Foot Plantar Pressure Profile Alteration after Microsurgical Great Toe-to-thumb Transfer

BACKGROUND: Microsurgical great toe-to-thumb transfer (mGTT) is a widely used procedure when immediate replantation of thumb is not feasible. The aim of this study was to investigate the alteration of plantar pressure profile of the donor foot after mGTT. METHODS: Twenty patients receiving microsurgical great toe-to-hand transfer between 1985 to 2014, and 16 healthy subjects were recruited. Group 1 consisted of 20 feet receiving mGTT, whereas group 2 consisted of 32 normal feet as control. The flap design in this study was to preserve 1 cm of the proximal phalanx to maintain the attachment of the plantar aponeurosis and intrinsic muscles. The Taiwan Chinese version of the Foot Function Index was used for patient-reported outcome measurement. A novel Emed-X system was used for dynamic plantar pressure measurement. A total of four parameters were collected, including peak pressure, contact area, contact time, and pressure–time integral. RESULTS: In group 1, the peak pressure redistributed under the first metatarsal bone and was significantly higher than group 2 (P < 0.05). There was no significant change of the contact area between the midfoot region of group 1 and group 2 (P > 0.05). Furthermore, similar foot clearance efficiency was demonstrated in group 1 and group 2 (P > 0.05). CONCLUSIONS: The windlass effect of the foot will not be affected when performing mGTT with preservation of 1 cm of the proximal phalanx. Therefore, this surgical procedure is highly recommended for clinical application.