Statistical Morphology and Fragment Mapping of Complex Proximal Humeral Fractures

Abstract

Background and Objectives: Proximal humerus fractures (PHFs) are common in the elderly, but the treatment results are often poor. A clear understanding of fracture morphology and distribution of cortical bone loss is important for improved surgical decision making, operative considerations, and new implant designs. The aim of this study was to develop a 3D segmentation fracture mapping technique to create a statistical description of the spatial pattern and cortical bone loss of complex PHFs. Materials and Methods: Fifty clinical computed tomography (CT) scans of complex PHFs and their contralateral intact shoulders were collected. In-house software was developed for semi-automated segmentation and fracture line detection and was combined with manual fracture reduction to the contralateral template in a commercial software. A statistical mean model of these cases was built and used to describe probability maps of the fracture lines and cortical fragments. Results: The fracture lines predominantly passed through the surgical neck and between the tuberosities and tendon insertions. The superior aspects of the tuberosities were constant fragments where comminution was less likely. Some fracture lines passed through the bicipital sulcus, but predominantly at its edges and curving around the tuberosities proximally and distally. Conclusion: A comprehensive and systematic approach was developed for processing clinical CT images of complex fractures into fracture morphology and fragment probability maps and applied on PHFs. This information creates an important basis for better understanding of fracture morphology that could be utilized in future studies for surgical training and implant design.

Morphology and novel classification of proximal humeral fractures

“…This may be related to the fact that the higher density of the articular surfaces was less susceptible to fracture, and the fractures in the patients included in the study by Hasan et al may have been the result of stronger trauma ( Tingart et al, 2003 ). In addition, Mys et al (2023) found that the incidence of fracture in the anatomical neck was lower, while in our study, the incidence of fractures was higher in the lower, posterior, and upper parts of the anatomical neck. Thus, the fracture morphology of complex PHFs was slightly different from that of all types of PHFs (including simple fractures).…”

“… Mys et al (2023) recently published a study on fracture morphology, which explained the complex morphology of PHFs by mapping 50 cases of complex PHFs. Most of the findings were in line with our results, with a high frequency around the surgical neck and articular fractures were infrequent ( Mys et al, 2023 ). However, despite many similarities with the research of Hasan et al in fracture morphology, the incidence of fracture in the intramuscular groove and articular surfaces was significantly different.…”

“…They found that the fractures predominated at the surgical neck, fractures frequently split greater tuberosity, and fractures were less likely to involve the attachment points of the rotator cuff muscles, which was similar to our study ( Hasan et al, 2017 ). Mys et al (2023) recently published a study on fracture morphology, which explained the complex morphology of PHFs by mapping 50 cases of complex PHFs. Most of the findings were in line with our results, with a high frequency around the surgical neck and articular fractures were infrequent ( Mys et al, 2023 ).…”

“…This visual representation allows doctors to better understand the distribution and shape of the fracture line and can also support the development of a more scientific classification for fractures ( Yao et al, 2022 ). The existing fracture mapping studies of PHFs are mostly limited to complex fractures (three-and four-part PHFs), while fracture map studies covering all fracture types are rare ( Hasan et al, 2017 ; Ju et al, 2022 ; Mys et al, 2023 ). Ren et al (2023) recently retrospectively collected 312 cases of proximal humeral fractures, analyzed the patterns of PHFs by 3D mapping, and found that these different fracture patterns may be closely related to different clinical prognoses.…”