[Therapeutic effect comparison of repairing digit degloving injury with two kinds of double island flap].

OBJECTIVE: To compare the double dorsal phalangeal flap (DDPF) with the combination of digital neurovascular island flap (NVIF) and first dorsal metacarpal artery flap (FDMA) in terms of repairing digit degloving injury.

METHODS: From October 2005 to March 2008, DDPF was used to repair 9 patients (9 fingers) with degloving injury of the thumb and index finger and completely amputated thumb and index finger (group A). From August 1996 to June 2007, NVIF and FDMA were used to repair 13 patients (13 fingers) with the thumb degloving injury and completely amputated or necrotic thumb (group B). In group A, there were 7 males and 2 females aged 19-48 years old, there were 4 cases of thumb and index finger degloving injury repair and 5 cases of completely amputated thumb and index finger reconstruction, the skin defect ranged from 6.0 cm x 3.5 cm to 7.0 cm x 4.5 cm, and the interval between injury and operation was 3-10 hours. The size of DDPF harvested during operation was 4.0 cm x 3.5 cm-5.0 cm x 4.0 cm. In group B, there were 10 males and 3 females aged 18-50 years old, there were 5 cases of thumb degloving injury repair and 8 cases of completely amputated or necrotic thumb reconstruction, the skin defect ranged from 6.0 cm x 3.0 cm to 7.0 cm x 4.5 cm, and the interval between injury and operation was 3 hours-5 days, and the size of NVIF and FDMA harvested during operation was 3.5 cm x 3.0 cm-5.0 cm x 4.0 cm. The donor site was repaired with the full-thickness skin graft.

RESULTS: All the flaps survived uneventfully except for 1 case in group A suffering from venous crisis 1 day after operation and 2 cases in group B suffering from FDMA artery crisis 4-12 hours after operation. Those flaps survived after symptomatic treatment. All the wounds healed by first intention. All patients in two groups were followed up for 1-12 years (average 3.2 years). All the donor sites were normal except for 3 cases in group B suffering from flexion contracture deformity of the proximal interphalangeal joint due to the scar contracture in the margin of NVIF donor site. According to Allen test, the skin temperature and color of the donor fingers in two groups were normal under room temperature; 1 case of group A and 6 NVIF donor fingers of group B were pale and cold under ice water. According to sensory recovery evaluation system, 16 fingers in group A were graded as S4, 1 as S3+, and 1 as S2; while in group B, 3 NVIF fingers were graded as S3, 6 NVIF fingers as S2, 4 NVIF fingers as S1, and 13 FDMA fingers as S4. The appearance of the recipient flap was satisfactory and the color was similar to the surrounding skin. The skin temperature and color of the flaps in two groups were normal under room temperature; 2 cases of group A and 4 recipient fingers of group B were pale and cold under ice water. In group A, all the palmar flap of the recipient finger achieved the reorientation of the recipient flap sensation; while in group B, 8 cases achieved the reorientation of the recipient flap sensation, and 5 cases had double sensation. For the two-point discrimination of the flap, group B was superior to that of group A in terms of the palmar aspect (P < 0.05), no significant difference was evident between two groups in terms of the dorsal aspect (P > 0.05), and the palmar aspect of each group was superior to the dorsal flap (P < 0.05).

CONCLUSION: DDPF is less invasive to donor finger, easy to be operated, able to partially restore the sensory of the injured finger, and suitable for the repair of the degloving injury of the thumb and the index finger. Combination of NVIF and FDMA can restore the fine sensory of recipient palmar flap better and is applicable for those patients suffering from digital nerve defects from the proximal phalanx and with high demand for the recovery of thumb sensory.