Imaging features of low trancondylar fracture of the distal humerus based on X-ray and 3D-CT reconstruction
HUA Ke-han
GONG Mao-qi
ZHA Ye-jun
JIANG Xie-yuan
Abstract：Objective To quantitatively evaluate the morphological features of low transcondylar fractures of the distal humerus by radiographic measurements based on X-ray and 3D-CT scan.Methods We retrospectively included patients with low transcondylar fractures of the distal humerus who were treated in our hospital from January 2013 to November 2019.And we excluded the patients without preoperative X-ray and CT scan of elbow joints in the format of digital imaging and communications in medicine(DICOM).Mimics 20.0 was used to measure radiographic parameters including the height of medial and lateral fracture line,the height of medial and lateral epicondyle,supracondylar height of medial and lateral fracture line,the angle between fracture line and articular surface as well as the angle between the fracture line and epicondylar level(acute angles were measured;positive numbers were recorded if the angular openings were towards the ulnar side;negative numbers were recorded if towards the radial side),fracture inclination angle in lateral view(dorsal angle between the anterior humeral line and fracture line of the proximal fracture fragment),and the proportion of the upper and lower parts of the olecranon fossa divided by the fracture line after simulated fracture reduction.The measurement data conforming to the normal distribution were expressed by((x)±s).For data that did not conform to a normal distribution,it was described using the median(the 25th percentile,the 75th percentile).Results A total of 51 patients were enrolled,aged 74(56,79)years(range:14-94 years),with a male to female ratio of 15:36.The affected side included 30 cases in right side and 21 cases in left side.The supracondylar height of the medial fracture line[5.26(3.79,6.97)mm]was significantly higher than the lateral side[1.05(0.24,2.28)mm](P<0.001).The angle between the fracture line and articular surface[11.21(6.40,15.14)°]as well as the angle between the fracture line and epicondylar level[5.60(3.00,7.75)°]were significantly larger than 0 degree(P<0.001).The inclination angle in lateral view[123.98(119.45,129.11)°]was significantly larger than 90 degrees(P<0.001).The proportion of the upper part of the olecranon fossa divided by the fracture line[64.3(57.50,68.01)%]was significantly larger than that of the lower part[35.63(31.99,42.50)%](P<0.001).There was no significant difference between male and female patients in the parameters above.Intraclass correlation coefficient of intra-rater reliability of all the measurementsabove were more than 0.75.Conclusions Low transcondylar fracture of the distal humerus has unique morphological features.The fracture line is higher on the medial side but lower on the lateral side,and it is higher on the volar side but lower on the dorsal side.The majority of these fractures manifests as"flexion-type-like"injury and the fracture line runs through the lower middle part of the olecranon fossa.There is no significant difference between male and female patients regarding to morphological features.
Keywords：HumerusFracturesDiagnostic imaging
Publication Date：2024-12-19
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 965-971 )