gms | German Medical Science

Objectives/Interrogation: Pulp and nail asymmetry is commonly seen in thumb duplication. In hypoplasia of both digits, conventional reconstruction or Bilhaut-Cloquet procedure and its modifications may not be possible or may lead to poor cosmetic outcome. To improve aesthetic and functional results, a novel reconstruction technique with neurovascular island flap with long-term outcome was developed.

Methods: 14 patients with thumb duplication aged 8 to 18 months were operated between 2002 and 2013 in our center. All patients had significant hypoplasia and asymmetry of the pulp and nail of the planned retained digit. A dorsal-based neurovascular island flap including part of the pulp tissue, nail bed, with or without the associated phalangeal bone was raised from the planned ablated digit basing on its single neurovascular bundle. On combining the flap to the proper digit, meticulous repair of the nail bed, nail fold and pulp tissue using fine sutures under magnification. All patients were followed up to monitor the aesthetic, functional and radiological outcome, using the Tada and JSSH scores. A novel aesthetic scoring system was proposed which assessed size, shape, scar, smoothness of nail, and symmetricity. Parents, an occupational therapist and a hand surgeon participated in assessment.

Results and Conclusions: The mean follow up period was 7 years 11 months. 13 patients underwent the flap procedure and all flaps survived. In 1 patient, flap procedure was not proceeded as the pedicle was not well developed. Nail width and pulp circumference were restored compared with the normal thumb (Figure 1 [Fig. 1]).

The mean Tada and JSSH scores were 4 (3-5) and 17.5 (16-19) respectively. Suture size, the use of microscope, or combination of bone did not affect outcome. The proposed aesthetic scoring system was able to assess and highlight the cosmetic aspect of the outcome, and correlated well with the parents' satisfaction (p=0.049).

In selected cases of thumb duplication with significant pulp hypoplasia and nail asymmetry, the neurovascular pulp and nail island flap is a safe and effective means to restore symmetry for improvement of aesthetics.