Temporal trajectories of artificial radiocaesium 137Cs in French rivers over the nuclear era reconstructed from sediment cores.

137Cs is a long-lived man-made radionuclide introduced in the environment worldwide at the early beginning of the nuclear Era during atmospheric nuclear testing's followed by the civil use of nuclear energy. Atmospheric fallout deposition of this major artificial radionuclide was reconstructed at the scale of French large river basins since 1945, and trajectories in French nuclearized rivers were established using sediment coring. Our results show that 137Cs contents in sediments of the studied rivers display a large spatial and temporal variability in response to the various anthropogenic pressures exerted on their catchment. The Loire, Rhone, and Rhine rivers were the most affected by atmospheric fallout from the global deposition from nuclear tests. Rhine and Rhone also received significant fallout from the Chernobyl accident in 1986 and recorded significant 137Cs concentrations in their sediments over the 1970-1985 period due to the regulatory releases from the nuclear industries. The Meuse River was notably impacted in the early 1970s by industrial releases. In contrast, the Seine River display the lowest 137Cs concentrations regardless of the period. All the rivers responded similarly over time to atmospheric fallout on their catchment, underlying a rather homogeneous resilience capacity of these river systems to this source of contamination.

Faster strength recovery and better strength ratio with arthroscopic Latarjet compared to the open technique: An observational study.

INTRODUCTION: The arthroscopic bone block has shown reliability and reproducibility regarding functional scores and shoulder mobility compared to the open bone block technique. The recovery of muscle strength, especially the strength ratio external rotator/internal rotator (ER/IR), is crucial to recovering satisfactory function. This ratio should be as near to 1 as possible, meaning a good strength balance. Little is known about the difference in strength recovery between the open and arthroscopic techniques. HYPOTHESIS: Arthroscopic Latarjet reduces surgical stress and improves the strength recovery and strength ratio. OBJECTIVES: To compare arthroscopic and open Latarjet procedures for shoulder muscle strength and functional outcomes. MATERIAL AND METHODS: It was an observational longitudinal and prospective cohort follow-up. Two groups of patients were accessible for comparison: 35 in an arthroscopy group and 38 in an open group. The main outcome was the muscle strength of shoulder muscles measured with a dynamometer and expressed in Newton (N) at day 21 (D21), D45, D90, D180, and D365 in the operated and contralateral shoulders. The measurements were made for the pectoralis major, the three deltoid fascicles, and the subscapularis. The shoulder ER/IR strength ratio was calculated. Other variables were the range of motion (ROM), the Walch-Duplay (WD), the Western Ontario Shoulder Instability score (WOSI), and the Visual Analogic Scale for pain assessment. The strength, ROM, and functional scores were compared between open and arthroscopy with linear mixed models. RESULTS: The median strengths at 52 weeks were significantly higher than at 3 weeks (P<10-4): anterior deltoid (AD) 8N (Q1:7, Q3: 9) versus 4N (Q1:2, Q3: 5), lateral deltoid (LD) 9N (Q1:9, Q3: 11) versus 6N (Q1:4, Q3: 7), posterior deltoid (PD) 14N (Q1:12, Q3: 15) versus 9N (Q1:8, Q3: 10), subscapularis 10N (Q1:9, Q3: 12) versus 7N (Q1:5, Q3: 8), and pectoralis major (PM) 11N (Q1:9, Q3: 12) versus 7N (Q1:5, Q3: 10). The overall strengths were lower in the open group compared to the arthroscopy group: AD -2.1N (CI95%[-3.1--1.2], p=0.0005), LD -1.3N (CI95% [-2.4--0.15], p=0.03), PD -0.35N (CI95% [-1-0.9], p=0.52), subscapularis -2.1N (CI95% [-3.3--0.7], p=0.006), and PM -1.4N (CI95% [-2.2--0.02], p=0.03). The ER/IR ratio was stable throughout the follow-up for both the operated and contralateral shoulders (p>0.5). The overall mean ratio was 1.3 (median 1.2, Q1: 1, Q3:1.45) for the operated shoulder and 1.1 (median 1, Q1: 0.9, Q3:1.3) for the contralateral shoulder (p=0.0004). The average ER/IR ratio was 0.27 points higher in the open group (CI95% [0.1-0.46], p=0.003). The ROM was similar between the two groups, and there was no correlation between the ER/IR ratio and the ROM (p>0.5). The VAS < 3 weeks and WD > 12 weeks were significantly poorer in the open group: +0.61 (CI95% [0.03-1.16] p=0.02), and -7.3 points (CI95% [-13--0.01], p=0.05), on average, respectively. CONCLUSION: The patients in the arthroscopy group had a better ER/IR strength ratio (closer to 1) and better WOSI after 12 weeks. The strength and the ROM were not correlated with each other. LEVEL OF EVIDENCE: III.

Quality and stability of reduction of operated acromioclavicular dislocation using dual acromioclavicular and coracoclavicular stabilization.

INTRODUCTION: Dual stabilization is advocated in acute acromioclavicular dislocation (ACD), but has been little assessed. OBJECTIVE: This preliminary study performed clinical and radiological assessment of dual acromioclavicular (AC) and coracoclavicular (CC) stabilization in acute ACD. The study hypothesis was that dual stabilization allows satisfactory reduction that remains stable over time. MATERIALS AND METHODS: A button was used under endoscopy for CC stabilization. For AC stabilization, a short approach was used; the joint was cleansed then stabilized by an anchored tape between the acromion and the clavicle to promote ligament healing. Clinical assessment was based on a visual analog pain scale (VAS), joint range of motion and Quick-DASH and Constant scores. Radiological reduction was assessed on the ratio of CC distance between the operated and healthy sides on two views. MRI was used in follow-up to screen for ligament healing: thickening and continuity. RESULTS: Thirty-five patients with stage 3-5 acute dislocation were included. At a minimum 24 months' follow-up, mean clinical scores were very satisfactory, with recovery of motion and pain relief. Radiography showed 94% stable reduction in both vertical and horizontal planes. MRI confirmed CC and AC ligament healing. Postoperative complications mainly comprised 4 cases of reduction loss (11%). One clavicle fracture occurred, at 6 months. CONCLUSION: Dual AC-CC stabilization provided very good radiographic reduction in both horizontal and vertical planes. Functional results were very satisfactory, and complications were few, with some cases of reduction loss. These good results encourage us to continue with dual stabilization in acute ACD. LEVEL OF EVIDENCE: II; prospective cohort.

Use of machine learning and deep learning to predict particulate 137Cs concentrations in a nuclearized river.

Cesium-137, discharged by nuclear installations under normal operations and deposited in watersheds following atmospheric testing and accidents (i.e. Chernobyl, Fukushima …), has been studied for decades. Thus, modelling of 137Cs concentration in rivers have been developed based on geochemical approaches and equilibrium assumptions (solid/liquid ratio) as this radionuclide has moved into rivers and oceans due to soil erosion. Recently a new approach is possible to model these concentrations with the popularization of data-driven models based on data acquired in the environment by monitoring networks. In this study, the concentrations of particulate cesium-137 measured near the mouth of the Rhône River (France), a highly nuclearized river, are simulated using two data-driven models, a Hierarchical Attention-Based Recurrent Highway Networks (HRHN) and a Random Forest Regressor (RF). The data-driven predictions were done using only hydrological data (water discharge and suspended solid fluxes) and industrial input of 137Cs. Although the data-driven models provided a better prediction than a recent empirical model, the best prediction (R2 = 0.71) was obtained with HRHN, a model that considers the temporal aspect of the monitoring data. The most important predictors were the hydrological data at the monitoring station and of the tributary that generate the most sediment flux (Durance River). In fact, the concentration of 137Cs in the perimeter of this study was more related to hydrology than to nuclear release, as there were few events with high 137Cs concentrations (concomitant nuclear release and low water discharge). However, the HRHN approach, which is more complex to implement than RF, can predict the concentrations of such events correctly despite their low representation of these events. The results of this study demonstrate the usefulness of data-driven models to assist monitoring programs by filling in gaps or helping to understand observed concentrations.

Arthroscopic approach in initial training: Study of a novice cohort using inverse direct and indirect approaches and its implication in the development of training programs.

INTRODUCTION: Arthroscopic training includes successive stages of observation, reproduction and then repetition. Learning through simulation in 2D virtual reality makes it possible to repeat these different stages to enhance the learner's experience in complete safety and a shorter timeframe. Some procedures require inversion of the optical and instrumental approaches in the axial plane, disrupting the existing psychomotor and technical skills. The objective of this study was to compare the degree of difficulty and the distribution of results for the same exercise carried out alternately in classical holding and inverted holding of the instruments in a cohort of novice learners. MATERIALS AND METHODS: Twenty-two medical students, novices in arthroscopic surgery, participated in the study. Each performed an exercise consisting of grasping ten targets with arthroscopic forceps and placing them in a basket on the VirtaMed ArthroS™ simulator. The exercise was performed with the scope and grasping instrument pointed away from the operator, "catch the stars front" (CTSF), then directed towards the operator, "catch the stars back" (CTSB). The simulator recorded several parameters making up an overall composite score ("overall performance score", OPS) out of 120 points. Voluntary abandonment of the exercise was also collected. RESULTS: All students completed the CTSF exercise but 6 dropped out of the CTSB exercise (27%, p=0.01). In the CTSF exercise, the average OPS was higher with 45.9 points versus 22.8 points in the CTSB exercise (p<0.001). By detailing the components of the OPS score, the parameters of interest on the Fundamentals of Arthroscopic Training (FAST) module of the simulator included: the distance traveled by the scope and the grasping forceps was significantly greater in the CTSB group (p<0.001), the duration of the exercise was significantly greater in the CTSB group (p<0.001), the time spent with the instruments in the videoscopic field was significantly lower in the CTSB group (p=0.001) and finally the absence of a significant difference in the camera alignment compared to the horizontal plane between the two groups. CONCLUSION: The exercise with the instruments directed towards the operator is more difficult with a greater distribution for all the secondary criteria except for the camera alignment, which suggests that it could be more discriminating. The dropout rate is also higher. It would therefore be interesting to introduce CTSB type training in initial training programs in arthroscopy. LEVEL OF EVIDENCE: III, comparative prospective study.

Wide awake local anesthesia no tourniquet (WALANT) versus axillary brachial plexus block for carpal tunnel release in a French public university hospital: Care pathways and operating room costs.

INTRODUCTION: The wide awake local anesthesia no tourniquet (WALANT) is a local anesthetic technique that theoretically cuts costs and shortens surgical waiting times, but this has yet to be demonstrated in France. The main objective of this study was to assess and compare the comprehensive care pathways and costs of performing carpal tunnel release (CTR) procedures in the ambulatory surgery unit using WALANT and axillary brachial plexus block (ABPB). METHODS: A total of 72 CTRs in 66 patients were reviewed after a minimum follow-up of 6 months. The anesthesia was performed by an anesthesiologist after a preoperative consultation. The surgical waiting time, operating room occupancy time, total time taken off work (TOW) and the return to work rate were recorded. The estimated total direct cost per patient (TDCPP) was the sum of the specialist consultation fees, the French diagnosis-related group (DRG) rates and the minimum daily cost of TOW (€27.30/day). RESULTS: Only the total operating room occupancy time differed significantly: 27minutes for the WALANT versus 37minutes for the ABPB (p=0.004). There were no complications or reoperations in either group. The total cost for the cohort was estimated at €190,970. The mean estimated TDCPP was €2,870 for the entire cohort, €2,543 for the ABPB and €2,713 for the WALANT (p=0.791). Twenty-seven of the 45 patients returned to work after a mean TOW of 3.1 months. Fourteen CTRs were preceded by a mean preoperative TOW of 27 days, which resulted in a cost of €24,948 (13% of the total cost). There were no significant differences in TOW or revision rate between WALANT and ABPB. CONCLUSION: Although WALANT significantly reduced operating room occupancy times in our public hospital, the societal costs were the same regardless of the anesthesia technique. Reducing surgical waiting times in France could result in a theoretical saving of nearly €14 million annually. LEVEL OF EVIDENCE: IV.

The use of the IAEA MARIS database in determining the variability of sediment distribution coefficients in the marine environment and potential implications for marine dispersion modelling.

A prototype tool has been developed for deriving sediment distribution coefficients,Kd, in the marine environment by harvesting simultaneous measurements of activity concentrations of radionuclides in seawater and sediments based on the International Atomic Energy Agency's Marine Radioactivity Information System (MARIS). As a case study, theKdvariability in the Baltic Sea was investigated as this region has been extensively monitored by HELCOM since 1984 resulting in a comprehensive dataset with good spatial and temporal coverage and required ancillary parameters. The prototype tool was used to derive a dataset ofin-situapparentKd(a)values derived from measurements of seawater and sediment in quasi-equilibrium conditions from the Baltic Sea over a period of approximately 35 years. For Cs, a comprehensive analysis of the Baltic SeaKd(a)dataset was undertaken, focusing on the temporal trend ofKd(a)and comparing the results toKdvalues derived elsewhere. For Sr and Pu, for which there were fewer data records available a more rudimentary analysis was carried out. The CsKd(a)median values derived from137Cs data in this study were estimated to be 2154 l kg-1for seabed sediment and 10 000 l kg-1for suspended sediment. The value derived for seabed sediment is in good agreement with the previously recommended ocean margin CsKdvalue of 4000 l kg-1. The analysis demonstrated the important distinction in the Baltic Sea betweenKdvalues for seabed sediment and suspended sediments, which differed by an order of magnitude. The analysis also highlighted the dependence ofKdvalues on the variation in both the salinity of seawater and the type of seabed sediment. Such variability can significantly influence outcomes when modelling the behaviour of radionuclides in marine dispersion modelling.

Contribution of shear wave elastography in evaluation of the deltoid in reverse shoulder arthroplasty: reproducibility study and preliminary results.

AIMS: The current difficulty of reverse shoulder arthroplasty (RSA) is soft tissue management, and adequate deltoid tension and at present there is no consensus and available tools (X-ray, MRI, EMG) remain difficult to apply in clinical follow-up. The objective of this study was (1) to determine reliability and feasibility of deltoid elasticity assessment using ultrasound elastographyand (2) to assess the change of deltoid stiffness after RSA by comparing shear wave speed (SWS) between healthy and RSA shoulders. MATERIAL AND METHODS: Twenty-six healthy (native shoulder, painless and complete range of motion) subjects and twelve patients with RSA were included. Two independent investigators performed 3 measurements on each segment. Measurements were bilateral. Anterior segment was also evaluated at 45° and 60° of passive abduction. Reliability and feasibility have been assessed (ISO5725-standard). RESULTS: Coefficient of measurements variation was less than 6.1% and 0.13 m/s. In the healthy group, SWS was not significantly different between anterior and middle segments; however, the SWS of the posterior segment was significantly lower than others (p<0.0001). In abduction position, compared to the rest position, SWS of the anterior segment decreased at 45° abduction (p=0.0003) and increased at 60° abduction (p<0.0001). Variability of measurement was higher in the RSA group. No significant difference was found between the SWS measurement of the operated and non-operated side. SWS measurements of the operated side of the anterior and middle segment were significantly higher compared to the healthy group. In abduction position, compared to rest position, no difference in SWS of the anterior segment was found at 45° abduction (p=0.71) and nor at 60° abduction (p=0.75). CONCLUSION: This study demonstrated feasibility and reliability of shoulder assessment with shear wave elastography. Reference values for asymptomatic patients can already be used in future studies on shoulder pathology and surgery.

Displaced three and four part proximal humeral fractures: prospective controlled randomized open-label two-arm study comparing intramedullary nailing and locking plate.

PURPOSE: The aim of this study was (1) to compare clinical and radiological outcomes of 3- and 4-part proximal humeral fractures using either IMN or LP (2) and to report complications related to each technique. METHODS: A prospective controlled randomized open-label two-arm study was performed. Ninety-nine consecutive adult patients with a 3- and 4-part displaced acute proximal humeral fractures were randomized to be treated with IMN (n = 49) or LP (n = 50). Constant, ASES and SST scores were recorded by the surgeon. Range of motion was evaluated. A visual analog scale (VAS) was used to assess shoulder pain. Complications and revision surgeries were reported. RESULTS: Eighty-five patients were analyzed, nine were lost, and five died during the follow-up period. The mean age was 73.7 years (± 13.3,, and the mean follow-up was 66 months (± 13.5). At last follow-up, VAS was lower in the IMN group (0.9 (± 1.1) vs. 1.9 (± 1.7), p = 0.001). The median Constant score was significantly higher in the IMN group (81.6 (± 10.9) points) vs. in the LP group (75.6 (± 19.5) points) (p = 0.043), and ASES score was also significantly higher in the IMN group (86.3 (± 9.5) vs. 75.2 (± 19.6), p = 0.001). There was no difference in the range of motion or SST scores between the two groups. Complications were seen higher in the LP group (9 (21%) vs. 22 (52%), p = 0.003). Revision surgery was higher in the LP group (37% vs. 21%). CONCLUSION: Satisfactory results were accomplished in both groups according to the reported clinical outcomes. Complication and revision rates were higher in LP group.

Arthroscopic Reduction and Fixation With a Knotless Double-Row Construct Provides Good Results for Displaced Greater Tuberosity Fractures.

PURPOSE: The purpose of the study is to describe the functional and structural outcomes of the arthroscopic 4-strand, knotless, double-row construct with suture tapes for the surgical treatment of displaced and/or comminuted greater tuberosity fractures of the humerus. METHODS: Patients were enrolled between December 2012 and January 2018. The main inclusion criteria were a comminuted and/or displaced tuberosity fracture with a displacement of at least 5 mm in any plane fixed under arthroscopy using a 4-strand, knotless, double-row construct. The technique involves reducing the displaced fragment with 2 medially placed, transtendinous anchors and compressing the greater tuberosity using the tapes from these medial anchors in 2 laterally placed anchors. The exclusion criteria were a fracture that was more than 10 days old at the time of surgery or a history of shoulder surgery and 3- or 4-part fractures. The postoperative rehabilitation protocol was similar for all patients. Constant scores, Quick Dash, return to work and sport, and complications were reported after a minimum follow-up period of 24 months. Bone healing was systematically evaluated on standardized radiographs, including lateral scapula view and anteroposterior views. RESULTS: Twenty-one patients were enrolled in this study. One patient did not complete the follow-up examination period and thus was excluded, leaving 20 patients in this study. At a median (SD) follow-up of 32 (9) months, the median (SD) Constant score was 94.7 (7.3) points, the median (SD) Quick Dash was 1.7 (4) points, and median (SD) visual analog scale score was 0.5 (1.4). All patients returned to previous work and sport level. No malunions or nonunions were seen. One conversion to open surgery was required for failure of the lateral row during surgery in a 62-year-old woman with osteopenic bone. Two patients experienced complex regional pain syndrome in the postoperative period that resolved after nonoperative treatment. CONCLUSIONS: In this series, the use of arthroscopy combined with the biomechanical properties of knotless double-row constructs contributed to postoperative satisfactory functional results and healing of greater tuberosity fracture. In addition, range of motion was early, and no hardware removal was required. However, care should be taken with osteopenic bone where anchorage can fail. LEVEL OF EVIDENCE: Level IV, case series.

Safety of shoulder arthroplasty in lung transplant recipients.

PURPOSE: Although shoulder arthroplasty is relatively safe in general population, it remains unclear in transplant recipient. Aim of this study was to determine outcomes and morbidity after shoulder arthroplasty in lung transplant recipients. METHODS: A retrospective analysis was performed at our university hospital center from 2001 to 2015. Main inclusion criterion was all lung transplant recipient who underwent shoulder arthroplasty. Clinical outcomes including Constant score, visual analogue scale (VAS), American Shoulder and Elbow Surgeons score (ASES) were determined in pre-operative period and a minimum follow-up of 36 months. Special attention was taken about complications. RESULTS: Among 700 lung transplant recipients, we identified 12 patients who underwent 14 shoulder arthroplasties. Arthroplasties were performed after proximal humeral avascular necrosis (n = 10), degenerative osteoarthritis (n = 1) and non-union of proximal humeral fracture (n = 1). 8 anatomical total shoulder arthroplasties and 6 reversed shoulder arthroplasties were performed. Mean follow-up was 61.4 months (± 22.1). Mean age was 47.1 (± 9.3) years. All patients had immunosuppression therapy at the time of surgery. Mean Constant score was improved at last follow-up [43(± 9.7) vs 94(± 4), p < 0.001]. VAS decreased from 6.4 (± 1.2) to 0.4 (± 0.8), p < 0.001. Mean ASES was improved from 33 (± 6) to 91 (± 5) at last follow-up (p < 0.001). Range of motion were improved between early post-operative evaluation and last follow-up: forward flexion: 85° (± 8°) vs 119°(± 13°); abduction: 83° (± 14°) vs 106°(± 23°); external rotation (RE1): 26° (± 7°) vs 36°(± 10°). At last follow-up, one revision was required for humeral prothesis loosening at 2 years post-surgery. One patient died due to acute pulmonary decompensation on chronic rejection 66 months after shoulder arthroplasty. CONCLUSION: Shoulder arthroplasty is a safe procedure in this vulnerable population of lung transplant recipients. Such results encourage us to continue arthroplasty surgery when required. LEVEL OF EVIDENCE: IV.

Arthroscopic knotless repair: an effective technique for small-sized supraspinatus tendon tears.

PURPOSE: The purpose was to evaluate the clinical and radiological results of knotless repair with flat-braided suture in full small-sized supraspinatus tendon tears (< 1 cm). METHODS: A consecutive series of 54 patients with isolated small supraspinatus tendon tear (< 1 cm and Goutallier index < 2) was evaluated in the study. Patients underwent a knotless arthroscopic repair using flat-braided suture (2 mm wide). Minimal follow-up required was 5 years. Changes in Murley-Constant score, ASES score, strength, and pain relief were assessed. The Sugaya score was used to confirm the tendon repair on MRI. Data were analyzed in two subgroups: technique with additional U point for dog ear deformity (group 1) and technique without additional U point (group 2). The immobilization period was 3 weeks long. Passive mobilization was immediate. RESULTS: Fifty-four patients were included. Mean age was 57 ± 4 years. The average follow-up was 68 ± 10 months. Average preoperative score of Constant was 51.2 ± 8.5 and 83.1 ± 14.6 at the end of the follow-up (p < 0.001). Mean VAS went from 5.8 ± 1.8 to 1.9 ± 2.1 (p < 0.001). Average forward elevation of the shoulder went from 86.3° ± 9 preoperatively to 169.6° ± 15.9 at the end of the follow-up (p < 0.001). The strength score was significantly higher post-operatively (18.4 vs. 8.3, p < 0.001.). The ASES score was significantly improved 49.1 ± 13.1 vs. 88.6 ± 15.8, p < 0.001). The MRI assessment revealed 94% of Sugaya 1-2. No significant difference was observed between group 1 and 2 regarding all clinical outcomes. Two complex regional pain syndromes were described with a favorable evolution. Three patients presented a retear requiring an iterative arthroscopic repair. CONCLUSION: The use of a knotless arthroscopic construct with flat-braided suture for small supraspinatus repair achieved excellent structural and clinical results. This technique is fully adequate for the arthroscopic treatment of such tears, enabling early mobilization. LEVEL OF EVIDENCE: Level III.

Solid/liquid ratios of trace elements and radionuclides during a Nuclear Power Plant liquid discharge in the Seine River: Field measurements vs geochemical modeling.

This study focuses on the determination of field solid/liquid ratios (Rd) values of trace element (TE) and radionuclide (RN) in the Seine River (France) during a concerted low radioactivity level liquid regulatory discharge performed by a Nuclear Power Plant (NPP) and their confrontation with Kd values calculated from geochemical modeling. This research focuses on how field Rd measurements of TE and RN can be representative of Kd values and how Kd models should be improved. For this purpose 5 sampling points of the Seine River during a NPP's liquid discharge were investigated: upstream from the discharge in order to assess the natural background values in the area of effluent discharge, the total river water mixing distance (with transect sampling), and 2 points downstream from this last area. The main parameters required determining field Rd of TE and RN and their geochemical modeling (Kd) were acquired. Filtered waters were analyzed for alkalinity, anions, cations, dissolved organic carbon (DOC), TE, and RN concentrations. Suspended particulate matter (SPM) was analyzed for particulate organic carbon (POC), TE and RN concentrations and mineralogical composition. Field Rd and Kd values are in good agreement for stable Cd, Cu, Ni, Pb and Zn and for 7Be. Conversely, measured field Rd for stable Ag, Ba, Sr, Co and Cs are systematically higher than modeled Kd values. Even if only the lowest possible values were obtained for 137Cs and 60Co Rd measurements, these estimated limits are higher than calculated Kd for 137Cs and in good agreement for 60Co. Finally, only two RN exhibit field Rd lower than calculated Kd: 234Th and 210Pb. Comparison of field Rd vs. modeled Kd values for TE and RN allows the identification, for each element, of the main involved adsorption phases and geochemical mechanisms controlling their fate and partitioning in river systems.

Radionuclides in waters and suspended sediments in the Rhone River (France) - Current contents, anthropic pressures and trajectories.

The Rhone River is one of the most nuclearized river in the world. Radionuclide concentrations in water and suspended sediments transferred to the marine environment were intensively monitored in this river over the last decades (2002-2018). Over this period of time, >12 and 25 time integrating samples were collected each year in filtered waters and suspended sediments, respectively, and analyzed for their radionuclide contents at ultra-trace levels by using top performance analytical tools. While >60% of plutonium, americium, cesium, cobalt, silver, beryllium and actinium radioisotopes are carried by sedimentary particles, sodium, tritium, antimony and strontium are mainly exported as dissolved species (>90%) due to their low affinity with particles. Most natural radionuclides contents show low seasonal variation. No significant trends are observed over the last two decades for these elements, even for 40K widely used in fertilizers after the middle of the last century, indicating that the basin has currently converged towards geochemical equilibrium for all of them. In contrast, the concentrations of numerous anthropogenic radionuclides originating from nuclear industries significantly declined since the beginning of the 2000s. Assuming no change of the current anthropic and climatic pressures over the next decades, apparent periods, i.e. the time required for a reduction by half the concentrations in the downstream part of the Rhône River, would be close to 6 years for most artificial radionuclides, except for tritium and other artificial radionuclides conveyed to the river by soil leaching and erosion (90Sr, 241Am, plutonium isotopes) which would be far longer. Referring to regional referential backgrounds, only few anthropogenic radionuclides specifically produced by nuclear industries are still detectable at the downstream part of the Rhone River and excess contents of tritium, 238Pu and 241Am are observed in filtered waters.

A comparative study of fixation methods in adults with two-thirds distal isolated ulnar shaft fractures with a minimum of 2 year follow-up.

BACKGROUND: Adult isolated ulnar shaft fractures (IUSF) are rare. There remains a need to establish the best methods to manage these fractures. The aim of this study was to compare two forms of treatment for IUSF: intramedullary stabilization by k-wire (IMF) versus Open Reduction Internal Fixation by plating (ORIF), in order to identify differences in clinical (1) and radiological outcomes (2), as well as comparative costs (3). HYPOTHESIS: The hypothesis of this study was assessing whether intramedullary stabilization was as feasible as plating in the treatment of isolated ulnar shaft fractures in clinical practice. PATIENTS AND METHODS: A retrospective analysis was undertaken on patients diagnosed IUSF between January 2015 and March 2017 with a minimum of 2 years follow-up. They were treated with IMF (group 1) or ORIF (group 2). Demographic information, clinical outcomes and complications were collected. Cost, including implant cost, operative time, sterilization and inpatient stay were compared. Radiographs were reviewed to evaluate axial angulation, shortening, displacement and residual deformity. RESULTS: 54 patients with a mean age of 41.2 years were treated by IMF (27/54) and ORIF (27/54). The mechanism of injury included high-energy (55%) and low-energy falls (45%). AO/OTA 2018 fracture classification was simple (39/54), wedge (14/54) and complex (1/54). The locations were 37/54 (70%) distal third and 17/54 (30%) mid-shaft fractures. There was no significant difference pre and post-operatively between the 2 groups regarding radiologic criteria. 3 cases of non-union, 4 delay-union and 1 regional complex syndrome occurred in group 2. No complication was reported in group 1. The function determined by range of motion (ROM) at wrist and elbow was excellent in 72% (group 1) and 80% (group2), 18% satisfactory in group 1 and 20% in group 2. There was no difference for QuickDASH and pain. Implant removal was necessary in 70% of patients without sequelae in nailing, 11% after plating. Average operation time was 29 ± 5 min for ORIF and 18 ± 6 min for IMF. Total estimated cost per patient was 3678.4€ for IMF and 7051.9€ for ORIF. CONCLUSIONS: Compared with ORIF, IMF significantly reduced the operation time and cost with lower complications. TYPE OF STUDY: Retrospective study. TYPE OF PROOF: Level 4.

Outcomes of reverse shoulder arthroplasty using a short stem through a superolateral approach.

BACKGROUND: Reverse shoulder arthroplasties have progressed in recent decades to become the most popular type of arthroplasty. Short stems with metaphyseal fixation have been developed to preserve bone stock and facilitate possible revision. Accurate positioning of these implants can be challenging using the superolateral approach. OBJECTIVE: This study aimed to evaluate the clinical and radiologic results of reverse short-stem arthroplasties using a superolateral approach with a minimum of 2 years' follow-up. METHODS: Between January 2015 and December 2016, a total of 76 patients underwent reverse shoulder arthroplasty surgery (79 shoulders) using a short uncemented humeral stem for shoulder arthritis with irreparable rotator cuff tear. Arthroplasties for post-traumatic osteoarthritis were excluded. Functional outcomes were assessed using Constant Score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), visual analog scale (VAS), and range of motion. Radiographic analysis was used to evaluate component loosening, implant position, and implant filling ratio. RESULTS: The mean age was 70.8 years. At a mean of 38.8-month follow-up, there were significant improvements in Constant score (44.2 to 87.9, P < .001), ASES score (36.2 to 84.3, P < .001), and VAS score (6.8 to 0.4, P < .001). Forward flexion improved from 89°to 131°(P < .001), and external rotation improved from 25° to 36°(P < .001). No evidence of periprosthetic loosening was visible. Mean varus of the humeral stem was 1°(±6°). The mean glenoidal inclination was 98°(±7°), which corresponds to a lower tilt of 8°. The average filling ratio was between 50% and 60% in both the metaphysis and the diaphysis. CONCLUSION: The clinical results obtained in this study were satisfying, with a significantly low complication rate. Hence, short-stem reverse shoulder arthroplasty using a superolateral approach, while taking particular care to protect the deltoid, remains our method of choice.

Arthroscopic Rotator Cuff Repair With a Knotless Suture Bridge Technique: Functional and Radiological Outcomes After a Minimum Follow-Up of 5 Years.

PURPOSE: To evaluate clinical and radiological outcomes of knotless suture bridge repair after a minimum of 5 years of follow-up. METHODS: A prospective consecutive series of full-thickness supraspinatus atraumatic chronic tears was evaluated in the study. Tears were medium or large. Further inclusion criteria were minimum clinical follow-up of 5 years with magnetic resonance imaging (MRI) at 24 months and fatty infiltration <2. Patients with shoulder stiffness, arthritis, or rotator cuff tear involving the subscapularis tendon were excluded. An arthroscopic cuff repair was performed using a knotless double-row suture bridge technique with braided suture tapes. Clinical outcomes were evaluated using the Constant score, the American Shoulder and Elbow Surgeons score, strength score, and a visual analog scale. Tendon healing was analyzed according to Sugaya MRI classification at 24 months. A Sugaya score of 1 or 2 was considered as tendon healing. Statistical analysis was performed with the Student's t-test. P = .05 were considered statistically significant. RESULTS: Sixty-eight patients were included in this series. Mean follow-up was equal to 68.8 ± 7 months. At last follow-up, the mean visual analog scale, American Shoulder and Elbow Surgeons score, and Constant scores improved significantly from 5.5 ± 1.6, 48.2 ± 13.1, 37.8 ± 8.3, to 2.1 ± 2.1 (P = 5.43 E-14), 87.4 ± 15.8 (P = 7.15 E-27), and 82.8 ± 14.7 (P = 1.01 E-33), respectively. Anteflexion improved from 99.3° ± 13.4° preoperatively to 136.6° ± 15.9° at last follow-up (P = 3.08 E-21). Strength score was significantly higher postoperatively (18.4 ± 6.7 vs 8.3 ± 3.5). MRI showed 88% (n = 57) of Sugaya 1-2 repairs. Patients with unhealed rotator cuffs showed significantly lower functional results than the Sugaya 1-2 group. No correlation between degree of retraction and rate of healing was observed. Four symptomatic patients (6%) required revision for failed rotator cuff repair. CONCLUSIONS: Despite potential confounding factors, arthroscopic knotless suture bridge repair of rotator cuff tears with acromioplasty demonstrated excellent long-term results of tendon healing, pain relief, and improvement of shoulder function. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopic knotless tape bridging with autologous platelet-rich fibrin gel augmentation: functional and structural results.

Background: Rotator cuff repairs remain a source of iterative ruptures and disappointing functional results. In this goal, autologous platelet-rich plasma (PRP) has been used to improve tendon healing. This prospective study assessed the contribution of fully autologous gel concentrates (platelet concentrates and thrombin) on healing after cuff repair.Methods: A consecutive series of 69 patients who underwent primary arthroscopic knotless tape bridging primary cuff repair of supraspinatus tear were evaluated. Two groups were created (A: n = 32, B: n = 37). Autologous PRP gel, obtained preoperatively by PRP mixed with autologous thrombin extracted from platelet-poor plasma, was injected at bone-tendon interface at end of repair in group A. Gel structure avoided evacuation of concentrates with irrigation liquid. Constant, QuickDash and Visual Analogue Scale (VAS) scores were assessed pre-operatively and then successively post-operatively. Healing was assessed by 24-month control MRI according to Sugaya's classification. Sugaya 3, 4, and 5 were considered as iterative ruptures.Results: Average age was 56 years (±7.8). Mean follow-up was similar: 28.6 months (±3.3) vs 32.4 months (±9.4). Mean preoperative Constant was similar: 53.4 (±3.4) vs 54.6 (±5.4). Group A patients received 3.5 ml (±1.5 ml) of autologous PRP gel. No specific complication of injection was found. We observed higher trend in favour of PRP without significativity: Constant 86.7 (±11.1) vs 81.6 (±14.4), p = 0.11; VAS: 0.6 (±0.3) vs 1.1 (±0.9), p = 0.13; Forward flexion: 139.5° (±14.4°) vs 137.7° (± 16.5°), p = 0.63; Strength score: 17.6 vs 14.8, p = 0.66; QuickDash: 6.2 (±5.3) vs 8.2 (±6.9), p = 0.32 . On MRI, 90% (n = 3) of repairs were healed in group A versus 86% (n = 5) in group B.Conclusion: In this preliminary study, the group treated with autologous PRP gel showed a trend towards better clinical and radiological results. These results were not significant at the last follow-up. Only significantly higher clinical results were found at 3 months.Study design: Therapeutic prospective comparative cohort study; Level of evidence III.

Extended Kd distributions for freshwater environment.

Many of the freshwater Kd values required for quantifying radionuclide transfer in the environment (e.g. ERICA Tool, Symbiose modelling platform) are either poorly reported in the literature or not available. To partially address this deficiency, Working Group 4 of the IAEA program MODARIA (2012-2015) has completed an update of the freshwater Kd databases and Kd distributions given in TRS 472 (IAEA, 2010). Over 2300 new values for 27 new elements were added to the dataset and 270 new Kd values were added for the 25 elements already included in TRS 472 (IAEA, 2010). For 49 chemical elements, the Kd values have been classified according to three solid-liquid exchange conditions (adsorption, desorption and field) as was previously carried out in TRS 472. Additionally, the Kd values were classified into two environmental components (suspended and deposited sediments). Each combination (radionuclide x component x condition) was associated with log-normal distributions when there was at least ten Kd values in the dataset and to a geometric mean when there was less than ten values. The enhanced Kd dataset shows that Kd values for suspended sediments are significantly higher than for deposited sediments and that the variability of Kd distributions are higher for deposited than for suspended sediments. For suspended sediments in field conditions, the variability of Kd distributions can be significantly reduced as a function of the suspended load that explains more than 50% of the variability of the Kd datasets of U, Si, Mo, Pb, S, Se, Cd, Ca, B, K, Ra and Po. The distinction between adsorption and desorption conditions is justified for deterministic calculations because the geometric means are systematically greater in desorption conditions. Conversely, this distinction is less relevant for probabilistic calculations due to systematic overlapping between the Kd distributions of these two conditions.

Results of heterodigital flexor digitorum profundus hemi-tendon transfer for 23 flexor tendon injuries in zones 1 or 2.

We report outcomes of reconstruction of zone 1 or 2 flexor tendon injuries using a heterodigital hemi-tendon transfer of the flexor digitorum profundus in 23 fingers of 23 patients. At mean follow-up of 57 months, the mean total active motion of the three finger joints including the metacarpophalangeal joint was 128 degrees preoperatively and 229 degrees at final follow up. According to Strickland criteria, the function was excellent for 14 fingers, good for seven fingers and poor for two fingers. The subgroup analysis showed that the results were better in cases of primary surgery, children, and for the index and little fingers. Complications included stiffness of three fingers, and rupture in one finger that was converted to a two-stage tendon reconstruction. We conclude that this technique restores good function in most patients with zone 1 and 2 flexor tendon injuries, in which primary tendon repair has not been performed or was unsuccessful, and where pulley reconstruction is not required. LEVEL OF EVIDENCE: IV.