The authors present the first reported case of a free microvascular one-stage flexor tendon reconstruction for flexor tendon loss in zone II. Their patient had an initial flexor laceration of the FDS and FDP tendons repaired elsewhere 18 months earlier, which was immobilized for three weeks postoperatively with no resultant active ROM. Three subsequent attempts at tenolysis were unsuccessful, and total AROM was 0 degrees. They performed excision of the remnant tendons and pulleys in zone II, with an immediate transfer of the ring finger FDS tendon and surrounding tenosynovium from the forearm, based on a perforator vessel from the ulnar artery, with a short segment of the ulnar artery at its base. The resultant defect in the ulnar artery was repaired primarily. The tendon flap was anastomosed to the superficial vascular arch, and the tendon was inset with a pull-out suture distally and Pulvertaft weave proximally to the FDP tendon. A2 and A4 pulleys were reconstructed with circumferential tendon grafts. Standard postoperative flexor tendon rehabilitation was initiated postoperatively. Results were favorable, with total AROM of 60 degrees at the PIP joint and 20 degrees at the DIP joint. The patient was able to return to work as a laborer.
The authors have used an ingenious modification of a pedicled flexor tendon transfer for secondary reconstruction, reported earlier by several authors, to perform a one-stage microvascular secondary flexor tendon reconstruction with satisfactory results. Their modification eliminates the need for sacrificing continuity of the ulnar artery to achieve vascularized tendon transfer. They theorize that the vascularized tendon/tenosynovium graft has the advantage of minimizing fibrosis and adhesions versus the more traditional non-vascularized graft by keeping the tendon enclosed within viable tenosynovium. Experimental studies on animals would be very useful in supporting this hypothesis. They identify shortcomings and difficulties in their technique, namely, the difficulty in adequately monitoring patency of the vascular anastomosis, uncertainty about the fate of the repaired defect in the ulnar artery, and the need for very precise setting of tension in the transfer. However, the technique does appear to have merit, especially in considering the benefit of a one-stage technique with immediate postoperative rehabilitation over more traditional two-stage non-vascularized grafting.
Flexor, Tendon, Graft, Vascularized, Reconstruction
Journal of Reconstructive Microsurgery