Application of extended ulnar parametacarpal perforator free flap for the reconstruction of total pulp defect of the thumb: A case report

Many procedures are available for the coverage of thumb pulp defects; however, to gain thumb function and esthetics, a similar tissue is desirable. If the length of the longitudinal defect is <2 cm, a volar advancement flap is appropriate; however, if the flap is >2 cm long or wider, retrograde or free flaps are required. Here, we present a case of thumb pulp reconstruction using an extended ulnar parametacarpal perforator (UPM) flap, which achieved excellent functional and esthetic outcomes. A 46-year-old man underwent reconstruction surgery of his thumb, which was a degloved total pulp. A sensate 5.2 × 3.2 cm UPM flap was designed on the ulnar side of the right palm and transferred to his thumb. The flap donor site was covered with a V-Y advancement flap on the dorsal side of the right hand. At 12 months postoperatively, the patient achieved a functional and natural thumb appearance with high satisfaction. The UPM flap can offer soft tissue similar to the pulp region in the digit without a palm scar at the donor site. This extended application is suitable for the reconstruction of a total pulp defect of the digit and is an alternative option for a hemi-pulp flap from the toe area.