Clinical study of digital six-axis external fixation frame based on CT data for tibiofibular fractures

Abstract

Objective: To investigate the clinical effect of applying the digital six-axis external fixation frame based on CT data in the treatment of tibiofibular fractures. Methods: The clinical data of 43 patients with tibiofibular fractures treated by the self-developed digital six-axis external fixation frame based on CT data at Integrated Orthopedic Department of Traditional Chinese Medicine (TCM) and Western Medicine,HongHui Hospital from January 2018 to January 2021 were retrospective analysis.There were 27 males and 16 females,aged (36.0±9.4) years(range:25 to 50 years).AO classification:15 cases of 42A,11 cases of 42B, and 17 cases of 42C.There were 7 open fractures and Gustilo fracture classification:2 cases of type Ⅰ,4 cases of type Ⅱ,and 1 case of type Ⅲ.The two or three plane rings were connected with six connecting rods to form a complete six-axis external fixation frame,and the distal and proximal fracture blocks were connected to the distal and proximal rings by fixation pins,and the lengths of the six connecting rods needed to be adjusted were calculated by using the supporting software according to the CT data after surgery,and then the lengths of the connecting rods were adjusted one by one to complete the reduction of the fracture. The reduction accuracy of this six-axis external fixation brace was evaluated by measuring postoperative radiographs; postoperative recovery and complications were collected,the time of brace removal was recorded,and the function of the affected limb was evaluated according to the Johner-Wruhs score at the final follow-up. Results: Postoperative radiographs showed that all patients achieved satisfactory reduction with lateral displacement(M(IQR)) of 2.3(2.5) mm (range:0.3 to 7.3 mm),anteroposterior displacement of 2.1 (2.4) mm (range:0.3 to 5.7 mm),anteroposterior angulation of 2.5(2.4)°(range:0 to 5°),internal and external angulation of 2.1(1.5)°(range:0 to 4°), and no significant internal or external rotational deformity was detected on the exterior.On the second postoperative day,all patients were able to walk with partial weight-bearing on crutches. All 43 patients were followed up for more than 6 months,with a follow-up period of (33.3±7.3) weeks (range:24 to 42 weeks).The external fixation frame was removed after the fracture healed.The external frame was removed at 20(3)weeks (range:18 to 25 weeks) postoperatively. Up to the final follow up, no secondary fracture occurred in any of them.The Johner-Wruhs score of the affected limb at the last follow-up was excellent in 39 cases and good in 4 cases. Conclusion: The digital six-axis external fixator based on CT data for tibiofibular fractures has the advantages of precise reduction,firm fixation,simple operation,rapid fracture healing,and minimal trauma, which is a minimally invasive method for treating tibiofibular fractures,especially suitable for patients with poor skin and soft tissue conditions such as open injuries.