Case of the fortnight
Department of Plastic Surgery, Hand Surgery and Reconstructive Microsurgery

Pollicization for Correction of Congenital Hypo Plastic Thumb

 

Thumb deficiencies are common congenital anomalies  found in children.  They account for approximately 11% of all birth defects of hand.  The deficiency can vary from minimal shortening to complete absence. (Please see table below)

 

 

Modified Blauth classification of hypoplastic thumb

 

Type I

Minimal shortening of thumb but normal function

 

Type II
  • Contracture of thumb-index web space
  • Lack of thenar muscle
  • Metacarpophalangeal joint instability

 

Type III

A

All Type II features, plus

  • Absent extrinsic Muscle
  • Skeletal Hypoplasia
  • Vestigial but intact CMC Joint

B

All Type II features, plus

  • Absent extrinsic Muscle
  • Metacarpal Aplasia
  • Unstable CMC

Type IV

Floating thumb (Pouce Flottant)

 

Type V

Absent thumb

 

Manske and McCaroll have proposed the modification of Blauth Classification by dividing type III into two sub categories A and B


Type IV Hypo PlasticThumb
 in a 1 year old child


Child is unable to grasp
objects using the thumb

Treatment
Treatment depends upon the deformity present.  Children with Type I deficiency need no treatment.  In Type II treatment consists of release of first web space, reconstruction of ulnar collateral ligament and opponens plasty.  In Type III there is instability of metacarpophalangeal joint requiring stabilization.

Pollicization
This surgery is now a well accepted technique for thumb reconstruction in case of Type III,  IV and V deformity.   Pollicization of index finger consist of transferring the index finger in the position of the thumb to achieve best possible hand function. This technique was first described by Gosset, in 1949 and modified and popularized by Buck Gramcko.  The main steps of pollicization are as follows.

1.  Creation of First web space by transposing a flap.
2.  Removal of second metacarpal and to rotate into new position to create a normal sized thumb
3.  To provide abduction and adduction of thumb by using the intrinsic muscle.

Post operative Photographs

The child now uses the new thumb as any other normal child.

 

The result of this surgery is extremely gratifying.  The result depends upon the presence of muscle in the index finger.  Pollicization is a technically demanding procedure requiring high levels of skill and good knowledge of Anatomy, Microsurgery and Biomechanics.  

 

Timing of the surgery is important to achieve optimal outcome.  The earlier the surgery is done, the better. The functional image of the thumb is formed in the brain at the age of 1 year. Therefore it is better to create a normal functioning hand by substituting the index finger for  the  missing  thumb  by that age.   Even if the child presents late, surgery is still beneficial to give a more functional thumb.  The advantages of  this  surgery are enormous and the child accepts the new thumb and starts using it naturally.  The final functional and cosmetic results are extremely good. The child gets a hand with a thumb with good mobility, sensation and strength. 

 

Pollicization

Pre Op

Post Op

THE SURGICAL TEAM

Dr. S Raja Sabapathy
Dr. Ravindra Bharathi
Dr. Hari Venkatramani
Dr. James D’ Silva
Dr. Gaurav Sawhney

The Anaesthetic Team

Dr. V  Ravindra Bhat
Dr. G. Venkateswaran

If you want to know about the “Story of the Thumb”   written by us for  “THE HINDU” please click the URL below.

http://www.hindu.com/thehindu/mag/2004/02/15/stories/2004021500220600.htm