The Duration of Bone Healing and Nonunion Ratio After Ulnar Shortening Osteotomy Using a 5-Hole Forearm Compression Plate With Transverse Osteotomy

Background: Ulnar shortening osteotomy using various osteotomy sites, osteotomy methods, and surgical techniques with a variety of implants has been reported, but nonunion rates and the duration of bone healing are not uniform by the authors. The purpose of this study was to investigate the duration of bone healing and nonunion ratio in patients who underwent ulnar shortening osteotomy by a 5-hole nonlocking plate with a simple transverse osteotomy for ulnar impaction syndrome and to determine the correlation between the gap length of the osteotomy site and the duration of bone healing.Methods: We assessed patients who underwent ulnar shortening osteotomy for ulnar impaction syndrome using a 5-hole nonlocking plate fixation followed by a simple transverse osteotomy between July 2012 and October 2021. This study was a case series study, and the level of evidence was IV.Results: A total of 80 patients were included. The mean age of the patients was 46.7 years, and 46 patients were men. The average bone union period was 41.8 +/- 18.7 weeks. The correlation between the gap length of the osteotomy site and the duration of bone union of the osteotomy site was not significant. The nonunion ratio of our method was 2.5%.Conclusion: The nonunion rate of our ulnar shortening osteotomy with a simple transverse osteotomy and a 5-hole nonlocking plate was comparable to that in previous reports, but our method required slightly longer periods for bone union. There was no correlation between the gap length of the osteotomy and the duration of bone union.Level of Evidence: Level IV (Case series)