Background: Fracture of the metaphyseal region of the distal ulna is an uncommon injury that has been reported to occur concomitantly with distal radius fracture. We aimed to report the incidence and types of distal ulnar head and neck fractures associated with distal radius fractures and compare outcomes in operatively versus non-operatively treated patients.
Methods: Over a 5-year period a distal radius fracture registry was maintained at our institution. Eleven of 512 consecutive patients had metaphyseal distal ulna fractures in association with distal radius fractures and at least 1-year follow-up. Baseline radiographs and functional data were obtained, and patients were followed at 1-week, 2-week, 3-week, 6-week, 3-month, 6-month, 1-year, and 2-year intervals. Patients were split into two treatment groups: Group 1 consisted of five non-operatively treated patients, and Group 2 consisted of six operatively treated patients.
Results: Four separate fracture patterns were observed: simple transverse or oblique fracture of the ulnar neck just proximal to the ulnar head, fracture of the neck region with concomitant fracture of the tip of the ulnar styloid, simple fracture of the ulnar head, and comminuted fracture of the ulnar head. There were no statistical differences between the two groups with regard to flexion, extension, supination, pronation, and functional outcomes.
Conclusions: Ulnar fracture patterns observed did not easily fall into previously described categories, and we have proposed a new classification system. Simple fractures of the ulnar neck or head often do not require operative fixation.