There is still controvesy on the treatment of distal ulna fractures associated with distal radius fractures. To clarify the selection criteria for treatment of distal ulna fractures at our institute and the treatment outcomes.
We investigated sixty three cases with distal ulna fractures associated with distal radius fractures from 2012 to 2020, excluding those under 15 years of age and those with open fractures of Gustilo classification 3. There were 14 men and 49 women, with an average age of 71 years, and 10 open fractures. Primary external fixation was performed in 17 cases, with an average waiting time of 0.5 days. All distal radius fractures were fixed with volar locking plates, with an average waiting time of 10.3 days. [Study design] Cross-sectional study, historical cohort study. [Statistical analysis] JMP15 was used. [Intervention] Treatment of the ulna was divided into three groups: conservative group (28 cases), ulna plate group (28 cases), and pinning group (7 cases), and a comparative study was conducted. [Outcomes] (1) AO fracture type (2) External fixation period (3) Range of motion (4) Readiographical evaluation.
(1) There was no significant difference between the groups in the radial AO classification, ulnar AO classification, and Biyani classification, but the plate group tended to have more 2R3C3, 2U3A2, and Biyani3. (2) The average external fixation period (from injury to removal of the external fixation, including the external fixation period) was 17.4 days in the conservative group, 17.7 days in the plate group, and 19.7 days in the pinning group, with no significant difference between the three groups (analysis of variance: P value 0.81). (3) The mean final range of motion was: conservative group: dorsiflexion 70°, palmar flexion 67°, supination 82°, pronation 83°; plate group: dorsiflexion 66°, palmar flexion 65°, supination 78°, pronation 73°; pinning group: dorsiflexion 62°, palmar flexion 60°, supination 73°, pronation 73°. (4) Bone union was achieved in all cases for the radius and in all cases except for one case in the conservative group for the ulna. The mean final ulnar variance was 0.1mm in the conservative group, 0mm in the plate group, and -0.6mm in the pinning group (analysis of variance: P value 0.61).
Plate fixation was selected for cases with severely comminuted distal radius fractures and cases that were easy to plate without a distal ulnar intra-articular fracture. There were no differences in range of motion or X-ray evaluation between treatment methods.
