An unusual cause of ankle pain: fracture of a talocalcaneal coalition as a differential diagnosis in an acute ankle sprain: a case report and literature review

Background: The acute ankle sprain is one of the most common injuries seen in trauma departments. Ankle sprains have an incidence of about one injury per 10 000 people a day. In contrast tarsal coalition is a rare condition occurring in not more than one percent of the population. Case presentation: We present the case of a 23 year old male patient with pain and local swelling after an acute ankle sprain. Initial clinical and radiological examination showed no pathologies. Due to prolonged pain, swelling and the inability of the patient to weight bear one week after trauma further diagnostics was performed. Imaging studies (MRI and CT) revealed a fracture of a talocalcaneal coalition. To the knowledge of the authors no fracture of a coalition was reported so far. Conclusion: This report highlights the presentation of symptomatic coalitions following trauma and furthermore, it points out the difficulties in the diagnosis and treatment of a rare entity after a common injury. A diagnostic algorithm has been developed to ensure not to miss a severe injury.<br

Instability of the posterior pelvic ring: introduction of innovative implants

Grüneweller N, Wähnert D, Vordemvenne T. Instability of the posterior pelvic ring: introduction of innovative implants. Journal of Orthopaedic Surgery and Research. 2021;16(1):625.BACKGROUND: Increasing numbers of posterior pelvic ring fractures, especially in elderly patients, demonstrate the need for soft tissue protecting surgical techniques. Standard of care is iliosacral screw osteosynthesis. This type of osteosynthesis has its limitations especially in patients with reduced bone properties. Therefore, the development of new and straightforward surgical techniques and implant designs is favorable.; METHODS: Introducing this modular system for the posterior pelvic ring, known complications of iliosacral screw osteosynthesis, such as implant loosening and malpositioning may be reduced, due to innovative mechanical characteristics.; RESULTS: The shown cases demonstrate the potential benefits of the system with a wide range of treatment options due to its modularity.; CONCLUSION: The modular implant system presented here can significantly facilitate and improve the stabilization of posterior pelvic ring instabilities. © 2021. The Author(s)

Removal of cement-augmented screws in distal femoral fractures and the effect of retained screws and cement on total knee arthroplasty: a biomechanical investigation

Wähnert D, Grüneweller N, Gueorguiev B, Vordemvenne T, Gehweiler D. Removal of cement-augmented screws in distal femoral fractures and the effect of retained screws and cement on total knee arthroplasty: a biomechanical investigation. Journal of Orthopaedics and Traumatology. 2021;22(1): 5.**Background** Given the increasing number of osteoporotic fractures of the distal femur, screw augmentation with bone cement is an option to enhance implant anchorage. However, in implant removal or revision surgeries, the cement cannot be removed from the distal femur without an extended surgical procedure. Therefore, the aims of this study were to investigate (1) whether cement augmentation has any influence on screw removal and removal torque, and (2) whether the implantation of a femoral component of a knee arthroplasty and its initial interface stability are affected by the remaining screws/cement. **Material and methods** Eight pairs of fresh-frozen human female cadaveric distal femurs (mean age, 86 years) with a simulated AO/OTA 33 A3 fracture were randomized in paired fashion to two groups and fixed with a distal femoral locking plate using cannulated perforated locking screws. Screw augmentation with bone cement was performed in one of the groups, while the other group received no screw augmentation. Following biomechanical testing until failure (results published separately), the screws were removed and the removal torque was measured. A femoral component of a knee arthroplasty was then implanted, and pull-out tests were performed after cement curing. Interference from broken screws/cement was assessed, and the maximum pull-out force was measured. **Results** The mean screw removal torque was not significantly different between the augmented (4.9 Nm, SD 0.9) and nonaugmented (4.6 Nm, SD 1.3,p = 0.65) screw groups. However, there were significantly more broken screws in in the augmented screw group (17 versus 9;p p = 0.94) screw groups. **Conclusion** The screw removal torque during implant removal surgery does not significantly differ between augmented and nonaugmented screws. In the augmented screw group, significantly more screws failed. To overcome this, the use of solid screws in holes B, C, and G can be considered. Additionally, it is possible to implant a femoral component for knee arthroplasty that retains the initial anchorage and does not suffer from interference with broken screws and/or residual cement. **Level of Evidence**

Medicine for people with disabilities : Special features of trauma surgical care of extremity injuries in people with severe mental and physical disabilities

Grüneweller N, Wähnert D, Schillians N, Komadinic A, Vordemvenne T. Medizin für Menschen mit Behinderungen. Besonderheiten in der unfallchirurgischen Versorgung von Extremitätenverletzungen bei Menschen mit schwerer geistiger und körperlicher Behinderung. Der Unfallchirurg. 2021.The v. Bodelschwingh Foundation Bethel can look back on atradition of more than 150 years in the treatment of people with disabilities. The trauma patient collective is regularly characterized by the most severe mental and physical developmental disorders and (multiple) disabilities, with and without behavioral disorders and concomitant internal diseases. This special combination requires treatment and indication assessment both medically and in nursing, which must be specifically weighed up and adapted in all treatment steps. Treatment guidelines or recommendations for this patient group do not exist in the literature. Furthermore, the treatment of fractures in people with disabilities cannot always follow established concepts. Due to ahigh postoperative complication rate, conservative treatment plays acrucial role. The decision for surgical treatment must be made on an interdisciplinary and individual basis, taking all factors into account. Special attention must be paid to the procedure to be chosen (stability, functional needs). © 2021. The Author(s)

Stabilization of Traumatic Iliosacral Instability Using Innovative Implants: A Biomechanical Comparison

Grüneweller N, Leunig J, Zderic I, Gueorguiev B, Wähnert D, Vordemvenne T. Stabilization of Traumatic Iliosacral Instability Using Innovative Implants: A Biomechanical Comparison. Journal of Clinical Medicine. 2023;13(1): 194.(1) Background: Demographic changes over the past decade have had a significant impact on pelvic ring fractures. They have increased dramatically in the orthogeriatric population. Surgeons are faced with implant fixation issues in the treatment of these fragility fractures. This study compares two innovative implants for stabilizing the iliosacral joint in a biomechanical setting. (2) Methods: An iliosacral screw with a preassembled plate allowing the placement of an additional short, angular stable screw in the ilium and a triangular fixation system consisting of a fenestrated ilium screw and an iliosacral screw quasi-statically inserted through the "fenestra" were instrumented in osteoporotic artificial bone models with a simulated Denis zone 1 fracture. Biomechanical testing was performed on a servo-hydraulic testing machine using increasing, synchronous axial and torsional sinusoidal cyclic loading to failure. (3) Results: The SI-Plate and TriFix showed comparable stiffness values. The values for fracture gap angle and screw tip cutout were significantly lower for the TriFix compared to the SI-Plate. In addition, the number of cycles to failure was significantly higher for the TriFix. (4) Conclusions: Implant anchorage and primary stability can be improved in iliosacral instability using the triangular stabilization system

Impact of the First and Second Wave of the SARS-CoV-2 Pandemic on Severe Trauma and the Care Structures in the German TraumaNetzwerk DGU®

Colcuc C, Fischer S, Leimkühler P, et al. Impact of the First and Second Wave of the SARS-CoV-2 Pandemic on Severe Trauma and the Care Structures in the German TraumaNetzwerk DGU®. Journal of Clinical Medicine. 2022;11(23): 7036.(1) Background: The aim of this study was to investigate the effects of the pandemic on transfer rates of severely injured patients within the German TraumaNetzwerk of the DGU. Furthermore, cause of accident, rescue times, and trauma cases are compared to pre-pandemic times. (2) Methods: For this investigation patients documented in the TraumaRegister DGU® from 2018 to 2020 were analyzed. The years 2018 and 2019 served as a comparison to 2020, the first COVID-19 pandemic year. All primary admissions and transfers were included if treated on an intensive care unit. (3) Results: Demographics (age, sex) and injury severity in 2020 were comparable with 2018/2019. In 2020, a significant decrease (3.7%) in car accidents was found. In contrast, a significant increase (3.2%) in bicycle accidents was seen. During the second wave, there was a significant burden of COVID-19 patients on hospitals. In this time, we found a significant increase in early transfers of trauma patients primarily from small level 3 to large level 1 centers. There was also a small but significant increase in rescue time, especially during the 2nd wave. (4) Conclusions: Our data confirm the importance of the network structures established in the TraumaNetzwerk DGU®, especially during the pandemic. The established structures allow smaller hospitals to spread their resources and prevent internal collapse. Therefore, the structures of the TraumaNetzwerk DGU® play a prominent role in stabilizing the healthcare system by helping to maintain both surgical and critical care capacity and providing adequate emergency care

Substitutional semi-rigid osteosynthesis technique for treatment of unstable pubic symphysis injuries: a biomechanical study

Berk T, Zderic I, Varga P, et al. Substitutional semi-rigid osteosynthesis technique for treatment of unstable pubic symphysis injuries: a biomechanical study. European Journal of Trauma and Emergency Surgery . 2023.BACKGROUND/PURPOSE: The surgical fixation of a symphyseal diastasis in partially or fully unstable pelvic ring injuries is an important element when stabilizing the anterior pelvic ring. Currently, open reduction and internal fixation (ORIF) by means of plating represents the gold standard treatment. Advances in percutaneous fixation techniques have shown improvements in blood loss, surgery time, and scar length. Therefore, this approach should also be adopted for treatment of symphyseal injuries. The technique could be important since failure rates, following ORIF at the symphysis, remain unacceptably high. The aim of this biomechanical study was to assess a semi-rigid fixation technique for treatment ofsuch anterior pelvic ring injuries versus current gold standards of plate osteosynthesis.; METHODS: An anterior pelvic ring injury type III APC according to the Young and Burgess classification was simulated in eighteen composite pelvises, assigned to three groups (n=6) for fixation with either a single plate, two orthogonally positioned plates, or the semi-rigid technique using an endobutton suture implant. Biomechanical testing was performed in a simulated upright standing position under progressively increasing cyclic loadingat 2Hz until failure or over 150,000cycles. Relative movements between the bone segments were captured by motion tracking.; RESULTS: Initial quasi-static and dynamic stiffness, as well as dynamic stiffness after 100,000 cycles, was not significantly different among the fixation techniques (p≥0.054).). The outcome measures for total displacement after 20,000, 40,000, 60,000, 80,000, and 100,000 cycles were associated with significantly higher values for the suture technique versus double plating (p=0.025), without further significant differences among the techniques (p≥0.349). Number of cycles to failure and load at failure were highest for double plating (150,000±0/100.0±0.0 N), followed by single plating (132,282±20,465/91.1±10.2 N), and the suture technique (116,088±12,169/83.0±6.1 N), with significantly lower values in the latter compared to the former (p=0.002)and nofurther significant differences among the techniques (p≥0.329).; CONCLUSION: From a biomechanical perspective, the semi-rigid technique for fixation of unstablepubic symphysis injuries demonstrated promising results with moderate to inferior behaviour compared to standard plating techniques regarding stiffness, cycles to failureand load atfailure. This knowledge could lay the foundation for realization offurther studies with larger sample sizes, focusing on the stabilization of the anterior pelvic ring. © 2023. The Author(s)