[Reconstruction of thumb through continuous lengthening of the first metacarpus]

Abstract

Goal of surgery: Reconstruction of the amputated thumb through continuous distraction with an Ilizarov ring fixator.

Indications: Traumatic loss of thumb at the level of the proximal half of the proximal phalanx.

Contraindications: Insufficient soft tissue coverage of stump. Stiff saddle joint.

Positioning and anaesthesia: Tourniquet. Brachial plexus or general anaesthesia.

Surgical technique: Installation of a ring fixator. Incomplete osteotomy at mid shaft of first metacarpus with chisel and completion through osteoclasia by twisting the chisel. Preserve palmar periosteum. Deepening of first web space if necessary after removal of external fixator. Use of Z-plasty and proximal transfer of adductor pollicis insertion.

Postoperative management: After 1 week continuous lengthening 0.7 mm/day in 3 daily increments. After removal of fixator plaster cast for 2 weeks.

Possible complications: Improper installation of fixator. Incomplete osteotomy. Too rapid or too slow distraction. Pin tract infection. Deep infection.

Results: Over a 2 year period 10 lengthenings. Average follow-up 23 months (10 to 36 months). Average gain in length 38.1 mm. Average length of treatment 163 days. Deepening of web space in 7 patients. Force of grasp 64% of opposite side. Pin tract infection: 4, too early removal of fixator: 1, revision of scar: 1 and correction of stump: 1. All patients were satisfied with the result but for scar at web space.