Imaging Acetabular Fractures

A Comparative Analysis of Commonly Used Surgical Approaches for Anterior Acetabular Fractures

Introduction Fractures of the acetabulum are inherently complex due to the anatomy of the innominate bones and also the presence of several vital neurovascular structures in the vicinity. Thus, the treatment of pelvic ring and acetabulum fractures is riddled with complexities and is considered among the most challenging surgeries for an orthopedic surgeon. When anterior access is necessary, such as in the anterior column, both columns, anterior column posterior hemitransverse, transverse, and T-type fractures, both the ilioinguinal and the anterior intrapelvic (AIP) or modified Rives-Stoppa methods are employed. The aim of this study is to compare the results from acetabular fractures treated with a modified Stoppa and ilioinguinal technique. Materials and methods We conducted a prospective cohort study to compare the outcomes of anterior acetabular fracture fixation using the modified Stoppa approach and the ilioinguinal approach. The outcomes measured were the amount of intraoperative bleeding, surgery duration, postoperative quality of fracture reduction, postoperative drain collection, and postoperative neurovascular status. The functional outcome was measured at three, six, and 12 months using the Merle d'Aubigné score. The radiological outcome was measured using the Matta scoring system. Results A significant difference was noticed in the two groups in the average blood loss and surgical duration, where the mean blood loss was 911.67 ± 143.05 ml in the ilioinguinal approach and 748.33 ± 165.30 ml in the modified Stoppa approach. While the ilioinguinal approach had a mean surgical duration of 190.33 ± 29.42 minutes, the modified Stoppa approach had 151.33 ± 23 minutes. The difference in postoperative fracture reduction in both groups was insignificant. The lateral femoral cutaneous nerve was compromised in 8.33% of cases in group A. The obturator nerve was compromised in 6.67% of cases in group B. The postoperative functional outcome was assessed by the modified Merle d'Aubigné score, and the radiological outcome was evaluated by the Matta score. The results obtained in both our study arms were comparable. Conclusion Based on our results, we can safely advocate the superiority of the Stoppa approach over a more extensive ilioinguinal approach. By virtue of being shorter in surgical duration and causing lesser blood loss, the Stoppa approach seems to be a better alternative, especially in elderly or polytrauma patients. As no difference was noted in the postoperative outcomes both clinically and radiologically, no approach showed superiority over the other in terms of patients' eventual functional outcomes.

Path Tracing vs. Volume Rendering Technique in Post-Surgical Assessment of Bone Flap in Oncologic Head and Neck Reconstructive Surgery: A Preliminary Study

This study aims to compare a relatively novel three-dimensional rendering called Path Tracing (PT) to the Volume Rendering technique (VR) in the post-surgical assessment of head and neck oncologic surgery followed by bone flap reconstruction. This retrospective study included 39 oncologic patients who underwent head and neck surgery with free bone flap reconstructions. All exams were acquired using a 64 Multi-Detector CT (MDCT). PT and VR images were created on a dedicated workstation. Five readers, with different expertise in bone flap reconstructive surgery, independently reviewed the images (two radiologists, one head and neck surgeon and two otorhinolaryngologists, respectively). Every observer evaluated the images according to a 5-point Likert scale. The parameters assessed were image quality, anatomical accuracy, bone flap evaluation, and metal artefact. Mean and median values for all the parameters across the observer were calculated. The scores of both reconstruction methods were compared using a Wilcoxon matched-pairs signed rank test. Inter-reader agreement was calculated using Spearman's rank correlation coefficient. PT was considered significantly superior to VR 3D reconstructions by all readers (p < 0.05). Inter-reader agreement was moderate to strong across four out of five readers. The agreement was stronger with PT images compared to VR images. In conclusion, PT reconstructions are significantly better than VR ones. Although they did not modify patient outcomes, they may improve the post-surgical evaluation of bone-free flap reconstructions following major head and neck surgery.

Fragility Fractures of the Acetabulum: Current Concepts for Improving Patients' Outcomes

The incidence of fragility fractures of the acetabulum (FFA) is constantly increasing. Generally, these fractures are related to a fall on the greater trochanter involving the anterior column. The management of FFA is extremely difficult considering both patients' comorbidities and poor bone quality. Both non-operative and several operative treatment protocols are available, and the choice among them is still ambiguous. The proposed surgical techniques for FFA [namely open reduction and internal fixation (ORIF), percutaneous fixation and total hip arthroplasty (THA)] are associated with a high complication rate. The treatment with the higher early mortality is the ORIF + THA, while the one with the lowest is the non-operative. However, at longer follow-up, this difference dreadfully change is becoming the opposite. Frequently ORIF, percutaneous fixation, and non-operative treatment need a subsequent re-operation through a THA. This latter could be extremely difficult, because of poor bone quality, acetabular mal union/non-union, bone gaps and hardware retention. However, the outcomes of each of the proposed treatment are mostly poor and controverted; therefore, a comprehensive patient evaluation and an accurate fracture description are required to appropriately manage acetabular fracture in the elderly.

Volumetric Markers of Body Composition May Improve Personalized Prediction of Major Arterial Bleeding After Pelvic Fracture: A Secondary Analysis of the Baltimore CT Prediction Model Cohort

METHODS

This work is a retrospective secondary analysis of a single institution cohort used in the development of the Baltimore CT prediction model. The cohort includes 115 consecutive patients that underwent admission contrast-enhanced CT of the abdomen and pelvis for blunt trauma with pelvic ring disruption followed by conventional angiography. Major arterial injury requiring angioembolization served as the outcome variable. Angioembolization was required in 73/115 patients (63% of the cohort). Average age was 46.9 years (±SD 20.4). Body composition measurements were determined as 2-dimensional (2D) or 3-dimensional (3D) parameters and included mid-L3 trabecular bone attenuation, abdominal visceral fat area or volume, and percent muscle fat fraction (as a marker of sarcopenia) measured using segmentation and histogram analysis.

RESULTS

Models incorporating 2D (Model B) or 3D markers (model C) of body composition showed improvement over the original Baltimore model (model A) in all parameters of performance, quality, and fit (area under the receiver-operating curve [AUC], Akaike information criterion, Brier score, Hosmer-Lemeshow test, and adjusted-R2). Area under the receiver-operating curve increased from 0.83 (A), to 0.86 (B), and 0.88 (C). The greatest improvement was seen with 3D parameters.

CONCLUSION

Once automated, quantitative visualization tools providing "free" 3D body composition information can be expected to improve personalized precision diagnostics, outcome prediction, and decision support in patients with bleeding pelvic fractures.

Cone-beam computed tomography cinematic rendering: clinical, teaching and research applications

Cone-beam computed tomography (CBCT) is an essential imaging method that increases the accuracy of diagnoses, planning and follow-up of endodontic complex cases. Image postprocessing and subsequent visualization relies on software for three-dimensional navigation, and application of indexation tools to provide clinically useful information according to a set of volumetric data. Image postprocessing has a crucial impact on diagnostic quality and various techniques have been employed on computed tomography (CT) and magnetic resonance imaging (MRI) data sets. These include: multiplanar reformations (MPR), maximum intensity projection (MIP) and volume rendering (VR). A recent advance in 3D data visualization is the new cinematic rendering reconstruction method, a technique that generates photorealistic 3D images from conventional CT and MRI data. This review discusses the importance of CBCT cinematic rendering for clinical decision-making, teaching, and research in Endodontics, and a presents series of cases that illustrate the diagnostic value of 3D cinematic rendering in clinical care.

An Automated Deep Learning Method for Tile AO/OTA Pelvic Fracture Severity Grading from Trauma whole-Body CT

Admission trauma whole-body CT is routinely employed as a first-line diagnostic tool for characterizing pelvic fracture severity. Tile AO/OTA grade based on the presence or absence of rotational and translational instability corresponds with need for interventions including massive transfusion and angioembolization. An automated method could be highly beneficial for point of care triage in this critical time-sensitive setting. A dataset of 373 trauma whole-body CTs collected from two busy level 1 trauma centers with consensus Tile AO/OTA grading by three trauma radiologists was used to train and test a triplanar parallel concatenated network incorporating orthogonal full-thickness multiplanar reformat (MPR) views as input with a ResNeXt-50 backbone. Input pelvic images were first derived using an automated registration and cropping technique. Performance of the network for classification of rotational and translational instability was compared with that of (1) an analogous triplanar architecture incorporating an LSTM RNN network, (2) a previously described 3D autoencoder-based method, and (3) grading by a fourth independent blinded radiologist with trauma expertise. Confusion matrix results were derived, anchored to peak Matthews correlation coefficient (MCC). Associations with clinical outcomes were determined using Fisher's exact test. The triplanar parallel concatenated method had the highest accuracies for discriminating translational and rotational instability (85% and 74%, respectively), with specificity, recall, and F1 score of 93.4%, 56.5%, and 0.63 for translational instability and 71.7%, 75.7%, and 0.77 for rotational instability. Accuracy of this method was equivalent to the single radiologist read for rotational instability (74.0% versus 76.7%, p = 0.40), but significantly higher for translational instability (85.0% versus 75.1, p = 0.0007). Mean inference time was < 0.1 s per test image. Translational instability determined with this method was associated with need for angioembolization and massive transfusion (p = 0.002-0.008). Saliency maps demonstrated that the network focused on the sacroiliac complex and pubic symphysis, in keeping with the AO/OTA grading paradigm. A multiview concatenated deep network leveraging 3D information from orthogonal thick-MPR images predicted rotationally and translationally unstable pelvic fractures with accuracy comparable to an independent reader with trauma radiology expertise. Model output demonstrated significant association with key clinical outcomes.

Bone Fracture Sensing Using Ultrasound Pitch-Catch Measurements: A Proof-of-Principle Study

The most common imaging method used to diagnose and monitor bone fractures and healing is multiple radiographic images performed by highly trained professionals with expensive equipment that can expose patients to high levels of ionizing radiation. Here we introduce and illustrate proof-of-concept of a potential alternative method for measuring bone fractures: ultrasound pitch-catch measurement technique. Measurements are performed with two piezoelectric transducers, housed in standard orthopedic screws and fixed on either side of simulated fractures, with and without an orthopedic plate, in ex vivo pig limb bones. Using this measurement method, we were able to detect significant differences between uncut and 2-, 5- and 10-mm-deep bone cuts using a two-sided t-test with an α level of 5%.