Surgical repair for deformities of the nail unit

Abstract

The nail unit is an integral part of the digit. Clinically, deformity of the nail unit often leads to dysfunction and adverse appearance.Common nail deformities include split, short, hooked, and absent nails, as well as onycholysis and nail malalignment. Compared with non-surgical methods including physical coverage and orthotics devices, surgical repair is the primary and valid treatment for such deformities. This review summarizes the classification of nail unit deformities and the associated reconstructive surgical techniques. | ANATOMY FOR NAIL SURG ERYThe basic nail unit is composed of a nail plate that attaches to the nail bed, nail folds that function as a frame for the nail plate, and a nail bed consisting of germinal and sterile matrices. The germinal matrix forms the nail plate, while the sterile matrix shapes and adheres to the extending nail 1,2 (Figure 1). The blood of the nail unit is supplied by the dorsal and volar proper digital arteries. These vessels merge at the distal interphalangeal joint, where they can be easily compressed by a tourniquet to minimize intraoperative hemorrhage. 2 The nail unit is innervated by paired palmar and plantar nerves. These nerves divide into branches just distal to the distal interphalangeal joint. Hence, nail surgery is usually performed under regional anesthesia, most commonly using a distal digital block or wing block. 3 | CL A SS IFI C ATI ON OF NAIL UNIT DEFORMIT YPatients with congenital, traumatic, and iatrogenic nail deformities should undergo appropriate surgery according to their anatomical classification. In the intact sterile and germinal matrices group, the nail bed and underlying bone are normal or near normal. Hence, only simple nail bed renovation is required in this group. In the partially amputated group, there are partial defects in the sterile and/or germinal matrices. To mend the defective nail bed, flaps or grafts are added to the procedure. Finally, in the completely amputated group, the whole nail unit is absent, with or without the distal phalanx defects. In these circumstances, nail unit reconstruction and occasionally bone grafts are required. However, for nail deformities caused by onychomycosis, 4

Reconceptualization of Proximal Nail Fold Reconstruction: Skin Grafting over the Nail Plate

“…Periungual defects can result in significant functional impairment and cosmetic disfigurement 3 ; therefore, reconstructions after injury and cancer resection are important. However, the structure of the periungual area is complicated, and the best method for reconstruction is not yet established.…”