Ulnar Longitudinal Deficiency (Ulnar Club Hand)

What is ulnar longitudinal deficiency?

A diagnosis of ulnar longitudinal deficiency, previously known as ulnar club hand, means that your child’s wrist is in a fixed and bent position toward the side of the hand with the little finger. It’s caused by an ulna (the bone that connects the elbow to the forearm) that wasn't formed correctly in the womb. Your child’s thumb may also be deformed or absent.

When describing a particular side of the arm, you may hear your child's doctor refer to the "radial side," which indicates the side of the arm on which the thumb lies, or the "ulnar side," which describes the side on which the little finger lies.

These terms are used rather than "inner" or "outer" arm because the palm of the hand can face either forward or backward.

Ulnar longitudinal deficiency is less common than radial longitudinal deficiency. It’s present in about 1 in 100,000 babies.

There are the four different types of ulnar longitudinal deficiency:

  • Type I: In the mildest cases, the ulna is merely slightly smaller than normal and there is minimal deviation at the wrist. This won’t cause many problems in your child’s development.
  • Type II: This is the most common form of ulnar longitudinal deficiency. It involves a partial absence of the ulna and the hand appears deviated toward the ulnar side. Bowing of the radius may also occur.
  • Type III: Your child’s ulna is completely absent, leading to limited range of motion at the wrist. The elbow joint may also be disturbed or even fused with no motion. There may also be underdevelopment or absence of the thumb, which interferes with hand function.
  • Type IV: Here, there’s an abnormal connection between your child’s radius and humerus, resulting in bowing of the radius and hand deformations.

How we care for ulnar longitudinal deficiency

Hand and Orthopedic Upper Extremity Program

The Hand and Orthopedic Upper Extremity Program provides comprehensive care involving occupational and physical therapy, splinting, casting and reconstructive surgeries for infants, children and adolescents with complex congenital, neuromuscular, sports-related oncologic and traumatic upper limb conditions.

You can have peace of mind knowing that the skilled experts in our Hand and Orthopedic Upper Extremity Program have treated thousands of babies and children with many hand conditions.  We provide expert diagnosis, treatment and care, and we benefit from our advanced clinical and scientific research.

Hand and Reconstructive Microsurgery Program

The specialists in the Hand and Reconstructive Microsurgery Program at Boston Children's are experts in the management of congenital and acquired hand deformities. We recognize the social elements involved in pediatric hand surgery, so an essential part of these operations has been making the child's hand as symmetrical as possible with his unaffected hand.