Madelung deformity is bilateral in two thirds of the patients. Rarely, a reversed Madelung deformity may occur in which the articular surface of the distal radius is angulated dorsally and the distal ulna assumes a relatively palmar position.

Madelung deformity can be broken down into four etiologic groups, as follows: post-traumatic, dysplastic, chromosomal or genetic, and idiopathic or primary. The post-traumatic deformity has been found after repetitive trauma or after a single traumatic event that disrupts the growth of the distal radial ulnar-volar physis. Bone dysplasias associated with Madelung deformity include multiple hereditary osteochondromatosis, Ollier disease, achondroplasia (see Plates 4-1 to 4-3), multiple epiphysial dysplasias (see Plate 4-12), enchondromatosis, gonadal dysgenesis (Turner syndrome), and the mucopolysaccharidoses (e.g., Hurler and Morquio syndromes; see Plate 4-18). The most important dysplasia associated with Madelung deformity, however, is dyschondrosteosis.

Although Madelung deformity is considered a congenital anomaly, symptoms do not usually begin until late childhood or early adolescence (6 to 13 years of age). One third of the cases of Madelung deformity are transmitted in an autosomal dominant fashion. The condition has a variable expression and 50% penetrance. Madelung deformity is bilateral in up to two thirds of the patients, and females are affected four times as often as males. The moderately short stature of the affected person has led to some confusion as to whether Madelung deformity is an isolated deformity in the distal radius or a form of dyschondrosteosis (Léri-Weill syndrome). However, dyschondrosteosis, which is characterized by other associated skeletal deformities, particularly in the tibia, in addition to Madelung deformity at the wrist, is probably a separate entity. Furthermore, a primary chromosomal association with Madelung deformity has been observed in the patients with Turner syndrome (with and XO karyotype).

Recently, Vickers approached Madelung deformity through an anterior approach and noted for the first time the presence of a large, abnormal, anterior wrist ligament between the anterior ulnar metaphysis of the distal radius and the carpus (Vickers’ ligament). Grossly, this ligament is a large, fibrous band about 5 to 7 mm thick. It is found under the pronator quadratus, originating well proximal to the majority of the physis, in a fossa on the ulnar side of the anterior surface of the radius. From here, it flows out onto the anterior surface of the lunate, inserting like the radiolunate ligament in the normal wrist. It may be that Vickers’ ligament is a stretched out coalescence of normal structures, formed as a consequence of an abnormal growth of the radial physis beneath it. This may suggest that Vickers’ ligament is a secondary rather than a primary cause of Madelung deformity. This is supported by the fact that if the ligament were present at birth, the tremendous growth of the child during the first 3 years of life should lead to Madelung deformity by the time the child is a toddler, an age when the deformity is never seen. Regardless, releasing this ligament when reconstructing the wrists with a fully developed Madelung deformity is critical.

Treatment. Because discomfort usually resolves or remains minimal and function is excellent, surgical treatment is rarely indicated. Operative management for Madelung deformity is indicated for pain relief and cosmetic improvement. Madelung initially advised his patients to avoid forced wrist extension and to use resting splints at night to relieve the pain. Persistent pain, usually due to nerve impingement between the distal ulna and underlying carpal bones, and extreme deformity are two other reasons for operative management. Limited wrist motion is not an indication for surgery, which does little to improve it.