Choosing the proper implant for extra-articular fractures of proximal phalanges: A study on 75 cases

INTRODUCTION

Phalangeal fractures are the most common fractures of the hand and in particular the proximal phalanx of the long fingers is the most involved. These fractures can ben conservatively managed but, when the fracture pattern is considered unstable, surgical treatment is recommended. However, there is no consensus in literature about the proper surgical option for extra-articular proximal phalanx fractures.

MATERIAL AND METHODS

We compared clinical and radiographical results after treatment of 75 cases of extra-articular proximal phalanx fractures using three different surgical techniques: closed reduction and internal fixation (CRIF) with Kirschner wires (G1 group), open reduction internal fixation (ORIF) with plates and screws or lag screws (G2 group), and closed reduction and intramedullary screw fixation (CRIMEF)(G3 group).

RESULTS

We found no significant differences in term of union rate and time to fracture healing between the three groups. However, we found a significant reduction in time to return at work and in TAM at the final follow-up examination in G3 group (treated with CRIMEF) when compared with both G1 and G2. No differences in complications rate were found between three groups.

DISCUSSION

The surgical variability in the management of extra-articular phalanx fractures create lacks on standard guide for treatment.

CONCLUSIONS

In conclusion, our results showed good clinical and radiographical results with all the three surgical options. However, the closed reduction and internal fixation with intramedullary screws (CRIMEF) seems to be better in terms of time to return to work and TAM at the final follow-up, probably due to good primary stability and little risk of soft tissue adherence development.

Expiratory Muscle Activity Counteracts Positive End-Expiratory Pressure and Is Associated with Fentanyl Dose in Patients with Acute Respiratory Distress Syndrome

Rationale: Hypoxemia during mechanical ventilation might be worsened by expiratory muscle activity, which reduces end-expiratory lung volume through lung collapse. A proposed mechanism of benefit of neuromuscular blockade in acute respiratory distress syndrome (ARDS) is the abolition of expiratory efforts. This may contribute to the restoration of lung volumes. The prevalence of this phenomenon, however, is unknown. Objectives: To investigate the incidence and amount of end-expiratory lung impedance (EELI) increase after the administration of neuromuscular blocking agents (NMBAs), clinical factors associated with this phenomenon, its impact on regional lung ventilation, and any association with changes in pleural pressure. Methods: We included mechanically ventilated patients with ARDS monitored with electrical impedance tomography (EIT) who received NMBAs in one of two centers. We measured changes in EELI, a surrogate for end-expiratory lung volume, before and after NMBA administration. In an additional 10 patients, we investigated the characteristic signatures of expiratory muscle activity depicted by EIT and esophageal catheters simultaneously. Clinical factors associated with EELI changes were assessed. Measurements and Main Results: We included 46 patients, half of whom showed an increase in EELI of >10% of the corresponding Vt (46.2%; IQR, 23.9-60.9%). The degree of EELI increase correlated positively with fentanyl dosage and negatively with changes in end-expiratory pleural pressures. This suggests that expiratory muscle activity might exert strong counter-effects against positive end-expiratory pressure that are possibly aggravated by fentanyl. Conclusions: Administration of NMBAs during EIT monitoring revealed activity of expiratory muscles in half of patients with ARDS. The resultant increase in EELI had a dose-response relationship with fentanyl dosage. This suggests a potential side effect of fentanyl during protective ventilation.

Feasibility of Setting the Tidal Volume Based on End-Expiratory Lung Volume: A Pilot Clinical Study

OBJECTIVES

To assess the feasibility of setting the tidal volume (TV) as 25% of the actual aerated lung volume (rather than on ideal body weight) in patients with Acute Respiratory Distress Syndrome (ARDS).

DESIGN

Physiologic prospective single-center pilot study.

SETTING

Medical ICU specialized in the care of patients with ARDS.

PATIENTS

Patients with moderate-severe ARDS deeply sedated or paralyzed, undergoing controlled mechanical ventilation with a ventilator able to measure the end-expiratory lung volume (EELV) with a washin, washout technique.

INTERVENTIONS

Three-phase study (baseline, strain-selected TV setting, ventilation with strain-selected TV for 24 hr). The TV was calculated as 25% of the measured EELV minus the static strain due to the applied positive end-expiratory pressure.

MEASUREMENTS AND MAIN RESULTS

Gas exchanges and respiratory mechanics were measured and compared in each phase. In addition, during the TV setting phase, driving pressure (DP) and lung strain (TV/EELV) were measured at different TVs to assess the correlation between the two measurements. The maintenance of the set strain-selected TV for 24 hours was safe and feasible in 76% of the patients enrolled. Three patients dropped out from the study because of the need to set a respiratory rate higher than 35 breaths per minute to avoid respiratory acidosis. The DP of the respiratory system was a satisfactory surrogate for strain in this population.

CONCLUSIONS

In our population of 17 patients with moderate to severe ARDS, setting TV based on the actual lung size was feasible. DP was a reliable surrogate of strain in these patients, and DP less than or equal to 8 cm H2O corresponded to a strain less than 0.25.

Individual response in patient's effort and driving pressure to variations in assistance during pressure support ventilation

BACKGROUND

During Pressure Support Ventilation (PSV) an inspiratory hold allows to measure plateau pressure (Pplat), driving pressure (∆P), respiratory system compliance (Crs) and pressure-muscle-index (PMI), an index of inspiratory effort. This study aims [1] to assess systematically how patient's effort (estimated with PMI), ∆P and tidal volume (Vt) change in response to variations in PSV and [2] to confirm the robustness of Crs measurement during PSV.

METHODS

18 patients recovering from acute respiratory failure and ventilated by PSV were cross-randomized to four steps of assistance above (+ 3 and + 6 cmH2O) and below (-3 and -6 cmH2O) clinically set PS. Inspiratory and expiratory holds were performed to measure Pplat, PMI, ∆P, Vt, Crs, P0.1 and occluded inspiratory airway pressure (Pocc). Electromyography of respiratory muscles was monitored noninvasively from body surface (sEMG).

RESULTS

As PSV was decreased, Pplat (from 20.5 ± 3.3 cmH2O to 16.7 ± 2.9, P < 0.001) and ∆P (from 12.5 ± 2.3 to 8.6 ± 2.3 cmH2O, P < 0.001) decreased much less than peak airway pressure did (from 21.7 ± 3.8 to 9.7 ± 3.8 cmH2O, P < 0.001), given the progressive increase of patient's effort (PMI from -1.2 ± 2.3 to 6.4 ± 3.2 cmH2O) in line with sEMG of the diaphragm (r = 0.614; P < 0.001). As ∆P increased linearly with Vt, Crs did not change through steps (P = 0.119).

CONCLUSION

Patients react to a decrease in PSV by increasing inspiratory effort-as estimated by PMI-keeping Vt and ∆P on a desired value, therefore, limiting the clinician's ability to modulate them. PMI appears a valuable index to assess the point of ventilatory overassistance when patients lose control over Vt like in a pressure-control mode. The measurement of Crs in PSV is constant-likely suggesting reliability-independently from the level of assistance and patient's effort.

A Novel Mask with Selective Ports for Inflow and Outflow Reduces CO2 Rebreathing during Non-Invasive Ventilation: A Physiological Study in Healthy Volunteers

BACKGROUND

CO2 rebreathing is one of the risks associated with noninvasive ventilation (NIV), possibly contributing to failure. In a bench study, we showed that a novel mask design, with separate limbs for inflow and outflow gases, significantly reduced CO2 rebreathing in different ventilation settings.

OBJECTIVES

The study aimed to test whether a new mask design could 1) reduce CO2 rebreathing in healthy volunteers during NIV (phase 1) and 2) reduce minute ventilation (phase 2).

MATERIALS AND METHODS

Healthy volunteers were randomly assigned to NIV using two masks in a crossover design: a traditional single-limb mask for inflow and outflow gases and a mask with two separated limbs. In phase 1, six ventilation settings were tested for each mask: CPAP (PEEP 5 cmH2O) and pressure support ventilation (PSV, PS Level 5 cmH2O) using a mechanical ventilator with a bias flow of 8 or 20 L/min; free-flow CPAP (PEEP 5 cmH2O) with 60 or 90 L/min of gas flow. A nasal cannula was inserted in one nostril of the volunteers and connected to a CO2 gas analyzer to measure CO2 during the respiratory cycle. In phase 2, volunteers underwent a prolonged time of ventilation in CPAP 90 L/min and PSV with 20 L/min of bias flow. During free-flow CPAP, electrical impedance tomography was used to record the change in impedance during tidal breathing and then estimate tidal volume.

RESULTS

Ten healthy adults were enrolled in phase 1, and 8 volunteers in phase 2. CO2 during inspiration was significantly lower in each setting with the two-limb versus the one-limb mask (p < 0.001). The maximum CO2 reduction was observed in the continuous-flow CPAP settings. EtCO2 was lower with the two-limb mask compared to the one-limb mask (p < 0.001). However, no difference in minute ventilation was observed between the two masks.

CONCLUSION

The new mask design with two ports for inhaled and exhaled gases reduced the amount of CO2 rebreathing in all tested ventilation settings. The CO2 rebreathing reduction did not decrease minute ventilation in healthy volunteers.

Hallux valgus associated to osteoarthritis: Clinical-radiological outcomes of modified SERI technique at mid- to long-term follow-up. A retrospective analysis

INTRODUCTION

Treatment of hallux valgus deformity associated with mild or moderate osteoarthritis (OA) is still a topic of debate. In the literature, there are few studies concerning the management of patients affected by this condition. This study aims to report the experience at mid- to long-term results of an original joint-preserving surgical technique.

MATERIALS AND METHODS

Patients affected by mild to moderate hallux valgus deformity and associated to grade 1-2 OA and treated with modified Simple-Effective-Rapid-Inexpensive (SERI) technique from 2008 to 2018 were selected. Inclusion criteria were mild or moderate hallux valgus angle (HVA) <40° and an intermetatarsal angle (IMA) <20° and associated grade 1-2 OA of the first metatarso-phalangeal joint (MTPJ).

RESULTS

128 feet in 120 consecutive patients, undergone modified SERI procedure, have been retrospectively reviewed at a mean follow-up of 5.1 ± 3.8 years (range 2-11). American Orthopaedics Foot Ankle Society (AOFAS) score that was significantly improved from 44.2 ± 13.2 to 88.2 ± 9.6. Pre-operative average HVA and IMA values decreased respectively from 31.6° ± 3.9° to 9.1° ± 4.4° and from 16.2° ± 3.8° to 7.2° ± 3.1°. The average distal metatarsal articular angle (DMAA) value improved from 28.2° ± 6.5° to 7.1° ± 6°. OA of the first MTPJ highlighted a grade 1 in 46 feet and a grade 2 in 82 feet pre-operatively and a grade 0 in 30 feet, grade 1 in 82 feet, and grade 2 in 16 feet at the final follow-up.

CONCLUSIONS

The modifications to the SERI technique could extend the indications to patients affected by hallux valgus with mild to moderate OA. The wider case series and the longer follow-up of this study make us believe this technique is very useful for improving the quality of life in these patients.

LEVEL OF EVIDENCE

IV.

Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database

PURPOSE

An inspiratory hold during patient-triggered assisted ventilation potentially allows to measure driving pressure and inspiratory effort. However, muscular activity can make this measurement unreliable. We aim to define the criteria for inspiratory holds reliability during patient-triggered breaths.

MATERIAL AND METHODS

Flow, airway and esophageal pressure recordings during patient-triggered breaths from a multicentre observational study (BEARDS, NCT03447288) were evaluated by six independent raters, to determine plateau pressure readability. Features of "readable" and "unreadable" holds were compared. Muscle pressure estimate from the hold was validated against other measures of inspiratory effort.

RESULTS

Ninety-two percent of the recordings were consistently judged as readable or unreadable by at least four raters. Plateau measurement showed a high consistency among raters. A short time from airway peak to plateau pressure and a stable and longer plateau characterized readable holds. Unreadable plateaus were associated with higher indexes of inspiratory effort. Muscular pressure computed from the hold showed a strong correlation with independent indexes of inspiratory effort.

CONCLUSION

The definition of objective parameters of plateau reliability during assisted-breath provides the clinician with a tool to target a safer assisted-ventilation and to detect the presence of high inspiratory effort.

Is hip morphology a risk factor for developing hip osteoarthritis? A systematic review with meta-analysis

OBJECTIVE

To appraise the highest evidence on hip morphology as a risk factor for developing hip osteoarthritis (OA).

DESIGN

We searched for studies evaluating the association between radiological hip morphology parameters and the prevalence, incidence or progression of hip OA (based on different radiographic and clinical criteria) in the MEDLINE, EMBASE, Web of Science, Scopus, Cochrane Library and PEDro databases from inception until June 2020. Prospective and cross-sectional studies were separately evaluated. Data are presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

We included 9 prospective and 21 cross-sectional studies in the meta-analysis, and evaluated 42,831 hips from 25,898 individuals (mean age: 59 years). Prospective studies showed that, compared with control hips, hips with cam morphology (alpha angle >60°; OR = 2.52, 95% CI: 1.83 to 3.46, P < 0.001) or hip dysplasia (lateral center-edge angle (LCEA) <25°; OR = 2.38, 95% CI: 1.84 to 3.07, P < 0.001), but not hips with pincer morphology (LCEA >39°; OR = 1.08, 95% CI: 0.57 to 2.07, P = 0.810), were more likely to develop hip OA than hips without these morphologies. Cross-sectional studies showed a greater prevalence of pincer morphology (LCEA >39°, OR = 3.71, 95% CI: 2.98 to 4.61, P < 0.001) and acetabular retroversion (crossover sign; OR = 2.65, 95% CI: 1.17 to 6.03, P = 0.020) in hips with OA than in control hips.

CONCLUSION

Cam morphology and hip dysplasia were consistently associated with the development of hip OA. Pincer morphology was associated with hip OA in cross-sectional but not in prospective studies. The heterogeneous quantification of pincer morphology on radiographs limits a clear conclusion on its association with hip OA.

Clinical value of electrical impedance tomography (EIT) in the management of patients with acute respiratory failure: a single centre experience

Objective.We will describe our clinical experience using electrical impedance tomography (EIT) in the management of mechanical ventilation in patients with acute respiratory failure and to determine to which extent EIT-guided positive end-expiratory pressure (PEEP) setting differed from clinically set values.Approach.We conducted a retrospective, observational cohort study performed in a hub centre for the treatment of acute respiratory failure and veno-venous extracorporeal membrane oxygenation (ECMO).Main results.Between January 2017 and December 2019, EIT was performed 54 times in 41 patients, not feasible only in one case because of signal instability. More than 50% was on veno-venous ECMO support. In 16 cases (30%), EIT was used for monitoring mechanical ventilation, i.e. to evaluate recruitability or sigh setting. In 37 cases (70%), EIT was used to set PEEP both with incremental (11 cases in nine patients) and decremental (26 cases, 18 patients) PEEP trial. Clinical PEEP before the decremental PEEP trial (PEEP_PRE) was 14.1 ± 3.4 cmH2O and clinical PEEP set by clinicians after the PEEP trial (PEEP_POST) was 13.6 ± 3.1 (p = ns). EIT analyses demonstrated that more hypoxic patients were higher derecruited when compared to less hypoxic patients that were, on the contrary, more overdistended (p < 0.05). No acute effects of PEEP adjustment based on EIT on respiratory mechanics or regional EIT parameters modification were observed.Significance.The variability of EIT findings in our population confirmed the need to provide ventilation settings individually tailored and EIT was confirmed to be an optimal useful clinical bedside noninvasive tool to provide real-time monitoring of the PEEP effect and ventilation distribution.

Effectiveness of standard cervical physiotherapy plus diaphragm manual therapy on pain in patients with chronic neck pain: A randomized controlled trial

BACKGROUND

Literature concerning the effect of diaphragm treatment to reduce neck pain symptoms is scarce. Aim of this trial was to investigate the effects of diaphragm manual therapy associated with standard physiotherapy treatment on pain in patients with Chronic Neck Pain (CNP).

METHODS

In a private practice clinic, subjects with CNP were randomly assigned to receive three 30-min treatment sessions of standard cervical physiotherapy and Diaphragm Manual Therapy (DMT) or Sham Diaphragm Technique (SDT). Participants and assessors were blinded to the assignment. Primary outcome was pain, secondary outcomes were cervical active range of motion, pain pressure threshold, disability and quality of life measured at baseline, before and after each session, at 3 and 6-months. Adverse events were monitored. A non-parametric multivariate approach (combined permutation test) was applied to assess the effect of the treatment on all the outcomes. An intention to treat analysis was performed.

RESULTS

Forty patients were randomly allocated to DMT and SDT groups. Combined permutation test showed a significant higher improvement in DMT group compared to SDT group (p-value = 0.0002). The between-group comparisons on single outcomes showed a statistically significant improvement only for pain pressure threshold on upper trapezius (adjusted p-value = 0.029). No adverse events related to the intervention were registered.

CONCLUSIONS

In patients with CNP, addition of diaphragm manual techniques to standard cervical treatment seems to give a better global outcome, but this improvement is of unclear clinical relevance; the primary outcome seems not to have a role. Further studies are needed to confirm and clarify these results.

TRIAL REGISTRATION

Release Date: July 18, 2017 Registered in ClinicalTrial.gov database ID: NCT03223285A.

Evidence of exposure to SARS-CoV-2 in cats and dogs from households in Italy

SARS-CoV-2 emerged from animals and is now easily transmitted between people. Sporadic detection of natural cases in animals alongside successful experimental infections of pets, such as cats, ferrets and dogs, raises questions about the susceptibility of animals under natural conditions of pet ownership. Here, we report a large-scale study to assess SARS-CoV-2 infection in 919 companion animals living in northern Italy, sampled at a time of frequent human infection. No animals tested PCR positive. However, 3.3% of dogs and 5.8% of cats had measurable SARS-CoV-2 neutralizing antibody titers, with dogs from COVID-19 positive households being significantly more likely to test positive than those from COVID-19 negative households. Understanding risk factors associated with this and their potential to infect other species requires urgent investigation.

Patient-reported outcomes in patients undergoing elective arthroplasty: the PaRIS-IOR study

Background

The number of hip and knee arthroplasties continues to rise worldwide. The Organization for Economic Cooperation and Development has launched the PaRIS Initiative for the systematic collection of Patient Reported Outcome Measures (PROMs) in patients undergoing elective hip and knee arthroplasty. The Rizzoli Orthopedic Institute (IOR) was selected as a pilot center for the Initiative (PaRIS-IOR study), because it hosts the Registry of Orthopedic Prosthetic Implants (RIPO). The objective of PaRIS-IOR study is to investigate the characteristics and temporal trend of PROMs in relation to the type of surgical intervention and patient profile. Here we report the preliminary results of the first study year.

Methods

The PaRIS-IOR is a prospective, single site, cohort study started on January 1st 2019 that consists of the administration of Euro Quality 5 Dimensions (EQ-5D), Hip disability and Osteoarthritis Outcome Score and Knee injury and Osteoarthritis Outcome Score Physical function Short-form (HOOS-PS, KOOS-PS) questionnaires to patients on the list for elective arthroplasty. Questionnaires data are linked with those routinely collected by the RIPO and regional administrative data, in order to track patients' medical history.

Results

The study population consists of 1,413 patients. Patients undergoing knee arthroplasty (n = 393) were older (68.4 vs 60.2 years; p &lt; 0.001), and had a higher prevalence of obesity (41.6 vs 22.6%; p &lt; 0.001) than patients undergoing hip arthroplasty (n = 1020). Female and obese patients reported a worse perceived health status both in the EQ-5D (p &lt; 0.001) and in the HOOS-PS and KOOS-PS (p &lt; 0.001). Among patients who underwent knee surgery, the younger ones reported a poorer perceived health in the general and the specific questionnaires.

Conclusions

The PaRIS-IOR study has potential important implications in targeting the factors affecting patient-reported functional outcomes and quality of life after joint arthroplasty.

Key messages

The PaRIS-IOR study underscores the poorer perception of health status in female and obese patients undergoing arthroplasty and in younger patients undergoing knee surgery. The routine adoption of PROMs may support surgeons in the management of patients undergoing hip and knee arthroplasty and policy-makers in improving healthcare quality in orthopedics.

Gumming Up The Works: Field Tests of a New Food-Grade Gum as Behavioral Disruptor for Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii Matsumura is an economically important pest of small and stone fruits. Its establishment in the Americas and Europe marked an important turning point in crop management programs. Ten years after its first detection, an effective integrated pest management program has yet to be developed and pesticides are mainly used to control this pest. Here we test a new behavioral control tool, with the aim to develop an alternative pest control strategy. A food-grade gum matrix, was evaluated under controlled and open field conditions for its ability to attract the pest and protect the ripening fruit. Here, we report that the gum effectively reduces fruit infestation when used under managed conditions. We show that a single point source can affect D. suzukii behavior over a 3.6 m radius and last for up to 21 d. Open field data reveal that the efficacy of the gum is significantly impacted by water content. We discuss these results in respect to the future implications for D. suzukii management, along with important considerations on gum mechanism of action, possible application strategies and economic suitability for growers.

Evidence of exposure to SARS-CoV-2 in cats and dogs from households in Italy

SARS-CoV-2 originated in animals and is now easily transmitted between people. Sporadic detection of natural cases in animals alongside successful experimental infections of pets, such as cats, ferrets and dogs, raises questions about the susceptibility of animals under natural conditions of pet ownership. Here we report a large-scale study to assess SARS-CoV-2 infection in 817 companion animals living in northern Italy, sampled at a time of frequent human infection. No animals tested PCR positive. However, 3.4% of dogs and 3.9% of cats had measurable SARS-CoV-2 neutralizing antibody titers, with dogs from COVID-19 positive households being significantly more likely to test positive than those from COVID-19 negative households. Understanding risk factors associated with this and their potential to infect other species requires urgent investigation.

One Sentence Summary

SARS-CoV-2 antibodies in pets from Italy.

Occurrence of pendelluft under pressure support ventilation in patients who failed a spontaneous breathing trial: an observational study

Background

Pendelluft, the movement of gas within different lung regions, is present in animal models of assisted mechanical ventilation and associated with lung overstretching. Due to rebreathing of CO₂ as compared to fresh gas, pendelluft might reduce ventilatory efficiency possibly exacerbating patient’s respiratory workload during weaning. Our aim was to measure pendelluft by electrical impedance tomography (EIT) in patients who failed a spontaneous breathing trial (SBT).

Methods

This is an observational study conducted in a general intensive care unit of a tertiary-level teaching hospital. EIT signal was recorded in 20 patients while pressure support (PS) ventilation was progressively reduced from clinical level (baseline) to 2 cmH₂O, as in an SBT; four ventral-to-dorsal lung regions of interest were identified for pendelluft measurement. A regional gas movement (> 6 mL) occurring in a direction opposite to the global EIT signal was considered diagnostic for high pendelluft.

Results

Eight patients out of 20 (40%) were classified as high-pendelluft; baseline clinical characteristics did not differ between high- and low-pendelluft patients. At PS reduction, pendelluft and EtCO₂ increased more in the high-pendelluft group (p < .001 and .011, respectively). The volume of gas subject to pendelluft moved almost completely from the ventral towards the dorsal lung regions, while the opposite movement was minimal (16.3 [10:32.8] vs. 0 [0:1.8] mL, p = .001). In a subgroup of patients, increased pendelluft volumes positively correlated with markers of respiratory distress such as increased respiratory rate, p0.1, and EtCO₂.

Conclusions

Occult pendelluft can be measured by EIT, and is frequently present in patients failing an SBT. When present, pendelluft increases with the reduction of ventilator support and is associated with increased EtCO₂, suggesting a reduction of the ability to eliminate CO₂.

Assisted mechanical ventilation promotes recovery of diaphragmatic thickness in critically ill patients: a prospective observational study

BACKGROUND

Diaphragm atrophy and dysfunction are consequences of mechanical ventilation and are determinants of clinical outcomes. We hypothesize that partial preservation of diaphragm function, such as during assisted modes of ventilation, will restore diaphragm thickness. We also aim to correlate the changes in diaphragm thickness and function to outcomes and clinical factors.

METHODS

This is a prospective, multicentre, observational study. Patients mechanically ventilated for more than 48 h in controlled mode and eventually switched to assisted ventilation were enrolled. Diaphragm ultrasound and clinical data collection were performed every 48 h until discharge or death. A threshold of 10% was used to define thinning during controlled and recovery of thickness during assisted ventilation. Patients were also classified based on the level of diaphragm activity during assisted ventilation. We evaluated the association between changes in diaphragm thickness and activity and clinical outcomes and data, such as ventilation parameters.

RESULTS

Sixty-two patients ventilated in controlled mode and then switched to the assisted mode of ventilation were enrolled. Diaphragm thickness significantly decreased during controlled ventilation (1.84 ± 0.44 to 1.49 ± 0.37 mm, p < 0.001) and was partially restored during assisted ventilation (1.49 ± 0.37 to 1.75 ± 0.43 mm, p < 0.001). A diaphragm thinning of more than 10% was associated with longer duration of controlled ventilation (10 [5, 15] versus 5 [4, 8.5] days, p = 0.004) and higher PEEP levels (12.6 ± 4 versus 10.4 ± 4 cmH₂O, p = 0.034). An increase in diaphragm thickness of more than 10% during assisted ventilation was not associated with any clinical outcome but with lower respiratory rate (16.7 ± 3.2 versus 19.2 ± 4 bpm, p = 0.019) and Rapid Shallow Breathing Index (37 ± 11 versus 44 ± 13, p = 0.029) and with higher Pressure Muscle Index (2 [0.5, 3] versus 0.4 [0, 1.9], p = 0.024). Change in diaphragm thickness was not related to diaphragm function expressed as diaphragm thickening fraction.

CONCLUSION

Mode of ventilation affects diaphragm thickness, and preservation of diaphragmatic contraction, as during assisted modes, can partially reverse the muscle atrophy process. Avoiding a strenuous inspiratory work, as measured by Rapid Shallow Breathing Index and Pressure Muscle Index, may help diaphragm thickness restoration.

Movement analysis in early infancy: Towards a motion biomarker of age

BACKGROUND

Early motor development is characterized by progressive changes in general movements paralleled by a gradual organization of the four limbs' repertoire towards the midline, as shown by computerised movement analysis.

AIMS

Our aim was to test the performance of quantitative computerised kinematic indexes as predictors of post-term age in an independent cohort of typically developing subjects at fidgety age, tested cross-sectionally.

SUBJECTS

We selected twelve low risk term infants, who were video recorded between 9 and 20 weeks (fidgety age) during one spontaneous movements session.

STUDY DESIGN

We correlated post-term age with I)indexes of coordination including interlimb correlation of velocity and position, II)indexes of distance, including interlimb and limb-to- ground, both expressed as linear distance and as probability of midline limbs position III)indexes of global movement quality by calculating Hjorth's activity, mobility and complexity parameters. All indexes were calculated for both upper and lower limbs.

RESULTS

Significant positive correlations were found between post-term age and indexes of distance, and probability of occurrence of upper-limb antigravity patterns, and with both indexes of global movement quality. By combining linear and non-linear parameters related to the upper limb kinematics, we determined individual post-term age with a mean error of <1 week (5.2 days). No correlations were found between age and indexes of coordination.

CONCLUSIONS

Quantitative computerised analysis of upper-limb movements is a promising predictor of post-term age in typically developing subjects at fidgety age.

Identification and Modulation of Microenvironment Is Crucial for Effective Mesenchymal Stromal Cell Therapy in Acute Lung Injury

Rationale: There are controversial reports on applications of mesenchymal stromal cells (MSCs) in patients with acute respiratory distress syndrome (ARDS). Objectives: We hypothesized that lung microenvironment was the main determinant of beneficial versus detrimental effects of MSCs during ARDS. Methods: Lung proteome was profiled in three models of injury induced by acid instillation and/or mechanical ventilation in mice. Human gene of glutathione peroxidase-1 was delivered before MSC administration; or MSCs carrying human gene of IL-10 or hepatocyte growth factor were administered after lung injury. An inhibitory cocktail against IL-6, fibronectin, and oxidative stress was used in in vitro studies using human small airway epithelial cells and human MSCs after exposure to plasma of patients with ARDS. Measurements and Main Results: Distinct proteomic profiles were observed in three lung injury models. Administration of MSCs protected lung from ventilator-induced injury, whereas it worsened acid-primed lung injuries associated with fibrotic development in lung environment that had high levels of IL-6 and fibronectin along with low antioxidant capacity. Correction of microenvironment with glutathione peroxidase-1, or treatment with MSCs carrying human gene of IL-10 or hepatocyte growth factor after acid-primed injury, reversed the detrimental effects of native MSCs. Proteomic profiles obtained in the mouse models were also similarly observed in human ARDS. Treatment with the inhibitory cocktail in samples of patients with ARDS retained protective effects of MSCs in small airway epithelial cells. Conclusions: MSCs can be beneficial or detrimental depending on microenvironment at the time of administration. Identification of potential beneficiaries seems to be crucial to guide MSC therapy in ARDS.

Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

Higher driving pressure during controlled mechanical ventilation is known to be associated with increased mortality in patients with acute respiratory distress syndrome.Whereas patients with acute respiratory distress syndrome are initially managed with controlled mechanical ventilation, as they improve, they are transitioned to assisted ventilation. Whether higher driving pressure assessed during pressure support (assisted) ventilation can be reliably assessed and whether higher driving pressure is associated with worse outcomes in patients with acute respiratory distress syndrome has not been well studied.

WHAT THIS ARTICLE TELLS US THAT IS NEW

This study shows that in the majority of adult patients with acute respiratory distress syndrome, both driving pressure and respiratory system compliance can be reliably measured during pressure support (assisted) ventilation.Higher driving pressure measured during pressure support (assisted) ventilation significantly associates with increased intensive care unit mortality, whereas peak inspiratory pressure does not.Lower respiratory system compliance also significantly associates with increased intensive care unit mortality.

BACKGROUND

Driving pressure, the difference between plateau pressure and positive end-expiratory pressure (PEEP), is closely associated with increased mortality in patients with acute respiratory distress syndrome (ARDS). Although this relationship has been demonstrated during controlled mechanical ventilation, plateau pressure is often not measured during spontaneous breathing because of concerns about validity. The objective of the present study is to verify whether driving pressure and respiratory system compliance are independently associated with increased mortality during assisted ventilation (i.e., pressure support ventilation).

METHODS

This is a retrospective cohort study conducted on 154 patients with ARDS in whom plateau pressure during the first three days of assisted ventilation was available. Associations between driving pressure, respiratory system compliance, and survival were assessed by univariable and multivariable analysis. In patients who underwent a computed tomography scan (n = 23) during the stage of assisted ventilation, the quantity of aerated lung was compared with respiratory system compliance measured on the same date.

RESULTS

In contrast to controlled mechanical ventilation, plateau pressure during assisted ventilation was higher than the sum of PEEP and pressure support (peak pressure). Driving pressure was higher (11 [9-14] vs. 10 [8-11] cm H2O; P = 0.004); compliance was lower (40 [30-50] vs. 51 [42-61] ml · cm H2O; P < 0.001); and peak pressure was similar, in nonsurvivors versus survivors. Lower respiratory system compliance (odds ratio, 0.92 [0.88-0.96]) and higher driving pressure (odds ratio, 1.34 [1.12-1.61]) were each independently associated with increased risk of death. Respiratory system compliance was correlated with the aerated lung volume (n = 23, r = 0.69, P < 0.0001).

CONCLUSIONS

In patients with ARDS, plateau pressure, driving pressure, and respiratory system compliance can be measured during assisted ventilation, and both higher driving pressure and lower compliance are associated with increased mortality.

Two different posterior-stabilized mobile-bearing TKA designs: navigator evaluation of intraoperative kinematic differences

PURPOSE

The purpose of this study was to compare two types of posterior-stabilized (PS) mobile-bearing (MB) total knee arthroplasties (TKAs). The hypothesis was that no major differences were going to be found among the two TKA designs.

METHODS

Two cohorts of patients who were divided according to implant design (Cohort A, new design gradually reducing radius PS MB TKA; Cohort B, traditional dual-radius PS MB TKA) were analyzed by means of intraoperative navigation. All operations were guided by a non-image-based navigation system that recorded relative femoral and tibial positions in native and implanted knees during the following kinematic tests: passive range of motion (PROM), varus-valgus stress test at 0° and 30° (VV0, VV30) and anterior/posterior drawer test at 90° of flexion (AP90).

RESULTS

There were no significative differences in kinematic tests between the two implants. Cohort A, however, showed a different post-implant trend for VV0 and VV30 that were lower than the pre-implant ones, as expected, while for Cohort B, the trend is opposite. However, the gradually reducing radius prosthesis (Cohort A) showed a trend of improving stability (29% compared to the preoperative status) in mid-flexion (VV30) which the traditional dual-radius design (Cohort B) would not. Moreover, we found no differences among postoperative results of the two TKA designs.

CONCLUSION

Despite design variations, no difference has been found among the prostheses in terms of PROM, rotations and translations. Both design kinematics did not show paradoxical external rotations, but an increase in femoral translation in mid-flexion without affecting the functioning of the prosthesis.

LEVEL OF EVIDENCE

II.

Neurological outcome of postanoxic refractory status epilepticus after aggressive treatment

Refractory status epilepticus (RSE) occurs in up to 30% of patients following resuscitation after cardiac arrest. The impact of aggressive treatment of postanoxic RSE on long-term neurological outcome remains uncertain. We investigated neurological outcome of cardiac arrest patients with RSE treated with a standardized aggressive protocol with antiepileptic drugs and anesthetics, compared with patients with other electroencephalographic (EEG) patterns. A prospective cohort of 166 consecutive patients with cardiac arrest in coma was stratified according to four independent EEG patterns (benign; RSE; generalized periodic discharges (GPDs); malignant nonepileptiform) and multimodal prognostic indicators. Primary outcomes were survival and cerebral performance category (CPC) at 6 months. Refractory status epilepticus occurred in 36 patients (21.7%) and was treated with an aggressive standardized protocol as long as multimodal prognostic indicators were not unfavorable. Refractory status epilepticus started after 3 ± 2.3 days after cardiac arrest and lasted 4.7 ± 4.3 days. A benign electroencephalographic patterns was recorded in 76 patients (45.8%), a periodic pattern (GPDs) in 13 patients (7.8%), and a malignant nonepileptiform EEG pattern in 41 patients (24.7%). The four EEG patterns were highly associated with different prognostic indicators (low flow time, clinical motor seizures, N20 responses, neuron-specific enolase (NSE), neuroimaging). Survival and good neurological outcome (CPC 1 or 2) at 6 months were 72.4% and 71.1% for benign EEG pattern, 54.3% and 44.4% for RSE, 15.4% and 0% for GPDs, and 2.4% and 0% for malignant nonepileptiform EEG pattern, respectively. Aggressive and prolonged treatment of RSE may be justified in cardiac arrest patients with favorable multimodal prognostic indicators. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

The basal to total insulin ratio in outpatients with diabetes on basal-bolus regimen

Objective

To evaluate the basal/total ratio of daily insulin dose (b/T) in outpatients with diabetes type 1 (DM1) and type 2 (DM2) on basal-bolus regimen, by investigating whether there is a relationship with HbA1c and episodes of hypoglycemia.

Methods

Multicentric, observational, cross-sectional study in Italy. Adult DM1 (n = 476) and DM2 (n = 541) outpatients, with eGFR >30 mL/min/1.73 m², on a basal-bolus regimen for at least six months, were recruited from 31 Italian Diabetes services between March and September 2016. Clinicaltrials.govID: NCT03489031.

Results

Total daily insulin dose was significantly higher in DM2 patients (52.3 ± 22.5 vs. 46 ± 20.9 U/day), but this difference disappeared when insulin doses were normalized for body weight. The b/T ratio was lower than 0.50 in both groups: 0.46 ± 0.14 in DM1 and 0.43 ± 0.15 in DM2 patients (p = 0.0011). The b/T was significantly higher in the patients taking metformin in both groups, and significantly different according to the type of basal insulin (Degludec, 0.48 in DM1 and 0.44 in DM2; Glargine, 0.44 in DM1 and 0.43 in DM2; Detemir, 0.45 in DM1 and 0.39 in DM2). The b/T ratio was not correlated in either group to HbA1c or incidence of hypoglycemia (<40 mg/dL, or requiring caregiver intervention, in the last three months). In the multivariate analysis, metformin use and age were independent predictors of the b/T ratio in both DM1 and DM2 patients, while the type of basal insulin was an independent predictor only in DM1.

Conclusion

The b/T ratio was independent of glycemic control and incidence of hypoglycemia.

Effect of Face Mask Design and Bias Flow on Rebreathing During Noninvasive Ventilation

BACKGROUND

Noninvasive ventilation (NIV) is used to treat respiratory failure because it reduces the risks of endotracheal intubation and postextubation respiratory failure. A wide range of different interfaces is available, but concerns exist about rebreathing. This study evaluated a total face mask with a 2-limb ventilation circuit and separate access for inflow and outflow gas, which was developed to reduce rebreathing.

METHODS

In a bench test, a standard total face mask (with a single connector to the ventilation circuit) and the modified total face mask were applied to a mannequin connected to an active breathing simulator. A known CO₂ flow (V̇_CO2 ) was delivered to the mannequin's trachea. We tested the following settings: CPAP with the mechanical PEEP valve set at 8 cm H₂O (with 60 and 90 L/min continuous flow) and pressure support of 6 and 12 cm H₂O (with 2 and 15 L/min bias flow). The settings were tested at simulated breathing frequencies of 15 and 30 breaths/min and with V̇_CO2 of 200 and 300 mL/min. The active simulator generated a tidal volume of 500 mL. Airway pressure, air flow, CO₂ concentration, and CO₂ flow as the product of air flow and CO₂ were recorded.

RESULTS

The mean volume of CO₂ rebreathed and the minimum CO₂ inspiratory concentration were significantly lower with the modified mask than with the standard mask. The 15 L/min bias flow significantly decreased rebreathing with the DiMax0 mask, whereas it had no effect with the traditional mask.

CONCLUSIONS

A face mask with a two-limb ventilation circuit and separate access for inflow and outflow gas reduces rebreathing during NIV. The addition of bias flow enhances this effect. Further studies are required to verify the clinical relevance.

Correction to: The basal to total insulin ratio in outpatients with diabetes on basal-bolus regimen

[This corrects the article DOI: 10.1007/s40200-018-0358-2.].

How cartilage status can be related to joint loads in anterior cruciate ligament reconstruction: a preliminary analysis including MRI t2 mapping and joint biomechanics

The knee is the largest and most complex joint in the human body. Traumatic events, such as anterior cruciate ligament (ACL) tear, can lead to an alteration of joint tissues homeostasis. Literature reports an evident correlation between abnormal joint biomechanics and the status of articular tissues. These alterations, due to a sub-optimal ACL reconstruction, may result in an increasing risk of developing degenerative pathologies, such as osteoarthritis. Thus, the identification of the optimal surgical technique is a highly demanding issue in ACL reconstruction. The aim of this study was to analyze the correlation between joint cartilage conditions and knee biomechanics in ACL reconstructions, by integrating MRI T2 mapping investigations, radiostereophotogrammetry-based gait analysis and subject-specific musculoskeletal modelling.

Neurologic outcome of postanoxic refractory status epilepticus after aggressive treatment

OBJECTIVE

To investigate neurologic outcome of patients with cardiac arrest with refractory status epilepticus (RSE) treated with a standardized aggressive protocol with antiepileptic drugs and anesthetics compared to patients with other EEG patterns.

METHODS

In the prospective cohort study, 166 consecutive patients with cardiac arrest in coma were stratified according to 4 independent EEG patterns (benign, RSE, generalized periodic discharges [GPDs], malignant nonepileptiform) and multimodal prognostic indicators. Primary outcomes were survival and cerebral performance category (CPC) at 6 months.

RESULTS

RSE occurred in 36 patients (21.7%) and was treated with an aggressive standardized protocol as long as multimodal prognostic indicators were not unfavorable. RSE started after 3 ± 2.3 days after cardiac arrest and lasted 4.7 ± 4.3 days. A benign EEG pattern was recorded in 76 patients (45.8%); a periodic pattern (GPDs) was seen in 13 patients (7.8%); and a malignant nonepileptiform EEG pattern was recorded in 41 patients (24.7%). The 4 EEG patterns were highly associated with different prognostic indicators (low-flow time, clinical motor seizures, N20 responses, neuron-specific enolase, neuroimaging). Survival and good neurologic outcome (CPC 1 or 2) at 6 months were 72.4% and 71.1% for benign EEG pattern, 54.3% and 44.4% for RSE, 15.4% and 0% for GPDs, and 2.4% and 0% for malignant nonepileptiform EEG pattern, respectively.

CONCLUSIONS

Aggressive and prolonged treatment of RSE may be justified in patients with cardiac arrest with favorable multimodal prognostic indicators.

Percutaneous treatment of hallux valgus: What's the evidence? A systematic review

Hallux and first MTP joint have a fundamental role in the transfer of the weight-bearing load during the normal ambulation. The aim of this paper is to review and analyze the available literature about the percutaneous surgical management of the hallux valgus to highlight its strengths and weakness, also comparing with other minimal invasive techniques. A systematic search of PubMed and Google Scholar databases has been performed, covering the period between 1981 and 2016. Various combinations of the keyword terms "PDO," "hallux valgus," "bunion," "percutaneous," "surgery," "non-invasive," "minimal invasive," "burr," "osteotomy," "distal," "linear," "saw" have been used.Four papers, published from 2005 to 2015, fulfilled the inclusion criteria. A total of 464 hallux valgus has been treated with a properly percutaneous distal first metatarsal osteotomy. Mean AOFAS score, retrieved from the 4 studies included in our review, has been recorded. There are different aspects that the foot and ankle non-experienced surgeon has to consider about percutaneous surgery: limitation of the tools, radioexposure, lack of direct visual control of the osteotomy and higher costs and patient risk due to surgical time.

Thrombosis in Cancer Patients Treated with Hematopoietic Growth Factors - A Meta-Analysis

Hematopoietic colony-stimulating factors (CSFs) are largely used in patients with cancer undergoing cytotoxic treatment to accelerate neutrophil recovery and decrease the incidence of febrile neutropenia. Clinical practice guidelines for their use have been recently established (1), taking into account clinical benefit, but also cost and toxicity. Vascular occlusions have been recently reported among the severe reactions associated with the use of CSFs, in anedoctal case reports (2, 3), consecutive case series (4) and randomized clinical trial (5, 6). However, the role of CSFs in the pathogenesis of thrombotic complications is difficult to ascertain, because pertinent data are scanty and widely distributed over a number of heterogenous investigations. We report here a systematic review of relevant articles, with the aims to estimate the prevalence of thrombosis associated with the use of CSFs and to assess if this rate is significantly higher than that observed in cancer patients not receiving CSFs.

Anterior cruciate ligament revision with Achilles tendon allograft in young athletes

BACKGROUND

Return to sport after revision ACL reconstruction is a controversial topic, several studies reported the results of different techniques and graft in sportsman, presenting an incredibly wide range of return to the same pre-injury activity level, from 0% to 100%. The purpose of this study was to evaluate the clinical outcomes and return to sport rate in young athletes after non anatomic double-bundle revision ACL reconstruction with Achilles allograft.

HYPOTHESIS

The present revision technique was effective in terms of stability, return to sport and functional outcomes.

MATERIAL AND METHODS

All the athletes undergone Revision ACL reconstruction with non-irradiated Achilles tendon allograft with a non-anatomical double-bundle technique were included in the study. A split Achilles tendon allograft was used to reproduce the anteromedial (AM) bundle using the over-the-top position, while the posterolateral (PL) bundle was reconstructed through a femoral tunnel located in the anatomical PL footprint. Sport activity, knee function with Lysholm score, knee laxity and re-injury or re-operations were evaluated.

RESULTS

Twenty-six athletes (23 males, three females) with a mean age of 23.4±3.6 years were evaluated at a mean follow-up of 6.0±1.6 years. Overall 69% of patients returned to sport both at elite (44%) or county level (56%) after a mean 6.7±1.5 (3-9 range) months. The mean Lysholm score showed a significant improvement from 64.4±8.1 at pre-operative status to 83.8±11.3 at final follow-up (P<.0001). Seven patients (30%) were rated as excellent, nine (39%) as good, five (22%) as fair and 2 (9%) as poor. Three patients (12%) experienced a further graft rupture after a mean 2.6 years, (3.5 months-48 months range) and two had >5mm side-to-side difference at KT-1000. Therefore, the overall survival rate at mean six years follow-up was 81%.

CONCLUSION

The ACL revision with a double-bundle technique using Achilles tendon allograft was successful in 81% of athletes at six years mean follow-up.

TYPE OF STUDY AND LEVEL OF EVIDENCE

Retrospective case series, level IV.

Radiation-pressure-driven ion Weibel instability and collisionless shocks

The Weibel instability from counterstreaming plasma flows is a basic process highly relevant for collisionless shock formation in astrophysics. In this paper we investigate, via two- and three-dimensional simulations, suitable configurations for laboratory investigations of the ion Weibel instability (IWI) driven by a fast quasineutral plasma flow launched into the target via the radiation pressure of an ultra-high-intensity laser pulse ("hole-boring" process). The use of S-polarized light at oblique incidence is found to be an optimal configuration for driving IWI, as it prevents the development of surface rippling observed at normal incidence that would lead to strong electron heating and would favor competing instabilities. Conditions for the evolution of IWI into a collisionless shock are also investigated.

Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction? a meta-analysis of 32 studies

AIMS

Our aim was to perform a meta-analysis of the outcomes of revision anterior cruciate ligament (ACL) reconstruction, comparing the use of different types of graft.

MATERIALS AND METHODS

A search was performed of Medline and Pubmed using the terms "Anterior Cruciate Ligament" and "ACL" combined with "revision", "re-operation" and "failure". Only studies that reported the outcome at a minimum follow-up of two years were included. Two authors reviewed the papers, and outcomes were subdivided into autograft and allograft. Autograft was subdivided into hamstring (HS) and bone-patellar tendon-bone (BPTB). Subjective and objective outcome measures were analysed and odds ratios with confidence intervals were calculated.

RESULTS

A total of 32 studies met the inclusion criteria. Five studies used HS autografts, eight reported using BPTB autografts, two used quadriceps tendon autografts and eight used various types. Seven studies reported using allografts, while the two remaining used both BPTB autografts and allografts. Overall, 1192 patients with a mean age of 28.7 years (22.5 to 39) and a mean follow-up of 5.4 years (2.0 to 9.6) were treated with autografts, while 269 patients with a mean age of 28.4 years (25 to 34.6) and a mean follow-up of 4.0 years (2.3 to 6.0) were treated with allografts. Regarding allografts, irradiation with 2.5 mrad was used in two studies while the graft was not irradiated in the seven remaining studies. Reconstructions following the use of autografts had better outcomes than those using allograft with respect to laxity, measured by KT-1000/2000 (MEDmetric Corporation) and the rates of complications and re-operations. Those following the use of allografts had better mean Lysholm and Tegner activity scores compared with autografts. If irradiated allografts were excluded from the analysis, outcomes no longer differed between the use of autografts and allografts. Comparing the types of autograft, all outcomes were similar except for HS grafts which had better International Knee Documentation Committee scores compared with BPTB grafts.

CONCLUSION

Autografts had better outcomes than allografts in revision ACL reconstruction, with lower post-operative laxity and rates of complications and re-operations. However, after excluding irradiated allografts, outcomes were similar between autografts and allografts. Overall, the choice of graft at revision ACL reconstruction should be on an individual basis considering, for instance, the preferred technique of the surgeon, whether a combined reconstruction is required, the type of graft that was previously used, whether the tunnels are enlarged and the availability of allograft. Cite this article: Bone Joint J 2017;99-B:714-23.

Noninvasive mechanical ventilation in early acute respiratory distress syndrome

Noninvasive ventilation (NIV) has a well-‑established role in the treatment of acute-‑on-‑chronic respiratory failure and cardiogenic pulmonary edema. Its role in acute hypoxemic respiratory failure has been increasingly investigated, but its impact on the management and outcome of the subset of patients with acute respiratory distress syndrome (ARDS) is still to be determined. ARDS could be a risk factor for NIV failure, and in these patients, delayed endotracheal intubation can lead to an increased mortality. On the other hand, in a subset of patients with ARDS, endotracheal intubation can be avoided when NIV is applied. This review summarizes the current practice of NIV use in patients with ARDS and underlines the importance of proper patient selection before an NIV trial as well as criteria that should be used to predict failure early enough. A brief overview of high-‑flow nasal cannula is also provided. The use of NIV in ARDS is still debated, and it is important to be aware of the potential limitations and pitfalls of this treatment, which, when properly applied, could reduce the incidence of endotracheal intubation.

Total knee replacement: intraoperative and postoperative kinematic assessment

BACKGROUND AND AIM

The main goals of the total knee arthroplasty (TKA) is to reduce the perceived pain and  restore knee mobility and function in case of osteoarthritic knees joints. Literature shows how the three major causes of TKA failures are related to wear, loosening and instability and this is due to a problem of imbalance and malalignment. Intraoperative and postoperative kinematics analysis could be of benefit for improving surgery outcome. The aim of the present paper is to give an overview of the two set-up with the highest accuracy for intraoperative and postoperative TKA kinematics evaluation, currently in use at Istituto Ortopedico Rizzoli. Introperative and Postoperative Evaluation: For intraoperative evaluation it has been presented a navigation system with a specifically developed software, while for the postoperative it has been presented the roentgen stereophotogrammetric analysis (RSA). The navigation system consists in a laptop connected with an optoelectronic localizer (Polaris, Northern Digital Inc, Canada).  Two reference arrays with passive optical markers and a marked probe are used to localize the knee joint in the 3D space and track the joint kinematics. The RSA is a radiographic technique used in orthopaedic field for measuring micromotion at bone/prosthesis interface or for joint kinematics evaluation. The RSA uses two X-ray sources synchronized with two digital flat-panels.

CONCLUSIONS

The present paper shows that using the navigation system allows the surgeon to easily perform kinematic and alignment evaluation during TKA surgery while the RSA allows a quantitative evaluation of the joint kinematics during the recovery time.

Bone texture analysis using CT-simulation scans to individuate risk parameters for radiation-induced insufficiency fractures

This study deals with the role of texture analysis as a predictive factor of radiation-induced insufficiency fractures in patients undergoing pelvic radiation.

INTRODUCTION

This study aims to assess the texture analysis (TA) of computed tomography (CT) simulation scans as a predictive factor of insufficiency fractures (IFs) in patients with pelvic malignancies undergoing radiation therapy (RT).

METHODS

We performed an analysis of patients undergoing pelvic RT from January 2010 to December 2014, 24 of whom had developed pelvic bone IFs. We analyzed CT-simulation images using ImageJ macro software and selected two regions of interest (ROIs), which are L5 body and the femoral head. TA parameters included mean (m), standard deviation (SD), skewness (sk), kurtosis (k), entropy (e), and uniformity (u). The IFs patients were compared (1:2 ratio) with controlled patients who had not developed IFs and matched for sex, age, menopausal status, type of tumor, use of chemotherapy, and RT dose. A reliability test of intra- and inter-reader ROI TA reproducibility with the intra-class correlation coefficient (ICC) was performed. Univariate and multivariate analyses (logistic regression) were applied for TA parameters observed both in the IFs and the controlled groups.

RESULTS

Inter- and intra-reader ROI TA was highly reproducible (ICC > 0.90). Significant TA parameters on paired t test included L5 m (p = 0.001), SD (p = 0.002), k (p = 0.006), e (p = 0.004), and u (p = 0.015) and femoral head m (p < 0.001) and SD (p = 0.001), whereas on logistic regression analysis, L5 e (p = 0.003) and u (p = 0.010) and femoral head m (p = 0.027), SD (p = 0.015), and sex (p = 0.044).

CONCLUSIONS

In our experience, bone CT TA could be correlated to the risk of radiation-induced IFs. Studies on a large patient series and methodological refinements are warranted.

Magnetic properties and element concentrations in lichens exposed to airborne pollutants released during cement production

The content of selected elements (Al, As, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Ti, V and Zn) was measured in samples of the lichen Evernia prunastri exposed for 30, 90 and 180 days around a cement mill, limestone and basalt quarries and urban and agricultural areas in SW Slovakia. Lichens transplanted around the investigated quarries and the cement mill rapidly (30 days) reflected the deposition of dust-associated elements, namely Ca (at the cement mill and the limestone quarry) and Fe, Ti and V (around the cement mill and the basalt quarry), and their content remained significantly higher throughout the whole period (30-180 days) with respect to the surrounding environment. Airborne pollutants (such as S) progressively increased in the study area from 30 to 180 days. The magnetic properties of lichen transplants exposed for 180 days have been characterized and compared with those of native lichens (Xanthoria parietina) and neighbouring bark, soil and rock samples, in order to test the suitability of native and transplanted samples as air pollution magnetic biomonitors. The magnetic mineralogy was homogeneous in all samples, with the exception of the samples from the basalt quarry. The transplants showed excellent correlations between the saturation remanent magnetization (Mrs) and the content of Fe. Native samples had a similar magnetic signature, but the values of the concentration-dependent magnetic parameters were up to two orders of magnitude higher, reflecting higher concentrations of magnetic particles. The concentrations of As, Ca and Cr in lichens correlated with Mrs values after neglecting the samples from the basalt quarry, which showed distinct magnetic properties, suggesting the cement mill as a likely source. Conversely, Ti and Mn were mostly (but not exclusively) associated with dust from the basalt quarry. It is suggested that the natural geological characteristics of the substrate may strongly affect the magnetic properties of lichen thalli. Taking this into account, the results of this study point out the suitability of lichens as air pollution magnetic biomonitors.

Kinematics of ACL and anterolateral ligament. Part I: Combined lesion

PURPOSE

To quantify the influence of ALL lesions on static and dynamic laxity in ACL-deficient knee.

METHODS

The study was performed in 10 fresh-frozen knees. The joints were analysed in the following conditions: intact, ACL resection and ACL + ALL resection. Testing parameters were defined as: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual-maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5 N m torque and internal rotation and acceleration during manual pivot-shift (PS) test. Kinematics was acquired by a navigation system; a testing rig and a torquemeter were used to control the limb position and the applied torque. Paired Student's t test was conducted to assess statistical difference, and significance was set at P < 0.05.

RESULTS

The ALL resection determined a significant increase in terms of internal rotation (INT30 P = 0.02, INT90 P = 0.03), while AP30 (P n.s) and AP90 (P n.s) were not affected. ALL resection produced a significant increase in terms of acceleration during PS test (P < 0.01), but no significant change in PS internal rotation was observed.

CONCLUSION

The ALL plays a significant role in controlling static internal rotation and acceleration during PS test. On the other hand, ALL resection did not produce any significant change in terms of anterior displacement. A trend was seen for the internal rotation during the pivot-shift test to increase after ALL resection was higher when compared to the intact and isolated ACL lesion states; however, the differences were not significant. The results highlight the clinical relevance of this structure that should be assessed before an ACL reconstruction in order to avoid residual laxity.

Electron Weibel instability in relativistic counterstreaming plasmas with flow-aligned external magnetic fields

The Weibel instability driven by two symmetric counterstreaming relativistic electron plasmas, also referred to as current-filamentation instability, is studied in a constant and uniform external magnetic field aligned with the plasma flows. Both the linear and nonlinear stages of the instability are investigated using analytical modeling and particle-in-cell simulations. While previous studies have already described the stabilizing effect of the magnetic field, we show here that the saturation stage is only weakly affected. The different mechanisms responsible for the saturation are discussed in detail in the relativistic cold fluid framework considering a single unstable mode. The application of an external field leads to a slight increase of the saturation level for large wavelengths, while it does not affect the small wavelengths. Multimode and temperature effects are then investigated. While at high temperature the saturation level is independent of the external magnetic field, at low but finite temperature the competition between different modes in the presence of an external magnetic field leads to a saturation level lower with respect to the unmagnetized case.

Total knee replacement: intraoperative and postoperative kinematic assessment

BACKGROUND AND AIM

The main goals of the total knee arthroplasty (TKA) is to reduce the perceived pain and  restore knee mobility and function in case of osteoarthritic knees joints. Literature shows how the three major causes of TKA failures are related to wear, loosening and instability and this is due to a problem of imbalance and malalignment. Intraoperative and postoperative kinematics analysis could be of benefit for improving surgery outcome. The aim of the present paper is to give an overview of the two set-up with the highest accuracy for intraoperative and postoperative TKA kinematics evaluation, currently in use at Istituto Ortopedico Rizzoli. Introperative and Postoperative Evaluation: For intraoperative evaluation it has been presented a navigation system with a specifically developed software, while for the postoperative it has been presented the roentgen stereophotogrammetric analysis (RSA). The navigation system consists in a laptop connected with an optoelectronic localizer (Polaris, Northern Digital Inc, Canada).  Two reference arrays with passive optical markers and a marked probe are used to localize the knee joint in the 3D space and track the joint kinematics. The RSA is a radiographic technique used in orthopaedic field for measuring micromotion at bone/prosthesis interface or for joint kinematics evaluation. The RSA uses two X-ray sources synchronized with two digital flat-panels.

CONCLUSIONS

The present paper shows that using the navigation system allows the surgeon to easily perform kinematic and alignment evaluation during TKA surgery while the RSA allows a quantitative evaluation of the joint kinematics during the recovery time.

ACL rupture and joint laxity progression: a quantitative in vivo analysis

PURPOSE

Benefits of an early reconstruction and the optimal time lapse between injury and surgery to reduce the effects of altered kinematics in ACL-deficient knees are still controversial.

AIM

The aim of this study was to clarify, through a quantitative in vivo evaluation, the effects of the time lapse between ACL injury and surgery in terms of changes in the pre-operative knee laxity.

METHODS

An in vivo study was performed on 99 patients who underwent ACL surgery. Just before the graft fixation, six laxity tests were performed for all the subjects at manual-maximum load: anterior-posterior displacement and internal-external rotation at 30° and 90° of knee flexion (AP30, AP90, IE30, IE90) as well as varus-valgus rotation (VV0, VV30) at 0° and 30° of flexion. Kinematics data were acquired by a navigation system. The Spearman rank correlation was used to assess correlation between rank and continuous data. Significance was set at P = 0.05.

RESULTS

The analysis highlighted a significant influence of the injury-to-surgery time lapse on VV0 and AP90 compared with pre-operative laxity levels. Meniscus status also significantly affected the pre-operative laxity in the VV0 (Spearman's ρ = 0.203, P = 0.038; GLM with meniscal correction partial η = 0.27, P = 0.007) and AP90 (Spearman's ρ = 0.329, P = 0.001; GLM with meniscal correction partial η = 0.318, P = 0.017) tests.

CONCLUSION

The main finding of this study is that patients with ACL rupture and a higher injury-to-surgery time present higher values of knee laxity involving AP90 displacement and VV30 rotation. Clinical relevance of the study is that ACL-deficient joint laxity, involving anterior-posterior displacement at 90° of knee flexion and varus-valgus rotation at 0° of flexion, is significantly affected by the lapse of injury-to-surgery time. This highlights the importance of considering the effects of delaying surgery when managing patients with such deficiency.

Technical variables of ACL surgical reconstruction: effect on post-operative static laxity and clinical implication

PURPOSE

The hypothesis was that an alteration of different surgical variables of ACL reconstruction would produce significant changes in post-operative static laxity of knee joint.

METHODS

Joint laxity was acquired by a surgical navigation system for 17 patients just after graft fixation during single-bundle reconstruction with extra-articular lateral tenodesis. The analysed laxity parameters were: internal/external rotation at 30° (IE30) and 90° (IE90) of flexion, varus/valgus rotation at 0° (VV0) and 30° (VV30) of flexion and anterior/posterior displacement at 30° (AP30) and 90° (AP90) of flexion. As surgical variables, the angles between the tibial tunnel and the three planes were defined as well as the lengths of the tunnel and the relationship between native footprints and tunnels. The same analysis was performed for the femoral side. All surgical variables were combined in a multivariate analysis to assess for predictive factors between them and post-operative laxities values. To quantify the performance of each multivariate model, the correlation ratio (η ²) and the corresponding P value (*P < 0.050) have been evaluated.

RESULTS

Multivariate analysis underlined statistically significant models for the estimation of: AP30 (η ² = 0.987; P = 0.014), IE30 (η ² = 0.995; P = 0.005), IE90 (η ² = 0.568; P = 0.010), VV0 (η ² = 0.932; P = 0.003). The parameters that greatly affected the identified models were the orientation of the tibial tunnel with respect to the three anatomical planes. The estimation of AP30, IE30 and IE90 got lower value as the orientation of the tibial tunnel with respect to transverse plane decreases. Considering the orientation to sagittal ([Formula: see text]) and coronal ([Formula: see text]) plane, we found that their reduction provoked a decrease in the estimation of AP30, IE30 and IE90 (except [Formula: see text] that did not appear in the estimation of AP30). The estimation of VV0 got an increase of [Formula: see text], and [Formula: see text] which led to a laxity reduction.

CONCLUSION

The main finding of the present in vivo study was the possibility to determine significant effects on post-operative static laxity level of different surgical variables of ACL reconstruction. In particular, the present study defined the conditions that minimize the different aspects of post-operative laxity at time-zero after surgery.

Does meniscus removal affect ACL-deficient knee laxity? An in vivo study

PURPOSE

The purpose of the present study was to determine, in vivo, the effect of different types of meniscectomy on an ACL-deficient knee.

METHODS

Using a computer-assisted navigation system, 56 consecutive patients (45 men and 11 women) were subjected to a biomechanical testing with Lachman test (AP30), drawer test (AP90), internal/external rotation test, varus/valgus rotation test and pivot-shift test. The patients were divided into three groups according to the status of the medial meniscus. Group BH, 8 patients with bucket-handle tear of medial meniscus underwent a subtotal meniscectomy; Group PHB, 19 patients with posterior horn body of medial meniscus tear underwent a partial meniscectomy; and Group CG with isolated ACL rupture, as a control group, with 29 patients.

RESULTS

A significant difference in anterior tibial translation was seen at 30 grades and in 90 grades between BH and PHB groups compared to the CG. In response to pivot-shift test, no significant differences in terms of AREA and POSTERIOR ACC were found among the three groups (n.s). Concerning the anterior displacement of the pivot shift a statistically significant differences among the three tested groups was found.

CONCLUSION

The present study shows that meniscal defects significantly affect the kinematics of an ACL-deficient knee in terms of anterior tibial translation under static and dynamic testing.