Fracture Mapping of Both-Column Acetabular Fractures

Both-column Acetabular Fractures with Posterior Wall Involved can be Managed through Single Anterior Approach by Evaluation of Computer-assisted Virtual Surgery Technique

OBJECTIVE

Posterior wall (PW) fractures were sometimes associated in both-column acetabular fractures. How to evaluate pre-operatively the necessity for the performance of the posterior approach was an issue to be solved. In order to solve this issue, the computer-assisted virtual surgery technique was used to evaluate if the involved PW in both-column acetabular fractures (BACF) should be managed through posterior approach and verify the feasibility of this method.

METHODS

Data of a consecutive cohort of 72 patients with both-acetabular fractures from January 2012 to January 2020 was collected for retrospective study, of which 44 patients had concomitant acetabular PW fractures, and patients without PW fractures were labeled as the BCAF group. Computer-assisted virtual surgery technique was performed pre-operatively to evaluate the necessity for performance of posterior approach in 44 patients, and posterior approach was required if more than 3 mm of displacement was still present in the reduced 3D model. The 23 patients without treatment through posterior approach were labeled as the BCAF-PW- group, and the 21 patients with treatment through posterior approach were labeled as the BCAF-PW+ group. Operation-related and post-operative parameters were recorded. The quality of reduction and functional outcomes were assessed by the Matta scoring system and modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data between every two groups. Also, the one-way analysis of variance (ANOVA) was used to analyze data between the three groups.

RESULTS

Comparing operation-related and post-operative parameters in the three groups, some PW fractures in both-column acetabular fractures could be ignored, and which could be evaluated pre-operatively for necessity of an additional posterior approach. Operative time (271.2 ± 32.8 mins) and intra-operative blood loss (1176.7 ± 211.1 mL) were significantly higher in the BCAF-PW+ group. The excellent/good of reduction (25/28 of the BCAF group, 21/23 of the BCAF-PW- group, 19/21 of the BCAF-PW+ group) and functional outcomes (24/28 of the BCAF group, 18/23 of the BCAF-PW- group, 18/21 of the BCAF-PW+ group) of three groups were similar. The incidence of complications, such as deep vein thrombosis (4/28 of the BCAF group >3/23 of the BCAF-PW- group >1/21 of the BCAF-PW+ group) and injury of lateral femoral cutaneous nerve (3/23 of the BCAF-PW- group >2/28 of the BCAF group >0/21 of the BCAF-PW+ group), was no significant difference.

CONCLUSION

The partial both-column acetabular fractures with PW involvement could be managed through a single anterior approach without another posterior approach by evaluation of computer-assisted virtual surgery technique.

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.

Is the T-shaped acetabular fracture really likes a "T"? A study based on three-dimensional fracture mapping

OBJECTIVES

To explore the morphological pattern of T-shaped acetabular fractures (T-SAFs) by mapping the fracture line using 3D software.

MATERIAL AND METHODS

We retrospectively reviewed 1298 consecutive patients with acetabular fractures, and a total of 56 T-SAF patients were enrolled. After the simulated reduction of each fracture in the software, the fracture lines of all patients were overlaid and plotted on a template. A frequency heat map was generated according to the differences in fracture line density distribution. According to the location of fracture lines, all cases were divided into three groups: posterior group, anterior group, extra-posterior group. In surgically treated patients, the surgical approach, fixation methods, and reduction quality were recorded or evaluated.

RESULTS

The transverse fracture line was sinuous without involving the acetabular roof, and the longitudinal fracture line sloped forward or backward along the edge of the acetabular fossa to split the obturator foramen. The anterior and posterior edges of the acetabular fossa, the transition zone of the acetabular roof and anterior wall, the transition zone of the superior pubic ramus and anterior wall, and the posterior wall near the greater sciatic notch were areas with high rates of fracture incidence. The posterior group included 26 patients (46.4%) and the distribution of fracture lines resembled a "T" or "Y". The anterior group included 25 patients (44.6%) and the distribution of fracture lines resembled a "7″. The extra-posterior group included 5 patients (8.9%) and the fracture lines run through the ischial body. The surgical strategies vary among different groups of T-SAF patients.

CONCLUSION

Our findings shed light on the characteristics of fracture lines for T-SAFs and provide a reference for surgical treatment strategies.

Displacement Pattern of Anterior and Posterior Column Fragments in Both-Column Acetabular Fractures: A 3D Reconstruction-Based Study

Background

Few studies have been conducted to examine the displacement characteristics of both-column acetabular fractures (BCAFs). The goal of this study was to investigate the displacement pattern of anterior column (AC) and posterior column (PC) fragments in BCAFs using 3D virtual software.

Materials and Methods

BCAFs were retrospectively reviewed, and 81 patients were enrolled. Computed tomography (CT) images were imported into Mimics software. A 3D model of each pelvis was generated. Four marked points and the rotation angle of each of the injured ACs and PCs were identified. The fracture fragments were reduced virtually using the software, and the change in coordinates of the marked points after reduction was recorded while the rotation angle was measured. The measurements of positional and directional displacement were analysed using the Mann–Whitney U test and the binomial test, respectively.

Results

There was a propensity for AC fragments to shift superomedially and to rotate externally (p < 0.001). Additionally, the posteroinferior fracture area of AC fragments showed the greatest displacement (p < 0.05). PC fragments moved superomedially (p < 0.001) and moved more at the proximal end than the distal end (p < 0.001). PC displacement was always accompanied by internal rotation (p < 0.001). Greater AC displacement was observed in the fracture area further away from the acetabulum (p < 0.05). Greater rotation was observed for the AC than the PC (p < 0.001).

Conclusion

After a BCAF occurs, there are regular patterns regarding the direction and distance of AC and PC fragment displacement. Information on these patterns may provide insight into the injury mechanism and fracture morphology and facilitate surgical decision-making for orthopaedic trauma surgeons.

Both-Column Acetabular Fractures: Should Pelvic Ring Reduction or Acetabulum be Performed First?

OBJECTIVE

Both-column acetabular fracture is a type that accumulates both the pelvis and acetabulum with complex fracture line alignment and has variant fracture fragments. The selection of different reduction landmarks and sequences produces different qualities of reduction. This study aims to compare the operation-related items, quality of reduction, and hip functional outcome by using different reduction landmarks and sequences for management of both-column acetabular fractures (BCAF).

METHODS

A consecutive cohort of 42 patients from January 2013 to January 2019 with BCAF were treated operatively with different reduction landmarks and sequences: pelvic ring fractures reduction first (PRFRF group) and acetabular fractures reduction first (AFRF group). Preoperative computer visual surgical procedures were applied. There were 22 patients in PRFRF group and 20 patients in AFRF group. The surgical details, complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. The functional outcome was evaluated by the modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data.

RESULTS

The real reduction sequence in both groups was almost identical to the preoperative surgical procedures. The excellent/good quality of reduction in PRFRF group (21/22) was better than AFRF group (17/20). Operative time (152.3 ± 16.3 mins) and intra-operative blood loss (639.5 ± 109.9ml) were significantly reduced in PRFRF group (p < 0.05). The incidence of deep vein thrombosis in PRFRF group (2/22) was less than AFRF group (4/20), but without statistical signification.

CONCLUSION

Selection of an appropriate reduction landmark and sequence could result in better quality of reduction, operative time, and decreased blood loss during treatment of BCAF.

Morphological Characteristics of the Posterior Wall Associated with Complex Acetabular Fractures: A Radiological Study Using 3D Software and Fracture Mapping Technique

Background

The aim of the study was to compare the morphological distinctions of the posterior wall (PW) in different complex acetabular fractures using 3D software and fracture mapping technique and ultimately to provide for improved clinical treatment.

Methods

One hundred and fourteen patients with complex acetabular fracture associated with PW were recruited. All patients were divided into two groups according to the injury mechanism of the PW: Group A (both-column and PW) and Group B (including posterior column and PW; T shape and PW; and transverse and PW). Fracture mapping was generated on the intra- and extrasurface of a standard template. The radiological parameters including spatial displacement, articular surface area, articular range, marginal impaction, and multifragments of the two groups were compared.

Results

The spatial displacement, intra-/extra-articular surface area, and start and end point in Group A were 10.9 mm (IQR, 8.4-15.2), 8.2 ± 2.6 cm², 17.9 ± 5.3 cm², 0.8° (IQR, -6.0-16.2), and 107.5° (IQR, 97.2-116.9), respectively. The results in Group B were 30.4 mm (IQR, 16.8-48.7), 4.1 ± 2.0 cm², 10.6 ± 4.4 cm², 29.5° (IQR, 19.2-38.0), and 117.5° (IQR, 98.2-127.2), respectively. Marginal impaction was defined by Letournel et al. All the differences between two groups were significant (P < 0.05). The fracture map in Group A showed an “L”-shaped pattern and a “cusp” on the ilium, and the PW was located at 1/5 to 1/4 of the posterosuperior part of the acetabulum. The fracture maps in Group B were scattered and lacked consistency, and the PWs were confined to 1/10 to 1/8 of the posterior acetabulum.

Conclusions

Quantitative measurements and fracture mapping represented the differences in morphological characteristics of PWs associated with complex acetabular fractures.