Radioulnar Synostosis

Radioulnar synostosis literally means a bony union between the two forearm bones.  Normally, the ulna bone acts as a straight “post” to anchor the wrist to the elbow.  The radius bone rotates around the ulna to allow the forearm to turn palm up and palm down.  This rotation is helpful for daily activities and allows many actitivies such as typing on the keyboard (palm down or “pronation”) or hold change (palm up or “supination”).  Almost all rotation comes through the forearm (ie the relationship between radius and ulna) but some can come through the wrist bones also.

Some kids are born with a bony connection between the radius and ulna.  This bony “bridge” can also develop after a trauma in an adult.  When that happens, the bones are no longer separate and the ability to rotate the forearm is not present.  Because the shoulder is so mobile, we can make up for some loss of forearm rotation with shoulder movement.  It is pretty easy to pull arm away from body- abduct- and the hand assumes a palm down position.  It is less easy to move the shoulder in such a way to allow the palm up position.

The bottom line is that kids adapt amazingly well to radioulnar synostosis.  Often, families do not even realize this condition is present until after kids start school.  There is no pain and, as noted above, some rotation can be achieved through the wrist.  When both sides are affected, it may be a little more challenging to adapt.  Additionally, it matters in which position the forearm is fused.  The forearm can be “stuck” in full palm up (supination), full palm down (pronation), or anywhere in between.  The best position is half- way between (the clapping position) which allows the patient to use the shoulder to help accommodate in both directions.  Palm down is better than palm up as so many of life’s activities are palm down (keyboarding, etc).

In a small number of kids, the forearm position causes trouble with activities.  In those, a small surgery can be done to reposition the forearm in a better position for function.  The pictures below show a patient positioned with both forearm in mid rotation.  He has no issues with function despite his limited rotation.

Synostosis with full elbow extension
Synostosis with full elbow flexion
Synostosis with attempted supination- palm up

Synostosis with attempted pronation- palm down

Xray showing synostosis near elbow.  The two bones are joined together.


  1. Hi,

    My daughter is also suffering like above. Can surgery help her to improve condition. Please advice.


  2. Thanks for the question on radioulnar synostosis. Sometimes surgery can help improve function but it depends on how much function is impaired by the condition. In other words, sometimes kids do just fine and can accomplish all tasks- in this situation I would not recommend surgery. However, in other cases- especially when the forearm is stuck in a more palm up or down position- surgery can reposition the arm into a more functional position. Good luck!

  3. I was born with radioulnar synostosis. My mother took me to a doctor when I was 12 at my request to know what was wrong with my arms. I will always be grateful to her because knowledge is power.
    I have an aunt and an uncle who also have radioulnar synostosis, both siblings of my father.
    I am now 50 yrs old. I never had corrective surgery, and I believe I have had, and still have, a full life.
    My curiosity on this condition has only flared up because I am experiencing a variety of, and degrees of, pains.
    Can you recommend a doctor in my area with sufficent experience?

  4. Thank you for your comments. It is unusual to develop pain at 50 when you have not had pain before. It could be coming from the elbow joint as sometimes patients also have a dislocation of the radial head. A great resource for finding a physician is The website will be able to direct you to a specialized hand surgeon in your area. Feel free to email me offline if I can help further.

  5. I am an 18 year old male with this condition in my left arm only. And I just want to tell others who are affected by this condition that I have played baseball my entire life and occasionally started varsity games at shortstop (known for getting a lot of ground balls hit to them).I learned to backhand every ground ball. I did not let this "deformity" define or control me and neither should you. Just remember, with every burden there is a blessing.

  6. I was also born with this condition on both of my arms; my left palm turns to a 45-50 degree angle while my right palm (dominant hand) can turn to 90 degree angle. My parents took me to Children's Hospital in Boston when I was 6/7 years old to find out if anything could be done to correct them. The doctors operated on my right elbow and I was in a cast for months with two skinny, silver "sticks" (not sure what they're called) inserted in my elbow. After my elbow healed, they took off my cast and removed the "sticks", and I still remember the intense pain I felt when they slowly and carefully took them out of my elbow, I tried so hard not to cry 🙁

    The operation allowed my right palm able to supinate a little more than my left, which is why it is able to turn at a 90 degree angle. I didn't really think too much of the situation since I was so young, but looking back I am glad I went through it and had my parents by my side. I am now 21 years old and have learned to accept this as part of who I am and learned to laugh at my failed attempts of getting change from a cashier. My arms make simple tasks a bit difficult and annoying at times but I am able to do most things in life just fine. I can drive, work, write, type, hold objects, do my makeup, and so much more with little difficulty. This condition doesn't hold me back. I was even a cashier for a couple years, but I absolutely HATED getting change from people, I always felt so awkward lol

    I always thought I was the only person in the world with radioulnar synostosis, I'm relieved to find out I'm not alone 🙂

  7. Hi, I also was born with radio ulna Synotosis in my left arm. My left arm was born in the supination position, meaning my hand should be stuck in the palm up position. However, my hand was born facing the other way, the pronation position (palm down). Luckily my aunt tried to put a braclet on me when I was almost one and noticed that my arm was off and I cried when they tried to turn my hand Palm up. At the time, we saw a specialist, but they had only heard of one other person having the same condition. My question to you is have you heard of this before? At 24 now, I'm trying to learn more so I can change my exercising habits. I've noticed that a lot of exercises put more strain on my shoulder and upper back, and sometimes lead to pain (which I learn to try to modify the exercise or not do it at all). Any suggested reading or sources that could point me to so I can tailor my exercises to work with this version of Synotosis. Thanks!

  8. Alex, thanks for writing and sharing your experience. What we find most challenging for kids is the palm up (supinated) or palm down (pronated) positions. Kids born with radioulnar synostosis in a neutral posture typically do very well with minor challenges only. But, when the forearm is "Stuck" in a more palm up or down position, tasks are harder. And, as a result, attempted movements put more stress on nearby joints. I believe that is what your are experiencing. Unfortunately, I do not know of any resources to provide more information but the simple answer is to avoid exercises which cause stress or pain. And, as a basic response, the idea of surgery is to put the forearm in that neutral posture to avoid some of the stress that you are experiencing. Good luck.

  9. I'ma mother of three children, all with congenital proximal radio ulnar synostosis.
    My oldest, now 20 years of age, has partial rotation of his left wrist, and full rotation of his right. We were unaware of his RUS until he started playing guitar at 15 years of age.
    My 5 year old twins have bilateral RUS, with both of them having their arms pronated. They underwent derotational osteotomies at Mater Children's Hospital, in Brisbane Australia, at roughly 2 to 3 years of age to fix their arms into a position between pronation and supernation. This has improved functionality, but they still are having issues with some activities, such as bouncing and catching balls.
    Is it normal for them to have ongoing difficulties after having surgery?

  10. Toni-Anne,

    Thank you for the question. It is really rare to have multiple kids with congenital proximal radioulnar synostosis. Do your kids have a syndrome? Your oldest seems to have a typical story where the lack of rotation may not be noted until a specific activity is a challenge. And your twins are also typical if the forearms are positioned in either a supination or pronation position.

    We would have treated your twins similarly. And generally, kids do very well. But it is not uncommon to notice some limitations as you state. Unfortunately, there is little that can be done.

    Thank you again for writing,

  11. Fortunately, there are no other medical conditions that we are aware of.
    One twin has a non-terminating sacral dimple, but that's more an indicator of spina bifida occulta.
    Interestingly, my monozygotic twin sister doesn't have any children with RUS.

  12. One of my twins was diagnosed with radio ulnar synostosis at onky a few months old. She is now nearly 3 and is starting to struggle with things like hand washing, holding a pencil and cleaning herself after using the toilet. Her hands are 'stuck' in a palm down position and she has zero rotation in either arm, her surgeon has recommended surgery in the next few years, however I am torn as to whether surgery is the best option or not!

  13. Thank you for the question. The complete palm down position can be tough for function, especially when both sides are in that position. While your daughter will figure things out and be able to accomplish most activities, there will be struggles with certain tasks in the future. A neutral position (1/2 way between palm up and palm down) is much better tolerated and typically allows better function. So, the bottom line is that in my experience, surgery can be very helpful. Good luck!

  14. I have the condition in my left arm and its in a fixed position with 0 rotation. I would like surgery that would give me the ability to have some rotation. Most of the post I have read are for children, when I was a child there were no options but with new technological advances in techniques there is a possibility to change the position for some or possibly full rotation. I would like references of doctors who perform the surgery in the United States, I reside in the state of Georgia. Please list them if anyone has information of doctors who perform the surgery in or out of Georgia it would be greatly appreciated.

  15. Anews,
    To date, we have not been successful in restoring forearm rotation despite numerous different surgeries that have been attempted. Unfortunately, technology has not yet proven helpful given the extreme complexities of forearm rotation.

  16. I have radialulnar stenosis dominate right arm. Fused in neutral position, cannot supinate my hand at all. Didn't pay attention to it until in grammar school could not do chin ups. I compensated and did pull ups because of shoulder compensation for pronation. As a result I became somewhat ambidextrious and use my left hand for many thing that would have normally made me use might right. I was athletic as a child and still as a 65 year old man. Played college tennis and still play today. Lucky for me it was just one arm and in the neutral position between pronation and suppination. I guess I was fortunate. I am starting to get some tennis elbow symptoms. Wondering if this condition could be related to my situation, not being able to rotate elbow.

  17. Steven,
    Thank you for sharing. Very helpful information. In response to your question, the synostosis may lead to accomodation at other joints which theoretically can cause problems over time. So, while there is no clear science on this issue, I share your belief. Good luck.


  19. Thank you for sharing Tiffany. Ultimately, your daughter will figure this out with (or without) our help. I do not have specific tips although there are different style pens which some find helpful. I agree with your doctors.

  20. Hi,

    I was born with Radioulnar Synostosis on both my arms, I am 21 years old now. My right arm can turn into the 90 degrees position while my left arm which is in handpalm down position can't turn at all. I'm having lots of trouble with my left arm, because it's never in a relaxed position and it's somewhat twisted, not symmetrical with my right arm. I am wondering if it's possible if my left arm can be positioned to a better position like my right arm.

  21. Hello Mesailu,
    Thank you for the question. Having an arm completely in the palm down position (fully pronated) is a functional challenge even though many activities including typing and writing may be easy.

    The only option is surgery- an osteotomy of the forearm bones to rotate them into a more generally functional position. It may be something for you to consider. It is a common surgery for patients with radioulnar synostosis. I hope that is helpful.

  22. I have radioulnar synostosis with my left arm. But its not as bad as a lot I've seen. I can move my palm almost up about 34 there. I really really want to join the military. Afraid I'll get denied. I feel like its a chapter I need to do in my life. Any thoughts?

  23. Dustin,
    I cannot answer the question on whether you will be accepted into the military as there are many factors that are considered. For most of my patients with synostosis, heavy activities (including military duty) are reasonable and well tolerated.
    Good luck.

  24. Hi. I am 17 and i was born with synostosis in my left arm. My arm is stuck in the palms down position. I have never had pain in my arm until the last few years. It wasn't often that i had this pain until the last couple months. Now the pain is almost everyday. It isn't an unbearable pain, but it is noticeable. To my knowledge i have not dislocated my elbow and i have never broken a bone. I was just concerned ad to whether or not this will go away in time or if i should go to a doctor about it.
    Thank you!!

  25. Hey Abbey. Thank you for the question and I am sorry you have pain. You are correct, this is unusual but it could be from strain related to the fixed position of the forearm. Given that the pain has been present for several months, it probably does make sense to see a doctor. Good luck.

  26. 15 years and have synostosis in my left arm. I think its the clapping position because it can turn half way. This means i am unable to do the bicep curl. Can this affect muscle growth?

  27. I am 42 years old and have this in my right arm. I am right handed but eat with my left hand and I'm sorry if this is too much information, but clean myself after the toilet with my left hand. Everything else I do with my right even though I cannot move my wrist too much. My mother had this in both arms. My daughter has no problem, thank God! My parents never thought to have it looked at, and I've asked my doctor a few times and all I be is a puzzled look. I always thought I was the only person like this. Good to know I'm not alone!

  28. I was born with rus in both my arms. My right arm is slightly better than my left. Thank God I'm right handed! My right hand faces inward towards my leg but my left hand faces palm down. They operated on my arm when I was 7 so that I would have better use of my hand. I was always in a lot of pain in my left elbow after the surgery that I remember wishing I hadn't had the operation. Now in seeing all these posts I am glad because it did make life easier although still complicated. My left wrist goes out of place while washing dishes, especially heavy pots. But I have learned to be careful when doing things and I find that now in my mid 40's I am in chronic pain in my elbows, neck, and hands…especially my thumbs. Also, I have issues with my hips to the point that I can't walk or it will stop me in my tracks because of very sharp pain just left to my tailbone. I believe it is related to my rus? Also, I experience numbness in both outer two fingers (ring and pinky fine) on both hand and in my feet. As a kid I only had chronic pain on my left elbow (the arm they operated on) but when I did something like hold a book for any period of time or hold grocery bags or things of that nature for more than ten minutes and the pain in my elbows was excruciating. Now I find that whenever I do something repeatedly like while cleaning the bathroom, mopping, laundry etc. I am in a lot of pain. Every job I've done whether manuel or sitting affects me in some way…even typing hurts my hand. So I am curious if you have any recommendations? I take a lot of ibuprofen when I do any type of activity where I use my hands for an extended amount of time. I believe I have carpal tunnel because of rus and I can't even peel potatoes…it just hurts. I am glad to see that there is now a blog and some support groups for this because I thought that I was alone. All I knew is that this was extremely rare. Before today I had never openly talked about this so I'm sorry for ranting and I'm done now��

  29. Sheila,
    Thank you for sharing your experience. I am sorry you are having pain, most patients with radioulnar synostosis do not. Seems like there may be more going on than only radioulnar synostosis. Good luck.

  30. It will definitely affect muscle growth. The lack of supination means many muscles in the forearm and upper arm remain underdeveloped or non-existent (e.g. supinator muscles). These muscles link with the scapular muscles, so there tends to be weakness in the upper back as well. I would not be surprised if patients with RUS exhibited higher-than-average incidence of postural deficiencies.

  31. Jonathan, thanks for chiming in. To be clear, the lack of forearm rotation due to the synostosis will, to some degree, affect the development of the forearm muscles that control rotation. However, the key muscles (pronator teres and supinator) cross the elbow joint so they will develop to a reasonable degree as the elbow joint-the ulnohumeral joint- is typically normal. In addition, the brachialis which helps with elbow flexion develops well.

    The bottom line in response to Callum's question on whether flexion of the elbow joint (biceps curl) will be limited is that in most patients the biceps curl is well maintained.

  32. Hi Charles, my name is Paul welch and I'm from the uk, I've just been told that my 2 year old son as got RS in his left arm, palm down I think, but he can turn it almost to a full clapping position, do u think surgery would be able to help it get an even better position?

  33. Hello Paul. It is difficult to know whether surgery will be helpful. While a small number of kids have a radioulnar synostosis that allows motion, most have no motion through the forearm. Sometimes the forearm is completely stiff and motion is really coming from the wrist joint. If this is the case, surgery will not help. I hope that helps. My email can be found at the bottom of each blog post and is:

  34. Hello Dr. My name is aiman and im from Malaysia. When i was 11, i broke my right hand when performing high jump. Then after few months during recovery, i found out that my right hand cant supinate, only pronation (which is in neutral position). It affected my muscle growth. What should i do to regain it? Is it necessary for surgery? Im now 21 years old and i have suffer it for 10 years. I hope you can give me the best answer. Thank you Dr.

  35. Aiman,

    Thank you for the question. I am sorry to learn of your lack of forearm rotation. An x-ray will be very helpful in understanding what might have been affected by the broken bone. It is also possible that the rotation was limited even before the fracture but only realized after your injury. Hopefully an orthopedic surgeon can help identify the problem. Treatment, however, may be trickier and there in not likely an easy 'solution'.

  36. I am 43, and have RUS bilaterally, with my palm facing down in both cases, absolutely zero movement.
    As a child, my parents took me to some specialists (who never gave us a diagnosis name…two students just did a presentation on my overcoming a disability and found the name for it), and everyone agreed that surgery could be attempted, but there was no knowing if the problem could be corrected. Now, this was the 70s, so there wasn't a lot of information and certainly no WWW to search. They suggested waiting until I was 25 to be sure everything was done growing and then they said they could attempt to break the bones apart and reset them.
    By that age, I'd become so accustomed to doing things "my way" that I really wasn't interested in going through the pain of surgery.

    To those of you with pain…I do sometimes feel an aching deep in my bones/where they're connected. My doc has given me meds for arthritis, but I take them very infrequently. It was worst when I was going through puberty and has just recently come back off and on.

    I was kept quiet as a child so that I wouldn't break myself…because they weren't sure how to fix me, but I did play volleyball and participated in track. Now as an adult I do obstacle course races and many other things.

    I've adapted just fine, though, like others, receiving change is the worst!! I do notice that to compensate, I roll my shoulders forward and have horrid posture…so those of you experiencing other symptoms, this could be why as well.

    Anyway. thanks for this site, because until today, I thought I was the only one. (my sister has passed on, but she had one arm this way, and so it makes sense that it's congenital)


  37. We are in NW Arkansas and my daughter is 12. She has recently started having a lot of pain because of her RUS. We are headed to the dr. today. she has not been officially diagnosed but the xrays they took at the hospital on Sunday show that her bones are fused. The tech said he'd never seen anything like it. i am interested to see what her ped says. i have printed out some articles on RUS to gie to him. He sent us to PT and OT for it a few years back to no avail. I really don't think he will know about it. Over the last couple days I have learned so much about it and I am thankful for groups like this. My daughter has done competitive cheer for the last 5 years and has not let it bother her. Now that it is painful, she fears she will have to stop cheering and tumbline.

  38. Jonathon you just brought so much peace to my mind … my son is 12 and has been playing sports since 6 , has been a hockey player and baseball player . He strives to be an elite athlete . I just made a doctors appointment. He says he is ok , it's limited on his left arm . I'm a nervous mom right now doing research

  39. Dr Goldfarb, My 7-yr old daughter has congenital RUS in her left arm. We learned of it when she was about 18months old. Recently, for about a year, she has been experiencing notable daily pain in her left arm near the wrist and near the elbow. So much so that she cries if someone touches the arm. We have visited an Orthopedic surgeon in the Berkeley/Oakland area, however, because the condition is rare…. they don't have a lot of experience with the condition. Usually, it seems, people don't have this sort of pain. We undertand that the arm muscle may be attempting to supinate the arm and pulling at the wrist, causing pain and tendentious throughout her arm. We are considering surgical options. We would like to get a second or third opinion on the condition. (We have done a CT Scan and x-rays) Do you have recommendations of hospitals that may have the most experience? Or individuals that we may want to consulate with? Thank you, Carrie

  40. Carrie,
    Thank you for the question and I am sorry that your daughter is having pain. You are correct, it is unusual to have any complaints. Two close- by options include Oakland Childrens Hospital (with orthopedic surgeons specializing in the upper extremity) and the Shriners Hospital in Sacramento. Good luck.

  41. Hi Dr Goldfarb I am 57 and my left arm is fused with mu palm downwards and has been since birth .. I have no elbow rotation and no wrist rotation . I have played guitar left handed and violin amd cello which was made left handed for me .. I have ridden horses sailed dighys been a ward Nurse District Nurse and theatre nurse now I have done a Degree in Art Sculpture … I have managed to adapt and I find a way to do things . So I would like to reassurre young people that there of usually ways to do most things although I only have the unilateral form . . I did not know that other people have this condition … The doctors did x ray my left arm when I was 12 years old and said the radius and ulnar were twisted around each other is this the same condition you refer to here? I think it is important though to be careful to avoid shoulder injury and hope people will seek advice from a physio on this issue .. Julie

  42. Hi I'm 27, Recently underwent derotational osteotomy for RUS,my doctor kept it in almost supination position, before surgery my hand is in semipronaed position,it was very good position,but now I am feeling very disappointed, with this position I can't drive or type keyboard,my question is that,can I go for another surgery for neutral position,is it recommended now?

  43. Asif,
    Thank you for the question. I am uncertain how to answer your question. If the position is making your function more difficult, then it would be reasonable to consider another surgery. The supinated position is, in my experience, difficult for function as you mention. Good luck.

  44. I have radioulnar synostosis. I'm 28 and 6'4. I wanted to add with the others that life with this "disability" is not that bad. There are certainly times where I am self conscious about how it looks and that effects a lot of what I do and what I wear, but I do not, AT ALL, consider myself less competant than others. Usually most people don't even notice or at least don't care. I still have been able to date attractive girls, make friends, whatever. I would like to change it but I can deal with it if I can't. Don't worry too much about it, embrace your differences.

  45. Hi! Happy to have found this thread. Born with RUS in my left arm only. Mom put me in baton as a child to help me learn to live with it. I'm 31 now and starting to experience elbow and shoulder pain. Not sure what kind of doctor to see since I'm not really a surgery candidate. Is an orthopedic surgeon the only one or are there others?

    How are people treating the pain?

    Would also love to know how others are building muscle. I love weights and it's a challenge to build upper body strength, evenly. There's a short thread about this on, but no answers yet. Would love to find a fitness trainer with this!

  46. ABn3d,
    Thank you for the comment and question. Pain is uncommon. Strengthening may help to a degree but therapy to correct (as possible) your mechanics probably will help. You are undoubtedly compensating for the lack of forearm rotation and perhaps selective strengthening with a therapist will help. A physiatrist is another type of expert who could help. Good luck.

  47. Hello Eppie- thank you for the question. Surgery for radioulnar synostosis is usually not required but may be helpful for function in certain situations (such as when both arms are affected or if the forearms are stuck in severe palm down or palm up position). If your daughter is functioning well at age 10, she probably would not benefit from surgery.

  48. I’m in my 60s. Fortunately, only my right arm has synostosis in full pronation. I come from a long line of left-handers and I myself am a lefty. So, my limitations have been few. I couldn’t play baseball well due to the condition, making me the butt of ostracism as a boy. I cannot lift a bulky heavy object with ease, so I’ve learned to take more with my normal arm. Otherwise, small tasks requiring manipulation cause me to work around them using my good hand. I worked on construction in summers as a student with little problem. Most people don’t notice my condition, but some do and can be quite insensitive. I put off truly insensitive people with the retort: “It’s a war injury,” which shuts them up immediately. Years ago, I met a fellow with the same condition (bilaterally). Our handshake was, to say the least, awkward.

    My parents took me to an orthopedic surgeon when I was four, and again at 18. The surgeon said there was no good option surgically. And he said he felt I functioned very well. My pediatrician always urged me to exercise that arm with weights, which I’ve always done.

    I have two daughters, neither having inherited the condition.

    So, I’ve managed to get through life just fine. But, oddly, I can’t say that I’ve always been used to it. I’m constantly cognizant of the deformity, its visibility and the physical limitations that come with it. Had there been a reliable fix, I would have jumped at it. But I also view myself as lucky – being unilateral and with no other associated conditions.

  49. James,
    Thank you for sharing your experiences. My patients have shared similar feelings and we typically offer surgery to reposition the forearm in less of a palm down position (ie, more neutral). Nonetheless, even in full pronation, as you so nicely share, function tends to be very good, if not occasionally awkward.

  50. interestingly I have a identical twin brother who is completely fine. we were premature twins so the debate was the doctors messed me up and that it wasn't a disorder(because apparently I was still developing)as my twin brother wasn't ready to go out and i pushed my way through.Another theory was he slept on my arm in the womb(yeah we were in the same one)apparently its the fact they have pictures where he is on top of me.. Do you think that is true?or was i naturally destined to have it.

  51. I'm 21 years old and I was born with this disorder in my left hand my right hand is completely normal,my family and I didn't find out about this until i was much older like 13 maybe, I was trying to play the guitar and couldn't we went and got x rays and found out my radius and ulna are fused at the elbow joint. I think its palm down and there is completely 0 rotation,but I'm an athlete i have played most sports from cricket,basketball(a bit hard but possible),baseball but I mostly play soccer no trouble with that. the only annoying thing is when it comes to like events serving myself food is a bit hard.and also its kinda smaller than my right hand so it just looks wrong so i'm usually just always in long sleeves.

  52. Thank you for your comments. Helpful to hear how functional you were and are. It is common that only one sibling is affected as in most patients, this is a sporadic finding rather than a genetic one. This is caused by a failure of separation of the radius and ulna during the developmental process. I do not think it has anything to do with his position in the womb. Good luck!

  53. Hi there, I have had 'limited supination' in both arms — 90 degree rotation– in both arms, my entire life and at 57, have just started experiencing shoulder pain that I attribute to overuse compensating for my lack of elbow rotation. I overextend the shoulder to get my right hand into the palm up position. Any remedies for this? (Other than avoidance activity?)

  54. Holmgren,
    Thank you for writing. We know that the outstanding mobility of the shoulders does help to minimize the functional limitations of the fused radius and ulna. This is 'easy' for trying to get the hands in the palm down position (pronation) but harder to achieve palm up (supination). We (people like me) worry about what happens over time but you are the first who has shared this pain. While avoidance is an option, there may be therapy that can help strengthen the shoulder muscles which might help. A good shoulder surgeon may also have options (even one who does not know much about the forearm). Good luck and let us know what happens.

  55. Hi , I've had RUS all m y life. I was a pretty good volleyball player despite not having good supination in either arm….about 45* I have always wanted to play the guitar, but can't get my left arm around the neck of the guitar. Is it reasonable to consider surgery to pursue this???

  56. Thank you for the question. While I would be pleased for you to find a way to play the guitar, I do not think that surgery likely makes sense. My reasoning is that to gain supination, you will lose pronation. That may be too high a cost. There may be modifications to allow you to play- a good occupational therapist may have ideas. Good luck.

  57. Hello. I was born with RUS in both arms. My left arm cannot turn supine past 90 and my right can only turn a bit past 90. So basically not at all. I was diagnosed on 9/11/01 when I was 13. I have noticed that the muscles in my forearms are noticeably smaller. Turning doorknobs requires me to dip my elbow. In fact My parents first noticed the condition when I was unable to open a door while carrying a paper grocery bag in my arms. Besides getting change in a drive through, bicep curls, fielding a ground ball, bowling, taking a football snap under center (very awkward) and other things like that, this issue hasn’t really affected me that much. I played college football for 4 years as a defensive back, where I could even hang clean 300lbs with a slightly awkward arm / wrist position. During my diagnosis I was told about and considered surgery. I am glad that I did not. At 30 I can say that I have lived a perfectly normal life. I can only hope I don’t experience pain in the future. In fact I am a jiu jitsu practitioner and have found that utilizing my “boney forearms” is very useful against my opponents. Have never met or talked to anyone else with it. Only began researching it lately. Hope this might help people with young kids.

  58. Braden,
    Thank you for the comment. Your perspective will be very helpful for families to read. I will add that, unfortunately, for some kids, the position of the RUS will interfere with activities more than you have experienced.

  59. Very glad to have come across this page. I'm 43 and always wanted to know why I can't drop or turn my left wrist and face the palm upwards. It gets stuck facing right when I turn from palm down to palm up. Realised this at age 10 when my karate teacher tried to manipulate my hand to a position I physically couldn't do. Also means I'm stuck at a basic level of guitar. Barre positions are impossible. Sounds like there are much more serious implications for some folks out there so guess I'm lucky. Again thanks for this page, I now have a name for my funny arm as mum calls it.

  60. Hello, I am a ballet dancer with Congenital Radioulnar Synopsis. Many aspects of ballet require the rotation of the forearm. I'm not sure if there are physio therapy exercises for resolving the issue??

  61. Hi everyone,

    I'm 34 year old male and live in Perth, Western Australia. I have bilateral radioulnar syntosis in the pronated position.

    I am a super active person and have tried almost every sport there is – golf, squash, tennis, snooker, hockey, shooting, ping pong, soccer, jiujitsu, boxing – just to name a few! The only 'problem' encountered is collecting change! I barely even think about not being 'normal'. Any way, even though knowing that surgery may have been an option, it was never an option that I wanted to take – I've found a way to do everything I wanted.

    I'm now at a stage in my life where my wife and I are pregnant with our first child – and so for the first time in my life I have begun to research the condition just to get an indication on whether my child would inherit the condition. Based on my reading there will be a 50% chance it will be passed down. If it is passed down I just hope it is no worse than my condition.

    There's no clear sign of this running in my family, although my grandfather may have a minor case of it but he seems to have rotation in both arms, which makes me wonder if mine is hereditary (baed on my grandfather's slight issue, I I'm guessing that it is).

    Like many here, I thought this condition was so rare and thought I was an outlier, I never expected to see so many people with the same experiences and similarities as myself. To be honest, it makes me feel less alone about it – and that if my child has what I have they'll be alright. I've never posted a comment or a blog in my life so I guess it shows that I'm a little concerned about what may happen 9 or so months down the line. If anyone has any advice or information to share on this, that would be much appreciated.

    Growing up, I would have loved to have spoken with someone who had the same thing; for advice or just to talk about how to feel about things. If anyone who's reading this wants to reach out, I'm here if you want to chat.

    Thanks for the forum, Dr Goldfarb.

  62. Ads,

    Thank you for writing. I look forward to any comments from the group. My only addition would be that the position of the synostosis matters (stuck in neutral vs palm up vs palm down) for function. So the fact that you are able to be so active is wonderful but not everyone with every position of their synostosis could like accomplish the same.

    I would also add that while this can be an autosomal dominant condition with a 50% chance of being passed on to your child (congrats), it can also be sporadic with a less predictable pattern of inheritance.

  63. I would suggest looking into unilateral training for most upper body compound movements like bench press, shoulder press, rows as you won't have the same movement on each. Maybe avoid the dumbbell curls as you'll be building strength from the compounds. Having said that, I'm bilaterally pronated, I weigh about 68kg but can easily curl 30kg per arm – all palm facing down – so there's no reason why you can't do dumbbell work on curls. In terms of shoulder pain, I've got some on my right side, and that it because my chest and shoulders work overtime – especially from weight training. But I'm also attributing that pain to being lazy on stretching, yoga etc so I'm now focusing on getting the weaker surrounding muscles stronger. Physiotherapy works – only if you do the work consistently. Good luck with training – it's a challenge sometimes but you always find a workaround. Actually, another good idea would be build grip strength on your left – that helps a bunch around building the forearm up around the elbow.

  64. Hello. We are from Russia. Our child (7 months old) has radial synostosis from birth (left arm, pronation, palm down, with dislocation of the radial head). At present, we conduct long-term (20 sessions) massage courses with ozokerite + paraffin + in parallel treatment with a chiropractor (orthopedic surgeon). These 2 specialists say that it’s realistically to separate the bones and “adjust” the radius bone “into place” and intend to do this. Do you think it's possible to do this? .. Faced with this in practice? Please comment.

  65. Thank you for the question. The literature is pretty clear that trying to put the radial head in place and separate the joined bones is rarely successful. That is also our experience over many years and I would not attempt this surgery any longer. There are so many forces acting on these bones that it just does not seem reasonable to expect that it would be successful.

  66. I am 33, and may have Kleinefelter syndrome. I was looking at some information that includes this syndrome. I don't know if I have it, and if I do, I have a pretty good range of motion – palm down is easy, middle is easy, but to achieve palm-up I absolutely have to use my shoulder. Otherwise, I am not able to rotate the last 60 degrees or so to fully palm-up.
    I first noticed this when playing baseball, when I favored turning my hand "backwards" (more pronated) from other children and avoiding palm-up positions to catch balls.

    Could you please point me to the right kind of doctor to check this?

  67. I am 44 and all my life I have never been able to turn my palms flat upward when my arm is bent. For example if getting change at stores, it would just fall, or if doing yoga I can’t turn palms upward on my knees. I always thought my wrists were messed up! Turns out I have a slight fusion also. Not bad enough that I can’t turn my hand enough to live my life normally, but enough so that I drop things, when I walk carrying cups i cannot keep them upright and spill, etc. It took all my life to find out about my arm bones.

  68. Hey all.
    I have RUS in both arms. They are palm down in resting position and I can turn both 90 degrees. Being as im 35 years old I have adapted well. To those of you looking for ways to help your kiddos if they are young enough they havent adapted or are struggling and there's a Dr by all means do what you think is best. However ive never had any surgeries on mine. I didnt know it was an actual thing that happens sometimes until I was about 18. My mother asked her dr who asked a colleague of his that worked in new york that had seen a case like mine. But as far as limitations there are few. Collecting change is awkward and people dont know how to take it. The technique I use is to form a cup with my fingers for them to drop the change in or use the cash to make a funnel to get the change in my finger cup. Lol. Sounds funny when I'm explaining it. We as humans adapt and it may be a struggle for some but you will adapt I promise. Anyway. As I said I'm 35 and I have adapted well enough that I am a union welder/pipefitter, I have blown glass, I do wood working, I do clay pottery, I do tie dye, I'm always trying things to see if I can do them. If I feel like my RUS is going to limit me I figure out a way to overcome it. Also ive never had any pains or issues from mine. Anyway I feel like I'm rambling at this point. However to anyone that is struggling with this I would like you to know, you are not alone. There are lots of us with this situation, dont think of it as a disability or a deformity. It makes us unique, own it.

    Positive vibes to all.
    Thank you for your time.

  69. Jorden,
    Thank you for your comments and tips. Really great wisdom for all! It is uncommon to be able to turn the forearm part- way but it does happen. More commonly, we compensate through extra wrist motion.

  70. This is a very late reply but I have been trying to find the name of the problem I have.
    I have this in my left arm, palm down. I an no 41 and have dealt with this my whole life. As it a normal thing for me, I forget that it is a disability, until I try and do normal things, like carry a box, eat fine dining, or simply giving someone a hug. As a kid it affected me more since I was unable to learn to play any of the string instruments. I do worry that, if I ever break my right arm, I will be incapacitated. Simply using a spoom with my left hand is a balancing act, with anelboy sticking out at an odd angle. I can position my hand and arm in the illusion that I have 90deg movement, but the reality is, my whole body will shift slighty. Its second nature.
    I advise anyone who doesnt find it a complete disruption to life, not worry about it. You apapt and its normal.

  71. I am 36 and I have never been able to turn my left hand to palm up position, it never has been able to turn. My mother thinks it was broken during delivery of my birth. Wonder what could be the issue there and is it something that can be fixed. I wouldn't care about breaking it and being in a cast for a few months that's fine, as long as it's able to turn how a normal hand does. Any suggestions?

  72. Erick,
    Thank you for the question. Most likely this is birth difference rather than a result of fracture (but obviously, I do not know that for certain). As noted on the blog, we can reposition the forearm into a different position but we cannot reliably restore motion. An xray would be very helpful.

  73. Dr Goldfarb, I’d would like to extend a hearty thanks for addressing questions and comments on this post. You provide great feedback- and encouragement – to those with RUS. It’s frustrating to suffer from it but good to know there’s someone out there who recognizes the issues. Thanks.

  74. I am an OT and I am seeing a 4 year old for therapy. Big issue is not being able to wipe herself well. Any suggestions? She is little so using a toilet wand seems challenging. I recommended a bidet for home, but what about school?

  75. Hello. Thank you for writing. I agree this can be a challenge especially with a full pronated (palm down) position. Those are the patients that I believe can benefit from surgery. Else, your suggestions are how we think about this challenge as well. Sorry that I do not have additinoal suggestions.

  76. Hello
    my names Ryan and I'm 19 in about 2 weeks, I was born with RUS, I inherited it from my dad. I didn’t know much about this condition until I recently started doing research about it and I didn’t know there was other people that had it until I came across this page and read about their situations.
    I can’t turn my left hand with my palm facing up (Supination), I can only turn my palm facing down (Pronation) and to the right (Clapping position). It hasn’t really affected me growing up through school until I turned about 16 and started getting into fitness which is when I realised I couldn’t do bicep curls properly but I found ways around it like hammer curls and using the tricep rope as a pull up motion as its flexible making it easier to curl.
    I was training to join the army which turned out pointless as I didn’t pass my medical due to this condition, I was rejected from the army which really let me down.
    Since I couldn’t go down the military route I went into the construction route and trained to be a bricklayer but I still find it hard at times to do certain stuff like picking things up and using techniques with tools as I ain’t got that supination motion to hold bricks etc from the bottom with my left hand.
    It gets stressful at times but I try to deal with it, I know my condition ain’t as bad as others but it still affects my life and joining the military is what I’ve wanted to do since I was a kid as living a ‘normal’ life just doesn’t interest me.
    Is it possible for me to have surgery to be able to have full motion in my left hand if not more than I currently have and if so where can I go for surgery, I’m From the UK, Liverpool. I don’t mind travelling if it means I can get this done as it would really change my life. If you need to contact me via email it’s:
    Hope you get back in touch soon would really appreciate it.

  77. Ryan- thank you for writing. Unfortunately, restoring forearm rotation is simply not possible. Even if addressed at an early age, we, as surgeons, cannot reliably improve motion. Surgeries generally reposition the forearm but it sounds as though your forearm is in as a good a position as possible. Good luck.

  78. Hello, I'm 15 and only have RS in my left arm and can rotate my wrist into a clapping position. It has restricted movements like bicep curls, boxing uppercuts, chin ups… is it worth getting surgery or is the success rate too low?

  79. My daughter was born with this condition in both arms. She only has about 5 degrees rotation in both arms. Her arms are in pronation . I discovered it when she was around 2 years old and we have been back and forth to the doctor for her entire life. Unfortunately none of her doctors had very much experience in treating the condition and never considered surgery no matter how many times I asked them. They send her to PT she has been in casts, braces, had numerous x rays and MRI. She is now 17 and experiencing tremendous amounts of pain every day, she's beginning to have numbness and shooting pains and the doctors are still opting out of surgery. This condition has made her have to quit her job, miss school, and miss out on other things because its causing her so much pain. I have researched Boston childrens hospital but we live in NC and cant afford the travel. I feel so helpless, I trusted her doctors but now I just don't know. My question to you is, do you think it is too late for surgery?

  80. Hello. I am sorry for your daughter's challenge. As you know, we cannot reliably restore motion but there are, as noted here, ways to reposition the forearms. That really can be done at any age. I would not promise that such a surgery would solve all of the listed issue but I would hope it could be helpful. Good luck.

  81. If the dislocated radial head is painful, excision is a good option. I do prefer to wait until the bones are finished growing before excision. There are risks with the procedure related to bone/ joint stability. For most patients, radial head excision does quite well.

  82. I'm 71. My parents discovered my unilateral RUS (right arm) when I was around 5 and took me to an orthopedic surgeon. I went back to see him at 18. He wisely advised that I avoid surgery, but that if I wanted to go ahead with it, he described a procedure that was not simply repositioning and would've resulted in diminished strength. I declined. My arm is in the fully pronated position. It hindered in me in some sports, particularly baseball and my handwriting is terrible. Fortunately, I come from a long line of left-handers and am one myself. Though born with this condition, I've never felt comfortable with it. It does hinder me somewhat in some basic functions, but these are minor. All that said, I'm grateful that I wasn't born with bilateral RUS.

  83. I want to say thank you, I also have RUS bilateral. My left hand is worse than my right. I can rotate my left only to clapping position, my right is better and can rotate about 70 degrees, which is good since I am right handed. I agree that getting change from a drive thru is a no go for me unless I do this amazing trick where I turn my left palm up backwards. They usually look at me funny but never question. I know mine is hereditary as I have an aunt and uncle both with the same disorder not as bad as mine. I have pretty much adapted to this and for me it was normal, could never play violin or guitar but life. Has been normal. I would suggest if you are a parent with a child that has RUS, let them try and adapt, obviously depending on the degree but you would be amazed at what they can overcome. Also means we are more special! My question is do you know how many diagnosed cases there are? Seems like a bunch more than the 350 journalized cases.

    1. Deanne,
      Thank you for writing and sharing your experiences. You are correct, every child is affected differently and yours, thankfully, is better positioned and allows at least some motion compared to others. And yes, this is uncommon but not incredibly rare. It is impossible to quantify but, for perspective, I see ~8 new patients with radioulnar synostosis each year. Thanks again,

    2. I have the exact same thing my left is worst than my right and only limits me at drive thru or when I try to play guitar or something. I’m so glad I’m not alone but it also sucks because I’m pretty sure I’m going to have to tell my recruiter about this and I won’t be able to join the military

  84. I am a 58 year old male and have this issue myself, it was / is a birth defect. Mine is slightly different in that at the elbow and wrist i have 2 bones but are then fused together about an inch or so from each joint. As the previous writer commented, i have grown up with this issue and is normal to me. I am fortunate in that my hands face down, so when they are by my side the palms face backwards.

    1. David- thank you for writing.I agree that many tolerate the position of the forearm as you note. But, a truly palm down (pronated) or palm up (supinated) position can be difficult for activities. (and especially so with bilateral issues.

  85. I am a 24 year old male and have found it extremely difficult when lifting weights and greatly hindered me when doing competitive sports like basketball and football? Are there any prognosis other than surgery. What are many results from the surgery?

    1. Rellyrell,
      Thank you for the question. As noted, the position of the forearm(s) matters to function. Sports can be a bit awkward depending on this position. A hand therapist might have some ideas about lifting weights (i.e., there can be adaptive equipment which can help). Aside from modifying your activities, there are no other nonsurgical options to my knowledge. Good luck.

  86. I am 28 years old I have RUS since birth in the left arm I never knew untill today what it was called. I’ve never seen a doctor for it. Thank you for this article. I can’t turn my left palm upwards.

  87. I am 79 years old and never knew there was a birth defect making it impossible to turn my hands over. I lived with this condition not knowing there was a name for it or anyone else who had it. Until I got carpal tunnel and had an xray for the pain I just adapted and did the best I could. I am now just waiting to fix the carpal tunnel and not fix my elbows. There are lots more handicaps than rus. Thanks for the advice.

    1. Mary Jo,

      Thank you for sharing your experience! I am glad that this did not slow you down too much and I agree, there are more serious challenges. But, when both ares are affected and when the position of fusion is severe (completely palms up or down), the functional issues are greater.

  88. I thought I was the only person in the world that had this issue. I’m 46 from Australia. I knew there was a problem in high school when I tried to play guitar! Also taking change from somebody, or even holding plates, holding a spoon, and even wiping my butt! There’s so many things I’ve adapted to do! I would love to know how other people have adapted to not ever seeing their palms face up!

    1. Pete- thank you for writing and sharing your experience! There are certainly differences from person to person with your situation, palms down, being one scenario. You highlight the ‘challenges’ perfectly. Others are ‘stuck’ with palms facing one another (ie, clapping position) which is easiest to adapt to, and other with palms up (hardest).

  89. 37 years later I finally understand what my condition is and thanks to all your information, I now understand why my mother declined doing surgery. I absolutely feel less alone. 🙂

  90. My family all have this. No one could ever tell us why? Never sought answers further then family Dr. My father, siblings, our children and grandchildren have in one or both arms. Thank you for this information

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