Altered EEG Patterns in Individuals with Disorganized Attachment: An EEG Microstates Study.

Over the past years, different studies provided preliminary evidence that Disorganized Attachment (DA) may have dysregulatory and disintegrative effects on both autonomic arousal regulation and brain connectivity. However, despite the clinical relevance of this construct, few studies have investigated the specific alterations underlying DA using electroencephalography (EEG). Thus, the main aim of the current study was to investigate EEG microstate parameters of DA in a non-clinical sample (N = 50) before (pre) and after (post) the administration of the Adult Attachment Interview (AAI). Two EEG eyes-closed Resting State (RS) recordings were performed before and after the AAI, which was used for classifying the participants [i.e., Disorganized/Unresolved (D/U) or Organized/Resolved (O/R) individuals] and to trigger the attachment system. Microstates parameters (i.e., Mean Duration, Time Coverage and Occurrence) were extracted from each recording using Cartool software. EEG microstates clustering analysis revealed 6 different maps (labeled A, B, C, D, E, F) in both groups (i.e., D/U and O/R individuals) and in both conditions (i.e., pre-AAI and post-AAI). In the pre-AAI condition, compared to O/R individuals, D/U participants showed a shorter Mean Duration and Time Coverage of Map F; in the post-AAI condition, a significant reduction in the Mean Duration of Map E was also observed in D/U individuals. Finally, in the "within" statistical analysis (i.e., pre-AAI vs. post-AAI), only the D/U group exhibited a significant increase in Time Coverage of Map F after the AAI. Since these maps are associated with brain networks involved in emotional information processing and mentalization (i.e., Salience Network and Default Mode Network), our result might reflect the deficit in the ability to mentalize caregiver's interaction as well as the increased sensitivity to attachment-related stimuli typically observed in individuals with a D/U state of mind.

Psychometric Properties of the Detachment and Compartmentalization Inventory (DCI) in an Italian Community Sample.

The Detachment and Compartmentalization Inventory (DCI) is a valid and reliable self-report instrument that assesses these two distinct forms of dissociative symptoms. However, there is limited research on the cross-cultural validation of the DCI. Therefore, this study aimed to develop an Italian translation of the DCI and examine its internal structure and psychometric properties (including internal consistency, convergent validity, and test-retest reliability) within an Italian-speaking community sample. The sample consisted of 1276 adults (887 females; mean age: 29.57 ± 10.96 years), who completed the DCI and other self-report measures evaluating dissociative experiences and childhood trauma. Confirmatory factor analyses supported the original two-factor model (χ2169 = 1312.80, RMSEA = 0.073, 95%CI 0.069-0.077; CFI = 0.94; TLI = 0.94; SRMR = 0.04). Additionally, the DCI exhibited good internal consistency, test-retest reliability, and convergent validity with another measure of dissociation. The study also confirmed the association between DCI scores and the severity of childhood trauma. Finally, a Receiver Operating Characteristic (ROC) curve analysis demonstrated that the DCI effectively distinguishes individuals who screened positively for dissociative disorders. Overall, these findings indicate that the Italian translation of the DCI possesses satisfactory psychometric properties, suggesting its utility as a screening tool for assessing detachment and compartmentalization experiences.

Significance of Elastic Coupling for Stresses and Leakage in Frictional Contacts.

We study how the commonly neglected coupling of normal and in-plane elastic response affects tribological properties when Hertzian or randomly rough indenters slide past an elastic body. Compressibility-induced coupling is found to substantially increase maximum tensile stresses, which cause materials to fail, and to decrease friction such that Amontons' law is violated macroscopically even when it holds microscopically. Confinement-induced coupling increases friction and enlarges domains of high tension. Moreover, both types of coupling affect the gap topography and thereby leakage. Thus, coupling can be much more than a minor perturbation of a mechanical contact.

Role of Reference Frames for a Safe Human-Robot Interaction.

Safety plays a key role in human-robot interactions in collaborative robot (cobot) applications. This paper provides a general procedure to guarantee safe workstations allowing human operations, robot contributions, the dynamical environment, and time-variant objects in a set of collaborative robotic tasks. The proposed methodology focuses on the contribution and the mapping of reference frames. Multiple reference frame representation agents are defined at the same time by considering egocentric, allocentric, and route-centric perspectives. The agents are processed to provide a minimal and effective assessment of the ongoing human-robot interactions. The proposed formulation is based on the generalization and proper synthesis of multiple cooperating reference frame agents at the same time. Accordingly, it is possible to achieve a real-time assessment of the safety-related implications through the implementation and fast calculation of proper safety-related quantitative indices. This allows us to define and promptly regulate the controlling parameters of the involved cobot without velocity limitations that are recognized as the main disadvantage. A set of experiments has been realized and investigated to demonstrate the feasibility and effectiveness of the research by using a seven-DOF anthropomorphic arm in combination with a psychometric test. The acquired results agree with the current literature in terms of the kinematic, position, and velocity aspects; use measurement methods based on tests provided to the operator; and introduce novel features of work cell arranging, including the use of virtual instrumentation. Finally, the associated analytical-topological treatments have enabled the development of a safe and comfortable measure to the human-robot relation with satisfactory experimental results compared to previous research. Nevertheless, the robot posture, human perception, and learning technologies would have to apply research from multidisciplinary fields such as psychology, gesture, communication, and social sciences in order to be prepared for positioning in real-world applications that offer new challenges for cobot applications.

The psychological impact of the COVID-19 lockdown in Italy: The moderating role of gender and emotion regulation.

Many researchers suggest that the COVID-19 pandemic may have more negative effects on women than men. Accordingly, we hypothesized that women would experience greater COVID-19 related distress and more psychopathological symptoms than men during the first COVID-19 lockdown in Italy. Moreover, we expected emotion regulation strategies (cognitive reappraisal and expressive suppression, as protective and risk factors respectively) to interact with gender in shaping psychological health. We administered an online questionnaire to 1519 participants during the first national COVID-19 lockdown in Italy. As predicted, women reported greater COVID-19 related distress and more psychopathological symptoms than men. Furthermore, women who made greater use of reappraisal reported lower levels of distress and fewer psychopathological symptoms. Suppression was associated with more psychopathological symptoms, but there were no interaction effects with gender. Our findings have implications for policymakers wishing to sustain women's health during stressful situations such as the COVID-19 outbreak and beyond.

The Relationship Between Childhood Trauma, Pathological Dissociation, and Behavioral Addictions in Young Adults: Findings from a Cross-Sectional Study.

Interactions between childhood trauma (CT) and dissociation can contribute to psychiatric disturbances. We explored this phenomenon in relation to behavioral addictions (BAs) in a sample (n = 633) of young adults (age: 18-34 years). Self-report measures investigating CT, dissociation, and symptoms related to gambling disorder, internet gaming disorder, problematic social media use, exercise dependence and compulsive buying were used. Scales related to BAs were summarized into a single measure ("Total Behavioral Addiction Index" - TBAI) for inferential analyses. A model analyzing the direct and indirect effects of CT on TBAI through the mediation of pathological dissociation was performed, controlling for confounding factors. Measures on CT, dissociation, and TBAI were significantly associated with each other (all p < .001). The total effect of CT on TBAI was significant (B = 0.063; CI: 0.045; 0.081); pathological dissociation significantly mediated such association (B = 0.023; CI: 0.013; 0.036). Our findings support the possibility that the interaction between CT and dissociation contributes to increase disturbances related to BAs.

Dissociative experiences of compartmentalization are associated with food addiction symptoms: results from a cross-sectional report.

PURPOSE: Studies have shown significant associations of dissociative symptoms with both eating and addictive disorders; however, the different forms of dissociation have been relatively understudied in relation to food addiction (FA). The main aim of this study was to investigate the association of certain forms of dissociative experiences (i.e., absorption, detachment and compartmentalization) with FA symptoms in a nonclinical sample. METHODS: Participants (N = 755; 543 women; age range: 18-65; mean age: 28.22 ± 9.99 years) were evaluated using self-report measures of FA, dissociation, eating disturbances, and general psychopathology. RESULTS: Compartmentalization experiences (defined as pathological over-segregation of higher mental functions) were independently associated with FA symptoms (ß = 0.174; p = 0.013; CI = [0.008; 0.064]) even when confounding factors were controlled for. CONCLUSION: This finding suggests that compartmentalization symptoms can have a role in the conceptualization of FA, with such two phenomena possibly sharing common pathogenic processes. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Decreased Resting State Inter- and Intra-Network Functional Connectivity Is Associated with Perceived Stress in a Sample of University Students: An eLORETA Study.

INTRODUCTION: Although the study of the Triple Network (TN) model has gained attention in the exploration of stress-related processes, the neurophysiological mechanisms of TN in relation to perceived stress have been relatively understudied in nonclinical samples so far. The main objective of the present study was to investigate, in a sample of university students, the association of perceived stress with resting state electroencephalography (EEG) functional connectivity in the TN. METHODS: Ninety university students (40 males and 50 females; mean age 22.30 ± 2.43 years; mean educational level 16.60 ± 1.62 years) were enrolled. EEG data were analyzed through the exact low-resolution electromagnetic tomography (eLORETA). RESULTS: Higher levels of perceived stress were associated with decreased delta EEG connectivity within the central executive network (CEN) and between the CEN and the salience network (SN). Higher levels of perceived stress were also associated with decreased theta EEG connectivity between the CEN and the SN. The associations between perceived stress and EEG connectivity data were significant even when relevant confounding factors (i.e., sex, age, educational level, and psychopathological symptoms) were controlled for. DISCUSSION: Taken together, our results suggest that higher levels of perceived stress are associated with a dysfunctional synchronization within the CEN and between the SN and the CEN. This functional pattern might in part reflect the negative impact of high levels of perceived stress on cognitive functioning.

Dissociative-Traumatic Dimension and Triple Network: An EEG Functional Connectivity Study in a Sample of University Students.

AIMS: We investigated the association among triple network electroencephalographic (EEG) functional connectivity, dissociative symptoms, and childhood trauma (CT) in a sample of university students. SAMPLING AND METHODS: Seventy-six participants (30 males and 46 females; mean age 22.12 ± 2.35) completed self-report measures investigating dissociative symptoms, CT, and depressive symptoms. Participants also performed an eyes-closed resting-state EEG recording. EEG analyses were conducted through the exact low-resolution electromagnetic tomography (eLORETA) software. RESULTS: A 2-step cluster analysis revealed 2 groups: participants (N = 23) with high dissociative-traumatic dimension symptoms (DTD+) and participants (N = 53) with low DTD symptoms (DTD-). Compared to DTD- subjects, DTD+ participants showed decreased theta connectivity between the salience network (SN) and central executive network (CEN), specifically between the right anterior insula and the left posterior parietal cortex. No significant correlation was detected between EEG data and clinical variables. CONCLUSION: Our results raise the possibility of a dysfunctional connectivity pattern occurring between the SN and CEN in individuals with high DTD symptoms. Such connectivity pattern might reflect the neuropsychophysiological disintegration related to pathological dissociation.

The association of problematic use of social media and online videogames with aggression is mediated by insomnia severity: A cross-sectional study in a sample of 18- to 24-year-old individuals.

One of the worrying concomitants of problematic use of Internet (PUI) is aggression. Although the mechanisms underlying such link have not been completely clarified, it has been suggested that problematic use of social media and online videogames (i.e., two common forms of PUI among young adults) lead to increased sleep disturbances which, in turn, represent a relevant trigger for aggression. We have tested this hypothesis in a sample (N = 480) of young individuals (351 females and 129 males; mean age: 21.76 ± 1.92 years; range: 18-24). Self-report measures investigating symptoms related to social media addiction (SMA), Internet gaming disorder (IGD), insomnia severity, and aggression were used. Mediational models analyzing the direct and indirect associations of SMA- and IGD-related symptoms on aggression severity through insomnia-related symptoms were performed controlling for confounding factors. The models showed that the total effects of SMA-related symptoms (B = 0.018; p = .010) and of IGD-related symptoms (B = 0.018; p = .041) on aggression severity were significant and that these associations were mediated by insomnia-related symptoms (respectively, p < .001 and p = .003). Our findings support the potential mediating role of insomnia severity in the association of SMA- and IGD-related disturbances with levels of aggression.

Analysis of the Leap Motion Controller's Performance in Measuring Wrist Rehabilitation Tasks Using an Industrial Robot Arm Reference.

The Leap Motion Controller (LMC) is a low-cost markerless optical sensor that performs measurements of various parameters of the hands that has been investigated for a wide range of different applications. Research attention still needs to focus on the evaluation of its precision and accuracy to fully understand its limitations and widen its range of applications. This paper presents the experimental validation of the LMC device to verify the feasibility of its use in assessing and tailoring wrist rehabilitation therapy for the treatment of physical disabilities through continuous exercises and integration with serious gaming environments. An experimental set up and analysis is proposed using an industrial robot as motion reference. The high repeatability of the selected robot is used for comparisons with the measurements obtained via a leap motion controller while performing the basic movements needed for rehabilitation exercises of the human wrist. Experimental tests are analyzed and discussed to demonstrate the feasibility of using the leap motion controller for wrist rehabilitation.

Current concepts in the diagnosis and treatment of adhesive capsulitis: role of diagnostic imaging and ultrasound-guided interventional procedures.

Adhesive capsulitis is a common cause of painful shoulder, characterized by pain and restricted range of motion of the glenohumeral joint. With a well-known clinical presentation, and an increasing understanding of its clinical and radiologic features, early diagnosis of adhesive capsulitis is becoming a reality. Although often treated conservatively, for refractory cases arthroscopic release and open capsulotomy have been the only therapeutic option for a long time. Therefore, in the last years, a particular effort was put into the development of novel minimal-invasive techniques capable of pain relief and functional range improvement of the glenohumeral joint. The purpose of this literature review is to report the main updates on diagnosis and treatment for adhesive capsulitis with a focus on imaging diagnosis techniques and novel minimally invasive ultrasound-guided treatments. Results showed that ultrasound-guided procedures come with a high success rate in terms of pain reduction and improved range of motion, thus making the ultrasound a unique tool capable of giving the operator real-time diagnostic information confirming the clinical suspicion, and subsequently performing an interventional procedure.

Online psychological counselling during lockdown reduces anxiety symptoms and negative affect: Insights from Italian framework.

Several studies have shown how COrona VIrus Disease 2019 (COVID-19) and the consequent isolation and quarantine measures could affect physical and mental well-being. Therefore, the increased request for support and assistance represents a critical challenge for clinicians requiring a reorganization of care systems. In this regard, online counselling has been identified as a useful tool in providing psychological assistance and support. Thus, the main purpose of the current study was to investigate the clinical usefulness of a single online counselling session in reducing psychopathological symptoms (i.e., state anxiety and negative affect) and increasing individual well-being and positive affect during the first Italian lockdown. Fifty-three subjects were enrolled and randomly assigned to receive an online counselling session [Online Counselling Group (OCG) = 26] or to act as controls [Waiting List Group (WLG) = 27]. In the post-assessment, compared to WLG, the OCG showed a significant decrease in negative affect (18.04 ± 6.30 vs. 30.26 ± 8.61; F1:47 = 29.45; p < .001; dppc2 = .92) and state anxiety (36.65 ± 8.35 vs. 48.04 ± 11.51; F1:47 = 17.86; p < .001; dppc2 = .49). Taking into account the cyclical nature of COVID-19, with the possibility of new peaks and waves, it would be appropriate to consider the versatility and usefulness of online psychological counselling in the management of COVID-19-related distress.

The association between social media addiction and eating disturbances is mediated by muscle dysmorphia-related symptoms: a cross-sectional study in a sample of young adults.

PURPOSE: Although the association between problematic use of the internet and eating disorders (EDs) in young adults has been previously established, its underlying mechanisms have not been completely clarified. It has been suggested that exposure to idealized very thin and toned body images (e.g., "thinspiration" and "fitspiration" trends) on social media might lead to increased feelings of body dissatisfaction which, in turn, can represent a trigger for EDs. We have tested this hypothesis in a sample (N = 721) of young adults (504 females, mean age: 24.13 ± 3.70 years; range 18-34). METHODS: Self-report measures investigating symptoms related to social media addiction (SMA), muscle dysmorphia (MD), and EDs were used. A mediational model analyzing the direct and indirect effects of SMA-related symptoms on ED-related symptoms through the mediating role of MD-related symptoms was performed controlling for confounding factors (e.g., socio-demographic variables, substances use, body mass index, psychopathological distress). RESULTS: The model showed that the total effect of SMA-related symptoms on ED-related symptoms was significant (B = 0.213; p = 0.022) and that this association was mediated by MD-related symptoms (B = 0.083; p = 0.021). DISCUSSION: Our findings support the possibility that MD-related symptoms play a relevant role in mediating the association between SMA severity and ED pathology. LEVEL OF EVIDENCE: Level III, evidence obtained from well-designed cohort or case-control analytic studies.

Stay home, stay safe, stay green: The role of gardening activities on mental health during the Covid-19 home confinement.

Social distancing and home confinement during the first wave of Covid-19 have been essential to helping governments to flatten the infection curve but raised concerns on possible negative consequences such as prolonged isolation or sedentary lifestyles. In this scenario, gardening activities have been identified as a plausible tool to buffer the mental health consequences of forced home confinement. In this paper, we investigate the relation between gardening and psychopathological distress during the lockdown of the first wave of Covid-19 in Italy. It is hypothesized that engagement in gardening activities promotes psychological health, through a reduction of Covid-related stress. An online survey was administered through sharing using social media to N = 303 participants during the March-May 2020 lockdown in Italy, measuring Covid-19 related distress, psychopathological distress, engagement in gardening activities plus a series of socio-demographic and residential covariates. As expected, a mediation model tested using a bootstrapping procedure showed that gardening is related to lower psychopathological distress through decreased Covid-19 related distress. Interestingly, results also showed that psychopathological distress was higher for women and unmarried respondents, and negatively associated with age and square meters per person at home. The theoretical and practical implications for social policies contrasting the Covid-19 pandemic are discussed.

Electroencephalographic (EEG) alterations in young women with high subclinical eating pathology levels: a quantitative EEG study.

PURPOSE: To explore electroencephalographic (EEG) alterations in young women with different eating disorder (ED) psychopathology levels. METHODS: Thirty-seven young women completed general and ED psychopathology (i.e., the ED Examination Questionnaire; EDE-Q) measures. EEG power spectra data were investigated in two conditions: (a) 5 min of resting state (RS) and (b) 5 min of RS after a single taste of a milkshake (ML-RS). EEG analyses were performed using exact Low-Resolution Electromagnetic Tomography software (eLORETA). RESULTS: Cluster analysis performed on the EDE-Q responses revealed a group of 17 women with high levels of ED pathology falling into the subclinical (i.e., sub-threshold) EDs category and a group of 20 women with low levels of ED pathology (controls). In the RS conditions, no significant modifications were observed between groups. Compared to controls, women with subclinical EDs showed an increase in theta activity in the parieto-occipital areas in the ML-RS condition. After controlling for body mass index and general psychopathology, theta activity in these brain structures was positively associated with EDE-Q global and subscale (restraint, shape and weight concern) scores. CONCLUSIONS: Our results may reflect the neurophysiological substrate of ED psychopathology core features like shape/weight concerns. Previous brain imaging and qEEG studies with full-syndrome ED patients also underscored the involvement of parieto-occipital areas in ED pathophysiology. These studies also found brain alterations in the RS condition, not observed here. This is notable given that full-syndrome and subclinical EDs are considered as different manifestations of the same disease along a severity spectrum. LEVEL OF EVIDENCE: Level V, cross-sectional, electroencephalographic, descriptive study.

Friction in rough contacts of linear viscoelastic surfaces with anisotropic statistical properties.

Viscoelastic rheology can have great effects on the contact mechanics of randomly rough surfaces with anisotropic statistical properties. In this paper, we investigate such effects in the framework of Persson's theory. We calculate the forces that arise in viscoelastic contacts because of the viscous dissipation occurring in the bulk material. Interestingly, the non-symmetric distribution of the normal contact pressure entails the occurrence of a force in the direction perpendicular to the sliding one. Such force does not carry out any work, and hence does not dissipate energy, but it is important for the global equilibrium of the system. Results are also compared with numerical exact calculations finding a quite good agreement. However, with the present method, we cannot capture the stretching of the contact clusters due to the viscoelasticity and, hence, the resulting change in the anisotropy of the deformed surface.

The Association among Default Mode Network Functional Connectivity, Mentalization, and Psychopathology in a Nonclinical Sample: An eLORETA Study.

AIMS: We investigated default mode network (DMN) electroencephalography (EEG) functional connectivity differences between individuals with self-reported high mentalization capability and low psychopathological symptoms, versus participants with mentalization impairments and high psychopathological symptoms. METHODS: Forty-nine students (35 women) with a mean age of 22.92 ± 2.53 years were administered the Mentalization Questionnaire (MZQ) and the Symptom Checklist-90-Revised. Five minutes of EEG during resting state were also recorded for each participant. DMN functional connectivity analyses were conducted by means of the exact Low Resolution Electric Tomography software (eLORETA). RESULTS: Compared to the individuals with high mentalization capability and lower self-reported psychopathological symptoms, participants with mentalization impairments and high psychopathological symptoms showed a decrease of EEG beta connectivity between: (i) the right and left medial frontal lobe, and (ii) the left medial frontal lobe and the right anterior cingulate cortex. Furthermore, while MZQ total score was positively associated with DMN network connections (i.e., right and left medial frontal lobes), several psychopathological symptoms (i.e., interpersonal sensitivity, depression, and psychoticism) were negatively associated with DMN connectivity. CONCLUSION: Our results may reflect a top-down emotion regulation deficit which is associated with both internalizing and externalizing behavior problems.

Alpha/Theta Neurofeedback Increases Mentalization and Default Mode Network Connectivity in a Non-Clinical Sample.

Several studies showed the effectiveness of alpha/theta (A/T) neurofeedback training in treating some psychiatric conditions. Despite the evidence of A/T effectiveness, the psychological and neurobiological bases of its effects is still unclear. The aim of the present study was to explore the usefulness of the A/T training in increasing mentalization in a non-clinical sample. The modifications of electroencephalographic (EEG) functional connectivity in Default Mode Network (DMN) associated with A/T training were also investigated. Forty-four subjects were enrolled in the study and randomly assigned to receive ten sessions of A/T training [neurofeedback group (NFG) = 22], or to act as controls [waiting list group (WLG) = 22]. All participants were administered the mentalization questionnaire (MZQ) and the Symptom Checklist-90-Revised (SCL-90-R). In the post training assessment, compared to WLG, NFG showed a significant increase of MZQ total scores (3.94 ± 0.73 vs. 3.53 ± 0.77; F1;43 = 8.19; p = 0.007; d = 0.863). Furthermore, A/T training was also associated with a significant increase of EEG functional connectivity in several DMN brain areas (e.g. Posterior Cingulate Cortex). Taken together our results support the usefulness of the A/T training in enhancing mentalization and DMN connectivity.

Surgical treatment of infected shoulder arthroplasty. A systematic review.

PURPOSE: To investigate the best surgical management of infected shoulder arthroplasty. METHODS: A literature review from 1996 to 2016 identified 15 level IV studies that met inclusion criteria. Persistent infection (PI) was considered as treatment failure. Success was regarded as the absence of symptomatic PI without necessity for further treatment. Surgical outcomes were reported according to the mean weighted Constant and Murley score (CMS) for each treatment group. RESULTS: Overall, 287 patients (146 males/141 females) were identified at a mean follow-up of 50.4 (range 32-99.6) months. The PI in the whole population was 11.5%. The pooled mean CMS, available for 218 patients, was 39 ± 13. Twenty-seven patients (9.4%) were treated with debridement (PI 29.6%, CMS 41 ± 12), 52 patients (18.1%) with resection arthroplasty (PI 11.5%, CMS 29 ± 16), 33 patients (11.5%) with permanent spacers (PI 6.1%, CMS 31 ± 14), 98 patients (34.2%) with two-stage revisions (PI 14.3%, CMS 42 ± 12) and 77 patients (26.8%) with one-stage revisions (PI 3.9%, CMS 49 ± 11). Debridement showed the highest PI rate (29.6%) and one-stage revisions reported the lowest PI rate (3.9%). Resection arthroplasty and spacers showed the poorest CMS when compared to the other procedures (p ≤ 0.0001). The debridement PI rate was significantly higher than almost any other procedure. CMS was significantly higher in patients undergoing revision compared to non-revision procedures (45 ± 12 vs. 35 ± 14) (p < 0.0001). One-stage revisions achieved significantly better results in terms of the PI rate compared to two-stage revisions (p = 0.0223), but not in terms of CMS. CONCLUSION: Debridement showed the highest PI rate (29.6%) and should not be recommended for the management of infected shoulder arthroplasty. Revisions reported better functional outcomes compared to non-revision procedures. The presence of a significantly lower PI rate with comparablely high mean CMS values suggests that one-stage (where technically applicable) could be superior to two-stage revisions. Unfortunately, well-designed randomized controlled trials using validated patient-based outcomes are lacking in this field. LEVEL OF EVIDENCE: Systematic Review of level IV studies, Level IV.