Early Stabilization Does Not Increase Complication Rates in Acetabular Fractures of the Elderly: A Retrospective Analysis from the German Pelvis Registry.

Background: The incidence of acetabular fractures in geriatric patients has increased. Although there are strong data supporting the early operative treatment of hip fractures in geriatric patients, the optimal timing for acetabular fractures remains unclear and for several reasons, delayed treatment after trauma is common. Methods: A retrospective analysis of the German Pelvis Registry between 2008 and 2017 was performed. Ultimately, 665 patients with fractures of the anterior column or anterior column and posterior hemitransverse were enrolled. Patients above and below 65 years of age with these fracture types were analyzed regarding surgery day (within 48 hours, between 2 and 4 days, after 4 days), complication rate, reduction quality, and hospital stay. Results: The complication rate of the geriatric group was twice as high as that of younger patients; however, this finding was independent of the timing of surgery. Reduction quality and hospital stay were independent of surgical timing. Conclusions: In contrast to other fracture types, such as proximal femur fractures, the timing of surgery for acetabular fractures does not have a significant impact on the patient's outcome. The optimal time for surgery cannot be determined using the current data. However, as expected, there is a significantly higher risk for postoperative complications in the geriatric population.

[Infected pseudarthrosis of the symphysis with persisting instability : Revision osteosynthesis with tantalum cage and silver ionized ITS plate after peri-implant infection with MRSE after osteosynthetic stabilization of a type C pelvic injury]. / Symphyseninstabilität mit Infekt : Rekonstruktion mittels Tantalum-Cage und silberbeschichteter ITS-Platte nach periimplantärem Infekt mit MRSE nach osteosynthetischer Stabilisierung einer Becken-C-Verletzung.

Overall symptomatic pseudathrosis after pelvic ring fracture is rare. A pseudarthrosis of the dorsal pelvic ring often leads to persisting pain due to instability and needs a consequent treatment strategy. Often a bacterial infection can be found in persisting pseudarthrosis notably in the anterior pelvic ring region. It is assumed that the peculiar anatomical site of the surgical approach - pubic region and abdominal skinfold - in particular accompanied with adipositas is predestined. Often patients with pseudathrosis and proof of bacterial infection show no symptoms. In these cases treatment is not mandatory. Patients however who complain about persisting pain limited treatment options exist.The following case report demonstrates a treatment strategy to achieve pelvic ring stability and infection eradication using a silver ionised plate and screws as well as a tantalum cage.

Treatment options in non-unions of the pelvis: A retrospective analysis of a single center experience over 12 years.

BACKGROUND: Non-unions and chronic instability of the pelvis remain rare complications after complex high velocity injuries with vertical and rotational instability of the pelvis. Treatment options are insufficiently supported by data evidence due to the rareness of this condition. PATIENTS AND METHODS: we conducted a single center, retrospective study of all non-unions and pelvic instabilities between 1.1.2008 and 1.1.2019, excluding fragility fractures. Patients' characteristics, fracture patterns, procedures and outcomes with regard to developing treatment options and successful union in the follow-up were obtained. RESULTS: 26 patients were included in this retrospective analysis. The mean age was 55 years (range 34-78 years). Seventy-seven percent of the patients were male. The standard procedure consisted of radical debridement of the non-union, interposition of autologous bone graft and rigid stabilization systems. Three patients were lost to follow up. In the remaining n = 23 patients (88%) consolidation of the non-union was achieved. The mean follow up was 31.3 months (range 6-144). Follow up showed that an iliolumbar fixation seems to be favorable regarding outcome and complications. DISCUSSION: Non-union and remaining instability of the pelvic ring represent a rare complication after high grade pelvic trauma. There are only limited data regarding the incidence and the treatment regimen is based on small study populations only. Based on our findings we recommend to combine autologous bone grafts with rigid fixation systems especially for non-union of the pelvis to restore the posterior sacroiliac arch.

Patients with complex proximal tibial fractures overestimate the prognosis of their injury.

PURPOSE: To investigate, if patients with complex proximal tibial fracture have realistic expectations on open reduction and internal fixation. METHODS: 114 patients (mean 49 years, SD ± 13) with closed AO-type B and C proximal tibial fracture were grouped (group B, respectively C). Prior to surgery expectations concerning knee function, pain, return to work/sports, and the risk for osteoarthritis was assessed with the Hospital for Special Surgery-Knee Surgery Expectations Survey (HFSS-KSE) and a non-validated ten-item survey. RESULTS: 92% of patients expected at least an almost natural knee postoperatively. All items regarding restoring knee function were ranked to be at least important in both groups. 65% in group B and 47% in group C expected at most occasional pain. 83% in group B and 67% in group C expected full return to work without any limitations. Patients with low physical work intensity expected significantly shorter incapacity to work in both groups (7.8, respectively 8.9 weeks). 71% in group B and 60% in group C expected to return to sports with at most small limitations. 33% in group B and 22% in group C assumed risk for osteoarthritis will be prevented by surgery. CONCLUSION: Expectations on surgery for complex proximal tibial fracture are high regardless of fracture type. The prognosis of many health and lifestyle domains was overestimated. The risk for osteoarthritis was underestimated. This study should sensitize surgeons to discuss realistic expectations. This may help to improve patient comprehension what leads to sensible expectations, resulting in improved patients´ satisfaction. LEVEL OF EVIDENCE: IV. TRIAL REGISTRATION NUMBER: 14104, Date of registration: 06/2015.

[Das unterschätzte Verletzungsrisiko beim Freizeitschlittenfahren]. / Das unterschätzte Verletzungsrisiko beim Rodeln im Freizeitsport.

BACKGROUND: Sledding is generally considered to be a relatively harmless winter leisure activity. The increased incidence of injuries, some of them severe, in our emergency department in the catchment area of several sledding slopes prompted an analysis of this patient population with respect to frequency and severity of injuries. PATIENTS AND METHODS: Based on the hospital documentation system, a retrospective evaluation of all emergency department visits in the winters 2016-2019 was performed. The words "sled", "sledge", "bob", "sledding", "sleighing", "sledging" were used as keywords, and the recorded data were analyzed with respect to outpatient treatment, inpatient treatment, inpatient treatment days, treatment days in the intensive care unit, number of necessary operations, injury patterns, and injury severity. RESULTS: A total of 175 injured patients were recorded over the 3­year period. In 94 patients (54%) the injury was classified as mild, 70 patients (40%) required inpatient treatment with an average length of stay of 8 days, resulting in a total of 590 inpatient treatment days. Surgical treatment was given to 49 (28%) of the injured with a total of 66 operations, 81 patients suffered from severe injuries up to multiple trauma with an injury severity score (ISS) of 34. DISCUSSION: The study demonstrates that sledding has a significantly higher injury potential than generally assumed and that the resulting costs and consequences of accidents are relevant. Especially on the designated sledge slopes, an increase in safety standards could be achieved through appropriate measures and rules.

Endoscopically assisted implant removal of a symphyseal pelvic plate - A case report.

INTRODUCTION: The approach-related morbidity rate in the care of pelvic fractures is still high. Endoscopic procedures are known to significantly reduce access-related complications. Recently, a new endoscopically assisted implantation technique for plate osteosynthesis on the anterior pelvic ring has been described as the "Endoscopic Approach to the Symphysis". CASE REPORT: We present a case of a 29-year old male with a pelvic injury (AO type 61B2.3a) initially treated with a supraacetabular external fixator. After one week the definitive stabilization was performed by an endoscopically assisted symphyseal plating as well as a percutaneous iliosacral screw on the right side. One year after primary surgery, we performed an endoscopically assisted removal of the symphyseal plate using standard laparoscopic instruments. RESULTS: We demonstrate the feasibility of an endoscopically assisted implant removal at the anterior pelvic ring. No complications occurred during the procedure. The patient was discharged after a regular time of surveillance and with an adequate decline of pain. DISCUSSION: While we were able to show that the endoscopically assisted implantation as well as the removal of a plate osteosynthesis on the anterior pelvic ring is possible, there is still further research necessary, especially regarding the development of specific endoscopic instruments. This should enable operating times similar to the standard open procedures.

FOOTPRINTS study protocol: rationale and methodology of a 3-year longitudinal observational study to phenotype patients with COPD.

INTRODUCTION: A better understanding is needed of the different phenotypes that exist for patients with chronic obstructive pulmonary disease (COPD), their relationship with the pathogenesis of COPD and how they may affect disease progression. Biomarkers, including those associated with emphysema, may assist in characterising patients and in predicting and monitoring the course of disease. The FOOTPRINTS study (study 352.2069) aims to identify biomarkers associated with emphysema, over a 3-year period. METHODS AND ANALYSIS: The FOOTPRINTS study is a prospective, longitudinal, multinational (12 countries), multicentre (51 sites) biomarker study, which has enrolled a total of 463 ex-smokers, including subjects without airflow limitation (as defined by the 2015 Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy report), patients with COPD across the GOLD stages 1-3 and patients with COPD and alpha1-antitrypsin deficiency. The study has an observational period lasting 156 weeks that includes seven site visits and additional phone interviews. Biomarkers in blood and sputum, imaging data (CT and magnetic resonance), clinical parameters, medical events of special interest and safety are being assessed at regular visits. Disease progression based on biomarker values and COPD phenotypes are being assessed using multivariate statistical prediction models. ETHICS AND DISSEMINATION: The study protocol was approved by the authorities and ethics committees/institutional review boards of the respective institutions where applicable, which included study sites in Belgium, Canada, Denmark, Finland, Germany, Japan, Korea, Poland, Spain, Sweden, UK and USA; written informed consent has been obtained from all study participants. Ethics committee approval was obtained for all participating sites prior to enrolment of the study participants. The study results will be reported in peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT02719184.

An inkjet-printed polysaccharide matrix for on-chip sample preparation in point-of-care cell counting chambers.

On-chip sample preparation in self-contained microfluidic devices is a key element to realize simple, low-cost, yet reliable in vitro diagnostics that can be carried out at the point-of-care (POC) with minimal training requirements by unskilled users. To address this largely unmet POC medical need, we have developed an optimized polysaccharide matrix containing the reagents which substantially improves our fully printed POC CD4 counting chambers for the monitoring of HIV patients. The simply designed counting chambers allow for capillary-driven filling with unprocessed whole blood. We carefully tailored a gellan/trehalose matrix for deposition by inkjet printing, which preserves the viability of immunostains during a shelf life of at least 3 months and enables controlled antibody release for intense and homogeneous immunofluorescent cell staining throughout the complete 60 mm2 image area within 30 min. Excellent agreement between CD4 counts obtained from our fully printed CD4 counting chambers and the gold standard, flow cytometry, is demonstrated using samples both from healthy donors and HIV-infected patients.

All-printed cell counting chambers with on-chip sample preparation for point-of-care CD4 counting.

We demonstrate the fabrication of fully printed microfluidic CD4 counting chips with complete on-chip sample preparation and their applicability as a CD4 counting assay using samples from healthy donors and HIV-infected patients. CD4 counting in low-income and resource-limited point-of-care settings is only practical and affordable, if disposable tests can be fabricated at very low cost and all manual sample preparation is avoided, while operation as well as quantification is fully automated and independent of the skills of the operator. Here, we show the successful use of (inkjet) printing methods both to fabricate microfluidic cell counting chambers with controlled heights, and to deposit hydrogel layers with embedded fluorophore-labeled antibodies for on-chip sample preparation and reagent storage. The maturation process of gelatin after deposition prevents antibody wash-off during blood inflow very well, while temperature-controlled dissolution of the matrix ensures complete antibody release for immunostaining after the inflow has stopped. The prevention of antibody wash-off together with the subsequent complete antibody release guarantees a homogeneous fluorescence background, making rapid and accurate CD4 counting possible. We show the successful application of our fully printed CD4 counting chips on samples from healthy donors as well as from HIV-infected patients and find an excellent agreement between results from our method and from the gold standard, flow cytometry, in both cases.

Temperature-Switch Cytometry-Releasing Antibody on Demand from Inkjet-Printed Gelatin for On-Chip Immunostaining.

Complete integration of all sample preparation steps in a microfluidic device greatly benefits point-of-care diagnostics. In the most simplistic approach, reagents are integrated in a microfluidic chip and dissolved upon filling with a sample fluid by capillary force. This will generally result in at least partial reagent wash-off during sample inflow. However, many applications, such as immunostaining-based cytometry, strongly rely on a homogeneous reagent distribution across the chip. The concept of initially preventing release (during inflow), followed by a triggered instantaneous and complete release on demand (after filling is completed) represents an elegant and simple solution to this problem. Here, we realize this controlled release by embedding antibodies in a gelatin layer integrated in a microfluidic chamber. The gelatin/antibody layer is deposited by inkjet printing. Maturation of this layer during the course of several weeks, due to the ongoing physical cross-linking of gelatin, slows down the antibody release, thereby reducing antibody wash-off during inflow, and consequently helping to meet the requirement for a homogeneous antibody distribution in the filled chamber. After inflow, complete antibody release is obtained by heating the gelatin layer above its sol-gel transition temperature, which causes the rapid dissolution of the entire gelatin/antibody layer at moderate temperatures. We demonstrate uniform and complete on-chip immunostaining of CD4 positive (CD4+) T-lymphocytes in whole blood samples, which is critical for accurate cell counts. The sample preparation is realized entirely on-chip, by applying temperature-switched antibody release from matured gelatin/antibody layers.

Controlled antibody release from gelatin for on-chip sample preparation.

A practical way to realize on-chip sample preparation for point-of-care diagnostics is to store the required reagents on a microfluidic device and release them in a controlled manner upon contact with the sample. For the development of such diagnostic devices, a fundamental understanding of the release kinetics of reagents from suitable materials in microfluidic chips is therefore essential. Here, we study the release kinetics of fluorophore-conjugated antibodies from (sub-) µm thick gelatin layers and several ways to control the release time. The observed antibody release is well-described by a diffusion model. Release times ranging from ∼20 s to ∼650 s were determined for layers with thicknesses (in the dry state) between 0.25 µm and 1.5 µm, corresponding to a diffusivity of 0.65 µm(2) s(-1) (in the swollen state) for our standard layer preparation conditions. By modifying the preparation conditions, we can influence the properties of gelatin to realize faster or slower release. Faster drying at increased temperatures leads to shorter release times, whereas slower drying at increased humidity yields slower release. As expected in a diffusive process, the release time increases with the size of the antibody. Moreover, the ionic strength of the release medium has a significant impact on the release kinetics. Applying these findings to cell counting chambers with on-chip sample preparation, we can tune the release to control the antibody distribution after inflow of blood in order to achieve homogeneous cell staining.

Vascularized Hypothenar Fat Pad Flap in Revision Surgery for Carpal Tunnel Syndrome.

OBJECTIVE: To evaluate the results of the hypothenar fat pad flap in revision surgery for carpal tunnel syndrome (CTS). PATIENTS AND METHODS: We retrospectively analyzed 18 consecutive patients (14 women, 4 men) who had recurrent CTS. The average age was 61 years. All patients had undergone the index carpal tunnel release 5 to 22 months ago. From November 2009 to November 2013, they were treated by decompression of the median nerve and a vascularized hypothenar fat pad flap. The intraoperative findings were assessed as well as the level of pain, recovery of sensory and motor dysfunction, Hoffmann-Tinel sign, nerve conduction studies, grip and pinch strength, and Disability of Hand and Shoulder Questionnaire (DASH) score. All patients were reevaluated at an average of 22 months after revision surgery. RESULTS: After revision surgery, 15 patients reported symptomatic improvement. No patient reported worsening of symptoms. A median DASH score of 18 was reached. Grip strength recovered to 90% of the contralateral side. Overall, 15 patients were satisfied with the result of the operation; 3 did not cope with pain and dysfunction. Recurrence was not found in any case. CONCLUSION: The hypothenar fat pad flap can be used successfully as an adjunct to microsurgical neurolysis for the treatment of recurrent CTS secondary to perineural scarring, although a functional deficit remains in some patients.

Filtration parameters influencing circulating tumor cell enrichment from whole blood.

Filtration can achieve circulating tumor cell (CTC) enrichment from blood. Key parameters such as flow-rate, applied pressure, and fixation, vary largely between assays and their influence is not well understood. Here, we used a filtration system, to monitor these parameters and determine their relationships. Whole blood, or its components, with and without spiked tumor cells were filtered through track-etched filters. We characterize cells passing through filter pores by their apparent viscosity; the viscosity of a fluid that would pass with the same flow. We measured a ratio of 5·10(4)∶10(2)∶1 for the apparent viscosities of 15 µm diameter MDA-231 cells, 10 µm white cells and 90 fl red cells passing through a 5 µm pore. Fixation increases the pressure needed to pass cells through 8 µm pores 25-fold and halves the recovery of spiked tumor cells. Filtration should be performed on unfixed samples at a pressure of ∼10 mbar for a 1 cm(2) track-etched filter with 5 µm pores. At this pressure MDA-231 cells move through the filter in 1 hour. If fixation is needed for sample preservation, a gentle fixative should be selected. The difference in apparent viscosity between CTC and blood cells is key in optimizing recovery of CTC.

Filter characteristics influencing circulating tumor cell enrichment from whole blood.

A variety of filters assays have been described to enrich circulating tumor cells (CTC) based on differences in physical characteristics of blood cells and CTC. In this study we evaluate different filter types to derive the properties of the ideal filter for CTC enrichment. Between 0.1 and 10 mL of whole blood spiked with cells from tumor cell lines were passed through silicon nitride microsieves, polymer track-etched filters and metal TEM grids with various pore sizes. The recovery and size of 9 different culture cell lines was determined and compared to the size of EpCAM+CK+CD45-DNA+ CTC from patients with metastatic breast, colorectal and prostate cancer. The 8 µm track-etched filter and the 5 µm microsieve had the best performance on MDA-231, PC3-9 and SKBR-3 cells, enriching >80% of cells from whole blood. TEM grids had poor recovery of ∼25%. Median diameter of cell lines ranged from 10.9-19.0 µm, compared to 13.1, 10.7, and 11.0 µm for breast, prostate and colorectal CTC, respectively. The 11.4 µm COLO-320 cell line had the lowest recovery of 17%. The ideal filter for CTC enrichment is constructed of a stiff, flat material, is inert to blood cells, has at least 100,000 regularly spaced 5 µm pores for 1 ml of blood with a ≤10% porosity. While cell size is an important factor in determining recovery, other factors must be involved as well. To evaluate a filtration procedure, cell lines with a median size of 11-13 µm should be used to challenge the system.

Phenoloxidase activity acts as a mosquito innate immune response against infection with Semliki Forest virus.

Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell- conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses.

Reliability and consequences of intraoperative 3D imaging to control positions of thoracic pedicle screws.

INTRODUCTION: The insertion of thoracic pedicle screws (T1-T10) is subject to a relevant rate of malplacement. The optimum implantation procedure is still a topic of controversial debate. Currently, a postoperative computed tomography is required to evaluate the screw positions. The present study was undertaken to clarify whether intraoperative 3D imaging is a reliable method of determining the position of thoracic pedicle screws. METHODS: This prospective study involved 40 consecutive patients with thoracic spinal injuries, with intraoperative 3D scans being performed to determine the positions of 240 pedicle screws in T1-T10. The results of the 3D scans were compared with the findings of postoperative CT scans, using a clinical classification system. RESULTS: The positions of 204 pedicle screws could be viewed by means of both 3D and CT scans and the results compared. The 3D scans achieved a sensitivity of 90.9 % and a specificity of 98.8 %. The rate of misclassification by the 3D scans was 2.5 %. Nine pedicle screws were classified as misplaced and their position corrected intraoperatively (3.8 %). No screws required postoperative revision. CONCLUSIONS: Performing an intraoperative 3D scan enables the position of thoracic pedicle screws to be determined with sufficient accuracy. The rate of revision surgery was reduced to 0 %.

Erythropoietin enhances the regeneration of traumatized tissue after combined muscle-nerve injury.

BACKGROUND: Erythropoietin (EPO) is a pleiotropic cytokine with neuroprotective, anti-inflammatory, and muscle regenerative properties. The purpose of our study was to analyze the regenerative capacity of systemically applied EPO in a combined muscle-nerve injury model. METHODS: We performed a crush injury to the left soleus muscle in 84 male Wistar rats. Using an instrumented clamp, the muscle was crushed over its complete length. Simultaneously, the ipsilateral sciatic nerve was sham manipulated or crushed. Upon induction of the trauma, animals received either EPO (E) (single application of 5,000 IU/kg body weight intraperitonial) or vehicle solution (K). After in vivo assessment of mechanical pain according to Frey, thermal hyperalgesia, latency of nerve conduction velocity, and strength of the soleus muscle were analyzed at days 1, 7, and 42 postinjury (n = 7 per group). Cell proliferation and apoptosis were assessed by means of histology and immunohistochemistry. RESULTS: Combined muscle-nerve injury showed a significant loss of muscle strength, which incompletely recovered within 42 days. Rats treated with EPO showed an increased muscle strength after 7 days and 42 days compared with the control group. Pain behavior was highest in the muscle-nerve injured animals at day 7. EPO decreased the pain and increased nerve conduction velocity. Nerve injury diminished proliferation of muscle cells, whereas simultaneous therapy with EPO resulted in a boost of bromdesoxyuridine-positive cells. CONCLUSIONS: EPO promoted muscle restoration and enhanced nerve recovery after combined muscle-nerve injury. Thus, EPO might represent an attractive therapeutic option to optimize the posttraumatic course after injury.

Hook plate fixation for acromioclavicular joint separations restores coracoclavicular distance more accurately than PDS augmentation, however presents with a high rate of acromial osteolysis.

INTRODUCTION: Hook plate fixation of acromioclavicular (AC) joint separations carries the disadvantage of compulsory implant removal, occasional implant fatigue and secondary loss of reduction. This study compares the clinical and radiological outcome of a new polyaxial angular stable hook plate (HP) with absorbable polydioxansulfate (PDS) sling. MATERIALS AND METHODS: Between 2002 and 2009, out of a consecutive series of 81 patients with symptomatic Rockwood type V lesions 52 patients received clinical and radiographic follow-up (HP: n = 27; PDS: n = 25). HP patients were prospectively analyzed and retrospectively compared with the PDS group. Radiological follow-up included comparative coraco- and acromioclavicular distance (CCD/ACD) measurements as percentage of the uninjured shoulder. For clinical follow-up a standardized functional shoulder assessment with Constant Score, DASH Score, Taft Score and a self-report questionnaire including the visual analog scale (VAS) was carried out. RESULTS: Direct postoperative radiographs showed an overcorrection of CCD in the HP group (-4.4% of the uninjured side) and failure of anatomic correction in the PDS group (+11.0%). After implant removal, CCD increased in the HP group extensively to 16.7% (overall loss of reduction: 21.1%) and 23.9% in the PDS group. Redisplacement (100% increase of CCD) occurred in five cases (HP: 2, PDS: 3) and partial loss of reduction in four cases of each group. Comparing functional results no differences could be seen between both the groups (Constant-Score HP: 91.2 points, PDS: 94.6 points; Taft-Score HP: 9.4 points, PDS: 10.0 points). The DASH-Score revealed better results for PDS group (3.4 points, HP: 8.0 points). Signs of acromial osteolysis appeared in five cases (18.5%) in HP group. There was no case of implant failure. The X-rays of six patients (HP: 4, PDS: 2) showed AC-joint-osteoarthritis. CONCLUSION: Hook plate fixation employing a polyaxial angular stable plate finally restores the coracoclavicular distance more accurately than augmentation with a PDS sling. Although in HP group no implant failure occurred, major disadvantages are initial overcorrection and acromial osteolysis. Both have no influence on final functional results.