Congenital thumb differences- current concepts

Abstract

Anomalies of the thumb development are not uncommon and may be associated with a number of syndromes also. These anomalies range from total absence to duplication. Reconstructive surgery for the creation of an opposable thumb is the most rewarding aspect of Hand Surgery and also the most challenging. Classification systems have been modified for better description. A number of procedures have been introduced to improve the functionality of the hand in anomalies and age old concepts are undergoing a metamorphosis to further this. A brief description of the common conditions and their treatment are discussed here and highlighted by selected clinical cases.

Keywords: Congenital; Hypoplastic thumb; Polydactyly; Thumb anomalies; Thumb duplication; Trigger thumb; Triphalangeal thumb.

Fig. 1

A. Photograph of the hand of a 2- year old child showing the flexion deformity of the Lt thumb interphalangeal joint. This is the usual presentation of trigger thumb. Fig. 1B. A transverse incision at the level of the MCP joint crease to expose and incise the A1 pulley is used. Fig. 1C. The flexor tendon is hooked and checked for gliding after the release of the pulley.

Fig. 2

A. Preoperative photograph of a 12-year old child with Wassel Type IV duplication. Note that the radial element is much smaller than the radial one and can be removed for better function and cosmesis. Fig. 2B. Radiographs of the thumb of the same patient as in Fig. 4 showing separate articulation of the two elements. Fig. 2C. Intraoperative photograph showing removal of the radial element. The collateral ligament was attached to this part and was transferred to the retained segment. This is a very important step in the procedure. Fig. 2D and E. Post-operative picture after ablation of the accessory segment. Fig. 2F. The IP and MCP joints were transfixed with K-wires for healing of the wound and transferred collateral ligament. Fig. 2G. Follow up composite picture of the patient 13 years after the primary surgery showing very good cosmesis and appearance of the thumb.

Fig. 3

Diagrammatic representation of the modified Bilhaut- Cloquet procedure used in reconstruction of Wassel type I,III and V thumb duplication (and selected Type II). The bony area shaded black in this diagram is removed and the fragments approximated.

Fig. 4

A & B. Photograph and X-ray appearance of the triphalangeal thumb in a 5-year old boy. Here the accessory phalanx is rectangular in shape. This was shortened and fused to the adjacent phalanx.

Fig. 5

A &B. Preoperative photograph and X-ray of a three-year old child with right sided Type III hypoplastic thumb Fig. 5C &D. Post-operative follow-up picture 8 years after multiple reconstructive procedures including thumb web release and dorsal sliding flap based on 1st dorsal metacarpal artery, ulnar collateral ligament reconstruction, metacarpal osteotomy and FDS opponensplasty. Note the good appearance and function. Patient also had closure of VSD and PDA at the age of 7.

Fig. 6

A,B,C, D. Preoperative and intraoperative photograph of a 4-year old child with Holt-Oram syndrome with Type IV hypoplastic thumb. She underwent ASD closure followed by centralization of the ulna at the age of 3. Filleting of the “poucce flottant “and pollicization was done 1 year later. Note the symphalangism in the digits including the index finger.

Fig. 7

A, C. Preoperative and post operative photograph of a 2 year old child with bilateral radial club hand and Type IV hypoplastic thumb. The floating segment was previously removed along with centralization. Fig. 7B and E. Preoperative and postoperative follow up radiographs of the child after pollicization. Fig. 7D. Post-operative follow up photograph of the child 3 years after the pollicization.

Fig. 8

A&B. Intraoperative photograph of a Huber’s transfer of the myo-cutaneous flap of abductor digiti minimi. Note the neurovascular bundle entering the deep aspect of the muscle (marked by the star).

Fig. 9

A,B. Preoperative and intraoperative photographs of a child who underwent a myo-cutaneous Huber transfer for opposition in a Blauth Type III A thumb hypoplasia. Fig. 9C&D. Postoperative follow up photographs showing the active abduction of the thumb and post-operative function after the Huber transfer.