Correction of bilateral congenital swan-neck deformity by use of Mitek mini anchor: a new technique.

Abstract

Congenital swan neck deformity is a rare condition, secondary to congenital laxity of the palmar plate of the proximal interphalangeal joint. Here, we describe a new surgical method which is based on the palmar plate reinforcement using the Mitek mini anchor system (Mitek Surgical Products Inc., Norwood, MA, USA). Four fingers of a patient with congenital swan neck deformities were corrected with this technique at two stages. First, the anchor was inserted into the volar surface of the proximal phalanx. The two sutures of the anchor system were then crossed the PIP joint in a V fashion. Two holes, 5mm apart from each other, were created through the middle phalanx distal to both insertion points of superficial flexor tendon. The suture ends of the anchor were passed through these holes from the volar to the dorsal side of the middle phalanx and then turned around the edges of the bone to the volar surface. They were tied to each other as the PIP joint was stabilised at 20 degrees flexion by use of a K-wire. The K-wire was removed 21 days later and a rehabilitation program was then initiated. A second operation for the two fingers of the opposite hand was performed 2 months after the first operation. No postoperative complications were encountered. At 2 years follow-up, the active range of motion was within normal limits at PIP and DIP joints of all four fingers without any recurrence of hyperextension or hyperflexion. The final result was satisfactory regarding both the functional and cosmetic aspects. The Mitek mini anchor offers a practical, reliable and functional reconstruction of the volar plate in the management of congenital swan neck deformities. We believe that it may also be used for the acquired deformities.