Anterior Interpositional Grafting for Scaphoid Nonunion with Dorsal Instability Rattern

Kim, Ik Dong; Ihn, Joo Chul; Kim, Poong Taek; Yang, Dong Lyul

Abstract

In thirteen adult male patient with scaphoid nonunion associated with DISI(Dorsal intercalated Segment Instability) defined as scapholunate angle is greater than 70 degrees of the radiolunate angle is greater than 10 degrees, anterior interpostitional bone grafting has been performed. Surgical procedure: 1) Closed reduction of lunate(reduction of DISI) by volar flexing of the wrist and holding the position by Kirschner wire inserted obliquely through the radial styloid to lunate. 2) Radical curettage of nonunion site and intraoperative measurement of the gap in the scaphoid through volar approach. 3) A bicortical wedge shaped graft from the iliac crest was then impacted between the fragments. 4) Temporary K-wire fixation of the grafted scaphoid from the scaphoid tubercle to prevent distortion of nonunion site and loss of fixation. 5) A Herbert screw was then inserted. Results: Mean patient age was 24.5 years, and mean duration of nonunion before surgery was 19.4 months. Mean follow-up time was 22.6 months. The nonunion involved the middle one-third of scaphoid in 11 patients and distal one-third in 2 patients. The mean postoperative grip strength was 39.4kg by Dynamometer(PC-5303J). The mean postoperative range of motion was volar flexion 50.5 degrees; dorsiflexion 47.3 degrees. The scaphlunate angle decreased from a mean of 78.8 preoperatively to 52.9 degrees postoperatively. The radiolunate angle was decresed from a mean of 16.8 degrees prope- ratively to a mean of 1.8 degrees postoperatively. Union was obtained in all 13 cases, According to Herbert and Fisher's formulation, 2 excellent, 10 good and 1 fair results were obtained from our study. The results of the series suggest that treatment of scaphoid nonunion associated with DISI by this method is an effective method that reconstitutes scaphoid anatomy and promotes excellent wrist function.