Dense 4D nanoscale reconstruction of living brain tissue.

Three-dimensional (3D) reconstruction of living brain tissue down to an individual synapse level would create opportunities for decoding the dynamics and structure-function relationships of the brain's complex and dense information processing network; however, this has been hindered by insufficient 3D resolution, inadequate signal-to-noise ratio and prohibitive light burden in optical imaging, whereas electron microscopy is inherently static. Here we solved these challenges by developing an integrated optical/machine-learning technology, LIONESS (live information-optimized nanoscopy enabling saturated segmentation). This leverages optical modifications to stimulated emission depletion microscopy in comprehensively, extracellularly labeled tissue and previous information on sample structure via machine learning to simultaneously achieve isotropic super-resolution, high signal-to-noise ratio and compatibility with living tissue. This allows dense deep-learning-based instance segmentation and 3D reconstruction at a synapse level, incorporating molecular, activity and morphodynamic information. LIONESS opens up avenues for studying the dynamic functional (nano-)architecture of living brain tissue.

Neurotransmitter signaling regulates distinct phases of multimodal human interneuron migration.

Inhibitory GABAergic interneurons migrate over long distances from their extracortical origin into the developing cortex. In humans, this process is uniquely slow and prolonged, and it is unclear whether guidance cues unique to humans govern the various phases of this complex developmental process. Here, we use fused cerebral organoids to identify key roles of neurotransmitter signaling pathways in guiding the migratory behavior of human cortical interneurons. We use scRNAseq to reveal expression of GABA, glutamate, glycine, and serotonin receptors along distinct maturation trajectories across interneuron migration. We develop an image analysis software package, TrackPal, to simultaneously assess 48 parameters for entire migration tracks of individual cells. By chemical screening, we show that different modes of interneuron migration depend on distinct neurotransmitter signaling pathways, linking transcriptional maturation of interneurons with their migratory behavior. Altogether, our study provides a comprehensive quantitative analysis of human interneuron migration and its functional modulation by neurotransmitter signaling.

Lateral rim variable angle locked plating versus tension band wiring of simple and complex patella fractures: a biomechanical study.

INTRODUCTION: Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. MATERIALS AND METHODS: Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. RESULTS: For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.

Anterior variable-angle locked plating versus tension band wiring of simple and complex patella fractures - a biomechanical investigation.

BACKGROUND: The aim of this study was to investigate the biomechanical performance of novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. METHODS: Sixteen pairs of human cadaveric knees were used to simulate two-part simple transverse AO/OTA 34-C1 and five-part complex AO/OTA 34-C3 patella fractures. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patella pole. Eight pairs with simple fractures were split for fixation via either tension band wiring (TBW) through two parallel cannulated screws or anterior variable-angle locked plating, whereas other eight pairs with complex fractures were split for either TBW through two parallel cannulated screws plus circumferential cerclage wiring, or anterior variable-angle locked plating using a cortical caudo-cranial polar screw. Each specimen was tested over 5000 cycles with a range of motion from 90° flexion to full extension by pulling on the quadriceps tendon. Interfragmentary movements were captured by motion tracking. RESULTS: For both fracture types, the longitudinal and shear articular displacements, measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following anterior variable-angle locked plating versus TBW, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures resulted in less interfragmentary displacement under extended cyclic loading.

Clavicular hook plate versus dog-bone technique for acute high-grade acromioclavicular joint dislocation: a retrospective cohort study comparing clinical outcome scores, complications, and costs.

INTRODUCTION: Arthroscopically assisted coracoclavicular (CC) ligament fixation techniques have been promoted as providing superior outcomes for the treatment of acute high-grade acromioclavicular joint (ACJ) dislocations. Nevertheless, there is a lack of high-level evidence for clinically relevant benefits. At our institute, orthopaedic surgeons use an arthroscopically assisted coracoclavicular ligament fixation technique (DB), while general trauma surgeons use a clavicular hook plate (cHP) technique. The aim of the study was to compare clinical outcomes, complication rates, and costs between the two groups. MATERIALS AND METHODS: The hospital database was searched for patients treated for acute traumatic high-grade (Rockwood Typ ≥ III) ACJ dislocation using either a cHP or arthroscopically assisted DB technique between 2010 and 2019. Seventy-nine patients could be included (56 patients in the cHP group and 23 in the DB group). QuickDASH scores, subjective shoulder value (SSV) scores, pain scores (numerical pain rating scale 10), and complication rates were retrospectively collected through phone interviews and by screening patient charts as well as surgical reports. Costs per patient were obtained from the hospital's accounting system. RESULTS: Mean follow-up was 54 ± 33.7 and 45 ± 21.7 months in the cHP and DB group, respectively. QuickDASH and SSV scores did not differ, but patients in the cHP group reported significantly lower pain scores (p = 0.033). More patients reported hypertrophic or disturbing scars (p = 0.49) and sensibility disturbances (p = 0.007) in the cHP group. Three patients suffered from a frozen shoulder in the DB group (p = 0.023). CONCLUSION: Patient-reported outcomes are excellent after long-term follow-up for both techniques. There are no clinically relevant differences in clinical outcome scores based on our results and a review of the literature. Both techniques certainly have their benefits regarding secondary outcome measures. LEVEL OF CLINICAL EVIDENCE: Level 3, retrospective cohort study.

Two-staged management of ankle fracture-dislocations with a posterior fragment: computer-tomography-based classification, treatment and its outcome.

INTRODUCTION: Trimalleolar fractures are difficult to treat and malreduction can lead to functional impairment. Involvement of the posterior malleolus has a poor predictive value. Current computed-tomography (CT)-based fracture classifications led to an increase in fixation of the posterior malleolus. The aim of this study was to describe the functional outcome after a two-stage stabilisation with direct fixation of the posterior fragment in trimalleolar dislocation fractures. MATERIALS AND METHODS: In a retrospective study, all patients presenting with a trimalleolar dislocation fracture, an available CT scan, and a two-stage operative stabilisation including the posterior malleolus by a posterior approach were included. All fractures were treated with initial external fixator and delayed definitive stabilisation including fixation of the posterior malleolus. Next to clinical and radiological follow-up, outcome measures (Foot and Ankle Outcome Score (FAOS), Numeric Rating Scale (NRS), Activity of Daily Living (ADL), Hulsmans implant removal score) and complications were analysed. RESULTS: Between 2008 and 2019, of 320 trimalleolar dislocation fractures, 39 patients were included. Mean follow-up was 49 months (standard deviation (SD) 29.7, range 16-148). Mean age was 60 years (SD 15.3, 17-84) with 69% female patients. The mean FAOS was 93/100 (SD 9.7, 57-100), NRS 2 (interquartile range (IQR) 0-3) and ADL 2 (IQR 1-2). Four patients showed a postoperative infection, three re-operations had to be performed and implants were removed in 24 individuals. CONCLUSION: A two-stage procedure of trimalleolar dislocation fractures with in-direct reduction and fixation of the posterior tibial fragment through a posterior approach leads to good functional outcome scores with a low rate of complications.

Clinical performance of the Femoral Neck System within 1 year in 125 patients with acute femoral neck fractures, a prospective observational case series.

INTRODUCTION: Osteosynthesis of femoral neck fractures (FNFs) is an important treatment option, especially for younger patients. We aimed to assess the rate of early implant-related complications in FNF osteosynthesis using the Femoral Neck System (FNS). PATIENTS AND METHODS: Consecutive patients diagnosed with displaced or nondisplaced FNFs were treated with FNS in this prospective, observational, multicenter investigation. Patients were followed up for minimally 3 months and up to 12 months if radiologic bone union and no pain was not achieved beforehand. Predefined treatment-related adverse events (AEs, defined as implant failure, loss of reduction, iatrogenic fractures, deep infection, and surgical revision), radiologic bone union, and patient-reported Harris hip score (HHS) and EQ-5D-5L index score were assessed. RESULTS: One hundred and twenty-five patients were included in the study. Thirty-eight (30.4%) fractures were displaced (Garden III and IV), and 37 (29.6%) were vertical fractures (Pauwels type III). Predefined treatment-related AE rate at 3 months was 8 patients, 6.4% (95% CI, 2.8-12.2), and at 12 months, 11 patients, 8.8% (95% CI, 4.5-15.2). Cumulative incidences of bone union were 68% at 3 months, 90% at 6 months, and 98% at 12 months. The mean changes of HHS and EQ-5D-5L index score between preinjury and at 12 months were -7.5 (95% CI, [ - 21.1] to [6.2]) and - 0.03 (95% CI, [ - 0.21] to [0.15]), respectively; neither were statistically significant. CONCLUSION: The current study on osteosynthesis of FNFs with the FNS resulted in treatment-related complication rates of 6.4% (95% CI, 2.8-12.2) at 3 months and 8.8% (95% CI, 4.5-15.2) at 12 months. On average, patients returned to preinjury function and quality of life. The current study may also indicate that the conventional wisdom of treating stable FNF in patients aged between 60 and 80 years with osteosynthesis may need to be reconsidered. REGISTRATION: The study is registered with ClinicalTrials.gov (registration number: NCT02422355).

Shoulder arthroplasty for proximal humeral fracture treatment: a retrospective functional outcome analysis.

PURPOSE: Following proximal humeral fractures hemiarthroplasty (HA) or reversed total shoulder arthroplasty (rTSA) are performed if osteosynthesis or conservative treatment is not possible. HA has been reported to result in decreased functional outcomes compared with rTSA. Secondary shoulder arthroplasty, performed after a different initial treatment, has also been associated with inferior outcomes. METHODS: Patients recieving a shoulder arthroplasty related to a proximal humeral fracture from 2010 to 2019 were included. A retrospective analysis of functional outcomes was performed using QuickDASH and subjective shoulder value (SSV). RESULTS: The mean [standard deviation (SD)] follow-up time among the 82 included patients was 48 (28) months. The mean age was 70 (10) years. The mean age for HA was significantly different from rTSA [57 (9) and 72 (21) years; p < .001]. The mean QuickDASH score for primary arthroplasty was 11 (2) versus 12 (16) for secondary arthroplasty (p = .313). The mean SSV for primary arthroplasty was 84 (22) versus 82 (17) for secondary arthroplasty (p = .578). The mean QuickDASH score for HA was 24 (36) versus 9 (15) for rTSA (p = .346). The mean SSV for HA was 70 (34) versus 86 (17) for rTSA (p = .578). CONCLUSION: Functional outcomes after fracture-related shoulder arthroplasty were excellent in an older population, even when performed secondarily after failed primary osteosynthesis or conservative treatment. No significant differences in shoulder function were identified between rTSA and HA, likely due to restrictive indications for HA.

Proximal humeral fracture-dislocation: Outcome analysis in osteosynthesis and arthroplasties.

PURPOSE: Proximal humeral fracture-dislocations (PHFD) are challenging to treat. In older patients, usually arthroplasty is performed. In younger patients, osteosynthesis is chosen. This study presents functional outcomes of these different treatment modalities. METHODS: All patients operated for PHFD from 2010 until 2017 were included. Osteosynthesis was performed in younger patients and if reconstruction was possible. Either an open deltopectoral approach or a minimal invasive plate osteosynthesis (MIPO) was performed. Hemiarthroplasty (HA) was done if reconstruction of the tubercles was possible, age was below 63 years and no signs of osteoarthritis were present. In all other cases, a reverse total shoulder arthroplasty (rTSA) was done. The primary endpoint was functional outcome assessed with the QuickDASH Score (QDS). Secondary outcomes were subjective shoulder value (SSV), complications, revisions, and conversion into arthroplasty. RESULTS: The mean follow-up of 40 patients was 56 ± 24 months. The mean QDS was 4.5 (0.6-9.1) and the mean SSV was 90 (80-98.6). Of these, 33 patients (mean age: 50) had an osteosynthesis, 25 were treated with MIPO. Only 18% were converted into an arthroplasty after a mean of 22 months. Among them, 7 patients received a primary arthroplasty (mean age: 68), no revisions were recorded. Subgroup analysis showed functional outcome deficits in avascular necrosis (AVN) compared to no AVN (p = 0.021), revision surgery compared to no revision (p = 0.040) and in HA compared to rTSA (p = 0.007). CONCLUSION: Both osteosynthesis and primary arthroplasty after PHFD can lead to good or even excellent functional outcome. Revision rates in osteosynthesis are high. Revision procedures or secondary conversion into arthroplasty after failed osteosynthesis decrease outcome scores significantly.

Concept for Minimally Invasive Hook Plate Stabilisation of the Acromioclavicular Joint.

AIMS: Despite the availability of various operative procedures, hook plates are still one of the main implants used for the treatment of acromioclavicular (AC) joint dislocation. The aim of this report is to present a novel minimally invasive operation technique for AC hook plate fixation. The functional outcomes of patients operated upon with this technique are presented. PATIENTS AND METHODS: A retrospective analysis was performed for 5 patients who were operated upon with minimally invasive hook plate fixation. The QuickDASH score (QDS) and subjective shoulder value (SSV) were used to express functional outcomes, and the numeric rating scale (NRS) was used to evaluate pain. RESULTS: The mean (SD) follow-up was 30±7 months. Patients were hospitalized for a mean of 3±1 days and operated upon for a mean of 54±7 minutes. Functional outcomes measured with the QDS showed a median (IQR) of 2.3 (0 - 6.8) and a median SSV relative to the healthy side of 95% (89 - 100). The median NRS was 0 (0 - 0). CONCLUSION: Minimally invasive hook plate fixation for acromioclavicular joint dislocation led to excellent functional outcome scores without complications in a small case series of 5 patients.

Osteosynthesis of scapular fractures: a retrospective cohort study.

PURPOSE: In recent years a trend from conservative to operative treatment of displaced scapula fractures has evolved. The aim of this study was to assess surgical and patient-based radiological and functional outcome after open reduction and internal fixation (ORIF) of displaced scapula fractures following predefined operative indications. METHODS: We retrospectively analyzed data of a consecutive series of patients with displaced scapula fractures following operative fixation at our institution between 06/2010 and 02/2020. The primary endpoint was a functional outcome using the QuickDASH score. Secondary outcomes were the Subjective Shoulder Value (SSV), numeric rating scale (NRS) for pain, Activities of Daily Living score (ADL) and complications. RESULTS: Twenty-six male patients were treated operatively. Twenty-three of whom were available for follow-up after a median follow-up time of 33 months (interquartile range [IQR] 8-70 months). In 18 (69%) cases a standard open approach and in 8 (31%) cases a minimal invasive (MI) approach was used. The median QuickDASH was 0 (IQR 0-0) with a median SSV of 95 (IQR 90-98). Patients reported a median NRS of 0 (IQR 0-1) and a median ADL score of 1 (IQR 1-1). Radiological fracture union was 100% without the occurrence of implant failure or mal-union. Two patients (7.7%) required early correction osteosynthesis, one patient (3.8%) developed a frozen shoulder 3 months postoperatively, and one patient (3.8%) presented with a superficial wound infection. CONCLUSION: Following previously published indications for ORIF of displaced scapula body and neck fractures a good functional outcome and a low rate of complications could be achieved.

Intracapsular Femoral Neck Fractures-A Surgical Management Algorithm.

Background and Objectives: Femoral neck fractures are common and constitute one of the largest healthcare burdens of the modern age. Fractures within the joint capsule (intracapsular) provide a specific surgical challenge due to the difficulty in predicting rates of bony union and whether the blood supply to the femoral head has been disrupted in a way that would lead to avascular necrosis. Most femoral neck fractures are treated surgically, aiming to maintain mobility, whilst reducing pain and complications associated with prolonged bedrest. Materials and Methods: We performed a narrative review of intracapsular hip fracture management, highlighting the latest advancements in fixation techniques, generating an evidence-based algorithm for their management. Results: Multiple different fracture configurations are encountered within the category of intracapsular hip fractures, with each pattern having different optimal surgical strategies. Additionally, these injuries typically occur in patients where further procedures due to operative complications are associated with a considerable increase in mortality, highlighting the need for choosing the correct index operation. Conclusions: Factors such as pathological causes for the fracture, pre-existing symptomatic osteoarthritis, patient's physiological age and fracture displacement all need to be considered when choosing optimal management.

Osteosynthesis of sternal fractures with double locking compression plate fixation: a retrospective cohort study.

PURPOSE: Sternal fractures are rare injuries and mostly treated non-operatively. In selected cases, internal fixation becomes necessary. No standard operative approach has been determined yet among experts. The aim of this study is to describe our treatment algorithm and results after operative stabilisation of sternal fractures with locking compression plates (LCP), mainly focusing on the functional outcome. METHODS: A retrospective cohort study was conducted. We included all patients after operative stabilisation of a sternal fracture between 2008 and 2016. Endpoints were the functional outcome using the Activities of Daily Living (ADL) score, pain analysed by the numeric rating scale (NRS), breathing ability, complications and implant removal. RESULTS: Eighteen out of 153 (12%) patients with a sternal fracture underwent operation. Three patients were lost to follow-up. Eleven out of 15 (73%) patients were treated with double straight LCP 3.5 mm implants and 4 (27%) patients with pre-countered LCP 3.5 mm implants. Mean follow-up was 57 months. The median ADL score was 1 (1-4), the median NRS was 0 (0-9), and respiratory complaints scored a median of 1 (1-4). No non-union, hardware failure or implant-related complication occurred. Post-operative complications were pneumonia (20%) and respiratory insufficiency (20%). Implants were removed in 4/15 (27%) patients; three times due to implant-related irritation, once on patient's request. CONCLUSION: Operative stabilisation of sternal fractures with double LCP 3.5 mm provides excellent long-term functional results and seems to be an appropriate option for internal fixation. The rate of post-operative complications is low; however, 27% had a second operation for implant removal.

Decrease surgery time by using an alternative lateral parapatellar approach for tibia shaft fracture nailing.

INTRODUCTION: Medial parapatellar or transpatellar ligament approaches are commonly used for nail osteosynthesis in tibia shaft fractures. The lower leg is normally in a hanging position to allow guide wire insertion and reaming of the tibia. However, this position complicates fracture reduction and retention, as well as image intensification throughout the procedure. A lateral parapatellar approach with the lower leg in a semi-extended, horizontal position has been previously described for proximal tibial fracture fixation. The purpose of the presented study was to share the lateral parapatellar approach technique used in our institution and to analyse its feasibility for tibia shaft fracture fixation when compared to a medial parapatellar and transpatellar incision technique. MATERIALS AND METHODS: All patients with tibial shaft fractures treated at our institution between 2009 and 2012 by intramedullary nailing through either a transpatellar, a medial parapatellar or a lateral parapatellar approach were reviewed. Demographics, injury pattern and the operative procedure, especially operation and fluoroscopy time, were analysed. RESULTS: 73 patients were enrolled into the study. Twenty-six patients were treated by use of a lateral parapatellar approach, whilst a transpatellar or a medial parapatellar approach was chosen in 29 and 18 cases, respectively. Patients' characteristics were similar regarding gender and body mass index. When compared to the transpatellar (126 ± 30 min) or the medial parapatellar approach (105 ± 29 min), surgical time was significantly shorter in the lateral parapatellar approach group (96 ± 29 min). Likewise, shorter image intensifier time was documented when a lateral parapatellar approach was chosen (211 ± 189 s) compared to the transpatellar (347 ± 204 s) or the medial parapatellar approach (241 ± 222 s). CONCLUSION: The extra-articular semi-extended tibial nailing technique using a lateral parapatellar approach was associated with a significant decrease in time of surgery, while fluoroscopy time was shorter but not significantly different between the three groups.

Operative Stabilization of Chest Wall Trauma: Single-Center Report of Initial Management and Long-Term Outcome.

BACKGROUND: Conservative treatment of even severe thoracic trauma including flail chest was traditionally the standard of care. Recently, we reported possible benefits of surgical chest wall stabilization in accordance with other groups. The aim of this study was to critically review our indications and results of internal fixation of rib fractures in the long-term course. METHODS: We retrospectively analyzed the data of a consecutive series of patients with internal rib fracture fixation at our institution from 8/2009 until 12/2014, and we retrospectively studied the late outcome through clinical examination or personal interview. RESULTS: From 1398 patients, 235 sustained a severe thoracic trauma (AIS ≥3). In 23 of these patients, 88 internal rib fixations were performed using the MatrixRIB® system. The median age of these operated patients was 56 years [interquartile range (IQR) 49-63] with a median ISS of 21 [IQR 16-29]. From 18 local resident patients, follow-up was obtained after an average time period of 27.6 (12-68) months. Most of these patients were free of pain and had no limitations in their daily routine. Out of all implants, 5 splint tips perforated the ribs in the postoperative course, but all patients remained clinically asymptomatic. Plate osteosynthesis showed no loss of reduction in the postoperative course. No cases of hardware prominence, wound infection or non-union occurred. CONCLUSIONS: In our carefully selected thoracic trauma patients, locked plate rib fixation seemed to be safe and beneficial not only in the early posttraumatic course, but also after months and years, patients remain asymptomatic and complete recovery as a rule. Trial registration number KEK BASEC Nr. 2016-01679.

Fluorogenic probes for live-cell imaging of the cytoskeleton.

We introduce far-red, fluorogenic probes that combine minimal cytotoxicity with excellent brightness and photostability for fluorescence imaging of actin and tubulin in living cells. Applied in stimulated emission depletion (STED) microscopy, they reveal the ninefold symmetry of the centrosome and the spatial organization of actin in the axon of cultured rat neurons with a resolution unprecedented for imaging cytoskeletal structures in living cells.

Femoral neck fracture osteosynthesis by the biplane double-supported screw fixation method (BDSF) reduces the risk of fixation failure: clinical outcomes in 207 patients.

INTRODUCTION: Osteosynthesis of femoral neck fractures is related up to 46% rate of complications. The novel method of biplane double-supported screw fixation (BDSF; Filipov's method) offers better stability using three medially diverging cannulated screws with two of them buttressed on the calcar. Biomechanically, the most effective component is the distal screw placed at steeper angle and supported on a large area along the distal and posterior cortex of the femoral neck following its spiral anterior curve. Thereby, BDSF achieves the strongest possible distal-posterior cortical support for the fixation construct, which allows for immediate full weight-bearing. The aim of this study was to evaluate the outcomes from the first 5-year period of BDSF clinical application. MATERIALS AND METHODS: Subject of this retrospective study were 207 patients with displaced Garden III-IV femoral neck fractures treated with BDSF. Three 7.3-mm cannulated screws were laid in two medially diverging oblique planes. The distal and the middle screws were supported on the calcar. The distal screw had additional support on the posterior neck cortex. RESULTS: The outcomes in 207 patients were analysed in 29.6 ± 16.8 months follow-up. Bone union occurred in 96.6% of the cases (males 97.6%, females 96.4%, P = 0.99). Rate of nonunion was 3.4%, including fixation failure (2.4%), pseudoarthrosis (0.5%) and nonunion with AVN (0.5%). Rate of AVN was 12.1% (males 4.8%, females 13.9%, P = 0.12). Modified Harris hip score was 86.2 ± 18.9 (range 10-100), with no significant difference between genders, P = 0.07. Older patients were admitted with significantly more comorbidities (P = 0.001), and on follow-up they were significantly less mobile (P = 0.005) and had significantly more difficulties to put socks and shoes on (P < 0.001). CONCLUSIONS: By providing additional cortical support, the novel BDSF method enhances femoral neck fracture fixation strength.

Semi-automated quantification of living cells with internalized nanostructures.

BACKGROUND: Nanostructures fabricated by different methods have become increasingly important for various applications in biology and medicine, such as agents for medical imaging or cancer therapy. In order to understand their interaction with living cells and their internalization kinetics, several attempts have been made in tagging them. Although methods have been developed to measure the number of nanostructures internalized by the cells, there are only few approaches aimed to measure the number of cells that internalize the nanostructures, and they are usually limited to fixed-cell studies. Flow cytometry can be used for live-cell assays on large populations of cells, however it is a single time point measurement, and does not include any information about cell morphology. To date many of the observations made on internalization events are limited to few time points and cells. RESULTS: In this study, we present a method for quantifying cells with internalized magnetic nanowires (NWs). A machine learning-based computational framework, CellCognition, is adapted and used to classify cells with internalized and no internalized NWs, labeled with the fluorogenic pH-dependent dye pHrodo™ Red, and subsequently to determine the percentage of cells with internalized NWs at different time points. In a "proof-of-concept", we performed a study on human colon carcinoma HCT 116 cells and human epithelial cervical cancer HeLa cells interacting with iron (Fe) and nickel (Ni) NWs. CONCLUSIONS: This study reports a novel method for the quantification of cells that internalize a specific type of nanostructures. This approach is suitable for high-throughput and real-time data analysis and has the potential to be used to study the interaction of different types of nanostructures in live-cell assays.

Elective implant removal in symptomatic patients after internal fixation of proximal humerus fractures improves clinical outcome.

BACKGROUND: Operative treatment is the standard for severely displaced proximal humerus fractures, but functional impairment can persist. Retaining of the implant can be a reason and in other fracture situations has proved to ameliorate patient satisfaction. The aim of this study was to analyse the functional outcome after locking plate removal in proximal humerus fractures. METHODS: In a two-year period, all symptomatic patients with plate osteosynthesis for proximal humerus fracture and hardware removal were retrospectively evaluated clinically and radiologically pre- and post-implant removal. Evaluation included Constant score, height of plate position and possible impingement, as well as intraoperative complications. RESULTS: Twenty patients met the inclusion criteria. The mean age was 56 ± 12 years. The plates were placed 6.9 ± 3 mm distal to the greater tubercle. The operation was performed in 35 ± 10 min and no intraoperative complications were reported. The Constant score improved significantly after implant removal from 71 to 76 (p = 0.008). CONCLUSION: Symptomatic patients after locked plate osteosynthesis for proximal humerus fractures showed statistically significant improvement of the Constant score after implant removal.

The influence of the operation technique and implant used in the treatment of periprosthetic hip and interprosthetic femur fractures: a systematic literature review of 1571 cases.

INTRODUCTION: A systematic literature review on periprosthetic/interprosthetic fracture fixation after hip arthroplasties was performed to summarize available clinical data. Operation techniques and implants used were evaluated as possible risk factors for outcomes. MATERIALS AND METHODS: MEDLINE and Cochrane databases were searched. Articles describing patients with postoperative periprosthetic femur fractures sustained around a hip arthroplasty and with interprosthetic fractures treated with plates, nails, screws and/or cerclage were included. Considered articles were from 2000 or newer. Eligible abstracts were screened by two independent persons and discrepancies were resolved by consensus. Absolute numbers of complications and/or reoperation events along with their corresponding rates were calculated according to operation technique and type of implant. Relative risks of having a complication and/or a reoperation according to the operation technique and the type of implant used were estimated. RESULTS: Available data from 49 prospective and retrospective studies were analyzed. Of 1574 fractures, 81.7 % were treated with plating. For 83.0 % of all fractures, an open approach was applied. The overall complication rate was 14.3 %. Fixation failure and nonunion were most often reported (fixation failure: 4.4 %; nonunion: 3.9 %). Nonunion and refracture occurred more often after open approaches than after minimal invasive osteosynthesis (nonunion: 4.5 vs. 0.0 %, p = 0.001; refracture: 3.8 vs. 0.6 %. p = 0.024). The relative risk for nonunion was 11.9 (95 % CI 4.5-31.5) times higher (p < 0.0001) for non-locking plates (13.0 %) than for locking plates (1.1 %). CONCLUSIONS: The clinical evidence of published studies dealing with periprosthetic/interprosthetic fractures after hip arthroplasty is generally low. This literature search suggested higher rates of nonunion and refracture after an open approach and a higher risk of nonunion for non-locking plates compared to locking plates. Based on the available clinical evidence, no treatment recommendations can be given.