Anatomical Characteristics and Surgical Treatments of Pincer Nail Deformity

Background Pincer nail deformity is a transverse overcurvature of the nail. This study aimed to define the anatomical characteristics of pincer nail deformity and to evaluate the surgical outcomes. Methods A retrospective review was conducted on 20 cases of pincer nail deformity of the great toe. Thirty subjects without pincer nail deformity or history of trauma of the feet were selected as the control group. Width and height indices were calculated, and interphalangeal angles and base widths of the distal phalanx were measured with radiography. We chose the surgical treatment methods considering perfusion-related factors such as age, diabetes mellitus, kidney disease, and peripheral vascular disease. The zigzag nail bed flap method (n=9) and the inverted T incision method (n=11) were used to repair deformities. The outcomes were evaluated 6 months after surgery. Results The interphalangeal angle was significantly greater in the preoperative patient group ($14.0^{\circ}{\pm}3.6^{\circ}$) than in the control group ($7.9^{\circ}{\pm}3.0^{\circ}$) (P<0.05). The postoperative width and height indices were very close to the measurements in the control group, and most patients were satisfied with the outcomes. Conclusions We believe that the width and height indices are useful for evaluating the deformity and outcomes of surgical treatments. We used two different surgical methods for the two patient groups with respect to the perfusion-related factors and found that the outcomes were all satisfactory. Consequently, we recommend taking into consideration the circulatory condition of the foot when deciding upon the surgical method for pincer nail deformity.