Tumor location affects the results of simple excision for multiple osteochondromas in the forearm.

BACKGROUND The effectiveness of excision of osteochondromas in controlling the progression of forearm and wrist deformity remains an issue of controversy. The purpose of this study was to analyze the effectiveness of tumor excision in the correction of forearm and wrist deformity due to multiple osteochondromas in children, with an interpretation of the results based on different patterns of deformity. METHODS Fourteen forearms in thirteen children with a follow-up of more than twenty-four months (average, fifty-three months) were included in the study. The forearms were divided into two groups on the basis of the location of the tumor and the pattern of deformity. In Group 1 (six forearms), the osteochondroma was only in the distal aspect of the ulna and caused compression of the radius. In Group 2 (eight forearms), tumors were in both the distal aspect of the ulna and the ulnar side of the distal part of the radius and were in contact with each other. Radial length, ulnar shortening, radial bowing, the radial articular angle, and carpal slip were measured as radiographic parameters. Ulnar shortening and radial bowing were expressed as a percentage of the radial length to make it possible to compare data between the individuals. Each parameter was evaluated before surgery and at the time of final follow-up. RESULTS In Group 1, the percentage of ulnar shortening and the percentage of radial bowing had improved at the time of final follow-up; however, in Group 2, both the radial articular angle and the percentage of radial bowing had deteriorated significantly after the tumor excision (p = 0.049 and p = 0.017, respectively), even though the percentage of ulnar shortening showed no change. CONCLUSIONS The effectiveness of simple excision of osteochondromas of the distal aspect of the forearm is influenced by the tumor location and is related to the pattern of the deformity. Simple tumor excision can correct the forearm deformity in patients with an isolated tumor of the distal part of the ulna. Conversely, in patients with tumors involving the distal part of the ulna and the ulnar side of the distal end of the radius, tumor excision alone is a less promising procedure for the correction of the deformity. LEVEL OF EVIDENCE Prognostic Level IV.