Post-traumatic RUS is a rare complication of forearm / elbow fractures. Early surgery 6-12 months after the initial injury can be helpful if the fused bone is completely taken out.
Surgery can improve quality of life for children with CRUS by correcting severe fixed pronation, but all methods carry complication risks related to the hardware used to secure rotational osteotomies.
A 10-year-old boy with CRUS had CT/3D imaging to precisely show the fused segment. The surgeons performed a derotational osteotomy of the radius with plate-and-screw fixation, and later removed the hardware to start rehab, which led to substantial improvement in upper-limb function.
Adult post-traumatic RUS is a rare complication of forearm fractures that completely blocks forearm rotation. Risk factors include fractures of both bones at the same level or extensive soft-tissue damage, and delayed or repeated surgery / single surgery for both bones. While there is no clear consensus on the treatment approach, individual planning and intensive rehab is important.
This study looked at adults who developed this problem in the forearm after an injury and then had surgery with one surgeon. Most people had the abnormal bone bridge removed (sometimes with extra procedures) and their arm function scores improved a lot after surgery. Surgery usually worked well, but it could still fail or have hardware problems, so planning each operation carefully was important.
Imaging from multiple children shows a wide range of ways proximal radioulnar fusion can develop over time. Several distinct patterns on X‑ray and MRI form a continuous spectrum from mild to severe bony changes. Recognizing these patterns can improve early diagnosis and help match treatment to each child’s specific anatomy.
Five children with severe fixed forearm rotation from this condition had rotational osteotomies on six forearms. Forearms were rotated to a more useful position and fixed with hardware, which improved daily use of the arm for most patients. Since complications such as nerve problems and compartment syndrome occurred in some cases, especially with large corrections, careful planning and monitoring are crucial.
The article explains how this condition develops before birth, how often it appears in families, and how it is usually diagnosed with exam and imaging. Several types and severities are described based on X‑ray features and the position of the radial head, but these patterns do not clearly predict function. Treatment options are compared, noting that many children can be managed without surgery, while operations such as rotational osteotomy are reserved for severe cases and carry a real risk of complications.
The study tested a surgery that rotates the fused part of the radius and ulna and holds it with a plate in children with this condition. Forearm position and function improved in most patients, with better ability to use the hand in daily activities. Complication and recurrence rates were low, showing that this operation is generally safe and workable when done with careful technique.
Children with CRUS underwent derotational osteotomy to move the forearm into a more useful position. Forearm rotation and function improved in nearly all patients, with a much lower complication rate than older reports. Careful control of the bone cut, stable pin fixation, and routine release of tight muscle compartments helped reduce nerve and circulation problems.
Multiple children with CRUS and severe fixed forearm rotation underwent derotational osteotomy, usually cutting through the fused segment and holding the bones with wires or other fixation. Most patients moved from a very pronated position into a more neutral or useful position, which made daily activities like eating and self‑care easier. Complications such as nerve symptoms and loss of correction occurred in some cases.
Seven adults with post‑traumatic proximal radioulnar synostosis had a small segment of the proximal radius (about 1 cm) removed just below the fused area. Forearm rotation improved from almost no movement (about 5°) to an average arc of 98° after surgery, and functional scores also rose noticeably. Complications included one case of re‑stiffening at the resection site and one case of temporary ulnar nerve numbness.
Recommended management for posttraumatic RUS includes optimizing the original fracture surgery to avoid bone debris between the bones, then another surgery to resection the bridge once the bone has matured, usually around 6-12 months. Other treatments like NSAIDs or low‑dose radiation and early, intensive rehab are reserved for higher‑risk cases.
Preferred treatment of posttraumatic RUS is surgical excision of the bony bridge once fractures have healed or the synostosis looks stable on X‑ray, sometimes with a tissue layer placed between the bones. Various interposition materials and rehabilitation plans are reported, but no single option clearly works best in all patients.
A 21‑year‑old man developed proximal radioulnar synostosis ten months after fractures of the proximal radius and ulna. The bony bridge between the two bones was cut out and a vascularized posterior interosseous island forearm flap was placed between them to keep the bones separated. Forearm rotation improved without recurrence of the bridge at follow‑up, showing that this flap method can maintain motion after resection.
A child with unilateral proximal CRUS and radial head dislocation had imaging that showed bone fusion near the elbow and abnormal bone shape. Surgery included freeing the joint, cutting and repositioning the proximal radius, fixing it with Kirschner wires, and rebuilding the annular ligament. At 6‑month follow‑up, elbow motion and forearm rotation improved, the radial head stayed in place, and no refusion of the proximal radioulnar joint was seen.
Thirty‑four children with CRUS and fixed pronation had derotational osteotomies at the shafts of the proximal radius and distal ulna, with small bone segments removed from both bones. The average forearm position improved to a more useful range, and most children were able to do daily tasks more easily after surgery. Complications were few and bone healing was reliable, showing that this two‑level osteotomy gives predictable correction.
Two adults developed post‑traumatic radioulnar synostosis after high‑energy forearm fractures with major soft‑tissue damage and delayed mobilization. Surgery removed the bony bridge and wrapped both radius and ulna with a strip of strong donor thigh tissue (allogenic fascia lata graft) to block new bone from growing between them. At 2‑year follow‑up, both patients had full forearm rotation, no pain, and no recurrence on X‑ray.
Three‑dimensional digital bone models from children with CRUS were used to measure a “forearm rotation angle” that reflects how twisted the forearm is. Larger rotation angles were linked with more severe bone deformities, such as greater tilt and rotation of the radius and ulna. These measurements help plan surgery by showing how much correction is needed and which parts of the bones contribute most to the deformity.
Computer‑aided design and 3D printing were used to plan rotational osteotomies for CRUS in a small group of patients. Patient‑specific cutting guides helped surgeons rotate the bones to the planned angle more accurately and reduced errors in the final forearm position. Forearm function and satisfaction improved, with no major complications linked to the guides.
Children with CRUS had corrective osteotomies planned using X‑rays to find the true axis of forearm rotation and choose precise cut levels. Average fixed pronation of about 71° was improved by roughly 64°, and most children ended up with excellent or good function and could handle daily tasks independently. The planning method produced consistent corrections across seven forearms and avoided major complications.
A 43‑year‑old man developed proximal radioulnar synostosis nine months after a Monteggia fracture that had been fixed with a plate. X‑rays and CT showed a bridge between the proximal radius and ulna, so surgeons removed the implant and excised the bridge. After surgery and physiotherapy, forearm rotation improved to nearly full pronation and supination, and daily activities were easier.
Children with CRUS and fixed pronation had derotational osteotomies at the shafts of both the radius and ulna, with small bone segments removed and the forearm rotated to a better position. Average forearm rotation position improved from strong pronation to near‑neutral, and daily function improved in most patients. Bone healing was reliable and complications were uncommon, showing this shaft‑level two‑bone osteotomy is an effective correction method.
A 14‑year‑old boy with bilateral CRUS also had osteoporosis, repeat low‑energy fractures of the forearm, and a non‑healed ulna fracture. Treatment focused on re‑fixing the ulna with bone grafting plus a structured physiotherapy program, without trying to separate the synostosis. After one year, the fracture was almost healed, forearm motion and daily‑activity scores improved on both sides, and the report concludes that firm fixation, bone grafting, and physiotherapy can be better choices than synostosis surgery for many CRUS patients with osteoporosis.
Twelve children (16 forearms) with CRUS had surgery, mostly derotational osteotomy at the synostosis level using wires, and two older children also needed an extra corrective radial osteotomy with plate fixation. All forearms were moved into a neutral functional position, with better self‑care, writing, and daily activities at 1-5 years of follow‑up, and no loss of elbow motion or deformity recurrence. Temporary radial nerve branch neuropathy occurred after 5 of 16 surgeries and one delayed bone healing happened after the two‑level osteotomy, but all nerve symptoms resolved and union was eventually achieved.
A 10‑year‑old girl with difficulty turning both forearms had X‑rays that showed bilateral proximal CRUS. Imaging, including CT, was used to map the fused segment and plan surgery. A corrective osteotomy was performed, and the report emphasizes how detailed imaging helped choose the cut level and correction angle for better function.
Bilateral CRUS in one patient was treated using a modified “reverse Sauvé‑Kapandji” procedure that combines derotational osteotomy with creating a new pseudo‑joint distally. Forearm rotation and hand use improved on both sides after surgery, giving better function in daily tasks. The report shows that this reverse Sauvé‑Kapandji approach can correct severe fixed rotation in CRUS without major complications.
Seven families with RUS and blood problems were studied, totaling nine affected people with issues ranging from a single low blood cell line to full bone marrow failure. Three different germline changes in the MECOM gene (two new) were found in five of these families, while two families had no detectable changes in MECOM or HOXA11. The cases show that the same MECOM variant can cause very different severities and ages of onset, and that RUS with blood problems is often a broad bone marrow failure syndrome rather than just low platelets.
Skeletal remains from prehispanic Peru showed bilateral CRUS, with fused radius and ulna on both sides. Bone wear and joint changes suggested the person had limits in forearm rotation but could still manage daily tasks like lifting and carrying. The case shows that CRUS existed in ancient populations and that long‑term adaptation to the deformity was possible without modern treatment.
Eleven adults with CRUS described how fixed forearm position limits everyday tasks, but also how they adapt and view it as “their normal” over time. Many reported knowing more about CRUS than their providers and often had to advocate for themselves because medical professionals lacked knowledge. The study highlights the need for individualized, client‑centered rehab, better communication, and stronger advocacy so people with CRUS can access appropriate support and accommodations.
Two adults with post‑traumatic radioulnar synostosis had the bony bridge removed and a local adipofascial flap (fat and fascia with its blood supply) placed between radius and ulna. At follow‑up, both regained a useful arc of forearm rotation and returned to daily activities with less difficulty. No recurrence of the bridge or major complications were reported, suggesting this flap can help keep the bones from re‑fusing.
Children with CRUS and severe fixed pronation had a one‑stage rotational osteotomy at the proximal ulna and distal radius, with small bone segments removed. Forearms were rotated into a more useful position, and most patients showed better use of the hands in daily life. Bone healing was reliable and complications were few, indicating this single‑stage two‑level osteotomy is a safe and effective option.
The article reviews both congenital and acquired forms of radioulnar synostosis, with emphasis on how they limit forearm rotation and daily function. Key sections cover typical anatomy changes, imaging findings, and indications for surgery versus conservative management in congenital cases. Treatment options, including derotational osteotomy for CRUS and resection with interposition for post‑traumatic cases, are summarized with their main benefits and risks.
Children with CRUS were studied using three‑dimensional motion analysis while they performed 10 everyday tasks. Results showed large compensatory movements at the shoulder and trunk, especially when the forearm was fixed in heavy pronation. These findings explain how children maintain function despite limited forearm rotation and support treatment plans that consider the whole upper body, not just the forearm.
Children with CRUS in several hospitals were checked to see how they did with and without surgery. Surgery that rotated the forearm bones closer to neutral improved arm position by about 60° and helped most children use their arms better, with fewer than 1 in 10 having problems. Some children with mild deformity did well without surgery, but those with very strong fixed pronation gained more independence in daily tasks after derotational osteotomy.
A young child with CRUS and trouble using the hand in daily tasks took part in a short, intensive hand‑therapy program. After therapy, tests showed better hand strength, coordination, and ease with activities like dressing and play. The report shows that focused hand therapy can improve function in CRUS even without surgery.
A large family with CRUS across three generations was described, with several members in each generation affected. Pedigree analysis supported autosomal dominant inheritance with variable expression, meaning some relatives had more severe deformity than others. The report highlights that CRUS can run strongly in families and that genetic counseling may be useful for affected kindreds.
A 4‑year‑old girl with bilateral CRUS was described, with limited forearm rotation but enough shoulder and wrist motion to manage most daily tasks. The report links the deformity to a timing error in early limb development and reviews how the bones normally separate before birth. Because function was acceptable, treatment was observation and follow‑up rather than surgery, showing that some children with CRUS can be managed without an operation.
Children with CRUS had an osteotomy at the synostosis level, and the forearm was slowly rotated into a better position using a circular external fixator. Gradual correction improved the resting position of the forearm and made daily activities easier, especially tasks like eating and self‑care. The method allowed large corrections with good bone healing and few nerve or blood‑flow problems, because rotation was spread out over time instead of done all at once.
Young adults with long‑standing proximal CRUS and a dislocated radial head had the radial head and proximal radius removed back to the end of the fused segment, then the cut radial shaft was wrapped with a strip of thigh fascia (tensor fascia lata graft). Forearm rotation did not return, but elbow flexion‑extension improved and painful elbow “locking” stopped, which made work and sports easier. The operation was simple, cost‑effective, and gave good pain relief and function in this small group.
The article summarizes how to time surgery (usually 6-12 months after injury when extra bone has matured) and explains which open surgical approach to choose based on where the bridge is and how far it extends. After excision, covering the raw bone with interposition tissue and starting early motion are recommended to lower the risk of the bridge growing back.
An adult developed proximal radioulnar synostosis from heterotopic bone after a metal radial head replacement. Surgery removed the extra bone between radius and ulna and placed a soft‑tissue barrier (such as acellular dermal matrix) to reduce the chance of it growing back. Forearm rotation improved after surgery, and no early recurrence of the bony bridge was reported.
Nine children with severe CRUS had a two‑stage, double‑level rotational osteotomy of both radius and ulna, first cutting the bones and later rotating the forearm into a better position in a cast. Average fixed pronation improved from about 76° to 20-30° pronation in dominant arms and 20° supination in non‑dominant arms, with solid bone healing in about 6 weeks and no loss of correction. No nerve, blood‑flow, or elbow‑motion problems occurred, and all children showed clear improvement in daily tasks like eating, washing, and writing.
A 43‑year‑old man in Nepal developed proximal radioulnar synostosis nine months after a Monteggia fracture that had been fixed with a plate. Imaging showed a bony bridge between the proximal radius and ulna, and surgeons removed this bridge along with the hardware. Forearm rotation improved after surgery and physiotherapy, and the report stresses that loss of pronation–supination after forearm fractures should raise suspicion for synostosis.
Adults with proximal radioulnar synostosis after trauma had the bony bridge removed and the anconeus muscle swung in between the radius and ulna as a living tissue spacer. Most patients gained a useful arc of forearm rotation and better elbow use in daily activities. Recurrence of the bridge was uncommon, showing that anconeus interposition can give reliable motion with a low complication rate.
Children and adults with RUS but normal blood counts were found to have specific changes in the MECOM gene, focusing on one hotspot amino acid (R781) in the EVI1 protein. Different changes at this same spot caused a wide range of bone findings, from isolated RUS to more complex limb differences. The study shows that MECOM‑related disease can appear without obvious blood problems, so genetic testing is useful even when only RUS is present.
Children with type IV CRUS who could not bend the elbow well had a blocked joint because the dislocated radial head was hitting the humerus. Radial head excision removed this mechanical block and restored a near‑normal arc of elbow flexion and extension, while forearm rotation stayed limited. The series shows that timely radial head removal can relieve painful elbow locking and improve daily activities in this subtype of CRUS.
A child with CRUS and severe motion limits had the fused bone carefully separated and a pedicled posterior interosseous fat graft placed between radius and ulna as a living spacer. Early results showed improved forearm rotation without immediate re‑fusion of the bones. The case suggests that using a vascularized fat graft can help keep the gap open after mobilization surgery.
Children with CRUS fixed in strong pronation had derotational osteotomies at the shafts of both radius and ulna to turn the forearm into a more useful position. Average forearm position moved from heavy pronation to near neutral or slight pronation, and all bones healed without major problems. No nerve or blood‑flow complications were reported, so this two‑bone shaft osteotomy was considered a simple and safe way to correct forearm position.
A newborn with very low platelets had bilateral radio‑ulnar synostosis and bent little fingers, and later work linked this pattern to mutations in the HOXA11 gene in similar patients. The report discusses how the same syndrome combines bone changes in the forearm with failure of megakaryocytes, causing severe thrombocytopenia. Management focused on treating the blood problem (including transfusions and monitoring) while the synostosis itself was observed rather than operated on in the neonatal period.
A baby with unilateral CRUS was not clearly diagnosed before birth, even though careful review of pregnancy ultrasounds later showed subtle elbow and forearm changes. The report explains which prenatal ultrasound and postnatal X‑ray signs can suggest CRUS and how easily the diagnosis can be missed. The authors recommend closer follow‑up and better imaging protocols when a fetus shows persistent abnormal forearm position, so families can receive earlier counseling and planning.
An African American child with radioulnar synostosis and low platelets (thrombocytopenia) was found to have a MECOM gene variant. The case supports that MECOM‑related disease can combine forearm bone fusion with serious blood problems, fitting into the RUSAT spectrum. Management focused on monitoring and treating the blood disorder rather than operating on the synostosis.
Ten children with proximal CRUS (12 forearms) had derotational osteotomies of the distal radius and proximal ulna fixed with plates, moving the forearm from an average of about 57° pronation to around neutral, with roughly 53° of correction. All osteotomies healed, Failla function scores improved from mostly fair/poor to mostly good/excellent, and no nerve, blood‑flow, or infection problems were reported. The paper also summarizes other osteotomy methods and supports plate‑fixed two‑bone derotation between ages 3-9 as a safe way to place the forearm in a more useful position.
Twelve children with proximal CRUS (14 forearms) and strong fixed pronation had a minimally invasive, single‑session double‑level rotational osteotomy of both radius and ulna using intramedullary K‑wires for fixation. The average forearm position was moved from heavy pronation into a more neutral or slightly pronated functional range, and most children gained easier use of the hands in daily life. All osteotomies healed without major nerve or blood‑flow problems, and the technique avoided large scars or a second surgery to remove plates.
In 329 children with CRUS, most had Type III changes on X‑ray, and this group almost always showed severe fixed pronation over 60°. The newer CMPOS system matched X‑ray types to clinical severity: Type I mainly had neutral or mild pronation, Type II moderate pronation, and Type III severe pronation. The study suggests that children with Type III in either system are more likely to need early intervention, while many with milder types can be managed with observation or physiotherapy.
Families with radioulnar synostosis plus serious blood problems were found to carry germline MECOM variants affecting the EVI1 protein, defining a syndrome called RUS with hematologic disease (RUSHD). The same MECOM change could cause very different marrow problems, from mild single low blood counts to severe bone marrow failure needing transplant, and onset ranged from infancy to adulthood. Management focused on monitoring and treating the marrow failure (often with bone marrow transplant), while the forearm fusion itself was not always operated on.
A 35‑year‑old carpenter with no history of trauma or surgery developed proximal radioulnar synostosis that completely blocked forearm rotation. Surgeons removed the bony bridge through combined posterior and anterior approaches and placed bone wax plus fascia between the bones, then started aggressive physiotherapy from day 2. At 2‑year follow‑up, the patient had painless, useful supination and pronation for work, with no sign of the bridge coming back.
People with SMAD6 gene changes often had RUS, sometimes with other bone differences in the skull or spine. SMAD6 loss‑of‑function variants were much more common in people with RUS than in healthy controls, showing this gene is a major cause of the condition. Many affected people had stable bone changes without life‑threatening illness, so care usually focused on watching growth and function rather than routine surgery.
Three children with type IV CRUS suddenly developed a stiff, bent elbow that would not straighten after the radial head got stuck under tight tissue in front of the joint. Gentle traction under anesthesia released the block in all three, and two children also had the misshapen radial head removed to stop the problem coming back. Follow‑up showed good elbow motion and pain relief after this combination of release, radial head excision, and rehab.
Children with CRUS and strong fixed pronation had a two‑stage, double‑level intraperiosteal derotational osteotomy of both radius and ulna. The forearm was rotated into a more useful position and held with casts, and most children showed better use of the hand in daily life. Bone healing was reliable with few complications, so this technique was considered a safe and simple option for severe deformity.
Adults with long‑standing proximal radioulnar synostosis and a dislocated radial head had the radial head and proximal radius removed down to the end of the fused segment, and the cut radial shaft was wrapped with a strip of thigh tissue (tensor fascia lata graft). Elbow bending and straightening improved, painful catching stopped, and patients could do daily activities more easily, even though forearm rotation stayed limited. The operation was simple, did not need special implants, and gave good pain relief and function in these delayed adult cases.
A 16‑year‑old boy broke the distal ulna with a minimally displaced greenstick fracture and was treated in a cast and then a splint. Three months later, he returned with complete loss of forearm rotation, and imaging showed a distal radioulnar synostosis. Surgical removal of the bony bridge restored forearm motion, and no recurrence was seen on follow‑up.
Ten adults with post‑traumatic radioulnar synostosis in Kuwait needed surgery because forearm rotation was severely blocked. Most had the bony bridge removed, often with tissue placed between radius and ulna and followed by rehab, which improved their pronation-supination arc and daily function. Complications and recurrences were uncommon in this series, but the paper stresses careful planning and early motion after surgery to protect the result.
Adults who had distal biceps tendon repair were checked to see how often painful radioulnar synostosis developed. Patients who took indomethacin after surgery had about a 1% synostosis rate, compared with about 38% in those who did not take it. No clear side effects like stomach bleeding or tendon re‑tear were linked to indomethacin in this group.
A computer tool was built to automatically plan osteotomy angles for CRUS using both 2‑D and 3‑D optimization. The method aimed to choose cutting planes that move the forearm into a more useful position while keeping bone shape and joint alignment close to normal. Tests on patient scans showed more accurate and personalized plans than standard manual planning.
Children with congenital proximal radioulnar synostosis had MRI and X‑ray scans to measure the size of the supinator muscle and the shape of the bones. A new three‑type system was created that groups cases by whether the bridge is fibrous or bony and how well the supinator is developed. Supinator muscle was present in every case, and its size clearly matched how severe the bony deformity looked on imaging.
Twenty patients with unilateral proximal CRUS and no surgery had wrist motion measured using a 3‑D motion analysis system. In patients older than 10 years, the affected side showed greater wrist rotation, especially more pronation, than the normal side, showing a clear compensatory hypermobility pattern. The 3‑D method closely matched goniometer readings and showed excellent reliability for measuring wrist rotation.
Twelve children with CRUS (14 forearms) and strong fixed pronation had a minimally invasive, single‑session double‑level rotational osteotomy of both forearm bones using intramedullary K‑wires. The average forearm position changed from marked pronation to a more neutral or slightly pronated angle, and most children showed better use of the hand in daily life. All osteotomies healed without major nerve or blood‑flow problems, and scars were small because only short incisions were needed.
Four unrelated people with RUS and other bone differences were found to have damaging changes in the AUTS2 gene. AUTS2 disruption affected gene networks that guide early bone development, linking this gene directly to abnormal limb patterning. The study identifies AUTS2 as another key RUS gene alongside NOG, MECOM, and SMAD6.
Children with proximal CRUS and a posteriorly dislocated radial head had a modified Kanaya osteotomy that changes where the bone is cut compared with the original procedure. The change in osteotomy site led to better forearm rotation, especially improved supination, in most treated arms. Complications were limited, so this modified technique was considered a useful option for this specific deformity pattern.
Children with severe CRUS deformity had derotational osteotomies to turn the forearm from heavy pronation into a more useful position. Most osteotomies were done through the synostosis and fixed with intramedullary wires or other devices, and bones healed in about 6-8 weeks. Forearm position and ability to do daily tasks improved, but osteotomies done directly at the synostosis had higher risks of nerve and blood‑flow problems than those done at the shafts.
Two patients with proximal radioulnar synostosis had the fused bone separated and a free microvascular fascio‑fat graft placed between the radius and ulna. Forearm rotation improved and no re‑fusion of the bones was seen during follow‑up. This technique shows that a living fat-fascia graft can act as an effective barrier to prevent the bones from growing back together.
A 26‑year‑old man with previously unrecognized CRUS sustained a fracture through the fused segment after a road traffic accident. Open reduction and internal fixation with a plate plus early, structured rehabilitation led to solid bone healing and near‑normal forearm motion by 6 months. The report shows that fractures through a CRUS segment can be fixed surgically with good function when the anatomy is carefully evaluated.
A 55‑year‑old woman developed radioulnar synostosis after an open both‑bone forearm fracture treated with intramedullary wires, where leftover fragments filled the interosseous space. Nine months later, the forearm was fixed with loss of pronation, and imaging showed a solid bone bridge between radius and ulna. Surgical excision of the bridge without interposition tissue, plus early physiotherapy, restored good pronation-supination by 12 months with no recurrence.
A patient developed radioulnar synostosis as a complication after a complex elbow injury that included fractures and ligament damage. Imaging showed abnormal bone formation connecting the radius and ulna, which caused loss of forearm rotation. Surgical excision of the bony bridge with appropriate fixation and rehabilitation improved motion and reduced pain.
Two children with proximal CRUS and severe twisting of the forearm bones had a complex reconstruction that removed most of the radius, reshaped the ulna, and replaced the missing radius with a piece of fibula bone to form a new joint. At follow‑up, both patients gained about 65-70 degrees of total forearm rotation with good daily use of the arm. The study proposes this large reconstruction for severe deformities with helical bone distortion, while milder cases do not need surgery.
A child with bilateral radio‑ulnar synostosis and extra minor anomalies was evaluated for an underlying genetic cause. Chromosome studies and further genetic testing were performed and showed an unbalanced chromosomal change involving deletion and duplication segments. The report links this chromosomal imbalance to both the limb findings and other physical differences, and recommends genetic counseling for the family.
The study links changes in the GREM1-FMN1 gene region to limb malformations, including forms of syndactyly and Cenani-Lenz-like hand and foot differences. It shows that these genomic rearrangements can either delete or duplicate regulatory DNA elements, which alters normal gene activity during limb development. The findings also support that disruption of this locus represents a shared genetic mechanism underlying several related limb malformation patterns.
Two people with post-traumatic radioulnar synostosis were treated by excising the bony bridge, inserting a free vascularized fat flap, and applying a dynamic splint to allow forearm rotation. After this approach, both patients gained useful pronation and supination without early recurrence of the synostosis. The combination of a vascularized fat graft as a living barrier and early motion reduced stiffness and improved arm function.
One adult soldier with radioulnar synostosis is described, with the condition causing limits in forearm rotation but not preventing work as a generator mechanic. Functional, cosmetic, and cultural challenges from the condition are outlined along with how this individual adapted to military duties. Published treatment options in the literature are briefly reviewed, emphasizing that many people can function well without surgery depending on job demands and severity of deformity.
Ten children with radioulnar synostosis and severe pronation deformity underwent derotation osteotomy at the synostosis site with K-wire fixation and casting. Average correction of the forearm position was 54 degrees, and nine children reported better ability to do daily activities after surgery. One child developed compartment syndrome leading to nonunion and forearm shortening, and complication risk was higher at older ages.
One adult developed distal radioulnar synostosis as a rare complication after percutaneous fixation of distal radius and ulnar styloid fractures. Surgical management with a modified Sauvé-Kapandji-type derotational procedure restored useful forearm rotation and wrist function. No recurrence of the synostosis or major complications were reported at follow-up, and daily activities were performed without major limitation.
A 7‑year‑old boy developed proximal radioulnar synostosis after high‑energy trauma to the elbow and forearm. Surgical treatment used a modified derotational osteotomy with excision of the bony bridge and soft tissue interposition to restore rotation. Forearm motion and daily function improved after surgery, with no recurrence of the synostosis at follow‑up.
A new X‑ray angle called the radial pronation angle is described to measure how much the radius is turned in children with radioulnar synostosis. Higher angles match more severe turning of the forearm and worse ability to rotate the arm. This angle provides doctors with a simple, repeatable way to grade deformity and help plan if surgery is needed.
One child with radioulnar synostosis and multiple brain abnormalities is described, carrying a 17q21.31 microdeletion involving the EFTUD2 gene. Facial differences, growth problems, and developmental delay are present along with limb changes. The report links this combination of findings to a rare craniofacial syndrome and expands the known features associated with EFTUD2-related conditions.
A 7-year-old boy developed distal radioulnar synostosis after a high-energy road traffic accident and initial open reduction and fixation of both forearm bones. One year later, synostosis resection with interposition of autologous fat restored full forearm rotation, with no recurrence at 16-month follow-up. A brief review of recent pediatric cases shows that early surgical resection with or without biological interposition with early rehabilitation usually leads to good motion and low recurrence.
Two children with congenital proximal radioulnar synostosis developed sudden, fixed elbow flexion that made arm use difficult. Surgical release around the elbow, without changing the forearm bones, corrected the acute flexion deformity and improved arm function. Elbows stayed stable with better motion at follow-up, and no new serious problems were reported.
A specific MECOM missense mutation linked to radioulnar synostosis with amegakaryocytic thrombocytopenia was modeled in mice to test its effects on blood formation. Heterozygous mutant mice showed low platelet counts and reduced hematopoietic stem and progenitor cells but did not develop radioulnar synostosis. These findings indicate that this mutation mainly acts as a loss-of-function allele in hematopoiesis and help explain how MECOM variants cause bone marrow failure in this syndrome.
A de novo missense change in the ZMAT2 gene was found in a 5-year-old boy with radioulnar synostosis using whole-exome sequencing. In zebrafish, lowering zmat2 levels caused fin and body patterning defects consistent with reduced bone morphogenetic protein signaling, which could be rescued by normal but not mutant zmat2. These findings show that ZMAT2 helps control bone development through the BMP pathway and that damaging mutations in this gene can contribute to radioulnar synostosis.
Two children with congenital proximal radioulnar synostosis developed sudden fixed elbow flexion that blocked arm motion. Surgical treatment removed tight front‑of‑elbow soft tissues and a hypoplastic, annular‑ligament-like structure, allowing full elbow extension while leaving the synostosis itself untreated. Elbow motion and daily function improved and stayed better at follow‑up without major new problems.
A 42-year-old woman developed proximal radioulnar synostosis after a conservatively treated radial head fracture, which caused severe loss of forearm rotation. Surgical excision of the bony bridge with an anconeus muscle flap placed between the radius and ulna restored functional pronation and supination. At follow-up, forearm motion remained good with no recurrence of the synostosis or major complications.
Sixty-three adults with same-level fractures of both forearm bones were treated with elastic stable intramedullary nailing and followed for at least one year. Bone healing occurred in all patients, and only one person (1.2%) developed radioulnar synostosis at the middle third of the forearm. Overall arm function scores were good or excellent in almost all cases, and open fractures or open reductions did not delay healing.
Twelve children with radioulnar synostosis and severe fixed pronation underwent derotation osteotomy through the fusion mass, rotating the forearm to about 10-20 degrees of supination and fixing it with K‑wires and a cast. Bone healing occurred in all patients in about seven weeks on average, with a mean rotational correction of about 78 degrees and clear improvement in daily activities like eating and handling objects. One child developed temporary posterior interosseous nerve palsy and another developed a mild ischemic contracture, but overall satisfaction and function were good after surgery.
An automated 3D measurement method is introduced to calculate several deformity angles and rotation parameters in congenital radioulnar synostosis using CT-based models. The system quantifies factors like radial and ulnar angulation and internal rotation, then summarizes deformity severity into indices that match clinical patterns. These automated measurements are designed to support diagnosis and to guide osteotomy planning by giving surgeons objective numbers for the deformities.
One adult with extensive post-traumatic radioulnar synostosis from the proximal to distal forearm had almost no forearm rotation. Treatment involved wide excision of the bony bridge combined with a free vascularized flap placed between the radius and ulna plus postoperative rehabilitation to allow rotation. Forearm motion and function improved without recurrence of the synostosis at follow-up.
Adults with post-traumatic radioulnar synostosis were treated by wide excision of the bony bridge plus interposition of a free fat flap between the radius and ulna. Most patients regained useful pronation and supination with low recurrence rates after surgery. The series supports using radical excision with soft-tissue interposition to lower the chance of the bones re-fusing while improving arm function.
Twenty children with congenital proximal radioulnar synostosis and severe fixed pronation were treated using a two-stage double-level rotational osteotomy of the radius and ulna. Forearms were gradually corrected into a more functional position with external fixation, leading to large improvements in forearm position and daily activities. Complications included transient nerve symptoms and occasional loss of some correction, but overall function and satisfaction were high.
Two boys from related parents each had a harmful change in the SMAD6 gene plus both skull bone fusion and forearm bone fusion. One boy also had learning and development problems, but neither had heart or major vessel defects on heart ultrasound. Lab tests showed that the SMAD6 changes made the protein work less well, so bone growth signals were not properly “braked,” helping explain why these bone fusions happened.
A child with congenital radioulnar synostosis had 3D CT scans used to create printed bone models and cutting guides for a planned rotational osteotomy. Surgeons used these patient-specific guides during proximal ulna-radius derotational osteotomy to place the forearm in a better functional position. Forearm position and daily arm use improved after surgery, showing that 3D printing can help plan and perform precise osteotomies in this condition.
Two adults with proximal radioulnar synostosis after trauma were treated by removing the bony bridge and filling the gap with a posterior interosseous adipofascial flap that keeps its own blood supply. The flap was rotated into the space between the radius and ulna and anchored through a small skin button so it stayed in place while early motion began. Forearm rotation improved, and no synostosis recurrence was seen at follow-up, suggesting this living pedicled flap is a reliable way to prevent the bones from re-fusing.
An adult with a “floating elbow” from high-energy trauma was treated with a humeral plate and intramedullary nails in the radius and ulna, then later developed radioulnar synostosis and radial nerve injury. CT scans showed a bony bridge between the radius and ulna in the proximal-mid forearm, causing loss of forearm rotation. Because elbow motion and function were acceptable and nerve recovery was progressing, no further surgery for the synostosis was performed, and the case highlights that intramedullary nailing plus severe trauma can increase synostosis risk.
A 70-year-old man developed proximal radioulnar synostosis with nonunion of the radial neck after a forearm injury and internal fixation. Surgical treatment included excision of the synostosis, bone grafting of the radial neck, and plate fixation to restore elbow and forearm function. Pain and motion improved after surgery, and the case highlights the need to consider synostosis plus nonunion when evaluating persistent elbow pain after trauma.
One adult with a very rare congenital fusion between the upper arm bone and both forearm bones (humero‑radioulnar synostosis) sustained fractures of the radius and ulna after a fall. The fused elbow made fracture management and rehabilitation more difficult, but bone healing and limb use improved with careful casting and follow-up. The report shows that even with this severe congenital deformity, forearm fractures can be treated successfully when the unusual anatomy is considered in planning.
Children with radioulnar synostosis and severe fixed pronation underwent derotational osteotomy of the proximal radius and distal ulna to place the forearm in a more useful position. After surgery, most patients showed clear improvement in daily tasks like eating, washing, and writing, with stable bone healing. Complications such as nerve irritation or partial loss of correction were uncommon and generally manageable, so overall function and satisfaction were good.
An adult developed proximal radioulnar synostosis exactly where an external fixator pin had crossed the forearm after a fracture. Surgical excision of the bony bridge restored forearm rotation and improved arm use. The report stresses careful pin placement during external fixation and early follow-up to catch this rare but serious complication.
A family with several members having both radioulnar synostosis and severe low platelet counts (congenital amegakaryocytic thrombocytopenia) is described, and all affected people share a mutation in the HOXA11 gene. The combination of arm bone fusion and blood problems defines a new inherited syndrome tied to this gene change. The report shows that HOXA11 is important not only for limb development but also for forming the cells that make platelets in the bone marrow.
A 4‑year‑old child with unilateral congenital proximal radioulnar synostosis is described, showing a fixed elbow deformity and inability to turn the forearm, but normal elbow bending and straightening. X‑rays confirmed fusion of the upper portions of the radius and ulna with no history of trauma. Management was non‑surgical with observation and psychological support, because surgery in this condition often has limited success and higher risk of complications.
Two children developed radioulnar synostosis after forearm injuries and were treated surgically once the bony bridge had matured. One child had simple excision of the synostosis, and the other had excision plus placement of a soft-tissue interposition flap between the radius and ulna. Both regained useful pronation and supination with no early recurrence, showing that carefully timed resection can restore rotation in growing children.
A 39‑year‑old man with bilateral proximal radioulnar synostosis and his 5‑year‑old daughter with unilateral proximal radioulnar synostosis are described, with both having fixed forearm pronation but otherwise normal health. Despite the deformity, the father worked as a vehicle driver without major difficulty, and the child had only mild limits in daily activities. Because surgery in this condition often fails and both functioned reasonably well, management was conservative with exercises and follow‑up, supporting that some familial cases can be observed without operation.
An infant presented with proximal radioulnar synostosis together with severe bone marrow failure causing low blood counts. Genetic testing did not find a HOXA11 mutation, showing that other genes besides HOXA11 can cause this combination of arm bone fusion and marrow failure. Supportive care and hematology follow-up were required, and the case broadened the known spectrum of radioulnar synostosis with bone marrow disease.
An adult with post-traumatic proximal radioulnar synostosis is used to illustrate a step-by-step surgical technique for removing the bony bridge between radius and ulna. The operation includes careful exposure, wide excision of the synostosis, and soft-tissue interposition to keep the bones apart while healing. Forearm rotation improved after surgery, and the report emphasizes technical points that help lower the risk of recurrence.
A 52‑year‑old woman developed proximal radioulnar synostosis from heterotopic bone after a metal radial head replacement for an elbow fracture. The abnormal bone bridge formed between the radius and ulna and blocked forearm rotation. Excision of the heterotopic bone improved motion, and the report discusses strategies to prevent and treat this kind of heterotopic ossification around the elbow.
The piece outlines different ways to manage post-traumatic radioulnar synostosis, including timing of surgery, how much bone to remove, and whether to add soft-tissue or flap interposition between the radius and ulna. Advantages and drawbacks of these options are compared, with emphasis on preventing recurrence and restoring useful forearm rotation. A practical treatment strategy is proposed to help surgeons choose the best approach based on synostosis location, patient needs, and risk factors.
A single patient with congenital “middle” radioulnar synostosis is described, where the bony bridge is located in the mid‑forearm rather than near the elbow. The forearm is fixed in pronation with limited rotation, but elbow and wrist motion are largely preserved. Because this pattern does not fit classic types, the report proposes it as a probable new subtype of congenital radioulnar synostosis and recommends careful imaging to recognize it.
One adult with long-standing post-traumatic radioulnar synostosis in the distal third of the forearm underwent excision of the bony bridge through a volar approach. The surgeon wrapped the patient’s own palmaris longus tendon around the exposed ulna and added free fat as an interposition layer to reduce re-ossification. At 10-year follow-up there was no recurrence of the synostosis, only modest gain in rotation, but the patient could do daily activities comfortably.
A 9‑year‑old girl developed distal radioulnar synostosis after Kirschner‑wire (K‑wire) fixation of a distal radius fracture. A bony bridge formed between the radius and ulna near the wrist, leading to loss of forearm rotation. The report emphasizes careful wire placement and early follow‑up, because wires that cross or irritate the interosseous space may increase the risk of this rare complication.
Many different osteotomy techniques for kids with radioulnar synostosis are summarized, focusing on what age to operate, how much to rotate the forearm, and where to cut the bones. Most children had surgery around age 5, bones usually healed in about 6–8 weeks, and target positions were near neutral or slight pronation/supination depending on side and whether one or both arms were involved. Cutting directly through the synostosis carried a much higher risk of nerve and blood vessel problems than cutting both forearm bones away from the fusion area.
A 3‑year‑old child is described with complete absence of the ulna on one side, fusion between the upper arm bone and radius (humeroradial synostosis), and only three fingers with soft tissue fusion in the hand. The forearm is very short and the elbow does not move, but the main focus is on detailing the bone and soft tissue anatomy with imaging. The report adds to the small number of published cases of isolated humeroradial synostosis and shows how careful imaging helps classify the malformation and plan future care.
A child with Alagille syndrome is described who also has bilateral proximal radioulnar synostosis, an association reported only once before. Imaging shows fixed bony fusion between the radius and ulna in both elbows, but arm use is fairly well preserved through compensating wrist and shoulder motion. Because daily function is acceptable and the child has multi‑system disease, management is conservative, and the report mainly emphasizes that radioulnar synostosis can rarely occur as part of Alagille syndrome.
A 22‑month‑old child with congenital bilateral proximal radioulnar synostosis is described, showing mild visible deformity at birth but later difficulty turning the forearms. X‑rays revealed about 5 cm of bony fusion between the radius and ulna near both elbows, with no other limb abnormalities. Because daily activities were still manageable and surgery carries risks, the child was managed conservatively with observation and counseling, and the report highlights the role of imaging in early diagnosis.
A 6‑year‑old girl presented with painless difficulty turning her forearms, and X‑rays showed bilateral congenital radioulnar synostosis without other major bone problems. Shoulder and wrist motions partly made up for the loss of rotation, and daily activities were only mildly limited. Management was conservative with physical therapy and education, since surgery can have high risks and is usually reserved for more severe functional loss.
A child developed proximal radioulnar synostosis after an isolated radial head fracture that had been treated nonoperatively in a cast. A bony bridge formed between radius and ulna near the elbow, severely limiting forearm rotation. Surgical excision of the synostosis restored useful pronation–supination, and the authors stress that even seemingly simple radial head fractures can rarely lead to this complication.
An infant aged 1½ months is described with bilateral congenital humeroradial synostosis, keeping both elbows fixed in about 110° flexion and preventing any elbow or forearm motion. There is no family history, no ulna or hand hypoplasia, and no associated syndromic or organ abnormalities. Because surgery has a high recurrence rate and the elbows are already in a reasonably functional position, the authors recommend conservative management and note that most such patients can eventually work but may need help with some self-care tasks.
An 8‑year‑old girl developed proximal radioulnar synostosis weeks after a minimally displaced radial neck fracture with an associated olecranon fracture that were treated only with closed reduction and casting. Over two and a half years she progressed to complete loss of forearm rotation with a large bony bridge across the proximal radioulnar joint. The authors highlight that even nonoperatively managed, mildly displaced radial neck fractures with concomitant elbow injuries can rarely lead to this complication and recommend closer radiographic and range‑of‑motion follow‑up.
Children with congenital radioulnar synostosis and severe fixed forearm pronation underwent derotation osteotomy to place the forearm in a more functional position. The operations were done at the radius and/or ulna, not by resecting the synostosis itself, and most patients achieved near-target resting angles with improved ability to perform daily tasks. Reported complications were infrequent, supporting derotation osteotomy as a useful option when conservative treatment is not enough.
A Chinese boy presented with congenital proximal radioulnar synostosis together with amegakaryocytic thrombocytopenia, and genetic testing revealed a novel missense mutation in the MECOM gene. The child had very low platelets and bone marrow showing markedly reduced megakaryocytes, consistent with an inherited bone marrow failure syndrome. This report expands the known spectrum of MECOM-associated radioulnar synostosis with thrombocytopenia (RUSAT type 2) and underscores the need for genetic evaluation when limb malformations coexist with cytopenias.
Surgery to separate the joined bones and place a tissue flap between them prevented the bones from growing back together in all cases. Forearm rotation improved after surgery, but turning the palm upward (supination) stayed harder to improve than turning it downward (pronation). The position of the joint between the radius and the upper arm bone often shifted to a more backward alignment after surgery, without a clear link to motion differences.
A 27‑year‑old man had congenital radioulnar synostosis together with complete absence of sperm and testicular dysfunction. Chromosome analysis showed a pseudodicentric Y chromosome, linking this structural Y‑chromosome abnormality with both the limb finding and infertility. This report expands the chromosomal abnormalities known to be associated with this skeletal pattern and male infertility.
This report describes a boy with radioulnar synostosis who was also found to have the XYY chromosome pattern. The combination shows that this bone difference can appear together with a sex chromosome change. The case adds to evidence that extra Y chromosomes may be linked with certain limb and growth differences.
A man with a severe arm injury and head trauma developed a solid bone bridge between the two forearm bones, which blocked rotation. Surgeons removed the bone bridge and placed a thin tissue flap based on the radial artery between the bones to stop it from growing back. After surgery and therapy, forearm rotation and hand use improved, and no new bone bridge formed over the follow-up period.
Forearms fixed in heavy inward rotation were corrected in one surgery by cutting and rotating the bones into a more functional position. Most patients kept good correction over time and could use their hands better in daily activities. Nerve problems and other complications were uncommon and usually improved, showing this method as a workable option when motion is severely limited.
Radioulnar synostosis is described together with blood problems like low platelets and bone marrow failure, and with specific gene changes. Known links include variants in the MECOM gene and named syndromes where arm bone changes occur with serious blood count problems. The article groups these medical and genetic findings to show how arm bone fusion and blood diseases are connected in several inherited conditions.
A 7-year-old boy had fusion of one forearm and a special Y chromosome called isodicentric Y. Growth and development were otherwise normal, and no other major birth differences were present. The case adds another example of a Y-chromosome structural change found together with this bone pattern.
A young child had long-standing trouble turning one forearm, and imaging showed fusion near the elbow on that side only. Surgery separated the fused area, reshaped nearby structures, and stabilized the joint, leading to better motion and function over several months. The report stresses checking for this problem in children with rotation limits, even when only one arm is affected and X-rays are not very clear at first.
Children with severe limits in forearm rotation had surgery that removed the fused segment and used soft-tissue interposition and other reconstructive steps rather than only rotating the bones. Many gained better arm motion and could do daily tasks more easily after healing. Complications were limited, but the article emphasizes careful planning and technique to avoid nerve injury and stiffness.
An 11-year-old girl with this condition suddenly lost the ability to fully straighten her elbow after a minor fall. Imaging showed bone fusion near the elbow and an abnormal shape and position of the radial head, along with tight joint tissues. Releasing the tight lateral joint capsule restored full elbow bending and straightening and stopped the snapping sensation during movement.
An 11-year-old girl with this condition suddenly lost the ability to fully straighten her elbow after a minor fall. Imaging showed bone fusion near the elbow and an abnormal shape and position of the radial head, along with tight joint tissues. Releasing the tight lateral joint capsule restored full elbow bending and straightening and stopped the snapping sensation during movement.
Six children with this condition had a bone cut through the fused area and the forearm was rotated into a more useful position, then fixed with pins. All arms healed in about 6–7 weeks, and the children could more easily eat, dress, and do self-care tasks after surgery. Only one child had mild, temporary nerve irritation that went away within about 12 days, supporting this method as effective and relatively safe.
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