A study on prediction of dorsal intra-articular bone fragment stability following simple volar plate internal fixation based on the anatomic indicators of CT Mimics three-dimensional reconstruction

CHANG Juntao; LIU Xiaobo; GAO Dongfang; HE Xiaohao; SUN Shuxia

doi:10.3969/j.issn.1674-3806.2025.03.14

Abstract：Objective To explore the value of the prediction of dorsal intra-articular bone fragment stability following simple volar plate internal fixation based on the anatomic indicators of computed tomography(CT)Materialise's interactive medical image control system(Mimics)three-dimensional reconstruction.Methods The clinical data of 165 patients with fractures of distal radius who were treated with simple volar plate internal fixation in Chongqing Jiulongpo Traditional Chinese Medicine Hospital from September 2021 to June 2023 were retrospectively analyzed.The patients were divided into a displacement group(30 cases,displaced dorsal intra-articular bone fragments＞2 mm)and a non-displacement group(135 cases,displaced dorsal intra-articular bone fragments≤2 mm)according to the displaced dorsal intra-articular bone fragments on the 2nd day after surgery and during outpatient follow-up of 6 months after surgery.The general clinical data and the anatomic indicator levels of CT Mimics three-dimensional reconstruction before surgery were compared between the two groups,and the correlation between each preoperative anatomical indicator and the distance of the displaced dorsal intra-articular bone fragments was analyzed.Multivariate logistic regression analysis was used to analyze the factors affecting the stability of the dorsal intra-articular bone fragments after surgery,and a Nomogram model was constructed based on the screened indicators.The application value of the Nomogram model was evaluated by using receiver operating characteristic(ROC)curve,calibration curve,and decision-making analysis curve.Results The proportion of patients with fracture AO classification of C3 in the displacement group was higher than that in the non-displacement group,with statistically significant difference betweent the two groups(P＜0.05).The volume,transverse to longitudinal diameter ratio,and transverse width of the bone fragments in the displacement group were smaller than those in the non-displacement group,while the total distance of the displaced bone fragments before surgery in the displacement group was greater than that in the non-displacement group,with statistically significant differences betweent the two groups(P＜0.05).The volume of bone fragments(r=-0.817,P＜0.001),transverse to longitudinal diameter ratio of bone fragments(r=-0.771,P＜0.001),and transverse width of bone fragments(r=-0.843,P＜0.001)were negatively correlated with the distance of the displaced dorsal intra-articular bone fragments after surgery,and the total distance of the displaced bone fragments before surgery was positively correlated with the distance of the displaced dorsal intra-articular bone fragments after surgery(r=0.746,P＜0.001).The results of multivariate logistic regression analysis showed that fracture AO classification of C3[OR(95％ CI)=2.368(2.015-2.784)],and longer total distance of the displaced bone fragments before surgery[OR(95％ CI)=1.277(1.163-1.402)]were independent risk factors for promoting the displaced dorsal intra-articular bone fragments after surgery(P＜0.05),and larger volume of bone fragments[OR(95％ CI)=0.464(0.268-0.802)],larger transverse to longitudinal diameter ratio of bone fragments[OR(95％ CI)=0.411(0.176-0.959)]and larger transverse width of bone fragments[OR(95％ CI)=0.421(0.225-0.786)]were protective factors that inhibited the occurrence of postoperative displaced dorsal intra-articular bone fragments(P＜0.05).Based on the fracture AO classification and the anatomic indicators of CT Mimics three-dimensional reconstruction before surgery,a Nomogram model for predicting postoperative displaced dorsal intra-articular bone fragments(C-index=0.857)was constructed.The results of receiver operating characteristic(ROC)curve,calibration curve,and decision-making analysis showed that this predictive model can effectively predict postoperative displaced dorsal intra-articular bone fragments in the patients,with good clinical application value.Conclusion The volume of bone fragments,transverse to longitudinal diameter ratio of bone fragments,transverse width of bone fragments and the total distance of the displaced bone fragments before surgery can be used to predict the stability of the dorsal intra-articular bone fragments after simple volar plate internal fixation surgery,which can assist clinicians in early identification of high-risk patients and improve their prognosis.