Artificial intelligence in commercial fracture detection products: a systematic review and meta-analysis of diagnostic test accuracy.

Conventional radiography (CR) is primarily utilized for fracture diagnosis. Artificial intelligence (AI) for CR is a rapidly growing field aimed at enhancing efficiency and increasing diagnostic accuracy. However, the diagnostic performance of commercially available AI fracture detection solutions (CAAI-FDS) for CR in various anatomical regions, their synergy with human assessment, as well as the influence of industry funding on reported accuracy are unknown. Peer-reviewed diagnostic test accuracy (DTA) studies were identified through a systematic review on Pubmed and Embase. Diagnostic performance measures were extracted especially for different subgroups such as product, type of rater (stand-alone AI, human unaided, human aided), funding, and anatomical region. Pooled measures were obtained with a bivariate random effects model. The impact of rater was evaluated with comparative meta-analysis. Seventeen DTA studies of seven CAAI-FDS analyzing 38,978 x-rays with 8,150 fractures were included. Stand-alone AI studies (n = 15) evaluated five CAAI-FDS; four with good sensitivities (> 90%) and moderate specificities (80-90%) and one with very poor sensitivity (< 60%) and excellent specificity (> 95%). Pooled sensitivities were good to excellent, and specificities were moderate to good in all anatomical regions (n = 7) apart from ribs (n = 4; poor sensitivity / moderate specificity) and spine (n = 4; excellent sensitivity / poor specificity). Funded studies (n = 4) had higher sensitivity (+ 5%) and lower specificity (-4%) than non-funded studies (n = 11). Sensitivity did not differ significantly between stand-alone AI and human AI aided ratings (p = 0.316) but specificity was significantly higher the latter group (p < 0.001). Sensitivity was significant lower in human unaided compared to human AI aided respectively stand-alone AI ratings (both p ≤ 0.001); specificity was higher in human unaided ratings compared to stand-alone AI (p < 0.001) and showed no significant differences AI aided ratings (p = 0.316). The study demonstrates good diagnostic accuracy across most CAAI-FDS and anatomical regions, with the highest performance achieved when used in conjunction with human assessment. Diagnostic accuracy appears lower for spine and rib fractures. The impact of industry funding on reported performance is small.

First In Vivo Electromyographic Analysis of Mechanical Load Scenarios of the Cervicothoracic Junction During Daily Activities as a Basis for Future Postoperative Behavioral Instructions.

STUDY DESIGN: Clinical Research. OBJECTIVES: Study participants were twenty- eigth healty volunteers. BACKGROUND: Soft tissue complications after posterior cervicothoracic fusion surgery occur frequently. Postoperative myofascial dehiscence (PMD) can cause disability and pain. So far, it is unknown whether patients can affect PMD development through behavioral adjustment. Consequently, this study aimed to analyze how much mechanical stress daily activities exert on the posterior muscles and fascia at the cervicothoracic junction. MATERIALS AND METHODS: Surface electromyography was applied next to the upper thoracic spine at the trapezius muscle. All volunteers performed 22 different daily activities, such as tooth brushing, dressing, standing up, and different horizontal positions. During the exercises, the electromyographic activity was measured. For each volunteer, root mean square values were determined. All exercises were then repeated with the use of a clavicular bandage to unload the shoulder and cervicothoracic muscles. Afterwards, the rankings were statistically compared interindividually. RESULTS: Among the different tasks, significant differences in regard to the root mean square values were noted. For instance, horizontal positions caused significantly lower muscle activation compared with all other exercises (P≤ 0.001). Notably, no relevant electromyographic differences were detected between the tasks with and without a clavicular bandage. CONCLUSIONS: This in vivo electromyographic analysis of cervicothoracic muscle activity during daily activities demonstrates that myofascial strain differs among various daily activities. Data indicate that potential postoperative mobilization protocols and behavioral instructions may have the potential to reduce the biomechanical load and consequently the risk of PMD and, therefore, may reduce the risk for surgical wound-related complications, disability, and need for revision surgery.

Standard imaging in the emergency department in geriatric patients with immobilizing pelvic pain after low-energy trauma or without trauma: X-ray vs. computed tomography.

PURPOSE: Geriatric pelvic ring injuries, evaluated solely by X-ray, are often misclassified or even missed. This can result in prolonged immobilization and persistent pelvic pain. The aim of this study was to assess the sensitivity and specificity of X-ray imaging in patients aged ≥ 70 years with immobilizing pelvic pain. METHODS: 107 geriatric patients (23 males, 84 females) with immobilizing pain after traumatic or atraumatic causes were included in this retrospective study. 91 patients had an anteroposterior (AP) X-ray of the pelvis and after that a computed tomography (CT) of the pelvis. All patients were treated in a level 1 trauma center from December 2018 to September 2020. The mean age was 83.07 ± 6.08 years. RESULTS: The overall evaluation of the diagnostic performance of AP Pelvic X-ray imaging in the study population compared to the CT pelvis ("gold standard") resulted in a sensitivity of (2.7 %) and a specificity of (94.4 %). Specific for pelvic ring fractures in the study population there was a sensitivity of (3.4 %) and a specificity of (94.4 %). CONCLUSION: The results highlights issues with the AP Pelvic X-ray as the diagnostic tool of choice in this study population, confirming the findings of previous studies on the underestimated problem of osteoporotic pelvic ring fractures in geriatric patients. This again confirms the need for a new optimized diagnostic algorithm, which takes into account the differences of the orthogeriatric patient cohort.

Lessons learned from biomechanical studies on cephalomedullary nails for the management of intertrochanteric fractures. A scoping review.

INTRODUCTION: The increasing socioeconomic need for optimal treatment of hip fractures in combination with the high diversity of available implants has raised numerous biomechanical questions. This study aims to provide a comprehensive overview of biomechanical research on the treatment of intertrochanteric fractures using cephalomedullary devices. METHODS: Following the PRISMA-P guidelines, a systematic literature search was performed on 31.12.2022. The databases PubMed/MEDLINE and Web of Science were searched. Scientific papers published between 01.01.2000 - 31.12.2022 were included when they reported data on implant properties related to the biomechanical stability for intertrochanteric fractures. Data extraction was undertaken using a synthesis approach, gathering data on criteria of implants, sample size, fracture type, bone material, and study results. RESULTS: The initial search identified a total of 1459 research papers, out of which forty-three papers were considered for final analysis. Due to the heterogeneous methods and parameters used in the included studies, meta-analysis was not feasible. A comprehensive assessment of implant characteristics and outcome parameters was conducted through biomechanical analysis. Various factors such as proximal and distal locking, nail diameter and length, fracture model, and bone material were thoroughly evaluated. CONCLUSION: This scoping review highlights the need for standardization in biomechanical studies on intertrochanteric fractures to ensure reliable and comparable results. Strategies such as avoiding varus, maintaining a sufficient tip-apex-distance, cement augmentation, and optimizing lesser trochanteric osteosynthesis enhance construct stability. Synthetic alternatives may offer advantages over cadaveric bone. Further research and meta-analyses are required to establish standardized protocols and enhance reliability.

Validation of direct CT measurement of malrotation in femoral neck fractures: A bone model study.

BACKGROUND: While postoperative malrotation in the subtrochanteric region is a well-known problem, malrotation after osteosynthesis in proximal femoral fractures has not been extensively studied. In this context, many methods for perioperatively assessment of femoral torsion have been described, but none of them is applicable in the basicervical region of the proximal femur. As an important difference in femoral neck fractures, the discontinuous neck fails to serve as a significant "pointer" for measurements and malfunctions to be placed in relation to the condylar plane. Considering postoperative maltorsion at any location as a substantial negative effect on patients' outcome and functional expectations, precise and patient-friendly rotation measurement standards in femoral neck fractures are desired in clinical practice. Recently, a novel computed tomography (CT) based geometric technique was described named "direct measurement" with promising results covering this diagnostic disparity, but still requires validation. Thus, we aimed to validate the previously described technique using a controlled range of displacement in a femoral neck fracture Sawbone® model. METHODS AND FINDINGS: A goniometer was designed to set retro- and anteversion of the proximal femur in a reproducible manner. Prospectively, all femurs underwent a CT scan and were measured 3D for displacement. The interclass correlation between the CT measurements and the goniometer measurements was calculated and was found to be very high (1.00, 95% confidence interval: 0.99-1.00; p < 0.001). For the mean of all measurements, the Pearson's correlation was 1.00 (p < 0.001). No significant differences in the measurements of both investigators were observed, with 20° of retroversion not significant (-1.20 ± 1.71; 95% confidence interval: -2.43-0.03; p = 0.054). CONCLUSION: This CT-based 3D measurement technique may allow for perioperative malrotation assessment in basicervical femoral neck fractures and appears to be feasible in femoral neck fractures when it comes to rare cases of osteosynthesis. Further investigations are still needed to define the thresholds of malrotation provoking functional impairment after osteosynthesis in basicervical femoral neck fractures.

Quality of lower limb preoperative skin preparation using colorless versus colored disinfectants-results of an experimental, randomized study in a close to reality setting.

BACKGROUND: Appropriate preoperative skin cleansing is important to control surgical site infections. Both colored and colorless skin disinfectants are available, however certain types of skin preparation, such as octenidine-dihydrochloride with alcohol have a long residual antimicrobial effect but are available only in colorless form. We hypothesized that colorless skin disinfectants lead to more incomplete skin preparation of lower limbs compared to colored agents. METHODS: We randomly assigned healthy volunteers to undergo a determined skin cleansing protocol for total hip arthroplasty in the supine position to either a colored or colorless skin cleansing protocol. The adequacy of skin preparation was compared between orthopedic consultants and residents. The colorless disinfectant was mixed with a fluorescent dye and missed skin areas were visualized using UV lamps. Both preparations were photo-documented following standardized protocols. The primary outcome of interest was the number of legs with an incomplete scrubbed area. The secondary outcome was the cumulative skin area not disinfected. RESULTS: Fifty-two healthy volunteers (104 legs; 52 colored and 52 colorless) underwent surgical skin preparation. The number of legs incompletely disinfected was significantly higher in colorless compared to colored disinfectant group (38.5% (n = 20) vs. 13.5% (n = 7); p = 0.007). Regardless of the disinfectant, consultants performed better than the residents. When using colored disinfectant, residents incompletely prepared the site in 23.1% (n = 6) compared with 57.7% (n = 15) with a colorless disinfectant (p = 0.023). Conversely consultants using colored disinfectant incompletely prepared the site in 3.8% (n = 1) compared with 19.2% (n = 5) for colorless disinfectant (p = 0.191). The total amount of uncleansed skin was significantly higher using colorless skin disinfectant (mean ± standard deviation: 8.78 cm2± 35.07 vs. 0.65 cm2 ± 2.66, p = 0.002). CONCLUSIONS: Application of colorless skin disinfectants for hip arthroplasty cleansing protocol led to decreased skin coverage among consultants and residents compared to colored preparations. Colored disinfectants remain the gold standard in hip surgery, however we should be aiming to develop newer colored disinfectants with long residual antimicrobial effects to enable visual control during the scrubbing process.

[Biological reconstruction of large bone defects : Masquelet technique and new procedures]. / Biologische Rekonstruktion von großen Knochendefekten : Masquelet-Technik und neue Verfahren.

Extensive diaphyseal and metaphyseal bone defects continue to pose a major challenge for orthopedic trauma surgeons. Various treatment options have been described for the biological reconstruction of these defects. The most frequently used methods are bone segment transport, the Masquelet technique and 3D printed scaffolds. As far as the Masquelet technique is concerned, in the first stage spacers, such as polymethyl methacrylate (PMMA), calcium sulfate or polypropylene are inserted into the bone defects to induce a foreign body membrane. In the second stage the bone defect surrounded by the induced membrane is filled with autologous cancellous bone. The time interval between the first and second interventions is usually 4-8 weeks whereby the induced membranes do not lose their bioactivity even with a latency period longer than 8 weeks. Three-dimensional printed scaffolds are increasingly used but large clinical studies are lacking in order to show the exact role of this procedure in the reconstruction of bone defects.

Posterior acetabular wall morphology is an independent risk factor that affects the occurrence of acetabular wall fracture in patients with traumatic, posterior hip dislocation.

PURPOSE: Smaller posterior acetabular walls have been shown to independently influence the risk for bipolar hip dislocation. We asked whether differences would also be observed in patients with traumatic posterior hip dislocation with and without posterior wall fractures. METHODS: Between 2012 and 2020 we observed 67 traumatic posterior hip dislocations. Of these, 43 traumatic posterior hip dislocations in 41 patients met the inclusion criteria. Eighteen dislocations were excluded with an acetabular fracture other than posterior wall fracture and six dislocations had insufficient computed tomography (CT) data. The mean age was 41 ± 11 years, 32 males and nine females. We observed 26 traumatic hip dislocations with posterior wall fractures and 17 without. All patients underwent polytrauma CT scans and postoperative/postinterventional pelvic CT scans. On axial CT-scans, posterior wall determining angles were measured. RESULTS: Patients with posterior wall fractures were not significantly older than patients without posterior wall fractures (42 ± 12 vs. 38 ± 10 years; p = 0.17). Patients without posterior wall fractures had significantly smaller posterior acetabular sector angles (84° ± 10°) than did patients with posterior wall fractures (105° ± 12°) (p < 0.01; OR 1.178). Likewise, the posterior wall angle was significantly smaller in patients without posterior wall fracture (62° ± 9°) than in those with posterior wall fractures (71° ± 8°) (p < 0.01; OR 1.141). CONCLUSION: Both posterior acetabular sector angle and posterior wall angle are independent factors determining the posterior wall fracture morphology in patients with traumatic posterior hip dislocation. Age and the observed trauma mechanism did not differentiate between traumatic posterior hip dislocations with and without posterior wall fractures.

Bone defect treatment: does the type and properties of the spacer affect the induction of Masquelet membrane? Evidence today.

PURPOSE: High clinical success rates have been reported with the Masquelet technique in the treatment of traumatic bone loss. An increasing number of studies suggest that various factors can influence the properties of induced membranes. Goal of this systematic review is to answer the following questions: (1) which are the ideal spacer properties (material, surface topography, antibiotic supplementation) to booster the quality and osteogenic potential of induced membranes? (2) what is the ideal time to perform the second-stage operation? METHODS: A systematic search using the keywords "((Masquelet) OR (Induced Periosteum)) AND ((Spacer) OR (Time))" was performed in PubMed, Embase and Cochrane Library according to PRISMA guidelines. Studies published up to the 23rd of February 2022 were included and assessed independently by two reviewers. RESULTS: Thirteen animal and 1 clinical studies were identified to address the above questions. Spacer materials used were PMMA, silicone, titanium, polypropylene, PVA, PCL and calcium sulfate. With the exception of PVA sponges, all solid materials could induce membranes. Low union rates have been reported with titanium and rough surfaced spacers. Scraping of the inner surface of the IM also increased bony union rates. In terms of the ideal timing to perform the second-stage evidence suggests that membranes older than 8 weeks continue to have regenerative capacities similar to younger ones. CONCLUSION: Membranes induced by smooth PMMA spacers loaded with low concentrations of antibiotics showed powerful osteogenic properties. Other materials such as Polypropylene or Calcium sulfate can also be used with good results. Despite current recommendation to perform the second stage operation in 4-8 weeks, membranes older than 8 weeks seem to have similar regenerative capacities to younger ones.

Clinical assessment of tibial torsion differences. Do we always need a computed tomography?

BACKGROUND: Tibial torsional malalignment presents a well-known complication of intramedullary nailing for tibial shaft fractures. PURPOSE: Objective of this study was to investigate the ability to clinically assess tibial torsion differences. Computed Tomography (CT) was used here as the gold standard. Further, intra- and inter-observer reliability of the clinical examination, and radiological measurements were calculated. METHODS: Fifty-one patients with torsion-difference CTs, obtained for various reasons, were asked to kneel on an examination couch with free hanging feet. All patients are positioned with 90° flexed knee and neutral ankle. A picture of the lower extremities was obtained from the back of the patient. Two blinded orthopedic surgeons were asked to look at the pictures and measure the tibial torsion with a digital goniometer, based on the axis of the femur in relation to the second ray of the foot. To determine the intra-observer variation, the torsional angles were calculated again after 4 weeks. To be able to compare values, two blinded radiologists calculated torsional differences based on computed tomography. RESULTS: All patients were able to be positioned for clinical assessment (n = 51). Clinical assessment of torsional difference revealed 4.55° ± 6.85 for the first, respectively, 4.55° ± 7.41 for the second investigator. The second measurement of the first investigator revealed a value of 4.57° ± 6.9. There was a good intra-observer agreement for clinical assessment (ICC 0.993, p < 0.001). Also, the inter-observer agreement showed a good inter-observer agreement (ICC 0.949, p < 0.001). Evaluation of radiological inter-observer assessment could also show a good inter-observer agreement (ICC 0.922, p < 0.001). The clinical method showed a good correlation to the CT method (0.839, p < 0.001). Additionally, the Bland-Altman plot was used to compare graphically both measurement techniques, which proved the agreement. CONCLUSION: In summary, computed tomography-assisted measurement of tibial torsion and clinical assessment correlated significantly good. In addition to that, clinical measurement has a good intra- and inter-observer reliability. Clinical examination is a reliable and cost-effective tool to detect mal-torsion and should be part of the repertoire of every surgeon.

Differences in hip fracture care in Europe: a systematic review of recent annual reports of hip fracture registries.

PURPOSE: Hip fractures are of growing interest due to their increasing number, subsequent functional decline and high institutionalization rate of patients, mortality, and costs. Several process measurements are essential for hip fracture care. To compare and improve these, hip fracture registries in Europe became popular. This systematic review aims to describe the differences between hip fracture registries in Europe as well as the differences in hip fracture treatment between countries. METHODS: A systematic search using the keywords "hip fracture" AND "national" AND "database OR audit OR registry OR register" was performed in PubMed, Embase and Cochrane Library according to PRISMA guidelines till 3rd December 2020. Recent annual reports of identified hip fracture registries in Europe were additionally identified in June 2021. Comparisons of most common case-mix, process and outcome measurements were performed. RESULTS: 11 registries in Europe were identified. Differences were observed regarding inclusion criteria of the different registries. Comparison of the different registries was difficult due to differences in the way to report measurements. While mortality rates differed substantially between countries, most of the process measurements met recommendations according to recent guidelines. CONCLUSION: Hip fracture registries were a valid tool to compare hospitals within one country. However, a comparison between registries of different countries should have also been easily possible. For this, the registries need to make their data easily accessible and further unify their way of measuring and reporting.

[Single Assessment Numeric Evaluation (SANE)-a promising and valid measuring tool related to patient-reported outcome measures (PROM)]. / Single Assessment Numeric Evaluation (SANE) ­ ein vielversprechendes, valides Messinstrument der "patient-reported outcome measures" (PROM).

Patient-reported outcome measures (PROMs) are clinical measurement tools that capture the health status and outcomes of medical interventions from the patient's perspective. The aim of this study was to investigate the correlation between the Oxford Elbow Score (OES) and Single Assessment Numeric Evaluation (SANE) retrospectively. The study examined 86 patients between December 2018 and February 2019 using the Pearson correlation coefficient between SANE and OES. OES and SANE correlated significantly (r = 0.903, p < 0.001), so that SANE can be considered a promising outcome parameter alongside established scores.

Conservative treatment of displaced isolated proximal humerus greater tuberosity fractures: preliminary results of a prospective, CT-based registry study.

BACKGROUND: Isolated greater tuberosity fractures are uncommon and account for approximately 2-19% [Emerg Radiol. 2018;25(3):235-246] of all proximal humerus fractures. Surgical treatment is the prevailing recommendation in cases of displacement of more than 5 mm for the general healthy population, while conservative treatment is considered to result in inferior outcomes and is not recommended. However, high-grade evidence is lacking for these recommendations. METHODS: Twenty patients with conservatively treated isolated greater tuberosity fracture were evaluated prospectively as part of a registry study. Morphological Mutch classification, displacement in millimeters, and direction of displacement were determined by computed tomography (CT). Degree of fragment displacement was classified (nondisplaced to minor: ≤ 5 mm; moderate: 6-10 mm; major: > 10 mm). Constant score (CS), age- and sex-adjusted Constant score (adj. CS), subjective shoulder value (SSV), and radiographic follow-up were compared at a minimum follow-up of 12 months. For statistical analysis, quantitative data were compared using Mann-Whitney U t-test. Statistical significance was set at p ≤ 0.05. RESULTS: Ninteen patients reached the minimum follow-up at an average of 19 months (range, 12-35 months). 13 patients were women. Average age at the time of injury was 51 years (range, 22-75 years). CS and adj. CS averaged 79 ± 17.5 points, and 91 ± 17.7 points, respectively. The SSV averaged 87 ± 17%. No statistically significant difference in clinical outcomes could be observed with respect to the degree of displacement among the three groups. CONCLUSION: The outcomes of conservatively treated displaced isolated greater tuberosity fractures are underestimated, and current indications for surgical treatment should be questioned. Further studies with larger numbers of patients and longer lengths of follow-up are needed. The protocol of this observational study is registered at ClinicalTrials.gov (NCT03060876). Date of registration: June 8, 2016.

Reliability analysis of CT torsion assessment after closed cephalomedullary nailing of trochanteric femoral fractures. A comparison study of six established methods.

BACKGROUND: Posttraumatic maltorsion and implant failure after closed reduction of proximal femoral fractures remain a cause of concern. Although the reproducibility of torsion measuring techniques on CT for femoral shaft fractures has been thoroughly analyzed, little is known about the trochanteric fractures. Apart from the well-known CT limitations, posttraumatic alteration of bony landmarks makes torsional assessment even more challenging. Main goal of this study was to examine the reliability of different CT techniques on trochanteric femoral fractures after closed nail fixation. Secondary goal was to see whether the measurements within the examined population were influenced by the fracture type and patient age or BMI. METHODS: 20 cases (AO.31-A1 or -A2) were retrospectively examined. Six established CT techniques for torsional assessment were performed from three different investigators twice at different time points. The intraclass correlation coefficient (ICC for 95% CI) was used to analyze the interobserver and intraobserver reliability. RESULTS: The Hernandez method (0.986) followed by the Jend method (0.982) by a mean difference of <1° showed the highest reliability. Although increasing fracture complexity from A1 to A2 led to an overall worsening of the measurement precision, the Hernandez and Jend techniques revealed a very good consistency. Within the examined population, age and BMI had no impact on the precision of the measurements. CONCLUSIONS: The Hernandez and Jend methods represent reliable alternatives for torsional assessment of trochanteric femur fractures treated with closed nail fixation when compared to the other measurement techniques here involved. Documentation of the torsion measuring method used in each case constitutes an essential element of the radiological reports.

Patella baja after intramedullary nailing of tibial fractures, using an infrapatellar/transtendinous approach, predicts worse patient reported outcome.

PURPOSE: After intramedullary nailing of tibial shaft fractures using an infrapatellar/transtendinous approach, several patients suffer anterior knee pain. We suspect that the approach is associated with soft tissue scars and the development of a postoperative patella baja. The goal of the study is to investigate whether the development of patella baja is associated with worse subjective outcomes. METHODS: We retrospectively analyzed all patients in our orthopedic trauma department between 2011 and 2020 who underwent tibial fracture fixation via intramedullary nailing via an infrapatellar/transtendinous approach. Pre- and postoperative lateral knee x-rays were evaluated by measurement of the Insall-Salvati Index, and nail tip position. All patients were asked to answer the self-assessment Kujala questionnaire and Lysholm questionnaire. RESULTS: We included 78 patients (age: 44 ± 18 years) with a minimum follow-up of 12 months. Mean follow up was 59 ± 25 months. We included 50 male and 28 female patients. Patella baja detected by Insall-Salvati Index could be observed in 8 (10.3%) patients. Patients with patella baja showed significant worse function measured by the Kujala score 54 ± 18 vs. 80 ± 14 (p < 0.01). Likewise, Lysholm score did show significant differences between both groups (60 ± 24 vs. 86 ± 11; p < 0.01). Nail tip position was not associated with worse subjective function. CONCLUSIONS: Patella baja in patients after tibial intramedullary nailing via an infrapatellar/transtendinous approach, is associated with worse subjective function and increased pain.

Applicability of Anatomic and Physiologic Scoring Systems for the Prediction of Outcome in Polytraumatized Patients with Blunt Aortic Injuries.

BACKGROUND: Most patients with blunt aortic injuries, who arrive alive in a clinic, suffer from traumatic pseudoaneurysms. Due to modern treatments, the perioperative mortality has significantly decreased. Therefore, it is unclear how exact the prediction of commonly used scoring systems of the outcome is. METHODS: We analyzed data on 65 polytraumatized patients with blunt aortic injuries. The following scores were calculated: injury severity score (ISS), new injury severity score (NISS), trauma and injury severity score (TRISS), revised trauma score coded (RTSc) and acute physiology and chronic health evaluation II (APACHE II). Subsequently, their predictive value was evaluated using Spearman´s and Kendall´s correlation analysis, logistic regression and receiver operating characteristics (ROC) curves. RESULTS: A proportion of 83% of the patients suffered from a thoracic aortic rupture or rupture with concomitant aortic wall dissection (54/65). The overall mortality was 24.6% (16/65). The sensitivity and specificity were calculated as the area under the receiver operating curves (AUC): NISS 0.812, ISS 0.791, APACHE II 0.884, RTSc 0.679 and TRISS 0.761. Logistic regression showed a slightly higher specificity to anatomical scoring systems (ISS 0.959, NISS 0.980, TRISS 0.957, APACHE II 0.938). The sensitivity was highest in the APACHE II with 0.545. Sensitivity and specificity for the RTSc were not significant. CONCLUSION: The predictive abilities of all scoring systems were very limited. All scoring systems, except the RTSc, had a high specificity but a low sensitivity. In our study population, the RTSc was not applicable. The APACHE II was the most sensitive score for mortality. Anatomical scoring systems showed a positive correlation with the amount of transfused blood products.

Clinical Outcome After Replacement of Distal Femur/Proximal Tibia in a Heterogeneous Patient Cohort: Function Following Tumour, Trauma, and Loosening.

BACKGROUND: Distal femur and proximal tibia replacements as limb-salvage procedures with good outcome parameters for patients with tumours have been broadly described. However, the overall midterm outcome in a mixed, heterogeneous patient collective is still unclear. PATIENTS AND METHODS: We retrospectively analysed 59 consecutive patients (33 for primary and 26 for revision surgery) between 1998 and 2017. Indication for implantation was tumour (n=16), periprosthetic fracture (n=14), traumatic fracture (n=14), infection (n=10), aseptic loosening (n=3), and pathological fracture (n=2). The mean follow-up duration was 3 years. Clinical functions were evaluated by Toronto Extremity Salvage Score and Knee Society Score. Knee extension and flexion force were measured. RESULTS: The overall survival rate of arthroplasties was 59% (n=35). Major complications were observed in 36 (61%) patients. During the follow-up period, 14 (24%) patients died. We recorded periprosthetic joint infection in 21 (36%) patients, recurrence of tumour in two (3%), and aseptic implant failure in three (5%). The mean Toronto Extremity Salvage Score was 66±33, and the mean Knee Society Score was 49±30. The mean extension force on the operated side was significantly reduced at 60° and 180° compared to the healthy side (p=0.0151 and p=0.0411, respectively). CONCLUSION: Distal femur and proximal tibia replacements showed limited clinical function in a heterogeneous patient collective. Indication for implantation should be considered carefully.

No Consequence for Lateral View X-Ray in Displaced Proximal Femoral Fractures in the Elderly.

Background: Due to demographic changes, proximal femoral fractures (PFF) in the elderly rise constantly. The standard diagnostic tool is still the X-ray of the pelvis/hip in two planes. Our hypothesis was that the lateral-view X-ray has little influence on classification, planning of the operative procedure, and choice of implant in geriatric patients. Methods: Retrospective analysis of all initial X-rays of PFF in geriatric patients (≥70 years) from May 2018 until August 2019 in a Level I Trauma center. Three experienced consultants categorized the fractures on the ap pelvis view and performed Garden and Pauwels classification as well as a two-staged classification displaced/nondisplaced [for femoral neck fractures (FNF)] or AO Classification [for intertrochanteric fractures (ITF)]. Afterward, they decided the operative strategy as well as implant choice [dynamic hip screw (DHS), intramedullary nail (IMN), or arthroplasty]. After 4 weeks, they categorized all fractures again with now available lateral view X-rays in a different order. Results: Two hundred seven patients (146 female, 61 male; 70.5 vs. 29.5%) with 90 FNF and 117 ITF (43.5 vs. 56.5%) could be included. Age was 84.6 ± 6.9 years. The treatment was in 45 cases DHS, in 82 cases IMN, and for the other 80 cases arthroplasty. The interobserver reliability of the classifications were poor, except for the two-staged classification [Fleiss-κ ap view only = 0.708 (CI 95% 0.604, 0.812) vs. additional lateral = 0.756 (CI 95% 0.644, 0.869)]. Moreover, independent from the classification, there were no significant changes in management and choice of implant with additional lateral view. Conclusions: Regarding our results, we consider the lateral view dispensable for standard X-ray of displaced PFF in geriatric patients. In nondisplaced fractures, it could be added secondary.

Direct measurement of malrotation of traumatic femoral neck fractures after osteosynthesis: Introduction of a novel method and interrater reliability.

BACKGROUND: In elderly patients, displaced femoral neck fractures are mostly treated by arthroplasty; however for younger patients (<50 years), open reduction and internal fixation is considered the gold standard approach. Despite there being no consensus on the specific procedure, everyday clinical practice in a level I trauma center has shown that postoperative maltorsion after internal fixation of femoral neck fractures can have a significantly worse impact on mobilization and outcome. Different methods for measurement of malrotations are reported in literature. However, any reported method for the assessment of a shaft malrotation in the femur does not work here. In femoral neck fractures, the pointer function of the femoral neck, which is absolutely essential for these techniques, is lost and cannot be set in relation to the condylar plane. These circumstances are not addressed in literature thus far. Therefore, we propose here a novel method to fill this diagnostic gap. METHODS AND FINDINGS: Three investigators (1 orthopaedic surgeons and 2 radiologists) measured the torsion of 20 legs on 10 patients using the Jarret method and a new geometric technique. To determine the intraobserver reliability the torsional angles were calculated again after 3 months. We applied a new geometric technique, without the need to include the femoral condyles in the measurement, to directly measure the angulation. For torsional difference, the interrater reliability -ICC (interclass correlation) between all investigators was 0.887 (good) (significance level: 95%CI, 0.668-0.969; p<0.001), by using the method of Jarret et al. and 0.933 (good) for the novel technique (significance level: 95%CI, 0.802-0.982; p<0.001). If the examinations are classified according to the patient side, our data show that for established methods, an ICC between the examiners on the right lower extremity is 0.978 (good) (95%CI, 0.936-0.994; p<0.001) and that on the left extremity is 0.955 (good) (95%CI, 0.867-0.988; p<0.001). Comparing with the new method, the right side assumes an ICC of 0.971 (good) (95%CI, 0.914-0.992; p<0.001), while the left side assumes an ICC of 0.910 (good) (95%CI, 0,736-0.976; p<0.001). When it comes to the intraobserver reliability, the measured cohort shows a significant better ICC for the novel method compared to Jarrett et al, with 0.907 respectively 0.786 for comparison in torsional differences. CONCLUSION: The established methods may fail in assessing this special aspect of malrotation after femoral neck fractures. Here, the method presented results in a significant difference between the injured and uninjured side and shows significant differences in results compared to conventional measurement methods. The inter- and intraobserver reliability determined in this study is excellent and even higher in the assessment of torsional differences than the established method. We believe that the measurement method presented in this study is a useful tool to objectify the postoperative deformities in this area and making therapy recommendations in the future.

A Retrospective Analysis of the Initial Effect of COVID-19 on German Prehospital Care During Lockdown in Germany.

INTRODUCTION: This retrospective cohort analysis examines the impact of the COVID-19 pandemic in the prehospital setting in Germany. The data of two emergency physician response units of a northern German region with 1.2 million citizens was analyzed retrospectively. MATERIALS AND METHODS: We analyzed the period March 16 to April 16 for the year 2020 when the lockdown took place in Germany and compare the results for the same period for the year 2019 and 2018. 1004 patients were included. Demographic data, the type of rescue missions, the number of missions per day, the National Advisory Committee for Aeronautics Score (NACA-score), the frequency of respiratory emergencies (COVID-19 and non-COVID-19 associated), as well as the number of deaths were documented. RESULTS: Mean age was 62.3±24.8 years and 576 (56.5%) were male. Number of missions were 397, 403 and 333 in 2018, 2019 and 2020 respectively. The control room registered a 22% reduction of rescue missions for the year 2020. Even the amount of emergency calls via the emergency number 112 was reduced by 17.4% between 2018 and 2020. 150 (14.9%) missions were due to respiratory emergencies. In 2020 10 missions (28.6% of respiratory emergencies) were COVID-19 related. In 2020 the NACA score increased significantly. CONCLUSION: We found a decreasing effect of the COVID-19 pandemic in Germany on the number of emergency calls as well as missions, and an increase of the severity of cases in preclinical care for a northern German region with 1.2 million citizens. The effect of these findings caused by COVID-19 on the health care system remains to be seen.