Distribution of radial fracture line and injury mechanisms based on three-dimensional frac-ture mapping technology

Chen Jingdi; Wang Taoran; Bi Long; Gao Jiakai; Chai Na; He Xiang; Song Chen

doi:10.3969/j.issn.1009-4237.2025.12.006

Abstract：Objective To analyze the characteristics of radial head fractures by medical image analysis and fracture mapping,and to provide reference for clinical diagnosis and treatment of these injuries.Methods A retro-spective study was conducted on 130 cases of adult radial head fractures treated in the Department of Orthopedics Trauma of the First Affiliated Hospital of Air Force Medical University from Jan.2021 to Jun.2023.Among them,70 were males and 60 were females;the median age was 36.4 years,range 18-60 years;61 cases involved the left side and 69 the right;82 cases were due to falls,18 to high-level falls,25 to road traffic injuries,and 5 to others.Based on preoperative plain films and CT images,the fracture morphology was observed and classified according to the fracture morphology and injury mechanism.Mimics 21.0 image processing software was used to reconstruct the 3D fracture model of the radial head.The position of the radial head in the neutral forearm position was divided into four quadrants(anterior lateral quadrant:AL;posterior lateral quadrant:PL;anterior medial quadrant:AM;pos-terior medial quadrant:PM).Observation,measurement and plotting of the fracture blocks and fracture lines were conducted.Through reconstruction,virtual reduction and image superposition,the fracture map was established to observe the distribution of fracture blocks and the shape of fracture lines.Results According to Mason classifica-tion,there were 10 cases of type I,78 type Ⅱ,27 type Ⅲ,and 15 type IV.While based on the injury mechanisms,there were 54 cases of vertical(direct)injuries to the elbow joint,30 lateral deviation injuries,18 posterior and me-dial rotational injuries,and 28 posterior and lateral rotational injuries.According to the fracture morphology,radial head fractures presented as separate ones or combined with other parts.The former were divided into fractures of the radial head that involve the joint surface(87 cases,mainly affecting the AL+PL,AM+PL and AM+AL+PL)and fractures of the radial neck(radial head tilt in 24 cases,mainly anterior tilt displacement);the latter were divided into elbow dislocation with radius head fractures and ulna coronoid process fractures(terrible triad of the elbow,8 cases,mainly affecting the AL+AM),transolecranon olecranon fractures and dislocation of the radius head,and pos-teromedial rotation injury with radius head fracture and dislocation(together 7 cases,mostly affecting the AL+AM+PL).Conclusion The cases of separate radial head fractures involve a wide range of radial heads,while radius head fractures associated with terrible triad of the elbow and those with olecranon dislocation mostly involve the AL+AM,and moreover,are relatively combined with comminuted fractures and significantly increased risk of transverse displacement.The assessment of radial head fractures should be based on Mason classification,elbow joint injury mechanisms and the fracture morphology.