Further follow-up on five cases of congenital clasped thumb, originally reported in 195511, is given, as well as our experience with twelve additional cases observed since that time. The long-term results of treatment with corrective plaster casts have remained good if the early response was good. No significant changes were noted with growth.
A classification is proposed and applied to our seventeen cases and the thirty-one cases reported by others in the literature. Thirty-three of the forty-eight cases were classified in Group I with weak or absent extensor tendons. The condition occurs predominantly in boys and is usually bilateral. There is frequently a positive family history.
In our Group I patients, sixteen thumbs were treated by immobilization in extension and abduction for a period of one to seven months. Good to excellent results were achieved in 69 per cent and a satisfactory result in 94 per cent. In one thumb, not seen until after the age of two years, the result was poor, with extension of the metacarpophalangeal joint of the thumb limited by 35 degrees.