Subchondral Radial and Ulnar K-Wire Positioning With Cancellous Bone Graft Shortens Union Time in Scaphoid Waist Nonunion

Abstract

Background Bone grafting in patients with scaphoid waist nonunion can present several technical challenges. In this study, we aimed to present a modified surgical technique for scaphoid waist nonunion, which consisted of subchondral radial and ulnar K-wires positions with cancellous bone graft, and to compare the clinical outcome of this modified technique with the conventional method. Methods We retrospectively reviewed 72 patients with scaphoid waist nonunion who had been surgically treated between January 2011 and December 2020. Of these, 34 patients were treated with the modified method and 38 with the conventional method. Debridement of the nonunion site was performed using a curette, rongeur, and microburr. Two or 3 K-wires were inserted along the cancellous portion of the scaphoid in the conventional method. In the modified method, 2 K-wires were inserted along the ulnar and radial subchondral portion of the scaphoid to increase the space for bone grafting in the cancellous portion of the scaphoid. The autologous cancellous bone grafted in both the methods. Demographic, radiological, and clinical outcomes were reviewed and compared between the groups. Results There were no significant differences in demographics and characteristics of nonunion between the 2 groups of patients. The modified method group showed significantly shorter union time than the conventional method group (conventional group: 13.0 ± 1.3 weeks, modified group: 11.4 ± 1.1 weeks; P < 0.001). The bony union rate was 97.1% for the modified method and 89.5% for the conventional method. Satisfactory clinical outcomes (excellent and good Mayo wrist scores) were achieved in 27 cases (81.8%) using the modified method and 22 cases (64.7%) using the conventional method. Conclusion Subchondral radial and ulnar K-wire positioning with cancellous bone graft (modified method) can improve the union time with satisfactory clinical outcomes in the treatment of scaphoid waist nonunion.