Stabilization of dorsal intra-articular fragment in distal radius fracture after volar locking plate fixation / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the risk factors that may affect the stabilization of dorsal intra-articular fragment in distal radius fracture after volar internal fixation.Methods:A retrospective analysis was performed of the patients with distal radius fracture who had been treated by volar internal fixation at Department of Traumatic Orthopedics, Tongji Hospital Affiliated to Tongji University from July 2016 to July 2020. After 3D reconstruction of their preoperative CT scans by software Mimics 20.0, 66 patients with a dorsal intra-articular fragment were screened out. They were 31 males and 35 females, aged from 23 to 78 years (average, 53.4 years). By the AO classification, there were 17 case of type C1, 22 cases of type C2, and 27 cases of type C3. The displacement of dorsal intra-articular fragment was judged by X-ray observation on postoperative day 2 and X-ray follow-up at the outpatient department. The 13 patients with displacement of dorsal intra-articular fragment>2 mm were assigned into a displacement group while the other 53 ones into a displacement-free group. The 2 groups were compared in terms of preoperative general data and anatomical data of the dorsal intra-articular fragment (total preoperative displacement, radius-ulnar length, dorsal-volar length, aspect ratio, proximal-distal length and volume) to analyze the correlations between them and displacement.Results:There was no significant difference in preoperative general data (age, gender, affected side, cause of injury or AO classification) between the 2 groups, showing comparability between groups ( P>0.05). All patients were followed up for 6 to 24 months (mean, 14 months) after surgery. There were no postoperative complications like neurovascular lesion or infection. None of the patients in the displacement group underwent revision surgery, and the fractures healed successfully during the postoperative follow-up. The total preoperative displacement in the displacement group was(10.0±1.3) mm, significantly larger than that in the displacement-free group [(7.8±1.5) mm]; the radius-ulnar length in the displacement group was (8.2±1.3) mm, significantly shorter than that in the displacement-free group [(10.8±2.3) mm]; the aspect ratio of the fragment in the displacement group was 1.2±0.2, significantly lower than that in the displacement-free group (1.4±0.2); the fragment volume in the displacement group was (690.5± 201.4) mm 3, significantly smaller than that in the displacement-free group [(995.8±295.0) mm 3]. There were significant differences in the above items between the 2 groups ( P<0.05). Conclusion:The total preoperative displacement, radius-ulnar length, aspect ratio and volume of a dorsal intra-articular fragment are important factors which may affect the displacement of the dorsal fragment after volar internal fixation.