Mapping of common rib fracture patterns and the subscapular flail chest associated with operative scapula fractures

[Treatment strategy for severe implosion injuries of the lateral chest wall]

In the majority of cases implosion injuries to the thoracic wall are caused by blunt, massive force acting on the thorax. Basically, different regions and directions of the acting energy have to be taken into account. In common usage, the term implosion injury has become established, especially for the sequelae of lateral energy impact. Particular attention should be paid to the stability of the shoulder girdle, the underlying hemithorax and its intrathoracic organs.

Three-Dimensional Mapping of Scapular Body, Neck, and Glenoid Fractures

OBJECTIVES

The purpose of this study was to report patterns of scapular fractures and define them with a contemporary methodology.

METHODS

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DESIGN

Retrospective study, 2015-2021.

SETTING

Single, academic, Level 1 trauma center.

PATIENT SELECTION CRITERIA

Consecutive patients ≥18 years, presenting with unilateral scapula fracture, with thin-slice (≤0.5-mm) bilateral computed tomography (CT) scans of the entirety of both the injured and uninjured scapulae.

OUTCOME MEASURES AND COMPARISONS

Thin-slice (0.5-mm) CT scans of injured and normal scapulae were obtained to create three-dimensional (3D) virtual models. 3D modeling software (Stryker Orthopedics Modeling and Analytics, Stryker Trauma GmbH, Kiel, Germany aka SOMA) was used to create a 3D map of fracture location and frequency. Fracture zones were delineated using anatomic landmarks to characterize fracture patterns.

RESULTS

Eighty-seven patients were identified with 75 (86%) extra-articular and 12 (14%) intra-articular fractures. The dominant fracture pattern emanated from the superior lateral border (zone E) to an area inferior to the spinomedial angle (zone B) and was present in 80% of extra-articular fractures. A second-most common fracture line propagated from the primary (most-common) line toward the inferior medial scapular border with a frequency of 36%. Bare zones (with 1 or no fractures present) were identified in 4 unique areas. Furthermore, intra-articular fractures were found to be heterogenous.

CONCLUSIONS

The 3D fracture map created in this study confirmed that extra-articular scapular fractures occur in certain patterns with a relatively high frequency. Results provide greater insight into scapular fracture locations and may help to study prognosis of injury and improve treatment strategy including operative approaches and surgical tactics.

Rib Fracture Map in High-Energy Injuries

OBJECTIVES

To use a novel rib unfurling technology to investigate the locations of multiple rib fractures occurring from high-energy trauma to discern if there are reproducible rib fracture patterns.

METHODS

Patients between the ages of 18 and 48 years presenting to a Level 1 academic trauma center with ≥2 rib fractures after a high-energy mechanism of injury between 2017 and 2019 were identified. Curved planar reformatting of CT scans was used to create two-dimensional unfurled rib images by flattening out the view of the ribs from a CT scan. Rib fractures were placed on a template map using a standardized measurement method, and subsequent frequency and heat maps were created.

RESULTS

Among 100 consecutive patients, 534 fractures on 454 ribs were identified. The most common high-energy mechanism of injury was motor vehicle accidents (41%). Flail chest occurred in 8% of patients. The mean number of ribs fractured per patient was 4.54 ± 3.14 and included a mean of 5.34 ± 4.38 total fractures. Among all fractures, 50.9% were located on ribs 4 through 7. The most common fracture location was located in the lateral or anterolateral zone of the rib cage.

CONCLUSIONS

Patients with multiple rib fractures from high-energy trauma have rib fractures with locations of common occurrence. An understanding of location and frequency of rib fractures can help inform surgical approaches, prognosis, indications, classifications, and implant design in the management of a complex population of patients with chest wall injury after trauma.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mapping of Orthopaedic Fractures for Optimal Surgical Guidance

Orthopaedic fractures may be difficult to treat surgically if accurate information on the fracture propagation and its exit points are not known. Even with two-dimensional (2D) radiographic images, it is difficult to be completely certain of the exact location of the fracture site, the fracture propagation pattern and the exit points of the fracture. Three-dimensional (3D) computerised tomographic models are better in providing surgeons with the extent of bone fractures, but they may still not be sufficient to allow surgeons to plan open reduction and internal fixation (ORIF) surgery.Fracture patterns and fracture maps are developed to be visual tools in 2D and 3D. These tools can be developed using fractured bones either before or after fracture reduction. Aside from being beneficial to surgeons during pre-surgical planning, these maps aid bioengineers who design fracture fixation plates and implants for these fractures, as well as represent fracture classifications.Fracture maps can be either created ex silico or in silico. Ex silico models are created using 3D printed bone models, onto which fracture patterns are marked. In silico fracture models are created by tracing the fracture lines from a fractured bone to a healthy bone template on a computer. The points of interest in both of these representations are the path of fracture propagation on the bone's surface and exit zones, which eventually determine the surgeon's choice of plate and fracture reduction. Both ex silico and in silico fracture maps are used for pre-surgical planning by the surgeons where they can plan the best way to reduce the fracture as well as template various implants in a low-risk environment before performing the surgery.Recently, fracture maps have been further digitised into heat maps. These heat maps provide visual representations of critical regions of fractures propagating through the bone and identify the weaker zones in the bone structure. These heat maps can allow engineers to develop optimal surgical plates to fix an array of fracture patterns propagating through the bone. Correlation of fractured regions with the mechanisms of injury, age, gender, etc. may improve fracture predictability in the future and optimise the intervention, along with making sure that surgeons do not miss fractures of the bone that may otherwise be hidden from plain sight.

Three-dimensional mapping of sternum fractures from high-energy trauma

BACKGROUND

Sternum fractures are relatively uncommon injuries, which generally occur as a result of a high-energy mechanism and are often associated with significant concomitant injuries. These injuries may result in decreased quality of life if not properly addressed and yet are rarely operated on. The purpose of this project is to evaluate high-energy sternum fracture patterns using a previously published three-dimensional (3D) computed tomography (CT) reconstruction process to produce fracture frequency maps.

METHODS

Patients 18 years and older presenting to a Level I trauma center with sternum fractures due to high-energy trauma between October 2013 and January 2022 were included. A 3D reconstruction and reduction was performed for each sternum using medical image processing software (Materialize NV, Leuven, Belgium). The reconstructions were subsequently overlaid onto a template sternum and normalized using bony landmarks. Fracture lines for each injured sternum were transferred onto the template, creating 3D frequency maps.

RESULTS

A total of 120 patients met inclusion criteria. The study population had a uniform age distribution and 57.5% were male. The most common mechanism of injury was motor vehicle collision (64.2%). The breakdown of sternum fractures were isolated sternal body (55.8%), isolated manubrium (31.7%), and combined sternal body and manubrium fractures (12.5%). No xiphoid fractures were observed. Sternal body fractures were a near even mix of transverse (31.7%), oblique (32.9%), and comminuted (35.4%), while 75.5% of manubrium fractures were oblique. The most common associated injuries included rib fractures (80.8%) and traumatic brain injury (61.7%).

CONCLUSION

This study presents the fractures from sternum injuries in 3D, and provides insight into reproducible sternum injury patterns that have not previously been analyzed in this format. This fracture mapping technique presents numerous injury patterns simultaneously, such that more frequent morphologies can be appreciated for different patient groups.

LEVEL OF EVIDENCE

Diagnostic Tests or Criteria; Level V.

Treatment and outcome in combined scapula and rib fractures: a retrospective study

PURPOSE

The primary aim was to describe the population characteristics of patients with combined scapula and rib fractures and outcomes associated with different treatment strategies.

METHODS

All adult (≥ 18 years) patients with concurrent ipsilateral scapula and rib fractures admitted to the study hospital between 1st January 2010 and 31st June 2021 were retrospectively reviewed.

RESULTS

A total of 223 patients were admitted with concurrent ipsilateral rib and scapula fractures. A total of 160 patients (72%) were treated conservatively, 63 patients (28%) operatively. Among operatively treated patients, 32 (51%) underwent rib fixation (RF) only, 24 (38%) underwent scapula fixation (SF) only, and seven patients (11%) underwent combined fixation of scapula and ribs (SRF). In general, more severely injured patients were treated with more extensive surgery. RF patients had a median hospital length of stay of 16 days, the SF patients 11 days and SRF patients 18 days. There were no significant differences in complications (pneumonia, recurrent pneumothorax and revision surgery) between groups.

CONCLUSION

Injury severity resulted in different treatment modalities. As a result, different patient characteristics between treatment groups were observed, which makes direct comparison between treatment modalities impossible. All treatment modalities seem feasible; however, the additional value of both rib and scapula fixation has yet to be proven in large multicentre studies.