Prevalence of Rotational Malalignment After Infrapatellar Versus Suprapatellar Intramedullary Nailing of Tibial Shaft Fractures.

Background: Up to 30% of patients with a tibial shaft fracture sustain iatrogenic rotational malalignment (RM) after infrapatellar (IP) nailing. Although IP nailing remains the management of choice for most patients, suprapatellar (SP) nailing has been gaining popularity. It is currently unknown whether SP nailing can provide superior outcomes with regard to tibial RM. The aim of this study was to compare the differences in the prevalence of RM following IP versus SP nailing. Methods: This retrospective study included 253 patients with a unilateral, closed tibial shaft fracture treated with either an IP or SP approach between January 2009 and April 2023 in a Level-I trauma center. All patients underwent a postoperative, protocolized, bilateral computed tomography (CT) scan for RM assessment. Results: RM was observed in 30% and 33% of patients treated with IP and SP nailing, respectively. These results indicate no significant difference (p = 0.639) in the prevalence of RM between approaches. Furthermore, there were no significant differences in the distribution (p = 0.553) and direction of RM (p = 0.771) between the 2 approaches. With the IP and SP approaches, nailing of left-sided tibial shaft fractures resulted in predominantly internal RM (85% and 73%, respectively), while nailing of right-sided tibial shaft fractures resulted in predominantly external RM (90% and 80%, respectively). The intraobserver reliability for the CT measurements was 0.95. Conclusions: The prevalence of RM was not influenced by the entry point of tibial nailing (i.e., IP versus SP). Hence, the choice of surgical approach should rely on factors other than the risk of RM. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Three-dimensional imaging of the forearm and hand: A comparison between two 3D imaging systems.

The conventional treatment for distal radius fractures typically involves immobilization of the injured extremity using a conventional forearm cast. These casts do cause all sorts of discomfort during wear and impose life-style restrictions on the wearer. Personalized 3D printed splints, designed using three-dimensional (3D) imaging systems, might overcome these problems. To obtain a patient specific splint, commercially available 3D camera systems are utilized to capture patient extremities, generating 3D models for splint design. This study investigates the feasibility of utilizing a new camera system (SPENTYS) to capture 3D surface scans of the forearm for the design of 3D printed splints. In a prospective observational cohort study involving 17 healthy participants, we conducted repeated 3D imaging using both the new (SPENTYS) and a reference system (3dMD) to assess intersystem accuracy and repeatability. The intersystem accuracy of the SPENTYS system was determined by comparison of the 3D surface scans with the reference system (3dMD). Comparison of consecutive images acquired per device determined the repeatability. Feasibility was measured with system usability score questionnaires distributed among professionals. The mean absolute difference between the two systems was 0.44 mm (SD:0.25). The mean absolute difference of the repeatability of the reference -and the SPENTYS system was respectively 0.40 mm (SD: 0.30) and 0.53 mm (SD: 0.25). Both repeatability and intersystem differences were within the self-reported 1 mm. The workflow was considered easy and effective, emphasizing the potential of this approach within a workflow to obtain patient specific splint.

Cast immobilization duration for distal radius fractures, a systematic review.

PURPOSE: The optimal duration of immobilization for the conservative treatment of non- or minimally displaced and displaced distal radius fractures remains under debate. This research aims to review studies of these treatments to add evidence regarding the optimal immobilization period. METHODS: A comprehensive database search was conducted. Studies investigating and comparing short (< 3 weeks) versus long (> 3 weeks) immobilizations for the conservative treatment of distal radius fractures were included. The studies were evaluated for radiological and functional outcomes, including pain, grip strength, and range of motion. Two reviewers independently reviewed all studies and performed the data extraction. RESULTS: The initial database search identified 11.981 studies, of which 16 (involving 1.118 patients) were ultimately included. Patient-reported outcome measurements, grip strength, range of motion, and radiological outcomes were often better after shorter immobilization treatments. Radiological outcomes were better with longer immobilization in two studies and shorter immobilization in one study. Fourteen studies concluded that early mobilization is preferred, while the remaining two studies observed better outcomes with longer immobilization. The data were unsuitable for meta-analysis due to their heterogeneous nature. CONCLUSION: Shorter immobilization for conservatively treated distal radius fractures often yield equal or better outcomes than longer immobilizations. The immobilization for non- or minimally displaced distal radius fractures could therefore be shortened to 3 weeks or less. Displaced and reduced distal radius fractures cannot be immobilized shorter than 4 weeks due to the risk of complications. Future research with homogeneous groups could elucidate the optimal duration of immobilization.

Mismatch Rate of Empirical Antimicrobial Treatment in Fracture-Related Infections.

OBJECTIVES: To evaluate the current standard of care regarding empirical antimicrobial therapy in fracture-related infections (FRIs). DESIGN: Retrospective cohort study. SETTING: Level I Trauma Center. PATIENT SELECTION CRITERIA: Adult patients treated for FRI with surgical debridement and empirical antibiotics between September 1, 2014, and August 31, 2022. Patients were excluded if less than 5 tissue samples for culture were taken, culture results were negative, or there was an antibiotic-free window of less than 3 days before debridement. OUTCOME MEASURES AND COMPARISONS: FRI microbial etiology, antimicrobial resistance patterns (standardized antimicrobial panels were tested for each pathogen), the mismatch rate between empirical antimicrobial therapy and antibiotic resistance of causative microorganism(s), and mismatching risk factors. RESULTS: In total, 75 patients were included [79% (59/75) men, mean age 51 years]. The most prevalent microorganisms were Staphylococcus aureus (52%, 39/75) and Staphylococcus epidermidis (41%, 31/75). The most frequently used empirical antibiotic was clindamycin (59%, 44/75), followed by combinations of gram-positive and gram-negative covering antibiotics (15%, 11/75). The overall mismatch rate was 51% (38/75) [95% confidence interval (CI), 0.39-0.62] and did not differ between extremities [upper: 31% (4/13) (95% CI, 0.09-0.61), lower: 55% (33/60) (95% CI, 0.42-0.68, P = 0.11)]. Mismatching empirical therapy occurred mostly in infections caused by S. epidermidis and gram-negative bacteria. Combination therapy of vancomycin with ceftazidime produced the lowest theoretical mismatch rate (8%, 6/71). Polymicrobial infections were an independent risk factor for mismatching (OR: 8.38, 95% CI, 2.53-27.75, P < 0.001). CONCLUSIONS: In patients with FRI, a mismatching of empirical antibiotic therapy occurred in half of patients, mainly due to lack of coverage for S. epidermidis , gram-negative bacteria, and polymicrobial infections. Empirical therapy with vancomycin and ceftazidime produced the lowest theoretical mismatch rates. This study showed the need for the consideration of gram-negative coverage in addition to standard broad gram-positive coverage. Future studies should investigate the effect of the proposed empirical therapy on long-term outcomes. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The effect of addition of 2DCT scans and 3DCT scans for the classification of tibial plateau fractures: a systematic review.

PURPOSE: In this systematic review, we evaluate the effect of radiographs and 2D and 3D imaging techniques on the interobserver agreement of six commonly used classification systems for tibial plateau fractures. METHODS: In accordance with PRISMA guidelines, PubMed, Cochrane, Embase and Web of Science were searched for studies regarding the effect of 2D and 3D imaging techniques on the interobserver agreement of tibial plateau classification systems. Studies validating new classification systems, not providing own data or only providing information on the interobserver agreement for radiographs were excluded. Studies were scored based on the ROBINS-I risk of bias tool. RESULTS: Our review analysed 14 studies on different classification systems used for tibial plateau fractures in clinical practice, with the Schatzker classification being the most commonly used classification system. The results showed that the addition of 2D CT led to a significant improvement of interobserver agreement for one study. However, other included studies showed varying levels of interobserver agreement, ranging from fair to substantial according to the interpretation by Landis and Koch. The addition of 3D CT resulted in a significant deterioration in one study for the Schatzker classification. Similar to the addition of 2D CT, the interobserver agreement for the Schatzker classification with the addition of 3D CT were heterogeneous ranging from fair to almost perfect according to the interpretation by Landis and Koch. CONCLUSIONS: The use of 2D CT can be recommended for classifying tibial plateau fractures with the Schatzker classification, AO/OTA classification and Hohl classification. The value of 3D CT on the interobserver agreement of commonly used classification systems remains uncertain and unproven. Therefore, we do not recommend the use of 3D CT for the classification of tibial plateau fractures. Overall, the advancement of imaging techniques is not in line with the advancement in interobserver agreement on fracture classification.

Are the non-weight bearing guidelines for the after treatment of calcaneal fractures still decisive? A Dutch survey among orthopaedic and trauma surgeons.

PURPOSE: The current rehabilitation for patients with surgically treated displaced intra-articular calcaneal fractures (DIACFs) consists of non-weightbearing for 8-12 weeks. The purpose of the present survey was to investigate the current pre-, peri- and post-operative practices among Dutch foot and ankle surgeons. Moreover, it aims to analyze whether surgeons comply to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) guidelines and which decision criteria were used in the determination of the start of weightbearing. METHODS: A survey was distributed among Dutch trauma and orthopaedic surgeons to determine the most common practices in postoperative weightbearing in patients with DIACFs. RESULTS: 75 surgeons responded to the survey. 33% of the respondents adhered to the AO guidelines. 4% of the respondents strictly followed non-weightbearing guidelines, while 96% interpret the AO guidelines or their local protocol freely, in any frequency. When respondents tended to deviate from the AO guidelines or local protocol, a good patients' compliance to therapy was expected. 83% of the respondents started weightbearing on the fracture, based on reported patient complaints. 87% of the respondents did not see any relation between early weightbearing and the occurrence of complications, including loosening of osteosynthesis materials. CONCLUSION: This study demonstrates that there is limited consensus on the rehabilitation for DIACFs. Moreover, it shows that most surgeons are inclined to interpret the current (AO) guideline or their own local protocol freely. New guidelines, supported with well-founded literature, could help surgeons in a more appropriate daily practice in weightbearing for the rehabilitation of calcaneal fractures.

The past, present and future of the conservative treatment of distal radius fractures.

The distal radius fracture is a common fracture with a prevalence of 17% on the emergency departments. The conservative treatment of distal radius fractures usually consists of three to six weeks of plaster immobilization. Several studies show that one week of plaster immobilization is safe for non- or minimally displaced distal radius fractures that do not need reduction. A shorter period of immobilization may lead to a better functional outcome, faster reintegration and participation in daily activities. Due to upcoming innovations such as three-dimensional printed splints for distal radius fractures, a patient specific splint can be produced which may offer more comfort. Furthermore, these three-dimensional printed splints are expected to be more environmental friendly in comparison with traditional plaster casts.

Can CT-based gap and step-off displacement predict outcome after nonoperative treatment of acetabular fractures?

Aims: The aim of this study was to investigate the association between fracture displacement and survivorship of the native hip joint without conversion to a total hip arthroplasty (THA), and to determine predictors for conversion to THA in patients treated nonoperatively for acetabular fractures. Methods: A multicentre cross-sectional study was performed in 170 patients who were treated nonoperatively for an acetabular fracture in three level 1 trauma centres. Using the post-injury diagnostic CT scan, the maximum gap and step-off values in the weightbearing dome were digitally measured by two trauma surgeons. Native hip survival was reported using Kaplan-Meier curves. Predictors for conversion to THA were determined using Cox regression analysis. Results: Of 170 patients, 22 (13%) subsequently received a THA. Native hip survival in patients with a step-off ≤ 2 mm, > 2 to 4 mm, or > 4 mm differed at five-year follow-up (respectively: 94% vs 70% vs 74%). Native hip survival in patients with a gap ≤ 2 mm, > 2 to 4 mm, or > 4 mm differed at five-year follow-up (respectively: 100% vs 84% vs 78%). Step-off displacement > 2 mm (> 2 to 4 mm hazard ratio (HR) 4.9, > 4 mm HR 5.6) and age > 60 years (HR 2.9) were independent predictors for conversion to THA at follow-up. Conclusion: Patients with minimally displaced acetabular fractures who opt for nonoperative fracture treatment may be informed that fracture displacement (e.g. gap and step-off) up to 2 mm, as measured on CT images, results in limited risk on conversion to THA. Step-off ≥ 2 mm and age > 60 years are predictors for conversion to THA and can be helpful in the shared decision-making process.

Hip Function after Surgically Treated Isolated Traumatic Acetabular Fracture: A Prospective Series of Consecutive Cases.

Purpose: Isolated acetabular fractures can occur as a result of a high energy impact on the hip joint. Surgery is required for most patients with an isolated acetabular fracture in order to alleviate pain, restore joint stability, and regain hip function. This study was conducted in order to examine the course of hip function in patients after surgical treatment of an isolated traumatic acetabular fracture. Materials and Methods: This prospective series of consecutive cases included patients who underwent surgery for treatment of an isolated acetabular fracture in a European level one trauma center between 2016 and 2020. Patients with relevant concomitant injuries were excluded. Scoring of hip function was performed by a trauma surgeon using the Modified Merle d'Aubigné and Postel score at six-week, 12-week, six-month, and one-year follow-up. Scores between 3-11 indicate poor, 12-14 fair, 15-17 good, and 18 excellent hip function. Results: Data on 46 patients were included. The mean score for hip function was 10 (95% confidence interval [CI] 7.09-12.91) at six-week follow-up (23 patients), 13.75 (95% CI 10.74-16.76) at 12-week follow-up (28 patients), 16 (95% CI 13.40-18.60) at six-month follow-up (25 patients), and 15.50 (95% CI 10.55-20.45) at one-year follow-up (17 patients). After one-year follow-up, the scores reflected an excellent outcome in 11 patients, good in five patients, and poor in one patient. Conclusion: This study reports on the course of hip function in patients who have undergone surgical treatment for isolated acetabular fractures. Restoration of excellent hip function takes six months.

Quantifying the Differences between 3D Virtual Planning and Attained Postoperative Reduction on CT for Patients with Tibial Plateau Fractures; a Clinical Feasibility Study.

Background: Three-Dimensional Virtual Planning (3DVP) has been proven to be effective for limiting intra-articular screw penetration and improving the quality of reduction for numerous fractures. However, the value of 3DVP for patients with tibial plateau fractures has yet to be determined. Purposes: The research question of this study is: Can Computed Tomography Micromotion Analysis (CTMA) provide a reliable quantification of the difference between 3DVP and the postoperative reduction on CT for tibial plateau fractures? Methods: Nine consecutive adult patients who received surgical treatment for a tibial plateau fracture and received pre- and postoperative CT scans were included from a level I trauma center in the Netherlands. The preoperative CT scans of the patients were uploaded in a 3DVP software. In this software, fracture fragments were reduced and the reduction was saved as a 3D file (STL). The quality of the reduction from the 3DVP software was compared with the postoperative results using CT Micromotion Analysis (CTMA). In this analysis, the translation of the largest intra-articular fragment was calculated by aligning the postoperative CT with the 3DVP. Coordinates and measurement points were defined in the X, Y, and Z axes. The combined values of X and Y were used to define the intra-articular gap. The Z-axis was defined as the line from cranial to caudal and was used to define intra-articular step-off. Results: The intra-articular step-off was 2.4 mm (Range 0.5-4.6). Moreover, the mean translation of the X-axis and Y-axis, which was defined as the intra-articular gap, was 4.2 mm (Range 0.6-10.7). Conclusions: 3DVP provides excellent insight into the fracture and its fragments. Utilizing the largest intra-articular fragment, it is feasible to quantify the difference between 3DVP and a postoperative CT using CTMA. A prospective study to further analyze the use of 3DVP in terms of intra-articular reduction and surgical and patient-related outcomes has been started by our team.

The symmetry of the left and right tibial plateau: a comparison of 200 tibial plateaus.

PURPOSE: This study aims to investigate the symmetry of the left and right tibial plateau in young healthy individuals to determine whether left-right mirroring can be reliably used to optimize preoperative 3D virtual planning for patients with tibial plateau fractures. METHODS: One hundred healthy subjects, without previous knee surgery, severe knee trauma, or signs of osteoarthritis were included for a previous dynamic imaging study of the knee. The subjects underwent a CT scan, scanning the left and right knee with a slice thickness of 0.8 mm. 3D surface models of the femur, patella, and tibia were created using a convolutional neural network. The 3D models of the left and right tibias were exported to MATLAB © and the tibias were mirrored. The mirrored tibias were superimposed on the contralateral tibia using a coherent point drift surface matching algorithm. Correspondence points on both surfaces were established, the mean root squared distance was calculated and visualized in a boxplot and heatmaps. RESULTS: The overall mean difference between correspondence points on the left and right tibial plateau is 0.6276 ± 0.0343 mm. The greatest differences between correspondence points were seen around two specific surfaces on the outside of the tibial plateau; where the distal tibia was cut 15 mm below the tibial plateau and around the tibiofibular joint. CONCLUSIONS: The differences between the left and right tibial plateau are small and therefore, we can be confident that the mirrored contralateral, unfractured, tibial plateau can be used as a template for 3D virtual preoperative planning for young patients without previous damage to the knee.

Entry Point Variation in the Osseous Fixation Pathway of the Anterior Column of the Pelvis-A Three-Dimensional Analysis.

Fractures of the superior pubic ramus can be treated with screw insertion into the osseous fixation pathway (OFP) of the anterior column (AC). The entry point determines whether the screw exits the OFP prematurely. This can be harmful when it enters the hip joint or damages soft tissues inside the lesser pelvis. The exact entry point varies between patients and can be difficult to ascertain on fluoroscopy during surgery. The aim of this study was to determine variation in the location of the entry point. A retrospective single center study was performed at a level 1 trauma center in the Netherlands. Nineteen adult patients were included with an undisplaced fracture of the superior pubic ramus on computer tomography (CT)-scan. Virtual three-dimensional (3D) models of the pelvises were created. Multiple screws were placed per AC and the models were superimposed. A total of 157 screws were placed, of which 109 did not exit the OFP prematurely. A universally reproducible entry point could not be identified. A typical crescent shaped region of entry points did exist and was located more laterally in females when compared to males. Three-dimensional virtual surgery planning can be helpful to identify the ideal entry points in each case.

Are 3D-printed Models of Tibial Plateau Fractures a Useful Addition to Understanding Fractures for Junior Surgeons?

BACKGROUND: Tibial plateau fractures are often complex, and they can be challenging to treat. Classifying fractures is often part of the treatment process, but intra- and interobserver reliability of fracture classification systems often is inadequate to the task, and classifications that lack reliability can mislead providers and result in harm to patients. Three-dimensionally (3D)-printed models might help in this regard, but whether that is the case for the classification of tibial plateau fractures, and whether the utility of such models might vary by the experience of the individual classifying the fractures, is unknown. QUESTIONS/PURPOSES: (1) Does the overall interobserver agreement improve when fractures are classified with 3D-printed models compared with conventional radiology? (2) Does interobserver agreement vary among attending and consultant trauma surgeons, senior surgical residents, and junior surgical residents? (3) Do surgeons' and surgical residents' confidence and accuracy improve when tibial plateau fractures are classified with an additional 3D model compared with conventional radiology? METHODS: Between 2012 and 2020, 113 patients with tibial plateau fractures were treated at a Level 1 trauma center. Forty-four patients were excluded based on the presence of bone diseases (such as osteoporosis) and the absence of a CT scan. To increase the chance to detect an improvement or deterioration and to prevent observers from losing focus during the classification, we decided to include 40 patients with tibial plateau fractures. Nine trauma surgeons, eight senior surgical residents, and eight junior surgical residents-none of whom underwent any study-specific pretraining-classified these fractures according to three often-used classification systems (Schatzker, OA/OTA, and the Luo three-column concept), with and without 3D-printed models, and they indicated their overall confidence on a 10-point Likert scale, with 0 meaning not confident at all and 10 absolutely certainty. To set the gold standard, a panel of three experienced trauma surgeons who had special expertise in knee surgery and 10 years to 25 years of experience in practice also classified the fractures until consensus was reached. The Fleiss kappa was used to determine interobserver agreement for fracture classification. Differences in confidence in assessing fractures with and without the 3D-printed model were compared using a paired t-test. Accuracy was calculated by comparing the participants' observations with the gold standard. RESULTS: The overall interobserver agreement improved minimally for fracture classification according to two of three classification systems (Schatzker: κconv = 0.514 versus κ3Dprint = 0.539; p = 0.005; AO/OTA:κconv = 0.359 versus κ3Dprint = 0.372; p = 0.03). However, none of the classification systems, even when used by our most experienced group of trauma surgeons, achieved more than moderate interobserver agreement, meaning that a large proportion of fractures were misclassified by at least one observer. Overall, there was no improvement in self-assessed confidence in classifying fractures or accuracy with 3D-printed models; confidence was high (about 7 points on a 10-point scale) as rated by all observers, despite moderate or worse accuracy and interobserver agreement. CONCLUSION: Although 3D-printed models minimally improved the overall interobserver agreement for two of three classification systems, none of the classification systems achieved more than moderate interobserver agreement. This suggests that even with 3D-printed models, many fractures would be misclassified, which could result in misleading communication, inaccurate prognostic assessments, unclear research, and incorrect treatment choices. Therefore, we cannot recommend the use of 3D-printed models in practice and research for classification of tibial plateau fractures. LEVEL OF EVIDENCE: Level III, diagnostic study.

A systematic review and meta-analyses on animal models used in bone adhesive research.

Currently, steel implants are used for osteosynthesis of (comminuted) fractures and intra-articular bone defects. These osteosyntheses can sometimes be complicated procedures and can have several drawbacks including stress shielding of the bone. A bone glue might be a safe and effective alternative to current materials. Despite numerous animal studies on bone adhesives, no such material is clinically applied yet. We have conducted a systematic review to summarize the evidence in experimental animal models used in research on bone adhesive materials for trauma and orthopedic surgery. Additionally, we analysed the efficacy of the different bone adhesives for different experimental designs. A heterogeneity in experimental parameters including animal species, defect types, and control measurements resulted in a wide variety in experimental models. In addition, no standard outcome measurements could be identified. Meta-analysis on bone regeneration between adhesive treatment and nonadhesive treatment showed a high heterogeneity and no statistically significant overall effect (M: -0.71, 95% confidence interval [CI]: -1.63-0.21, p = 0.13). Besides, currently there is not enough evidence to draw conclusions based on the effectiveness of the individual types of adhesives or experimental models. A positive statistically significant effect was found for the adhesive treatment in comparison with conventional osteosynthesis materials (M: 2.49, 95% CI: 1.20-3.79, p = 0.0002). To enhance progression in bone adhesive research and provide valuable evidence for clinical application, more standard experimental parameters and a higher reporting quality in animal studies are needed. Statement of Clinical Significance: Current materials restoring anatomical alignments of bones have several drawbacks. A (biodegradable) adhesive for fixating bone defects can be a treatment breakthrough. Although numerous bone adhesives have been researched, most seemed to fail at the preclinical stage. An overview in this field is missing. This systematic review highlights the relevant parameters for design of experimental bone adhesive studies. It demonstrates evidence regarding benefit of bone adhesives but also that the quality of reporting and the risk of bias in studies need to be improved. The results will aid in designing better quality animal studies for bone adhesive research with higher translational value.

Clinical Examination of the Pelvic Ring in the Prehospital Phase.

INTRODUCTION: Instable pelvic fractures are associated with significant hemorrhage and shock. Instability of the pelvic ring should be tested with the manual compression test (MCT) and instable pelvic ring fractures should prompt mechanical stabilization. However, the accuracy of the prehospital MCT in patients, that sustained a high energetic trauma, is still unknown. SETTING: Radboudumc Nijmegen, level 1 trauma center, the Netherlands. METHODS: This prospective blind observational study included all patients after a high impact blunt trauma treated by an experienced Helicopter Emergency Medical Service (HEMS) physician. Nominal arranged questionnaires were filled in by the HEMS physician prior to the radiological examination of the patient. RESULTS: We included 56 patients of which 11 sustained a pelvic ring fracture. 13 patients were treated with pelvic compression devices, of which only five patients had a pelvic ring fracture. Prehospital performed clinical examination by the HEMS physicians had an overall sensitivity of 0.45 (95% CI 0.16-0.75) and a specificity of 0.93 (95% CI 0.29-0.96). CONCLUSION: Pelvic ring instability cannot accurately be diagnosed in the prehospital setting, based on the MCT. The use of the pelvic binder should standard in high impact blunt trauma patients, independently of the MCT or trauma mechanism.

Isolated iliac wing fractures : are they really that benign?

The aim of this study was to review the incidence, management and outcome of isolated iliac wing fractures and to compare them with other type A, B and C fractures. From 2004 to 2015, the data of 547 patient with a pelvic fracture regarding age, gender, RTS, ISS, treatment, complications and mortality were analyzed and a comparison was made between iliac wing fractures and the other pelvic fractures. We encountered 30 isolated iliac wing fractures. The ISS, shock class, transfusion rate, complications and mortality were comparable to those of patients with an unstable pelvic fracture. Concomitant injuries were observed in 93% of the patients. None of the fractures were operatively stabilized. Isolated iliac wing fractures are rare, and operative stabilization of the fracture itself is often not necessary. However, these fractures are serious injuries with characteristics resembling those of patients with an unstable pelvic ring injury.

Epidemiology of Pelvic Ring Fractures in a Level 1 Trauma Center in the Netherlands.

PURPOSE: This study was conducted to study the epidemiology, classification, treatment and outcome of a large patient group with pelvic ring injury in a level 1 trauma center in the Netherlands. MATERIALS AND METHODS: In the period of 2004 to 2014, we encountered 537 patients with a pelvic fracture. Many of them are due to a high energy trauma and therefore many concomitant injuries are observed. Tile A fractures were seen in 137 patients (25.5%), Tile B fractures in 211 (39.3%) and Tile C fractures in 189 patients (35.2%). RESULTS: Patients with unstable fracture types (Tile B1 and B3, Tile C) had significantly higher injury severity score, transfusion rates, need for laparotomy and definitive operative stabilization and complication rate. However, mortality did not differ significantly among Tile A, B or C fractures. CONCLUSION: Overall outcome was good with a mortality rate of 13.6%, which is comparable with other rAelpmorotsst. half of the patients treated could directly be dismissed to their own homes.

Correct Positioning of Percutaneous Iliosacral Screws With Computer-Navigated Versus Fluoroscopically Guided Surgery in Traumatic Pelvic Ring Fractures.

OBJECTIVES: To assess the correct positioning of iliosacral screw in patients with unstable traumatic pelvic ring injury by comparing fluoroscopically guided computer-navigated surgery (CNS) with conventional fluoroscopy (CF) through reviewing postoperative computed tomography (CT) and clinical indicators. DESIGN: A comparative multicenter cohort study. SETTING: Two level I Trauma Centers in the Netherlands. PATIENTS: The computer-navigated group (n = 56) and the CF group (n = 24) were comparable regarding age (mean, 43 years), sex (58%, male), body mass index (25 kg/m), injury severity score (27), injury-to-surgery interval (7 days), and Orthopaedic Trauma Association classification (40% 61-B, 60% 61-C). MAIN OUTCOME MEASUREMENTS: The position of the iliosacral screws was evaluated on postoperative CT. In addition, clinical morbidity and reoperation were assessed. RESULTS: In the CNS group, a total of 111 screws were placed (2.0 per patient), of which 83% were placed correctly. In the CF group, 39 screws (1.6 per patient) were placed, 82% of them correctly.Inadequate fixation included neural foramina hit [12 screws (11%) in the CNS group versus 3 screws (8%) in the CF group, P = 0.76] and extraosseous dislocation [7 screws (6%) vs. 4 screws (10%), respectively, P = 0.47]. Five patients required reoperation, all in the CNS group, P = 0.32. We observed more adequate positioning with increased surgical experience, P = 0.12. CONCLUSIONS: In contrast to what has been suggested by previous studies, we found no benefit from computer-navigated iliosacral screw fixation compared with fluoroscopically guided surgery regarding the correct positioning of iliosacral screw on postoperative CT and related morbidity. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Forward ray tracing for image projection prediction and surface reconstruction in the evaluation of corneal topography systems.

A forward ray tracing (FRT) model is presented to determine the exact image projection in a general corneal topography system. Consequently, the skew ray error in Placido-based topography is demonstrated. A quantitative analysis comparing FRT-based algorithms and Placido-based algorithms in reconstructing the front surface of the cornea shows that arc step algorithms are more sensitive to noise (imprecise). Furthermore, they are less accurate in determining corneal aberrations particularly the quadrafoil aberration. On the other hand, FRT-based algorithms are more accurate and more precise showing that point to point corneal topography is superior compared to its Placido-based counterpart.

Constant volume of the human lens and decrease in surface area of the capsular bag during accommodation: an MRI and Scheimpflug study.

PURPOSE: A change in surface area of the capsular bag and a change in volume of the lens can indicate whether a change in the shape of the lens during accommodation is due to the compressibility or the elasticity of the lens material. METHODS: 3D magnetic resonance imaging (MRI) was used to image the complete shape of the lens in a group of five healthy subjects between 18 and 35 years of age. A parametric representation of the cross-sectional shape was fitted to the edges of the lens, which were determined with a Canny edge filter. Based on a partition of the lens into eight parts, the parametric shape makes it possible to calculate the mean cross-sectional area, the volume, and the surface area as a function of accommodation. Corrected Scheimpflug imaging was used to validate the results obtained with MRI. RESULTS: No significant difference in central anterior and posterior radius of curvature and thickness was found between the MRI and Scheimpflug measurements. In accordance with the Helmholtz accommodation theory, a decrease in the anterior and posterior radius of curvature and equatorial diameter and an increase in lens thickness occurred with accommodation. During accommodation, the mean cross-sectional area increased and the surface area decreased. However, no significant change in lens volume was found. CONCLUSIONS: The preservation of lens volume implies that the internal human lens material can be assumed to be incompressible and is undergoing elastic deformation. Furthermore, the change in surface area indicates that the capsular bag also undergoes elastic deformation.