gms | German Medical Science

Objectives: The aim of this study is to evaluate the outcomes of the reconstruction in emergency of the amputated thumb using isolated or associated homodigital and heterodigital flap techniques in those situations when microsurgical replantation is not possible due to local or general conditions. The study is based on evaluation of the functional (thumb length, sensitivity, motility active joint movement and cortical reintegration) and aesthetic outcomes.

Method: Thirty two patients aged between 18 and 65 years old, with complete posttraumatic amputation of the thumb at the level of interphalangeal joint or proximal phalanx were evaluated. In most cases the mechanism of amputation involved avulsions and crushing by industrial machines or hand powered cutting tools. In 8 cases, the reconstruction was done using the Mantero-Bertolotti technique with an O'Brien flap, and in 6 cases the use of a single heterodigital neurovascular Littler flap was sufficient. The association of the two techniques with a Littler's flap instead of the O'Brien flap in the Mantero-Bertolotti reconstruction was the choice in 14 patients. In other 4 cases the reconstruction algorithm included the use of a Foucher (cerf-volant), Simonetta or Hueston flap.

Results: The results has been evaluated based on age, injury complexity, size of the flap, mobility, sensitivity, cortical reintegration of the new pulp. The best average range of motion of the new thumb in those cases in which we applied the associated technique (Littler's flap instead of the O'Brien flap in the Mantero-Bertolotti reconstruction) using Kapandji score (8 score). Regarding the sensibility, we achieved a protective sensibility of the new thumb. At the two point discrimination test (2PD test), the results were between 7-11 mm. At the light touch deep pressure test (SW test), all the patients felt the blue monofilament and 24 out of 32 felt the violet monofilament. Concerning the problem of cortical reintegration when Littler flap was used, 55% (11 patients out of 20) declared that they recognize the sensibility as coming from the new thumb.

Conclusion: The use of isolated or combinated homodigital and heterodigital, flap techniques is a proper choice for reconstructing the amputated thumb in those cases when the microsurgical replantation is not possible. The good outcomes we obtained are comparable with those of the thumb replantation, although the microsurgical replantantions remains the goldstandard in thumb amputation.