Department of hand surgery & Microsurgery.

Clasped thumb

What is a clasped thumb?

Clasped thumb is a condition that causes the child’s thumb to lose its normal appearance and movements.

What causes a clasped thumb?

The structure which helps to bend the thumb is known as tendon. Thumb has tendons to straighten it and bend it. In children with clasped thumbs, there is a problem in the development of tendons to straighten ( extend ) the thumb.

What are the symptoms of a clasped thumb?

The diagnosis of clasped thumb is often delayed because an infant frequently holds the thumb within the palm for the first 3-4 months. Children may have problems in straightening the thumb and it may remain inside the palm. Depending on the severity of disability clasped thumb is divided into 3 types

Type 1 : Child’s thumb joints are loose. Children may have problems in lifting their thumb due to problems in the tendons alone.

Type 2 : Child will have features of type 1 with additional problems in ligaments of joints and muscles of the palm.

Type 3 : Associated with other congenital disorders ( Arthrogryposis, mental retardation, Aphasia, Shuffling gait )

How do we care for a clasped thumb ?

In children with type 1 clasped thumb, splinting the thumb is an important part of treatment. Full time splinting for 6 months has been shown to be effective.Many studies have shown that good results are obtained in 70% of children who are splinted within 12 months of birth. In contrast, splinting was effective in only 21% of children older than 1 year and in none older than 2 years. So identifying the problem and starting early splinting prevents contractures in the thumb.

Surgery is warranted for children who have failed splinting or are initially seen when older than 2 years.

The precise timing of surgery is dependent on multiple factors, including the age of the child, degree of deformity and patience of the family. A delay in surgery upto 2 years of age in a child is not detrimental .