in ulnar deficiency
After reconstruction.  Note separated fingers and skin donor site at elbow for grafts.
Syndactyly reconstruction in ulnar deficiency


  1. Hello- My 4 month old son was born with ULD. When would you or wouldn't you recommend lengthening? My son's ULD appears to be Type II, he has all 5 fingers and likely radial head dislocation. Lastly, in your experience does the limb length discrepancy stay about the same with age? Thanks for the important work you do and for sharing information. It is much appreciated!

  2. Jennifer, thanks for the comment/ question. First, the limb length discrepancy does stay about the same proportionally with growth. Second, the question on whether to lengthen is a tough one, especially without radiographs. Certainly, the idea of lengthening to allow reduction of the radial head is appealing as it has the potential to allow normal development of the elbow joint (the radio- capitellar joint). If you are going to do it, it needs to be in the relatively near future. However, it is simply difficult to provide the joint reduction and will require multiple surgeries over the years with growth. I tend against the operation.

  3. My daughter, who is now 1, was born with radiohumeral synostosis, type 3A blaut of the thumb, and no elbow joint. Although she has all 5 fingers, with only a small thumb, I am so proud of what she has accomplished. This posting, with the picture of the little girl, just made my day. I am so thankful to have my daughter!!

  4. Thank you for posting and I am so happy to hear that she is doing so well. Sometimes there is a surgery that can improve function, especially to stabilize and/ or position the thumb (even though it sounds like she is doing just fine). Good luck!

  5. My grand daughter has her ulna missing on her left arm she has all 5 fingers her wrist turns slightly to the left and she does not stretch her fingers much. The plastic surgeon she went to showed us some exercises to get her to try to get her to straighten them out she is starting not to keep her hand in a fist and she also grabs her left hand and pulls it herself is there something else we can do to help her she seems to get frustrated when she tries to hold her bottle?

  6. Susan, thanks for question. The short answer is maybe there are things that can be done. However, despite your good description, the details of your granddaughter's condition are key to understanding her status and giving you the best advice.

    As I have written before, I believe strongly that you want your granddaughter to be cared for by someone who has a lot of experience with children born with hand and upper extremity differences. While your plastic surgeon may be very qualified and have a lot of experience, make sure. If there is any doubt, find someone who has a passion for children with birth differences (and experience with problems like your granddaughter) and seek them out for opinion and care.

    I hope that helps.

  7. Can I ask more about the multiple surgeries over the years with growth comment? We have a six month old that has been diagnosed with ulnar defiency. His right is 1mm shorter than radius (radial head dislocation (-20 extension), absent pinky finger and hyposplastic thumb and first finger) His left ulna is longer than the radius but he has radial head dislocation (-20 extension) and his thumb does not bend. It was suggested that we lengthen the ulna at 12 months to close the dislocation. I think we understood it as one surgery, but I guess you're saying as the child grows and the bone grows at a slower rate, the dislocation will reoccur and lengthening would need to continue until child stops growing??? Thank you for creating this blog, there is so little information out there on ULD and radial head dislocation. Thank you, Melanie

  8. Melanie,
    First congratulations on your 6- month old! I know that the lack of clear information and guidelines must be difficult for you as a parent. Part of the reason for this lack of information is that there are so many variables/ differences between kids. It is difficult for me to give clear thoughts with limited information and without an examination and x-rays. However, I can say that it is a challenge to think that you can just lengthen the ulna and the radial head will fall back into place. It might but unfortunately it doesn't always. Also, I would expect that there would be more lengthenings required over the years. And finally, even if the radial head fell into place, there still would be limited forearm rotation. I hope that helps somewhat. Good luck!

  9. Dr Goldfarb, Thank you for getting back to me. Our son has several things going on, but so far the lower extremities have been our main focus and we've seen specialists in Baltimore and Florida for that along with our current care in Ann Arbor. No one that we've seen seems to have the expertise that you have in upper extremities and I'm wondering is there a way to contact you to ask more specific questions? Thanks very much, Melanie

  10. Hi my name is jessica my son is 9 months old he was born with hand and limb deformation and with out elbow on both hands he has 2 fingers on his right hand and 1 on his left hand is there anything that could be done to help him

  11. Thanks for your question, Jessica, and congratulations on the birth of your son. While it is difficult to know based on this question, it sounds as though your son may have ulnar deficiency. Sometimes there are options which can help with function and most commonly, these surgeries are performed on the hand. Feel free to contact me offline if I can help further.

  12. Hi. My name is Heather and I have a 9 week old daughter who just received X-rays on her left arm showing her radius fused to her humerus and a short ulna. She only has 2 digits on her hand with one appearing to be a thumb and all bones and joints in both fingers. The orthopedist that we saw said that an elbow joint could not be created if she wasn't born with one so there was no point in doing surgery. I was wondering if this was really the case and/or should I seek out s second opinion? I'm an occupational therapist so I'm looking at what options would give her the most independent function. Her X-ray looks similar to the one posted in this article with the ulnar appearing to be longer. Thank you for your input!

  13. Heather, congratulations on the birth of you daughter. A small group of kids have an ulna which theoretically means that if you separated the radius and humerus, you could provide motion. I have had mixed results with this technique. Most kids like your daughter do not have the ulna and, as your physician stated, the elbow joint cannot be restored. The good news is that her function will be really, really good (especially if the other arm is not affected). I hope that helps, good luck.

  14. hi my name is shiovellie august am from santa elena cayo, belize city.My 9year old son was born on march 3rd 2007. He has both hand missing his ulna bones, i took him to see many specialist in belize city however he was never diagnosed with any medication or intentions of surgery due to the fact that he has his ten fingers, five on each hand. he can write, play, feed himself, clean himself, lift items and do many normal things another kids can do. am very worried now because he is getting older but his hands are not growing longer over the years i have been monitoring them and notice that they are still at his hips. i have been taking him every year on his birth day month to do xtray but they still haven't change do he need surgery? u can email me at if u can help

  15. Shiovellie,
    Your son's situation sounds different that most kids with ulnar deficiency. It is common, however, for kids with absent radius or ulna to have a short forearm. The forearms should still grow, but just not as long as in other kids. Sometimes we can lengthen the forearm bones if the length is hurting his function.
    I hope that is helpful.

  16. My beautiful baby boy (8 weeks on Tuesday!) has recently had an x ray showing he has no elbow joint, with a fused ulner (short) & humerus, with no radius on his left arm. He has a wrist joint, thumb & little finger, missing the three digits in between.
    Most of the comments refer to a radius fused with the humerus rather than the ulner, so would I be right to assume that is more common?
    Does the fact it's his ulner (shirt) fused with no radius effect the movement compared to a radius with short or no ulna?

  17. Congratulations on your boy! You are correct in that a radiohumeral synostosis is much more common as part of an ulnar deficiency (this is likely a Type IV). The other factor favoring a diagnosis of ulnar deficiency is the presence of a thumb. Obviously, x-rays are the key to making this diagnosis.

  18. Hello I have a 4month old daughter who has the exact same 2 fingered hand as above. I am so relieved to come across this article as it shows us the process she will be going through. Is it ideal to wait until she is a year old to split the fingers- even though they are different lengths? And do you know what may of caused this as noone seems to be able to provide us with a explanation unfortunately. Thanks

  19. If the fingers are well aligned and not of dramatically different lengths, I would probably wait for the surgery (balancing anesthesia safety with the desire for early treatment). But, early surgery could make sense if one finger is deviating because of the tether. This is caused by a failure of the signals which should allow the fingers to separate. This is a failure at the molecular level.

  20. I am 32 and female. I have ulna deficiency in my right arm and am missing my pinky finger. I just wanted to write because I see many concerned parents. I am married and have 2 beautiful girls who have no deformation. I have a bachelor's degree and held jobs before becoming a stay at home mom.
    Growing up I played softball, did chores, and took 9 years of piano lessons. I feel in love with piano and do believe it gave me maximum dexterity. My mom let me try everything and was very good about not pointing out my difference or initiating conversation about it.
    I can imagine how terrifying it is to have a child with any condition, but as far as my type, I haven't really been that limited.

  21. Hi
    My son who is 16 weeka,was born without an ulna with 3 digits on his right hand and with 4 digits on his left. He is scheduled for surgery once he is 24 weeks.. I am a littke bit scared and not too sure if I should let them go ahead with the surgery.

  22. Hi my son has ulna deficiency he is now 31 yrs and nothing has ever held him back. I can remember him first fastening his own shoe laces ay 5yrs old and felt very emotional as I thought he would never do that, he has led a normal life and has never let it hold him back. I never made any allowances for him ot treat him any different and neither did the rest of family and friends so it was never an issue. He has been a DJ from the age of 15 years, drove a car from 17 years(automatic) and is in his last year of university to become a social worker, I am very proud of what he has over come and achieved in life, so please don't worry too much about your little ones, there will be a few sad moments but in all they will lead a happy, normal life. Please feel free to get in touch if I can help.

  23. Thank you for your positive comments. And I agree, in general. However, every child and every birth anomaly is different. Some kids will need more assistance (both physically and/ or emotionally) while others perhaps even less. Nonetheless, thank you.

  24. My 1 year old granddaughter born with apert syndrome has no elbow joints and cannot bend both arms what is this called and what can we do so she can achieve basic living skills like eating washing her hair etc.

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