IN 1878, MADELUNG (8) described a painful abnormality of the wrist and forearm which characteristically began in adolescence. The radiographic alterations of the radius and ulna were described later. The most complete review of the subject is that of Anton et al. (1), who collected and summarized the literature through 1938. Considering this clinical and radiographic abnormality a deformity rather than a syndrome, these workers distinguished it from Madelung's disease, which is characterized by diffuse symmetrical lipomatosis of the upper part of the back, shoulders, and neck. They also suggested that the deformity of the wrist and forearm be considered a dyschondroplasia of the distal radial epiphysis. While this may be a logical name for the entity, it has not found wide usage, Madelung's deformity remaining the preferred term. In 1929, Léri and Weill (7) reported a case of dwarfism and radiographic alterations of the forearm and wrist similar to Madelung's deformity, although no reference was made to Madelung's original description. Believing this represented a previously undescribed generalized osseous dysplasia, they gave it the name “dyschon-drostéose.” There have since been other occasional reports of this condition. Herdman, Langer, and Good (4) and Langer (6) arrived at the following conclusion regarding the relationship of Madelung's deformity to the Léri-Weill syndrome: “Madelung's deformity of the forearm is the most striking feature of dyschondrosteosis, and it is our feeling that all cases with this deformity, except when it is secondary to trauma or infection, should be included under the heading of dyschondrosteosis” (4). Maroteaux and Lamy (10) concurred with this opinion. We have studied the radiographs of 17 patients with abnormalities of the wrist and forearm which were characteristic of Madelung's deformity according to the criteria set forth by Dannenberg et al. (2). In 2 patients the evolution of Madelung's deformity was observed radiographically. In some cases variable shortening of the ulna and humerus was noted. Six patients (CASES 1–6, TABLE II) are felt to represent examples of dyschondrosteosis. Radiographic Observations The radiographic criteria for the diagnosis of Madelung's deformity as proposed by Dannenberg et al. (2) have been utilized in the analysis of our patients. These criteria are presented below, regrouped according to the bones primarily affected: A. Alterations Which Primarily Involve the Radius 1. Double Curvature (Ulnar and Dorsal) (Figs. 1 and 2): Ulnar curvature was present in all but one patient and varied from 8 to 30°. Volar curvature was much less constant and involved only the distal diaphysis and metaphysis. 2. Decreased Length (Fig. 1): The radius was 0.5 to 6.0 ern shorter than normal for the stated age in each instance.3