Nonunion of the Ulnar Styloid Associated With Distal Radius Malunion

Malunion is a complication of distal radius fractures and may be associated with a nonunion of the ulnar styloid. We tested the null hypothesis that there is no difference in outcome between patients without ulnar styloid fracture and those with the ulnar styloid nonunion after corrective radial osteotomy for distal radius malunion.A total of 19 patients with dorsally angulated distal radius malunion who had simultaneous radial closing-wedge and ulnar shortening osteotomies were included. There were 16 women and 3 men with a mean age of 63 years. All patients were followed up for a minimum of 1 year. During surgery, the accompanying ulnar styloid nonunion was not internally fixed in any patient. Eight patients had no ulnar styloid fracture, and 11 had a nonunion of the ulnar styloid. Each group of patients was evaluated on the basis of objective radiographic measurements and functional outcomes as determined on the basis of clinical examination, including wrist motion, grip strength, pain-rating score, Mayo wrist score, and Disabilities of the Arm, Shoulder, and Hand score.There were no differences in the demographic and preoperative radiographic measurements between the nonfracture and nonunion groups. Postoperative radiographic measurements and functional outcomes improved significantly compared with the preoperative status in both groups. There were no significant differences in postoperative radiographic measurements, motion, strength, pain scores, Mayo scores, or Disabilities of the Arm, Shoulder, and Hand scores between the 2 groups. Four of the 11 ulnar styloid nonunions were healed within 1 to 12 months after corrective radial osteotomy.An accompanying ulnar styloid nonunion in patients with distal radius malunion has no apparent adverse effect on outcome or function after corrective radial osteotomy. An accompanying nonunion of the ulnar styloid can heal following corrective radial osteotomy.