Among other movements, the forearm is capable of pronation and supination, which is to say rotation about the long axis of the forearm. In this movement the ulna, which is connected to the humerus by a simple hinge-joint, remains stationary, while the radius rotates, carrying the wrist and hand with it. To allow this rotation, the proximal (elbow) end of the radius is held in proximity to the ulna by a ligament known as the annular ligament. This is a circular ligamentous structure within which the radius is free, with constraints existing elsewhere in the forearm, to rotate. The proximal end of the radius in young children is conical, with the wider end of the cone nearest the elbow. With the passage of time the shape of this bone changes, becoming more cylindrical but with the proximal end being widened.If the forearm of a young child is pulled, it is possible for this traction to pull the radius into the annular ligament with enough force to cause it to be jammed therein. This causes significant pain, partial limitation of flexion/extension of the elbow and total loss of pronation/supination in the affected arm. The situation is rare in adults, or in older children, because the changing shape of the radius associated with growth prevents it. Diagnosis
Diagnosis is often based on symptoms. X-rays may be done to rule out other problems. Treatment
To resolve the problem, the affected arm is moved in a way that causes the joint to move back into a normal position.
The endoscope allows minimally invasive  access through the natural ear canal, rather than through the usual 5 cm incision behind the ear utilized in traditional microscopic surgery. The 30 degrees endoscope allows access to the bony area of the Eustachian tube to address any obstructive pathologies. Prognosis
It is important that the patient attend periodic follow-up checks, because even after careful microscopic surgical removal, cholesteatomas may recur. Such recurrence may arise many years, or even decades, after treatment. A residual cholesteatoma may develop if the initial surgery failed to completely remove the original; residual cholesteatomas typically become evident within the first few years after the initial surgery. A recurrent cholesteatoma is a new cholesteatoma that develops when the underlying causes of the initial cholesteatoma are still present. Such causes can include, for example, poor Eustachian tube function, which results in retraction of the ear drum, and failure of the normal outward migration of skin.In a retrospective study of 345 patients with middle ear cholesteatoma operated on by the same surgeon, the overall 5-year recurrence rate was 11.8%. In a different study with a mean follow-up period of 7.3 years, the recurrence rate was 12.3%, with the recurrence rate being higher in children than in adults. The use of the endoscope as an ancillary instrument has been shown to reduce the incidence of residual cholesteatoma.