Madelung deformity is a condition where one of the two forearm bones, the radius, doesn’t grow properly near the wrist. The inner edge of the radius grows slower than the rest, causing the wrist to develop an abnormal shape. It’s most often noticed during adolescence, when the bones are growing rapidly, and it affects girls far more frequently than boys.
What Happens Inside the Wrist
Your forearm has two bones running from your elbow to your wrist: the radius (on the thumb side) and the ulna (on the pinky side). In Madelung deformity, a section of the radius near the wrist fails to grow at a normal rate, specifically along its inner, palm-side edge. This uneven growth causes the end of the radius to tilt and angle more than it should.
Because the radius falls behind, the ulna keeps growing at its normal pace and ends up relatively too long. This creates the most visible sign of the condition: a prominent bump on the back of the wrist where the end of the ulna sticks out. The small bones of the wrist (the carpal bones) shift forward and settle into a V-shaped arrangement that shows clearly on X-rays. This altered alignment changes how the wrist moves and distributes force, which is why people with the condition often experience pain, stiffness, or limited range of motion.
A key structure involved is an abnormal band of tissue sometimes called the Vickers ligament. This tissue tethers the growth plate of the radius on its inner side, physically restricting bone growth in that area while the rest of the growth plate continues developing normally. In children who still have years of growth remaining, this tethering effect compounds over time, making the deformity progressively worse until the bones stop growing.
Genetic Causes and Associated Conditions
The most common genetic link is a mutation or deletion in a gene called SHOX, located on the sex chromosomes. SHOX plays a direct role in limb bone growth. When it’s missing or altered, the long bones of the arms and legs tend to be shorter than expected. Up to 70% of people with a related condition called Léri-Weill dyschondrosteosis, which combines short stature with Madelung deformity, carry a detectable SHOX abnormality. These include large deletions of the gene, smaller point mutations, and deletions in nearby regulatory regions that control how the gene functions.
Because SHOX sits on the sex chromosomes, Madelung deformity also appears in Turner syndrome, a condition where girls are born with a missing or partially missing X chromosome. In one study of 187 pediatric Turner syndrome patients, about 3.7% had X-ray findings consistent with Madelung deformity. Turner syndrome affects skeletal development in multiple ways, so wrist changes may be just one part of a broader pattern.
Not every case traces back to a gene. Madelung deformity can also result from injury to the growth plate, infection, or other conditions that damage the developing bone. These acquired forms look similar on imaging but tend to affect only one wrist, whereas genetic cases usually involve both.
Symptoms and When They Appear
The deformity typically becomes noticeable during the adolescent growth spurt, roughly between ages 8 and 14. Early on, a child or teenager might notice that one or both wrists look slightly different, with the ulna appearing more prominent on the back of the hand. Pain is variable. Some people have very little discomfort, while others develop aching during activities that load the wrist, like pushing off a surface, gripping tightly, or bearing weight on their hands.
Functional limitations often center on wrist rotation and extension. Turning the palm fully upward (supination) or bending the wrist backward can feel restricted or painful. Over time, grip strength may also decrease. The severity ranges widely. Some people live with the condition for years before it’s even diagnosed, while others seek medical attention early because the wrist looks noticeably different or daily activities become uncomfortable.
How It’s Diagnosed
Diagnosis starts with a physical exam, but X-rays confirm it. On a standard front-to-back wrist X-ray, doctors look for increased tilting of the radius, a sunken position of one of the carpal bones (the lunate), and the characteristic V-shaped arrangement of the wrist bones. A side-view X-ray reveals the forward tilt of the radius and a shift of the carpal bones toward the palm.
Specific measurements help distinguish true Madelung deformity from a wrist that’s simply a bit unusual. Research has established diagnostic thresholds: an ulnar tilt of 33 degrees or greater, lunate sinking of 4 millimeters or more, a lunate fossa angle of 40 degrees or greater, and forward displacement of the carpal bones by 20 millimeters or more. When these values are met, the diagnosis is generally clear-cut. Genetic testing for SHOX mutations may be recommended if both wrists are affected or if there’s a family history of short stature.
Treatment Options
There are no standardized treatment guidelines for Madelung deformity, so management is tailored to each person based on age, severity, and how much the condition affects daily life.
Conservative Management
For mild cases with minimal pain, non-surgical approaches are often the first step. Wrist splints can reduce discomfort during activities, and physical therapy may help maintain range of motion and strengthen the surrounding muscles. Activity modification, like avoiding heavy loading through the wrist, can keep symptoms manageable. Many people with mild deformity function well without surgery.
Surgery for Growing Children
In children and adolescents who still have growth remaining, one option is a procedure called physiolysis. This involves removing the abnormal tissue (the Vickers ligament) and the damaged portion of the growth plate, then placing a fat graft to prevent a bony bridge from forming again. The goal is to release the tether and let the radius resume more normal growth. Evidence suggests this approach, performed in early skeletal maturity, may stabilize mild deformities and prevent them from worsening.
Surgery for Advanced Cases
When the deformity is more severe, with significant loss of wrist motion (more than 20 degrees) and pronounced sinking and displacement of the carpal bones, surgical correction of the bone itself is typically needed. The main approaches fall into three categories: lengthening the radius with a corrective cut and repositioning (osteotomy), shortening the ulna to restore more balanced alignment, or combining both procedures. The choice depends on which bone contributes more to the mismatch and what specific measurements show on X-rays.
Recovery and Long-Term Outlook
After corrective surgery, the wrist is typically immobilized for several weeks while the bone heals, followed by a course of physical therapy to restore motion and strength. Long-term studies of patients treated with radial or ulnar osteotomy show that most people achieve a functional wrist afterward. In one medium to long-term follow-up, patients averaged a flexion-extension arc of 134 degrees and a pronation-supination arc of 142 degrees, both close to what’s needed for most daily tasks. Pain levels varied, with an average score of about 2 out of 10 on a pain scale.
The condition does not typically worsen once the bones finish growing. For people diagnosed in their teens, the deformity stabilizes in early adulthood. Some people develop mild arthritis in the wrist over decades, particularly if the carpal alignment was significantly disrupted, but this isn’t inevitable. For those with genetic forms tied to SHOX mutations, the wrist is just one aspect of skeletal health to monitor alongside overall growth and bone development.