Pitfalls in diagnosing carpal tunnel syndrome.

The aim of this paper is to point out the differential diagnosis be-tween a thumb hypoplasia type 1/11 and a carpal tunnel syndrome. Both syndromes have symptoms in common. Two children and an adult with hypoplastic thumbs were sent to our department with the diagnosis carpal tunnel syndrome. In both children, the diagnosis was changed after an exact history and examination, and in one child an opponensplasty was done. The adult patient had already been operated unsuccessfully for a carpal tunnel syndrome elsewhere and again at our department. The exact diagnosis was only made after the second operation,when an extended questioning was done. This shows how important a careful history taking, an exact clinical examination, X-ray examinations of both hands, knowledge of type 1/11 hypoplasia, and finally electroneurography and sonography are important for a correct diagnosis.