The Snow-Fink Technique as an Opposition Tendon Transfer for Children Born with a Hypoplastic or Absent Thumb

Abstract

An opposition transfer using the FDS tendon of the ring finger through a window in the transverse carpal ligament is a simple and reliable technique for improving thumb function in children born with an absent or hypoplastic thumb. This transfer does not produce a concave deformity in the hypothenar eminence like the Huber transfer, provides better pronation, and affords concurrent stabilization of the MCP joint.

Congenital thumb differences- current concepts

“…and a MCP chondrodesis when multiaxial. The Snow-Fink transfer 27 of FDS R to the abductor pollicis brevis muscle with an aperture made in the transverse carpal ligament as a pulley is useful in situations when the MCP joint is stable. In case of multiaxial instability an MCP joint chondrodesis provides stability and then opposition can be provided by a tendon transfer.…”

Surgical techniques for reconstruction of the hypoplastic thumb

“…The design of the flaps needs to allow access to the MP joint and might be influenced by previous scars. A four-flap web plasty (Figure 2(a), (b), and (d)), five-flap Z-plasty, or double-opposing Z-plasty are the most commonly used procedures (Abdel-Ghani and Amro, 2004; Christen and Dautel, 2013; de Kraker et al., 2016; Lister, 1991; Neviaser, 1979; Oberlin and Gilbert, 1984; Ogino and Ishii, 1995; Ogino et al., 1986; Smith et al., 2012; Vuillermin et al., 2016; Yoon and Jones, 2015). A two-flap Z-plasty tends to create a V-shaped rather than a U-shaped web.…”

“…The use of the FDS opposition transfer allows for reconstruction of the UCL with a tendon slip, for cases in which it is considered that stability cannot be achieved with imbrication of local soft tissue (Christen and Dautel, 2013; de Kraker et al., 2016; Lister, 1991; Tonkin, 2011; Vergara Amador, 2008; Vuillermin et al., 2016; Yoon and Jones, 2015). A low donor site morbidity is claimed for the ring finger FDS opposition transfer because independent ring finger proximal interphalangeal (PIP) joint flexion is rarely necessary for the daily activities of these patients (the ability to play a musical instrument may be diminished), though strength for power grip may be compromised (De Kraker et al., 2016; Vuillermin et al., 2016).…”