Radioulnar synostosis is a medical term used to describe an abnormal connection between the two bones of the forearm, known as the radius and the ulna. This is normally a congenital condition, meaning that the affected person is born with the defect, and it usually affects both arms. In some cases, radioulnar synostosis develops as a result of traumatic injury to the arm, as in the case of a fracture involving either of these two bones. Treatment generally involves surgical intervention, although the surgery is not always successful. Any questions or concerns about radioulnar synostosis in an individual situation should be discussed with a doctor or other medical professional.
There are three basic types of radioulnar synostosis, each classified by the location of the abnormal connection. In the first type, the head of the radius is either connected to the ulna or is missing completely. In the next type of radioulnar synostosis, the head of the radius has an abnormal shape and is dislocated, connecting with the upper shaft of the ulna. In the final type, the radius and ulna are fused together by a ligament. Regardless of the exact type of connection present, this condition prevents the arm from bending and working in a normal fashion.
In most cases, radioulnar synostosis is a congenital condition, meaning that a person is born with it. In more than half of these cases, both arms are affected. Occasionally, the fusion of these bones may occur after trauma to the arm, especially a fracture to either the radius or the ulna. Due to the variance in severity of the disability caused by this condition, each patient must be evaluated individually in order to determine the best treatment option.
Surgical separation of the bones is not often recommended, as this procedure does not carry a high percentage of positive results. In some cases, this may be the only surgical option and may allow some additional usage of the affected arm. Due to the potential risks, many doctors will recommend physical therapy as a way to get as much use out of the arm as possible instead of attempting this procedure.
A surgical procedure known as an osteotomy may be helpful in severe cases of radioulnar synostosis. This is a procedure that may involve changing the length of one of the bones or may be used to change the alignment of the bones of the arm. An osteotomy often allows the affected arm to become functional, although the level of function may vary, depending on the individual situation. Full use of the arm may not always be possible, even with surgical intervention.