In this uncommon condition there is congenital fusion of the proximal ends of the radius and ulna, fixing the forearm in varying degrees of pronation. In about 60 percent of cases, involvement is bilateral.
Male and female incidence is approximately equal.
There are three types of radioulnar synostosis.
First type is true congenital radioulnar synostosis where ulna and the upper end of the radius are closely fused together. The radial head may be fused to the ulna, or it may be completely absent.
The radial shaft is bowed to a greater degree than normal and is longer and thicker than the ulna. A
The second type is that in which the radial head is malformed and posteriorly dislocated.The proximal end of the radius is fused with the upper shaft of the ulna.
In the third type, the rarest, the ulna and radius may be attached, at a point just distal to their upper ends, by a short, thick, interosseous ligament that prevents any pronation or supination, just as if the bones were fused together. This is not a true synostosis.
Congenital radioulnar synostosis is hereditary in some cases, appearing to be a dominant trait . It is caused by a developmental arrest of longitudinal segmentation.
Clinical Findings
There is no motion of the radius or the ulna, and the forearm is usually fixed in a position of mid-or hyperpronation.
The lack of supination of the forearm is compensated for somewhat by rotation at the glenohumeral joint, though it is impossible for the palm to be fully supinated. The elbow joint and the wrist are able to move freely, though extension of the elbow may be somewhat limited.
The degree of functional disability varies according to the position in which the forearm is fixed. It may be minimal if the condition is unilateral.
The child may have difficulty with such activities as turning a doorknob, buttoning shirts, and handling eating utensils.
The involved forearm is thinner than normal and somewhat twisted in appearance.
Treatment
Each patients should be individually evaluated to determine the treatment required. Surgical separation of the synostosis is not advised, as results have been poor.
In cases of extreme pronation, an osteotomy in the proximal thirds of the radius and ulna may be performed to place the forearm in functional position.
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DeeDee, My son is now 13 and has radial ulna syntosis in his left arm, he would be very happy to discuss this with your son as he manages brilliantly, he is even a goalkeeper! I don’t know how we are allowed to get in touch with each other? Dr Singh could you please advise, thanks
Dr Arun Pal Singh Reply:
July 8th, 2011 at 11:11 pm
@Linda Miller,
You can join communities. There is not much activity it is fantastic way of interacting and sharing.
Check it out here
http://communities.boneandspine.com/groups/congenital-radioulnar-synostosis/
I too am surprised to hear of so many others with the same problem as I have. I’ve lived with limited rotation in my arms for as long as I can remember. The biggest challenges for me have been taking change, typing, and properly using eating utensils…..like so many others have commented on! Also, as a girl, I wasn’t able to participate in gymnastics either. Playing sports wasn’t a big deal until I became interested in tennis during high school. The coach was constantly telling me to “straighten out my arms”!! The problem I’m having now, at 36 years old, is keeping my left arm from “locking up”. I learned to knit about a year ago and I’m assuming the stiffness is from holding my arms in a certain postion for a length of time. Only now I’m unable to get it extended back to what I consider normal. It’s too sore to stretch and much easier to just compensate but I know I need to see someone about what I need to do. Anyone have any ideas?? I also have a 5 year old son with the same problem:(
My son is 5 years and has radio ulna synostosis in both hands. He cannot rotate his hands and it is difficult for him to perform basic jobs of life – like coloring (as in shading), shampooing, combing, holding utensils, catching a ball. I had seen many doctors and i came accross one doctor who suggested correction of the ulna for my son. He said that in the surgery they would cut the bone in the forearm and place it in a way that my son is able to shake hands with people and hold things and do basic routine work easily. And i went for it. My son has been operated only last month and i am yet to see changes in him. It is too early to make out the difference. There is an improvement but can’t say much at this stage. May be in a few months i will be able to judge if i have done right or wrong by getting this surgery performed on my sons hand. I am crossing my fingers and hoping that it is good for my boy.
I am a 46 year old man I was born with congenital forearm fusion in both arms left is worse then the right, because of this I have carpal tunnel in both wrists. I have had bone pain in the right and left arms but lately the pain is getting much worse in my right arm it goes from my wrist to my clavicle im having a real hard time with lifting my hand to my face without excruciating pain in forearm and shoulder. I’m right handed, my left arm hardly gets used it’s weak and smaller then the right I have pain in the left but but not as bad as the right.
when I was checked out by a doctor when I was little because I couldn’t hold 6 M&M’s In my up turned cupped hands. they said they could fix my issue after fully grown but the chance that it would be successful was 50/50
I apt not to do it.
wow there is alot of folks with this issue!
playing a guitar is impossible in my case, scratching the middle of the back is also impossible, holding dishes on the back of your hand. I found driving is my best thing I can do holding the steering wheel is quite comfortable carry a cup with you when collecting change I get some ugly looks when you flip your arm over backwards to collect change, by the way no one can beat you in arm wrestling for one your arm will never hit the table unless they brake your one bone if your like me my radius and ulna are fused 75% , you can make you hand cup really good if you bring your elbows to your chest. I figured Id say some of what I can do witch isn’t much but it’s better then nothen and if anyone of you would like to email me.
Ed Note: Email address removed, not allowed.
If you are looking for connecting with others with same condition, please join here and invite others.
I am a 39 year old male who never looked up “my arm thing” before on the web. I had an x-ray when I was younger and fully understand the condition. (My bones are fused about 75 %) However, I thought it was so rare that I never would encounter anyone else with it. Although it made me feel even more uneasy during adolescence, and I got my fair share of teasing, it has had little affect on my life. People think it’s cool when I hold a plate on the top of my hand; and when I shake hands, I am immune to the macho guy thing of having the “dominant position”, as it is impossible for my hand to be “dominated” in a hand shake. I do have carpel tunnel in both arms (but working on a computer your whole life will do that too), and I deal with a lot of pain in my hands when doing a lot of heavy lifting (moving and such). I cannot master chopsticks and don’t hold utensils like most people, and I have to make some adjustments to my golf grip and swing, but if that is the worst I have to deal with in life then I am way ahead of the game. As one of my buddies told me, “It’s just your ‘thing’”.
Thanks to you all for posting. For some reason I feel much better knowing there are others out there with the same thing. How cool!
I’m so glad I found this page, I’m going through a rough patch with my condition, I cannot supinate my left hand and for the longest time I have felt so alone in this. Anyway… I have wanted to go to school for cutting hair and I am finally on my way to do it, than I suddenly remembered my hand…. I asked the admissions advisor if she thought it was impossible and she seemed hesitant at first, but than she said I should be fine. I don’t know what to do now…. I want to cut hair, but the more and more I watch videos of people cutting hair I see how important it is to supinate your left hand…. =/ I talked to my mom about it tonight and she told me I could do it and that I have adapted all my life, but I don’t know… I just don’t see this as something I can pull off… what are your thoughts? comments?
Veronica,
I have been a part of this comment page for awhile now. I am 38 and have it in both arms. Let me just say that I have been having pain in my wrists, elbows, shoulders, and scapulas. It doesn’t stop me from accomplishing the things i wanted to do. I use my debit card for everything I buy, I have learned to use the back of my hands to carry plates (sure I get the looks), I am the most proud of the fact that I am a drummer, a pianist, and play all guitars with my left OVER the neck of the guitar. What I’m trying to say is that you can do anything, having this condition, if you’re willing to find some sort of pain management (deep tissue massages seem to help the muscles best) and not caring about those goofy looks from people. This condition didn’t stop me from living my life or accomplishing my dreams, it shouldn’t stop you from yours. P.S. No doctor will know what to do except run a bunch of tests costing you money, just to tell you either try the surgery (not!) or keep coming back for useless follow up appointments. Good luck finding a doctor in your area who SPECIALIZES in this condition! I hope I was able to help in some way. Good luck, maybe I’ll get a haircut from you one day. I would be honored!
Veronica,
I have been a part of this comment page for awhile now. I am 38 and have it in both arms. Let me just say that I have been having pain in my wrists, elbows, shoulders, and scapulas. It doesn’t stop me from accomplishing the things i wanted to do. I use my debit card for everything I buy, I have learned to use the back of my hands to carry plates (sure I get the looks), I am the most proud of the fact that I am a live and studi performer filing in as a drummer, a pianist, and all types of guitars with my left hand playing chords (or notes for bass guitar) OVER the neck of the guitar instead of under like everyone else. What I’m trying to say is that you can do anything, having this condition, if you’re willing to find some sort of pain management (deep tissue massages seem to help the muscles best) and not caring about those goofy looks from people. This condition didn’t stop me from living my life or accomplishing my dreams, it shouldn’t stop you from yours. P.S. No doctor will know what to do except run a bunch of tests costing you money, just to tell you either try the surgery (not!) or keep coming back for useless follow up appointments. Good luck finding a doctor in your area who SPECIALIZES in this condition! I hope I was able to help in some way. Good luck, maybe I’ll get a haircut from you one day. I would be honored!
I am 19 years old, and I just realized that I had this condition some 2-3 months back, until then, I very much did happen to notice that there was something weird with my hands. For so long, into my existence, I’ve been thinking that I am a little less flexible than others, going to the gym is kind of hard, its when I do my biceps that they start giggling, my hand position, palm outwards, and bringing the dumbles to your shoulders, It actually does look funny
It ain’t my fault I’m born this way 
and yeah, its alright with this condition, I think there are actually people, who are far more worse when it comes to being handicapped, holding utensils is tough…but yeah….livin on 
Hello all. I am a middle aged woman with congenital radial ulnar fusion, like all of you. However, only in my left arm. All my life I dealt with the odd things everyone has mentioned…but not being able to cup my hands always bothered me. However as life went on I just became adjusted to this is the way it is and did not think much of it. Being older now I can say it was not a terrible problem I could not deal with. I think one of the larger issues was that I always carried everything in my right arm, including my children which now has caused a curve in my spine. So I would encourage young people to strengthen both sides of your arms equally. I also am a tennis player and since I was a child I adapted by tossing the ball by forming a circle with my left thumb and index finger. It has worked beautifully for me for decades. Although right handed I learned to play guitar left handed since this was possible with my arm situation. So much is possible, however I only have this condition in one arm. I agree with the person who mentioned deep tissue massage for those muscles, tendons and ligaments that can become painful. I also understand the biceps curl problem too, but you can adjust, just do it over hand rather than under hand.