Dr Paul Brunault
email: paul.brunault@univ-tours.fr

Dr Sasha Mathieu
email: sasha.mathieu@etu.parisdescartes.fr

Cathie Faussat

Dr Servane Barrault
email: servane.barrault@univ-tours.fr

Pr Isabelle Varescon
email: isabelle.varescon@parisdescartes.fr

Impulsivity facets and cognitive distortions associated with problem gambling: Differences between ADHD and non-ADHD gamblers

Keywords: Attention-deficit/hyperactivity disorder, gambling disorder, behavioral addictions, personality traits, emotion regulation. Résumé Trouble Déficit de l'Attention avec ou sans Hyperactivité, comportementales, traits de personnalité, regulation émotionnelle

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Gambling disorder is a clinical disorder characterized by a persistent and recurrent problematic gambling behavior leading to clinically significant impairment or distress, as indicated in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) by the existence of at least four out of the nine DSM-5 diagnostic criteria over a 12-month period (American Psychiatric Association, 2013). Prevalence rate for adult problem gambling (last 12 months) in the overall population can be estimated between .5% and 3%, with three to four times as many people having subclinical problems or harms (Abbott, 2020), and with a higher prevalence in male than female (American Psychiatric Association, 2013). There is also some variations in prevalence rates across countries, because greater gambling availability is associated with increased prevalence rates of gambling disorder, and commercial gambling has been a major growth industry for the last three decades (Abbott, 2020).

Gambling disorder, which is now recognized in the DSM-5 as a behavioral addiction (i.e., a non-substancerelated addictive disorder), typically involves the combination of biological (e.g., genetic factors such as dopamine D2A1 allele receptor gene, biologically based traits of impulsivity), psychological (e.g., psychiatric disorders such as mood, anxiety and other addictive disorders, stressful life events, personality traits such as impulsivity, risk taking or proneness to boredom, or cognitive distortions), and ecological (e.g., increased availability and increased accessibility of gambling) risk factors [START_REF] Blaszczynski | A pathways model of problem and pathological gambling[END_REF].

Among the psychiatric disorders associated with gambling disorder, adult attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent and important risk factor [START_REF] Fatséas | Gambling behaviors and psychopathology related to Attention-Deficit/Hyperactivity Disorder (ADHD) in problem and non-problem adult gamblers[END_REF][START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF]. ADHD is a neurodevelopmental disorder that is defined by a persistent pattern of inattention and / or hyperactivity-impulsivity that interferes with functioning or development beginning in childhood (before the age of 12). Although initially defined in childhood, with an estimated prevalence of approximately five percent of children [START_REF] Polanczyk | The worldwide prevalence of ADHD: a systematic review and metaregression analysis[END_REF], it is now demonstrated that ADHD persists during adulthood in approximately one out of two patients, with an estimated prevalence ranging from 2.1% to 2.8% in adults [START_REF] Fayyad | The descriptive epidemiology of DSM-IV Adult ADHD in the World Health Organization World Mental Health Surveys[END_REF][START_REF] Vitola | Exploring DSM-5 ADHD criteria beyond young adulthood: phenomenology, psychometric properties and prevalence in a large three-decade birth cohort[END_REF]. It is important to screen for and treat as appropriate adult ADHD in patients with addictive disorders, and especially in patients with gambling disorder, because adult ADHD affects from 20% to 25% of adult patients seeking treatment for gambling disorder [START_REF] Fatséas | Gambling behaviors and psychopathology related to Attention-Deficit/Hyperactivity Disorder (ADHD) in problem and non-problem adult gamblers[END_REF][START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF][START_REF] Waluk | The Relationship Between Problem Gambling and Attention Deficit Hyperactivity Disorder[END_REF] and, when present, is associated with poorer outcomes [START_REF] Romo | Gambling and Attention Deficit Hyperactivity Disorders (ADHD) in a Population of French Students[END_REF].

Although the positive association between ADHD and problem gambling is now well established [START_REF] Fatséas | Gambling behaviors and psychopathology related to Attention-Deficit/Hyperactivity Disorder (ADHD) in problem and non-problem adult gamblers[END_REF][START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF][START_REF] Romo | Gambling and Attention Deficit Hyperactivity Disorders (ADHD) in a Population of French Students[END_REF][START_REF] Waluk | The Relationship Between Problem Gambling and Attention Deficit Hyperactivity Disorder[END_REF], we currently lack an understanding of the mechanisms underlying this association. In line with individual difference theory, which postulates that individual differences are essential to understanding behavior and disorders, we may assume that the factors contributing to gambling disorder might be different in people with ADHD than in those without it (i.e., categorical view of ADHD), as well as between people depending on their level of ADHD symptoms (i.e., dimensional view of ADHD: ADHD symptoms rather than ADHD diagnosis). Interestingly, such a differential contribution might be helpful in proposing different management strategies based on the patient's personality profile [START_REF] Roberts | Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample[END_REF].

In this study, we chose to focus on impulsivity and cognitive distortions as two measures that could contribute differently to problem gambling in patients with or without ADHD. We chose these two factors because they are among the most established risk factors for gambling disorder and predictors for gambling treatment [START_REF] Blaszczynski | A pathways model of problem and pathological gambling[END_REF][START_REF] Chamberlain | Latent class analysis of gambling subtypes and impulsive/compulsive associations: Time to rethink diagnostic boundaries for gambling disorder?[END_REF]Johansson et al., 2009), and, most importantly, they are psychological factors that are important treatment targets and susceptible to change (e.g., through psychotherapeutic strategies such as cognitive-behavioral therapy or emotion-regulation therapy). First, impulsivity is both a core feature of ADHD [START_REF] Kooij | European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD[END_REF] and a robust risk factor for gambling disorder [START_REF] Fatséas | Gambling behaviors and psychopathology related to Attention-Deficit/Hyperactivity Disorder (ADHD) in problem and non-problem adult gamblers[END_REF]. One interesting comprehensive model of impulsivity that is useful to disentangle the contribution of different impulsivity traits to addictive disorders was proposed by [START_REF] Whiteside | The five factor model and impulsivity: Using a structural model of personality to understand impulsivity[END_REF].

According to these authors, five distinct personality traits may be associated with impulsive behavior: negative urgency (i.e., the tendency to act rashly when faced with distress), positive urgency (i.e., the tendency to act rashly when faced with a very positive mood), lack of premeditation (i.e., the tendency to act without thinking), lack of perseverance (i.e., the inability to remain focused on a task) and sensation seeking (i.e., the tendency to seek out novel and thrilling experiences) [START_REF] Cyders | Examination of a short English version of the UPPS-P Impulsive Behavior Scale[END_REF]. On the other hand, cognitive distortions (i.e., irrational beliefs and erroneous perceptions about gambling and luck) are another integral component of the development, maintenance, and treatment of pathological gambling/gambling disorder [START_REF] Challet-Bouju | Cognitive Remediation Interventions for Gambling Disorder: A Systematic Review[END_REF][START_REF] Fortune | Cognitive distortions as a component and treatment focus of pathological gambling: a review[END_REF]. Examples of cognitive distortions include illusion of control (i.e., expectancy of a personal success probability inappropriately higher than the objective probability would warrant), superstition (i.e., thought that the gambler has a reliable means of manipulating the outcome in his or her favour), interpretative control (i.e., magnification of gambling skill that does result in the gambler having exaggerated self-confidence and that leads to ignoring the severity of the losses) or predictive control (i.e., belief that the gambler has the skill to make accurate predictions, for example when he or she thinks that a series of losses is expected to be compensated for by chasing behavior, which is defined as a more frequent involvement, an increased persistence and an elevated monetary risk in an effort to recoup money that has been lost) [START_REF] Fortune | Cognitive distortions as a component and treatment focus of pathological gambling: a review[END_REF][START_REF] Raylu | The Gambling Related Cognitions Scale (GRCS): Development, confirmatory factor validation and psychometric properties[END_REF].

Recent research has revealed several important facts about the relationship between ADHD, impulsivity traits, cognitive distortions and problem gambling [START_REF] Lopez | A multidimensional approach of impulsivity in adult attention deficit hyperactivity disorder[END_REF][START_REF] Miller | Impulsivity and Attention Deficit-Hyperactivity Disorder: Subtype Classification Using the UPPS Impulsive Behavior Scale[END_REF][START_REF] Romo | Gambling and Attention Deficit Hyperactivity Disorders (ADHD) in a Population of French Students[END_REF]. First, patients with ADHD reported higher scores than the overall population in negative urgency, lack of premeditation, lack of perseverance, and sometimes in sensation seeking [START_REF] Lopez | A multidimensional approach of impulsivity in adult attention deficit hyperactivity disorder[END_REF][START_REF] Miller | Impulsivity and Attention Deficit-Hyperactivity Disorder: Subtype Classification Using the UPPS Impulsive Behavior Scale[END_REF]. Secondly, gambling disorder was independently predicted by ADHD symptoms, negative urgency, and lack of perseverance [START_REF] Romo | Gambling and Attention Deficit Hyperactivity Disorders (ADHD) in a Population of French Students[END_REF].

Finally, problem gambling was also linked to cognitive distortions; these irrational beliefs about gambling and their role in the onset and maintenance of problem gambling are now well-documented in the literature [START_REF] Clark | Disordered gambling: the evolving concept of behavioral addiction[END_REF][START_REF] Mathieu | Gambling Motives: Do They Explain Cognitive Distortions in Male Poker Gamblers[END_REF]. Another recent study showed that the presence of ADHD was linked to higher levels of cognitive distortions among problem gamblers [START_REF] Romo | Cognitive distortions and ADHD in pathological gambling: A national longitudinal case-control cohort study[END_REF].

Examination of the relative contribution of impulsivity facets and cognitive distortions to gambling disorder in patients with ADHD diagnosis/symptoms may lead to interesting therapeutic advances, for example customized addiction treatments for a given patient depending on his/her ADHD profile. Such an approach has already been successfully taken in patients with ADHD and substance use disorders [START_REF] Pedersen | The indirect effects of childhood attention deficit hyperactivity disorder on alcohol problems in adulthood through unique facets of impulsivity[END_REF][START_REF] Roberts | Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample[END_REF]: [START_REF] Roberts | Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample[END_REF] tested the hypothesis that different impulsivity facets may contribute to the increased levels of substance abuse in people with ADHD symptoms. They found that negative urgency, sensation seeking and lack of premeditation predicted alcohol use and alcohol abuse, while only negative urgency predicted tobacco and cannabis use [START_REF] Roberts | Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample[END_REF]. Moreover, it was found that emotional impulsivity (i.e., high positive urgency and/or high negative urgency) may place children with ADHD at increased risk of alcohol problems in adulthood [START_REF] Pedersen | The indirect effects of childhood attention deficit hyperactivity disorder on alcohol problems in adulthood through unique facets of impulsivity[END_REF]. To our knowledge, no study compared the impulsivity facets associated with problem gambling between gamblers with versus without ADHD, and no studies compared the cognitive distortions associated with problem gambling between gamblers with versus without ADHD. Given that, to the best of our knowledge, no previous studies have investigated this hypothesis, we have taken here an exploratory approach to the topic. This study's main objective was to compare the impulsivity facets associated with problem gambling between male gamblers with versus without self-reported ADHD (i.e., to test whether there was an interaction effect between ADHD and each of these five impulsivity facets). We hypothesized that the negative urgency and positive urgency dimensions would be associated with problem gambling in both ADHD and non-ADHD male gamblers, while the other impulsivity facets (i.e., lack of premeditation, sensation seeking, lack of perseverance) would be associated with problem gambling only in the non-ADHD group. Our secondary objective was to compare the gambling-related cognitions associated with problem gambling between male gamblers with versus without self-reported ADHD (i.e., to test whether there was an interaction effect between ADHD and each of these five gambling-related cognitions). We hypothesized that gambling-related cognitions would be equally associated with problem gambling in both ADHD and non-ADHD gamblers (no interaction effect). Finally, we also tested our hypotheses using a dimensional approach to ADHD, by considering ADHD as a continuous variable (ADHD symptom score) in addition to the categorical approach.

Material and methods

Participants

Participants were recruited through online gambling forums (e.g., Bet Clever, Club Poker, which are sports betting and poker sites) between June and October 2016, with the help of an advertisement posted on gambling forums with the permission of the website's administrators. We included gamblers who were over 18 years old, spoke fluent French, and were involved in a regular gambling activity (i.e., at least once a week; for more details, see [START_REF] Barrault | Cognitive distortions, anxiety, and depression among regular and pathological gambling online poker players[END_REF]. Interested gamblers had to click on a LimeSurvey ® link that led them to the online questionnaires (including an information notice and consent form in advance of the questionnaires). This population has already been described in a previous published study as focusing on gambling motives and cognitive distortions in gamblers [START_REF] Mathieu | Gambling Motives: Do They Explain Cognitive Distortions in Male Poker Gamblers[END_REF]. Two hundred and ninety-eight (n = 298) gamblers answered the whole questionnaire; of these, 97.4% were men (n = 290). Due to the very small sub-sample of women (n = 8), only men were included in this study. Of the initial sample (n = 298), eleven gamblers were withdrawn from the study (eight were excluded because they were female, and three were excluded because they had missing data for at least one of the self-administered questionnaires used in this study). Our final population was thus based on 287 male gamblers.

Materials

Socio-demographic characteristics

Age, gender, marital status (married or in a relationship versus single), level of education (completion of the baccalaureate or beyond versus educational level below the baccalaureate), and the types of games played (i.e., strategic or mixed strategic-chance gambling activity; offline and/or online gambling) were assessed using a selfadministered questionnaire.

Problem gambling

Problem gambling was assessed using the total score of the South Oaks Gambling Screen (SOGS), which is a 20-item self-administered questionnaire for problem gambling [START_REF] Lesieur | The South Oaks Gambling Screen (SOGS): a new instrument for the identification of pathological gamblers[END_REF]French validation: Lejoyeux, 1999). Item examples include "When you gamble, how often do you go back another day to win back money you lost", "Did you ever gamble more than you intended to", or "Have you ever borrowed from someone and not paid them back as a result of your gambling?". The SOGS can be interpreted using a total score that indicates the severity of gambling, or as an ordinal variable (a score less than or equal to 2 corresponds to the absence of problem gambling, a score of 3 or 4 corresponds to problem gambling, and a score equal to or higher than 5 characterizes probable pathological gambling). In this study, as has often been done before [START_REF] Mathieu | Gambling Motives: Do They Explain Cognitive Distortions in Male Poker Gamblers[END_REF][START_REF] Stark | Beyond description: Understanding gender differences in problem gambling[END_REF], the SOGS variable was considered a binary one: no problem gambling (SOGS total score < 3) vs. problem gambling (SOGS total score≥3; category that includes both problem gambling and potential pathological gambling).. The existence of current problem gambling was assessed over the past 12 months. The SOGS shows acceptable psychometrics in problem gamblers [START_REF] Stinchfield | Reliability, validity, and classification accuracy of the South Oaks Gambling Screen (SOGS)[END_REF]. In our sample, the internal consistency was adequate (Cronbach's alpha = .79) Self-reported ADHD Self-reported ADHD was assessed using the Adult ADHD Self-Report Scale-V1.1 (ASRS-V1.1), which is a sixitem self-administered questionnaire designed with the help of the World Health Organization to screen for ADHD (based on Diagnostic and Statistical Manual of Mental Disorders, Fourth edition, Text Revised, criteria) in both community surveys and clinical settings [START_REF] Kessler | The World Health Organization Adult ADHD Self-Report Scale (ASRS): a short screening scale for use in the general population[END_REF]. In this study, we used the French adaptation of the ASRS that was proposed by the World Health Organization and that is presented in Supplemental Table 1. Item examples include "How often do you have problems remembering appointments or obligations?" or "How often do you fidget or squirm with your hands or feet when you have to sit down for a long time?". Each item is assessed using a five-point Likert scale ranging from one ("never") to five ("very often"), with different cut-offs depending on the considered item: for items 1 to 3, an item is considered significant when the person answered at least three on the Likert scale; for items 4 to 6, an item is considered significant when the person answered at least four on the Likert scale. This allows the calculation of a total ASRS score that ranges from zero to six. Given that the presence of at least four significant items (i.e., a total ASRS score≥4 ) is considered to be highly consistent with ADHD diagnosis in adults [START_REF] Kessler | The World Health Organization Adult ADHD Self-Report Scale (ASRS): a short screening scale for use in the general population[END_REF], we differentiated gamblers with self-reported ADHD from those without self-reported ADHD based on this cut-off.

The ASRS is effective for screening adults for ADHD (Cronbach's α was in the range of .63 to .72 in the overall population) (Kessler, Adler, Gruber, Sarawate, Spencer, Van Brunt, 2007), with a good internal consistency (α = .84) and construct validity in adult patients with addictive disorders (van de [START_REF] Van De Glind | Validity of the Adult ADHD Self-Report Scale (ASRS) as a screener for adult ADHD in treatment seeking substance use disorder patients[END_REF]. In our sample, the internal consistency was α=.69. We also tested our hypotheses using a dimensional approach to ADHD (ASRS total score that ranges from zero to six).

Impulsivity

Impulsivity facets were assessed using the French version of the UPPS Impulsive Behavior Scale, short version (UPPS-P) [START_REF] Billieux | Validation of a short French version of the UPPS-P Impulsive Behavior Scale[END_REF]. The UPPS-P is a 20-item self-administered questionnaire that is based on the UPPS [START_REF] Whiteside | Validation of the UPPS impulsive behaviour scale: a four-factor model of impulsivity[END_REF][START_REF] Whiteside | The five factor model and impulsivity: Using a structural model of personality to understand impulsivity[END_REF] and one measure of positive urgency [START_REF] Cyders | Integration of impulsivity and positive mood to predict risky behavior: development and validation of a measure of positive urgency[END_REF]. The UPPS-P assesses five impulsivity facets (all defined above in the Introduction): negative urgency (four items), e.g., "When I am upset, I often act without thinking" (reversed score); positive urgency (four items), e.g., "I tend to act without thinking when I am really excited" (reversed score), lack of premeditation (four items), e.g., "I like to stop and think things over before I do them", lack of perseverance (four items), e.g., "I generally like to see things through the end", and sensation seeking (four items), e.g., "I welcome new and exciting experiences and sensations, even if they are a little frightening and unconventional" (reversed score), [START_REF] Cyders | Examination of a short English version of the UPPS-P Impulsive Behavior Scale[END_REF]. Each item is assessed using a four-point Likert scale ranging from one ("agree strongly") to five ("disagree strongly"). The UPPS-P enables the calculation of a sub-score for each impulsivity facet, with a higher score indicating a higher intensity of the facet under consideration (items belonging to the positive urgency, negative urgency, and sensation seeking subscales are reversely scored). In our study, internal consistencies were good for negative urgency (α = .82), positive urgency (α = .82), lack of premeditation (α = .82), and lack of perseverance (α = .86) and acceptable for sensation seeking (α = .79).

Gambling-related cognitions

Gambling-related cognitions were measured using the French version of the Gambling-Related Cognitions Scale (GRCS), which is a 23-item self-report that records common thoughts associated with problem gambling [START_REF] Raylu | The Gambling Related Cognitions Scale (GRCS): Development, confirmatory factor validation and psychometric properties[END_REF]French validation: Grall-Bronnec et al., 2012). This questionnaire has a seven-point Likert scale ranging from one (strongly disagree) to seven (strongly agree). Items are grouped into five subscales: interpretative control/bias (four items), e.g., "relating my winnings to my skill and ability makes me continue gambling"; illusion of control (four items), e.g., "I have specific rituals and behaviors that increase my chances of winning"; predictive control (six items), e.g., "losses when gambling, are bound to be followed by a series of wins"; gambling-related expectancies (four items), e.g., "gambling makes things seem better"; and perceived inability to stop gambling (five items), e.g., "it is difficult to stop gambling as I am so out of control." The higher each sub-score is, the greater the corresponding gambling-related cognition is. In our sample, internal consistencies were α = .55 for interpretative control/bias, α = .74 for illusion of control, α = .54 for predictive control, α = .60 for gambling-related expectancies and α = .84 for perceived inability to stop gambling.

Data analyses

Analyses were conducted using SPSS version 22 (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0 Armonk, NY: IBM Corp.) and SAS version 9.3 (SAS Institute, Cary, NC). All analyses were twotailed; p-values < .05 were considered statistically significant.

Descriptive statistics included percentages for ordinal variables; means and standard deviations for continuous variables. Factors associated with problem gambling (SOGS score ≥ 3) were first identified using a series of univariate logistic regressions. Then, for each impulsivity facet and for each gambling-related cognition, to assess whether their association with problem gambling was different according to ADHD status (ASRS score ≥ 4 versus ASRS score < 4), we fitted multivariate logistic regression models considering an interaction term between the studied dimension and the ADHD status. All these latter models were adjusted on marital status but not age nor educational level, because marital status was the only variable with a p-value <.20 in univariate analysis. Results were reported using Forest plots. We also computed the same statistical analyses by considering the "ADHD" variable as a continuous variable (number of ADHD symptoms = ASRS total score, that ranges from zero to six) rather than ADHD status. These additional analyses were driven by the fact that there is an ongoing debate on whether ADHD should be best considered from a dimensional or from a categorical point of view. We followed here the advice from [START_REF] Coghill | Annual Research Review : Categories versus dimensions in the classification and conceptualisation of child and adolescent mental disorders -implications of recent empirical study[END_REF] who proposed that when we lack data demonstrating the latent structure of a disorders, "one possible way forward is the possibility for studies to routinely include both categorical and dimensional conceptualisations and measurements of disorder" [START_REF] Coghill | Annual Research Review : Categories versus dimensions in the classification and conceptualisation of child and adolescent mental disorders -implications of recent empirical study[END_REF].

Ethical considerations

This study was approved by the Ethics Committee of Paris Descartes University (IRB number: 20162200001072). All procedures were performed in accordance with the ethical standards of the national and/or institutional research committee as well as with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All participants took part freely and voluntarily in the study, and we obtained informed consent from all individual participants before the inclusion in the study.

Results

Descriptive data

The descriptive statistics of the whole sample (n = 287), as well as those of persons with and without problem gambling, are presented in Table 1. The prevalence of problem gambling was 33.4%. Self-reported ADHD was observed in 21.6% of our population. Participants had mixed gambling practices, involving both online and offline activities, as well as both strategic games and mixed (strategic and chance) games. They played offline: poker (74.6%), sports betting (22.3%), blackjack (12.9%), lottery or scratch games (8.7%) and horse-race betting (8.7%); and online: poker (89.5%), sports betting (38%), horse-race betting (4.9%), lottery or scratch games (3.5%), and black jack (1.4%). In Table 1, we also described and compared the characteristics of gamblers with problem gambling versus those with no problem gambling (univariate logistic regression analyses). Table 2 presents the correlations between gambling severity (SOGS score), ADHD symptoms (ASRS score), impulsivity facets (UPPS-P scores), gambling-related cognitions (GRCS scores), and age.

Factors associated with problem gambling in the whole sample

Table 1 presents the factors associated with problem gambling in univariate analyses. In the whole sample, problem gambling was not associated with educational level, marital status or age. Problem gambling was also associated with four out of the five UPPS-P impulsivity facet sub-scores (negative urgency, positive urgency, lack of premeditation and sensation seeking, but not lack of perseverance), and with three out of the five gambling-related cognitions (i.e., illusion of control, gambling-related expectancies, and perceived inability to stop gambling, but not interpretative control/bias nor predictive control) (Table 1). Results were the same whether ADHD was regarded a categorical (ADHD status) or as a continuous (number of ADHD symptoms) variable.

Are the factors associated with problem gambling different between ADHD and non-ADHD gamblers ?

A series of logistic regression analyses with interaction terms were used to investigate whether the association between impulsivity facets and problem gambling, as well as the association between cognitive distortions and problem gambling, might be different depending on ADHD status (Table 3). For better clarity, these results were presented graphically using Forest plots (Figure 1 and Figure 2).

PLEASE INSERT HERE FIGURE 1 AND FIGURE 2

The association between impulsivity facets and problem gambling was different between ADHD and non-ADHD gamblers for lack of premeditation and sensation seeking (i.e., lack of premeditation and sensation seeking were associated with problem gambling only in the non-ADHD group: interaction effects), but not for negative urgency or positive urgency (i.e., negative urgency and positive urgency were associated with problem gambling in both ADHD and non-ADHD gamblers: no interaction effects). Lack of perseverance was not associated with problem gambling, and there was no interaction effect. The association between gambling-related cognitions and problem gambling was confirmed for illusion of control, predictive control, gambling-related expectancies, and perceived inability to stop gambling, but not for interpretative control/bias. There was no interaction effect: no difference in these associations between ADHD and non-ADHD gamblers (Table 3).

Are the factors associated with problem gambling different depending on the number of ADHD symptoms?

We obtained the same results when considering ADHD as a continuous variable (number of ADHD symptoms) or as a categorical one (ADHD status) (Supplemental Table 2): lack of premeditation and sensation seeking were associated with problem gambling, with significant interaction effects; negative urgency and positive urgency were associated with problem gambling in both ADHD and non-ADHD gamblers, with no interaction effects. Illusion of control, predictive control, gambling-related expectancies, and perceived inability to stop gambling, but not interpretative control/bias, were associated with problem gambling, with no interaction effect (Supplemental Table 2).

Discussion

This research aimed to compare the association between impulsivity facets and problem gambling, as well as between gambling-related cognitions and problem gambling, between male gamblers with ADHD versus without ADHD. While negative urgency and positive urgency were associated with problem gambling in both groups, sensation seeking and lack of premeditation were associated with problem gambling only in the non-ADHD group. We found no different association between gambling-related cognitions and problem gambling between ADHD and non-ADHD gamblers: illusion of control, gambling-related expectancies, and perceived inability to stop gambling were associated with problem gambling, but there was no interaction effect. We confirmed these results using a dimensional approach to ADHD.

Our main result is that negative urgency and positive urgency were the only impulsivity facets associated with problem gambling in male ADHD gamblers. These results are in line with those obtained in alcohol use disorders: elevated levels of emotional impulsivity place children with ADHD at increased risk of alcohol problems in adulthood [START_REF] Pedersen | The indirect effects of childhood attention deficit hyperactivity disorder on alcohol problems in adulthood through unique facets of impulsivity[END_REF]. Moreover, positive and negative urgency are personality traits that represent individual differences in the disposition to engage in rash action when experiencing an intense emotion, either an extreme positive or negative affect [START_REF] Cyders | Emotion-based Dispositions to Rash Action: Positive and Negative Urgency[END_REF]. In this connection, our results highlight here the central role of emotion dysregulation in ADHD (cf. [START_REF] Shaw | Emotional dysregulation and Attention-Deficit/Hyperactivity Disorder[END_REF] and its unique contribution to problem gambling in this population. Emotion regulation can be defined as "an individual's ability to modify an emotional state so as to promote adaptive, goal-oriented behaviors; it encompasses the processes that enable an individual to select, attend to, and appraise emotionallyarousing stimuli, and to do so flexibly" [START_REF] Thompson | Emotion regulation: A theme in search of definition[END_REF]. Emotion dysregulation is assumed to arise when these adaptive processes are impaired, leading to behavior that defeats the individual's interests. In ADHD, emotion dysregulation is reported in 34 to 70% of adults and is correlated with the severity of ADHD symptoms [START_REF] Shaw | Emotional dysregulation and Attention-Deficit/Hyperactivity Disorder[END_REF]. Because emotion dysregulation in ADHD patients may arise from deficits in orienting toward, recognizing, and/or allocating attention to emotional stimuli, the assessment of the specific underlying process(es) involved in emotion regulation for a given patient may guide therapeutic approaches that could treat and prevent problem gambling.

Although ADHD patients usually report higher scores than the overall population in sensation seeking, lack of premeditation and lack of perseverance [START_REF] Lopez | A multidimensional approach of impulsivity in adult attention deficit hyperactivity disorder[END_REF], our data support the proposition that in male ADHD gamblers, sensation seeking and lack of premeditation, although prevalent in this population, are not risk factors for problem gambling. These results are in line with studies conducted in the field of non-behavioral addictive disorders. [START_REF] Belin | High Impulsivity Predicts the Switch to Compulsive Cocaine-Taking[END_REF] demonstrated in a preclinical model that high impulsivity predicted the development of addictive-like behavior, while novelty seeking, a phenotype close to sensation seeking, predicted the propensity to initiate cocaine self-administration but not addictive-like behavior. Consistent with these findings, [START_REF] Ersche | Drug addiction endophenotypes: impulsive versus sensation-seeking personality traits[END_REF] also showed the differential association between personality traits and drug use/addiction: impulsivity was found to be mediating the risk for stimulant dependence potentially exacerbated by chronic drug exposure, whereas abnormal sensation seeking was hypothesized to be more likely an effect of stimulant drug abuse. In ADHD patients, we may explain our results by the fact that high sensation seeking and lack of perseverance may be associated with gambling use rather than problem gambling, and high sensation seeking could thus reflect the severity of ADHD rather than a specific vulnerability risk factor for problem gambling.

In gamblers without ADHD, we found that sensation seeking and lack of premeditation were additional risk factors for problem gambling. After adjustment for marital status, we found that sensation seeking, but not lack of premeditation, was associated with problem gambling. The association between sensation seeking and gambling disorder has already been observed in previous studies with a small effect-size [START_REF] Müller | Is Sensation Seeking a correlate of excessive behaviors and behavioral addictions? A detailed examination of patients with Gambling Disorder and Internet Addiction[END_REF]. This relatively weak association in the whole sample might be due to the confounding effect of ADHD, and such an association could increase when non-ADHD gamblers are included. Alternatively, this association might also be explained by the specificity of our sample (i.e., we included mainly gamblers playing strategic games rather than only games of chance), because sensation seeking is associated with gambling disorder in strategic gamblers, but not in non-strategic gamblers [START_REF] Bonnaire | Sensation seeking in a community sample of French gamblers: Comparison between strategic and non-strategic gamblers[END_REF].

Our study confirms the high prevalence of ADHD in gamblers and the strong association between ADHD and problem gambling. We found that 21.6% of our sample met criteria for self-reported ADHD, which is close to the prevalence observed in previous studies conducted in clinical samples with the same selfadministered questionnaire (namely, 25% and20.7%, respectively in Fatséas et al., 2016 and[START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF], and higher than those observed in patients seeking treatment for substance-related disorders: 13% for van de [START_REF] Van De Glind | Validity of the Adult ADHD Self-Report Scale (ASRS) as a screener for adult ADHD in treatment seeking substance use disorder patients[END_REF]), 19.4% for Lugoboni et al. (2017). This high prevalence observed for a non-clinical sample might be explained by our exclusively male sample (the prevalence of ADHD might be higher in males than in females, although this explanation is subject to discussion because ADHD might be underdiagnosed in women ; see [START_REF] Polanczyk | The worldwide prevalence of ADHD: a systematic review and metaregression analysis[END_REF]. , and by the fact that we considered "problem gambling" to be a category including both problem gambling and potential pathological gambling. The association between ADHD and problem gambling remained significant after adjustment for impulsivity facets, ADHD being the variable that was most strongly associated with problem gambling. This result confirms the central role of ADHD in gambling disorder. Screening for ADHD in gamblers is a challenge, partly because ADHD and gambling disorder share several neurocognitive abnormalities such as high impulsivity [START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF]; hence, ADHD symptoms may be mixed up with personality traits that are risk factors for gambling disorder or with gambling disorder symptoms themselves. ADHD in gamblers is a hidden disorder [START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF] and we have confirmed it in a population of male online gamblers. Interestingly, we obtained the same results whether ADHD was regarded as ADHD status or ADHD symptoms, indicating that the categorical and the dimensional approach to ADHD both seem relevant in this context. Future studies should not only focus on ADHD diagnosis, but also on ADHD symptoms; and we may assume that we should not limit ourselves to the treatment of ADHD diagnosis, but also take into account ADHD symptoms.

Our results do not demonstrate a different association between gambling-related cognitions and problem gambling in ADHD gamblers versus non-ADHD gamblers. Although patients with ADHD may experience a higher severity of gambling-related cognitions-which is in line with the results of [START_REF] Romo | Cognitive distortions and ADHD in pathological gambling: A national longitudinal case-control cohort study[END_REF]-the relative impact of each cognitive distortion did not differ between ADHD and non-ADHD gamblers. The association between cognitive distortions and problem gambling/gambling disorder is in line with previous studies, as previous research has demonstrated that irrational beliefs were a risk factor for, rather than a consequence of, gambling disorder [START_REF] Barrault | Cognitive distortions, anxiety, and depression among regular and pathological gambling online poker players[END_REF][START_REF] Romo | Cognitive distortions and ADHD in pathological gambling: A national longitudinal case-control cohort study[END_REF]. All of these distortions can be targeted by psychotherapy (e.g., cognitive and behavioural therapy/cognitive restructuring), on either an individual or a group basis [START_REF] Chrétien | Cognitive restructuring of gamblingrelated thoughts: A systematic review[END_REF]. Such a treatment is crucial given that reduction of gambling cognitive distortions is one of the main predictors of gambling recovery [START_REF] Rossini-Dib | A naturalistic study of recovering gamblers: What gets better and when they get better[END_REF] and given that cognitive distortions mediate the relationship between depression symptoms and gambling severity [START_REF] Schluter | Gambling-related cognitive distortions mediate the relationship between depression and disordered gambling severity[END_REF]. Our results support the idea that gambling-related cognitions should be equally considered and treated appropriately in both ADHD and non-ADHD problem gamblers, and that there seems to be no specific gambling-related cognitions in ADHD problem gamblers. Adequate management of gambling-related cognitions is one of the cornerstones of problem gambling treatment, with some cognitive behavioral therapies such as cognitive restructuring/cognitive remediation being effective in improving both conditions [START_REF] Challet-Bouju | Cognitive Remediation Interventions for Gambling Disorder: A Systematic Review[END_REF][START_REF] Fortune | Cognitive distortions as a component and treatment focus of pathological gambling: a review[END_REF].

Our study has several practical implications. The demonstration that specific impulsivity pathways contribute to specific substance-related and addictive disorders/gambling disorder in patients with ADHD may aid targeted intervention efforts [START_REF] Roberts | Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample[END_REF]. In our study, we uunderscore the specific contribution of negative urgency and positive urgency to problem gambling in ADHD patients: therapeutic approaches targeting emotional dysregulation should be systematically proposed to this population. To this end, [START_REF] Shaw | Emotional dysregulation and Attention-Deficit/Hyperactivity Disorder[END_REF] put forward the potential benefits of psychostimulants, selective serotonin reuptake inhibitors, and postsynaptic 15 alpha-2 adrenoreceptor agonists, whose promising benefits should be confirmed in clinical populations. Other important therapeutic options [START_REF] Mongia | Cognitive behavior therapy for adults with attention-deficit/hyperactivity disorder: a review of recent randomized controlled trials[END_REF] include: (1) cognitive and behavioral therapy, which could help individuals with ADHD recognize and label emotions accurately, challenge emotions that are not appropriate, and cope with intense negative emotional reactions; (2) mindfulness training, which promotes a non-judgmental, present-centered focused awareness of emotions; and (3) cognitive training, which could improve executive functions such as working memory and planning abilities. In gamblers without ADHD, based on our results, we can assume that therapeutic approaches should include both treatments targeting emotion dysregulation, as mentioned above, as well as psychotherapeutic strategies targeting high sensation seeking and low premeditation (i.e., cognitive training). As pointed out by [START_REF] Hershberger | The relationship between the UPPS-P impulsive personality traits and substance use psychotherapy outcomes: A meta-analysis[END_REF], the measurement and targeting of impulsive personality traits in psychotherapy is an important step in the patient management as it has strong potential to improve clinical outcomes across substance-use disorders and a wide range of clinical problems and disorders. To implement therapeutic approaches assessing and targeting emotional dysregulation and impulsivity, ambulatory assessment could be a promising tool. Another implication is the need to assess ADHD systematically in male gamblers when determining the contribution of impulsivity facets to problem gambling: ADHD is a major risk factor for gambling disorder and a hidden disorder in this population [START_REF] Grall-Bronnec | Attention deficit hyperactivity disorder among pathological and at-risk gamblers seeking treatment: a hidden disorder[END_REF] as well as a moderating variable of the relationships between impulsivity facets and problem gambling.

Our study's limitations include its cross-sectional design, which does not allow any causality interpretation; the use of self-administered scales based on adult symptoms to assess both ADHD (use of the ASRS may have increased the prevalence of self-reported ADHD) and problem gambling (use of the SOGS); and the specificity of our population (i.e., males with higher degrees of education than the overall population who gamble online and that play strategic games rather than both non-strategic and strategic games), which limits the generalizability of our findings. Another limitation is the lack of assessment of ADHD or gamblingrelated treatment. Future studies should take into account this variable as a potential confounding factor to better study the association between impulsivity facets, cognitive distortions and problem gambling in males with ADHD versus those without ADHD. Another limitation pertains to the latent structure of ADHD in adults: some authors stated that ADHD has a dimensional rather than a categorical latent structure in children and adolescents [START_REF] Coghill | Annual Research Review : Categories versus dimensions in the classification and conceptualisation of child and adolescent mental disorders -implications of recent empirical study[END_REF]), but we lack such studies in adults populations. Our main hypothesis was driven by a categorical approach, which is in line with the DSM-5, but future studies should better investigate what is the exact latent structure of ADHD in adults. In the meantime, we may assume that future studies should use both a categorical and a dimensional approach that are two useful and complementary approaches.

Conclusion

In conclusion, our results support the hypothesis that different impulsivity facets are associated with problem gambling in male gamblers with versus without ADHD. In gamblers with ADHD, problem gambling is related to negative urgency and positive urgency, but not to sensation seeking, lack of perseverance or lack of premeditation; in gamblers without ADHD, however, problem gambling is related not only to negative urgency and positive urgency, but also to sensation seeking and lack of premeditation. Four out of the five cognitive distortions (i.e., illusion of control, gambling-related expectancies, and perceived inability to stop gambling) were associated with problem gambling, with no difference between gamblers with versus without ADHD. We obtained the same results when considering ADHD symptoms rather than ADHD status. Our study demonstrates the central role of emotion dysregulation as a potential vulnerability risk factor for problem gambling both in gamblers with and in those without ADHD, and the additional contribution of sensation seeking and lack of premeditation in problem gamblers without ADHD.

Data accessibility: all data are available on request. Note. We used Spearman's correlation tests because some variables did not meet normality assumptions. Gambling severity was assessed using the South Oaks Gambling Screen (SOGS) total score. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale (ASRS). Impulsivity facets were assessed using the UPPS Impulsive Behavior Scale, short version (UPPS-P). Gambling-related cognitions (i.e., interpretative control/bias, illusion of control, predictive control, gambling-related expectancies, perceived inability to stop gambling) were assessed using the Gambling Related Cognition Scale (GRCS). * p<.05; ** p<.01; *** p<.001. *adjusted for marital status and ADHD status (ADHD considered as a dichotomous variable).

TABLES

Note. We present here the Odds ratio of the association between a given impulsivity facet and problem gambling in each group (gamblers with or without ADHD), as well as the association between a given gambling-related cognition and problem gambling in each group (gamblers with or without ADHD), and we compared the odds-ratio between these two groups (test for interaction effect). ADHD: Attention-deficit/hyperactivity disorder; ASRS: Adult ADHD Self-Report Scale; GRCS: Gambling-Related Cognitions Scale; UPPS-P: UPPS Impulsive Behavior Scale, short version.

FIGURES Figure 1. Association between impulsivity facets and problem gambling: comparison between gamblers with versus without ADHD

Note. We present here forest plots based on fitted multiple logistic regression models (dependent variable: problem gambling; independent variables: a given impulsivity facet, ADHD status, marital status, and the interaction term "a given impulsivity facet*ADHD status"). Multivariate models were adjusted for marital status.

ADHD: attention-deficit/hyperactivity disorder; OR: Odds-ratio; UPPS-P: UPPS Impulsive Behavior Scale, short version.

Figure 2. Association between gambling-related cognitions and problem gambling: comparison between gamblers with versus without ADHD

Note. We present here forest plots based on fitted multiple logistic regression models (dependent variable: problem gambling; independent variables: a given gambling-related cognition, ADHD status, marital status, and the interaction term "a given gambling-related cognition*ADHD status"). Multivariate models were adjusted for marital status. ADHD: attention-deficit/hyperactivity disorder; GRCS: Gambling-related cognition scale; OR: Odds-ratio; UPPS-P: UPPS Impulsive Behavior Scale, short version.

Table 1 . Descriptive data of the whole sample (n = 287), and comparison between persons with versus without problem gambling

 1 Descriptive data are presented as mean ± standard deviation (SD) or percentage (number). ADHD: attention-deficit/hyperactivity disorder; ASRS: Adult ADHD Self-Report Scale; GRCS: Gambling-Related Cognitions Scale; SOGS: South Oaks Gambling Screen; UPPS-P: UPPS Impulsive Behavior Scale, short version.

	Total sample	Problem	No problem	OR [95% CI]
	(n=287)	gambling	gambling
		(n=96)	(n=191)

Table 2 . Correlation matrix between gambling severity, ADHD symptoms, impulsivity facets, gambling-related cognitions, and age in the whole sample

 2 .38 *** .22 *** .36 *** -12. Perceived inability to stop gambling (GRCS) 47 *** .24 *** .23 *** .46 *** .23 *** .20 *** .22 *** .27 *** .24 *** .24 *** .53 *** -

	1	2	3	4	5	6	7	8	9	10	11	12	13

*

Table 3 . Predictors of problem gambling in multivariate logistic regressions, with a comparison between persons with versus without ADHD Multivariate logistic regressions*

 3

		ADHD	No ADHD	Interaction
		OR [95% CI]	OR [95% CI]	p-value
	Marital status	-	-	-
	ASRS status	-	-	-
	ASRS score	-	-	-
	Impulsivity facets (UPPS-P)
	Negative urgency	1.36 [1.10-1.67]	1.20 [1.09-1.33]	.31
	Positive urgency	1.21 [1.01-1.46]	1.23 [1.10-1.38]	.88
	Lack of premeditation	0.96 [0.77-1.21]	1.32 [1.15-1.52]	.02
	Lack of perseverance	0.96 [0.80-1.16]	1.09 [0.98-1.22]	.25
	Sensation seeking	0.96 [0.75-1.24]	1.33 [1.16-1.53]	.03
	Gambling-related cognitions
	(GRCS)
	Interpretative control/bias	0.99 [0.89-1.10]	1.01 [0.95-1.08]	.71
	Illusion of control	1.09 [0.98-1.22]	1.18 [1.06-1.32]	.32
	Predictive control	1.05 [0.96-1.15]	1.04 [1.00-1.10]	.92
	Gambling-related expectancies	1.06 [0.95-1.18]	1.13 [1.05-1.21]	.35
	Perceived inability to stop gambling	1.24 [1.11-1.38]	1.14 [1.08-1.19]	.16

of the responsible committee on human experimentation (institutional and national) and with the Helsinki This research was supported by grants from the GIS Jeu et Société (FDJ; Grant number CF UNI 001 3105). The funding organization was involved only in financing the grant and had no role in the design or conduct of the study; data collection, analysis, and interpretation; preparation, review and approval of the manuscript.


Keywords: traumatisme, pied, lambeau, perte de substances, microchirurgie

Traitement des pertes de substances traumatiques du pied Résumé La prise en charge des pertes de substances traumatiques osseuses et des parties molles du pied nécessite une considération particulière de l'anatomie et de la physiologie de ce segment. Les causes des traumatismes du pied sont multiples et souvent violentes induisant une souffrance tissulaire évolutive ce qui requière parfois un parage en plusieurs étapes.

L'objectif thérapeutique est de reconstruire un pied fonctionnel permettant l'appui, une marche et un chaussage indolores en restituant un cadre osseux stable, une couverture résistante et adaptée aux différentes zones du pied. La couverture doit être fine pour le dos du pied et matelassée pour les zones plantaires. La sensibilité plantaire doit également être une préoccupation du chirurgien reconstructeur.

Pour relever ce défi chirurgical il est important de maîtriser un vaste arsenal thérapeutique allant des greffes conventionnelles aux lambeaux libres composites, afin de proposer la solution la plus adaptée au type, à la taille et à la localisation de la perte de substance tout en générant le moins de séquelles du site donneur. La collaboration pluridisciplinaire entre chirurgiens plasticiens, orthopédistes et médecin est préconisée pour mener à bien cette reconstruction.

Introduction

Le pied, segment le plus caudal du corps humain, assume les fonctions d'appui et de marche en supportant le poids du corps. Les pertes de substance (PDS) du pied, notamment post traumatiques, peuvent entraîner des troubles fonctionnels et esthétiques importants nécessitant une prise en charge adéquate, le plus souvent pluridisciplinaire. L'objectif thérapeutique principal est de reconstruire un pied fonctionnel avec un appui, une marche et un chaussage indolores. Cet article traite de la prise en charge des pertes de substance traumatiques des parties molles et osseuses du pied via une approche chirurgicale ostéoplastique en prenant en considération les particularités anatomiques et physiologiques du pied ainsi que la transversalité des problématiques thérapeutiques.

Particularités anatomiques et physiologiques du pied

Le pied est le segment le plus caudal du membre inférieur, situé en distalité de la cheville. Il est constitué de 3 portions, le tarse, le métatarse et les phalanges. Sa conformation dessine une voûte à concavité inférieure sur les axes sagittal et frontal. Il va recevoir les transmissions de forces de l'ensemble du corps par le talus qui va les répartir équitablement entre l'avant pied et le talon. On parle plus précisément de trépied plantaire avec 3 points d'appui aux niveaux du calcanéum, des têtes des 1 er et 5 ème métatarsiens [START_REF] Hallock | The mangled foot and ankle: soft tissue salvage techniques[END_REF]. Sur le plan fonctionnel, ces zones sont d'avantage sujettes aux contraintes mécaniques. L'appui et la marche sont les fonctions principales du pied, ce qu'il faudra considérer lors de sa reconstruction.

La face dorsale du pied, couverte par une peau fine, est propice aux pertes de substance pluritissulaires avec exposition rapide des structures tendineuses, vasculaires et nerveuses puis osseuses, tandis que la face plantaire, bien matelassée, assure la fonction de supporter le poids du corps [START_REF] Cho | An algorithmic approach for managing orthopaedic surgical wounds of the foot and ankle[END_REF][START_REF] Hollenbeck | Longitudinal outcomes and application of the subunit principle to 165 foot and ankle free tissue transfers[END_REF][START_REF] Struckmann | Free and pedicled flaps for reconstruction of the weightbearing sole of the foot: a comparative analysis of functional results[END_REF]. La sensibilité du pied, surtout celle des zones d'appui, doit être prise en compte lors de la chirurgie reconstructrice car la nociception a un rôle de protection sur la formation de plaie ultérieure [START_REF] Ducic | Innervated free flaps for foot reconstruction: a review[END_REF]. Enfin, il faudra également considérer le caractère terminal de la vascularisation du pied, limitant le champ exploitable des sites donneurs comprenant des vaisseaux de calibre régressant et un réseau anastomotique limité en distalité [START_REF] Struckmann | Free and pedicled flaps for reconstruction of the weightbearing sole of the foot: a comparative analysis of functional results[END_REF].

Attitude thérapeutique autour de la reconstruction des PDS du pied

Différentes étiologies peuvent être responsables des pertes de substance du pied. Les causes traumatiques restent l'étiologie la plus fréquente. Nous recensons également les étiologies carcinologiques, vasculaires, diabétiques et d'escarres, mais qui ne seront pas traitées dans cet article.

Les traumatismes du pied impliquent des spécificités de prise en charge qui, si elles sont négligées, risquent d'aboutir une reconstruction insatisfaisante. Les traumatismes peuvent concerner exclusivement le pied ou s'étendre au membre inférieur rendant la reconstruction plus sophistiquée. Parmi les traumatismes, l'écrasement reste le mécanisme le plus fréquent, mais également le plus pernicieux car ces lésions sont souvent délabrantes avec une souffrance tissulaire évolutive et insidieuse. D'autres types de traumatisme peuvent également être rencontrés. Le pied étant généralement protégé par le chaussage, les PDS d'étiologie traumatique surviennent sur des mécanismes violents : traumatismes balistiques [START_REF] Bartlett | Clinical update: gunshot wound ballistics[END_REF], de « blastes » et d'arrachement [START_REF] Dougherty | Battlefield extremity injuries in Operation Iraqi Freedom[END_REF][START_REF] Doukas | The Military Extremity Trauma Amputation/Limb Salvage (METALS) study: outcomes of amputation versus limb salvage following major lower-extremity trauma[END_REF]. Le traitement de ces lésions va engendrer 2 niveaux de prise en charge. L'urgence, qui mobilisera des soins en vue de préserver le maximum de tissus puis la reconstruction du segment traumatisé après un inventaire exhaustif des PDS pour une reconstruction la plus anatomique possible.

Soins en urgence

Soins vasculaires

L'urgence absolue est d'assurer la vascularisation du membre traumatisé. Lors de traumatismes sévères, il est possible de rencontrer une ischémie aigüe du pied [START_REF] Lin | The functional outcome of lower-extremity fractures with vascular injury[END_REF]. Cette ischémie peut être secondaire à une compression extrinsèque plus ou moins haute du membre inférieur ou à une interruption de la continuité vasculaire des axes de la jambe. A noter qu'une atteinte d'un axe vasculaire de la jambe est fréquemment rencontrée dans les traumatismes niveau ≥ IIIb sur l'échelle de Gustillo [START_REF] Haddock | Lower extremity arterial injury patterns and reconstructive outcomes in patients with severe lower extremity trauma: a 26-year review[END_REF]. La réduction d'une fracture déplacée est parfois suffisante pour rétablir la vascularisation du pied. Si non, il sera nécessaire de rétablir la continuité du flux vasculaire par anastomoses directes artérielle et veineuse, ou en interposant une greffe vasculaire ou encore un lambeau porte vaisseau en urgence [START_REF] Percival | Reperfusion strategies in the management of extremity vascular injury with ischaemia[END_REF][START_REF] Mccarthy | Combined arterial reconstruction and free tissue transfer for limb salvage[END_REF][START_REF] Casey | Limb salvage after vascular reconstruction followed by tissue transfer during the Global War on Terror[END_REF].

Parage et lavage

Une fois l'urgence vasculaire écartée, l'attention se portera sur le parage et le lavage. Quelque soit l'étiologie de la PDS, un parage de bonne qualité est le fondement d'une reconstruction réussie. L'étendue du parage ne doit pas être dictée par la prévision d'une technique de reconstruction mais doit être rigoureux et exhaustif sur les tissus voués à la nécrose ou à la surinfection. Le parage complet révèlera la réelle étendue de la PDS qui orientera sur le choix thérapeutique [START_REF] Heller | Lower extremity microsurgical reconstruction[END_REF]. Pour les mécanismes d'écrasement, l'étape du parage peut nécessiter plusieurs interventions chirurgicales en raison d'un effet retard de l'écrasement sur le préjudice tissulaire. Un deuxième bilan lésionnel est souvent nécessaire à 24 -48 heures du traumatisme initial. Un parage incomplet peut faire le lit d'une infection locorégionale responsable de trouble de cicatrisation puis d'une nécrose, a fortiori pour les reconstructions osseuses [START_REF] Hill | Re-evaluating the paradigm of early free flap coverage in lower extremity trauma[END_REF][START_REF] Robson | Wound infection. A failure of wound healing caused by an imbalance of bacteria[END_REF].

Stabilisation osseuse

Toute déformation du cadre osseux devra être ré axée, stabilisée par une ostéosynthèse fiable puis immobilisée. Une stabilisation osseuse précoce effectuée dans les 13 heures suivant le traumatisme préviendrait la survenue de pseudarthrose [START_REF] Harley | The effect of time to definitive treatment on the rate of nonunion and infection in open fractures[END_REF]. Une réflexion sur l'indication d'une fixation externe est souvent de mise, permettant une stabilisation à distance du foyer de fracture [START_REF] Gustilo | Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses[END_REF]. A toutes ces étapes, il est intéressant pour le reconstructeur d'y participer, afin d'anticiper et de préserver les différentes alternatives thérapeutiques.

Dans les cas où le geste osseux devra être complété d'une couverture cutanée, 2 situations pourront se présenter :

-Les chirurgiens orthopédiste et reconstructeur sont d'emblée simultanément disponibles. Le bilan lésionnel est prédictible et fixé après le premier parage, réalisant le cas de figure idéal permettant la reconstruction « tout en 1 temps » osseuse et des parties molles, complétée de prélèvements bactériologiques en vue d'une antibiothérapie probabiliste [START_REF] Arnez | Immediate reconstruction of the lower extremity--an update[END_REF][START_REF] Tropet | Emergency management of type IIIB open tibial fractures[END_REF].

-Le chirurgien reconstructeur ne peut se joindre au chirurgien orthopédiste à l'accueil du patient ou quand plusieurs étapes de parage sont à envisager. Il est alors préférable de ne pas user de matériel d'ostéosynthèse au risque de l'exposer, le contaminer et de devoir le déposer in fine avant la consolidation obtenue. Dans ce cas de figure, mieux vaut ré axer et stabiliser l'os par une fixation externe et protéger le foyer par un pansement [START_REF] Gustilo | Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses[END_REF]. Les dispositifs par thérapie à pression négative nous semble particulièrement adaptée à cette situation. Certains centres discutent l'usage du ciment imprégné d'antibiotique dans l'attente de la reconstruction osseuse [START_REF] Moehring | Comparison of antibiotic beads and intravenous antibiotics in open fractures[END_REF]. La couverture cutanée se fera alors dans le même temps que la reconstruction osseuse finale [START_REF] Hill | Re-evaluating the paradigm of early free flap coverage in lower extremity trauma[END_REF]. L'antibiothérapie probabiliste ne sera pas indiquée sauf en cas de sepsis suspecté, au risque de sélectionner des bactéries résistantes qui freineront l'efficacité de l'antibiothérapie une fois le matériel d'ostéosynthèse posé et la couverture achevée, et de biaiser le résultat des prélèvements bactériologiques effectués pour l'étape de la reconstruction.

Amputation du pied

L'amputation devra également être discutée en fonction de l'étendue de la PDS et de l'état général du patient. Ce choix thérapeutique sera d'autant plus sensé dans les cas où la sensibilité plantaire ne pourra être restaurée [START_REF] Baker | The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care[END_REF]. Il s'agira d'un choix thérapeutique moins invalidant qu'une reconstruction instable associée à des douleurs chroniques. Cependant, il est psychologiquement plus difficile d'accepter pour le patient un pied potentiellement non fonctionnel et douloureux plutôt qu'une amputation comme choix thérapeutique premier [START_REF] Chung | A cost-utility analysis of amputation versus salvage for Gustilo type IIIB and IIIC open tibial fractures[END_REF][START_REF] Akula | A meta-analysis of amputation versus limb salvage in mangled lower limb injuries--the patient perspective[END_REF].

Contrairement aux traumatismes sévères et étendus d'un membre inférieur où la discussion d'une amputation est indiquée de première intention pour éviter un état de choc, il est rare de procéder à une amputation du pied pour des raisons hémodynamiques. Les indications d'amputation de première intention pour les causes traumatiques du membre inférieur peuvent être orientées par des scores homologués comme les scores de MESS ou NISSSA [START_REF] Lin | The functional outcome of lower-extremity fractures with vascular injury[END_REF][START_REF] Copes | Progress in characterizing anatomic injury[END_REF][START_REF] Mcnamara | Severe open fractures of the lower extremity: a retrospective evaluation of the Mangled Extremity Severity Score (MESS)[END_REF][START_REF] Durrant | Orthoplastic classification systems: the good, the bad, and the ungainly[END_REF].

Bilan préalable à la reconstruction

Un bilan de l'arbre vasculaire est incontournable en vue de la reconstruction du pied par des lambeaux locorégionaux ou libres. Une précaution particulière devra être portée sur les traumatismes par écrasement, pouvant générer des micro lésions de la paroi interne vasculaire rendant le vaisseau inexploitable pour accueillir des anastomoses de lambeaux libres. Dans ces cas, il est préférable de remonter la dissection du vaisseau dans une zone moins contuse et moins inflammatoire afin d'accéder à un vaisseau nourricier en meilleur état [START_REF] Lorenzo | Selection of the recipient vein in microvascular flap reconstruction of the lower extremity: analysis of 362 free-tissue transfers[END_REF]. Ce cas de figure nécessitera alors un lambeau avec un pédicule suffisamment long ou une allonge du pédicule par une greffe veineuse [START_REF] Yazar | Selection of recipient vessel in traumatic lower extremity[END_REF].

Les patients avec un terrain vasculaire défavorable restent difficiles à soigner. La diminution de la perfusion tissulaire va compromettre la cicatrisation limitant le champ de l'arsenal thérapeutique. Les patients avec un terrain diabétique peuvent s'apparenter aux patients vasculaires, en raison d'une atteinte de la micro circulation puis de la macro circulation. A cela va s'ajouter les troubles métaboliques qui ne font que limiter le processus de cicatrisation. Il est indispensable de jauger l'imprégnation glycémique du patient diabétique en dosant l'Hba1c. Il est recommandé d'avoir une Hba1c < 7% pour entamer le processus de reconstruction.

Solutions et techniques de reconstructions de la profondeur à la peau

Reconstruction osseuse

Le couple pied-cheville va agir comme un cardan hétérocinétique dont l'intégrité des différentes articulations permet la marche en terrain accidenté. Il est alors important de rétablir lorsque la technique le permet, pas uniquement la charpente osseuse, mais bien cette chaine articulaire qui donnera plus qu'un appui stable, une marche stable.

La reconstruction osseuse concerne principalement le métatarse et le tarse. Le talus et le naviculaire sont les os du tarse les plus concernés en raison de leur exposition au dos du pied et de leur vascularisation linéaire et terminale qui est limitée par la grande étendue des surfaces cartilagineuse .

Si le pied peut être comparé à une arche, le calcanéum, les têtes des 1 er et 5 ème métatarsiens seraient les piliers au contact du sol, et les diaphyses des 1 er et 5 ème métatarsiens les voûtes médiale et latérale. La reconstruction de ces zones sont donc à privilégier.

En cas de PDS osseuse <3,5 cm, une greffe osseuse conventionnelle est possible. L'épine iliaque antéro supérieure reste la source préférentielle de prélèvement d'os cortical et spongieux. Un volume de 20cm3 d'os spongieux peut y être prélevé [START_REF] Dawson | The reamer-irrigator-aspirator as a device for harvesting bone graft compared with iliac crest bone graft: union rates and complications[END_REF]. L'épine iliaque postérieure peut également être une source de prélèvement osseux, mais son accès est rarement aisé lors de reconstruction du pied. Les métaphyses proximale et distale du tibia constituent également une bonne source de prélèvement d'os spongieux, permettant d'obtenir jusqu'à 40cm3 sans complication sur le site donneur [START_REF] Herford | Medial approach for tibial bone graft: Anatomic study and clinical technique[END_REF][START_REF] Van Damme | A modification of the tibial bone-graft-harvesting technique[END_REF]. En raison des risques septiques et de pseudarthrose dus à l'inflammation locale, il est parfois préférable de différer ces greffes à 2 mois de la couverture cutanée [START_REF] Sinclair | Primary free-flap cover of open tibial fractures[END_REF][START_REF] Fischer | The timing of flap coverage, bone-grafting, and intramedullary nailing in patients who have a fracture of the tibial shaft with extensive soft-tissue injury[END_REF]. Du ciment peut être intercalé dans l'intervalle, en vue d'aboutir à une membrane induite [START_REF] Masquelet | Reconstruction of the long bones by the induced membrane and spongy autograft[END_REF].

Concernant les os du tarse en particulier pour le talus et le naviculaire, en raison des problématiques de vascularisation évoquées précédemment, il est préférable de proposer d'emblée un transfert osseux vascularisé. Pour cela il est envisageable de transférer de la crête iliaque antérieure et si besoin associer une palette cutanée vascularisée par les branches superficielle ou profonde de l'artère circonflexe iliaque [START_REF] Peek | Functional total and subtotal heel reconstruction with free composite osteofasciocutaneous groin flaps of the deep circumflex iliac vessels[END_REF][START_REF] Stanec | Heel reconstruction with an iliac osteocutaneous free flap: 10year follow-up[END_REF][START_REF] Yoshimatsu | Superficial Circumflex Iliac Artery Perforator Flap: An Anatomical Study of the Correlation of the Superficial and the Deep Branches of the Artery and Evaluation of Perfusion from the Deep Branch to the Sartorius Muscle and the Iliac Bone[END_REF], ou encore un transfert de condyle fémoral médial avec une palette cutanée vascularisée par le cercle anastomotique péri articulaire du genou [START_REF] Mattiassich | Reconstruction with vascularized medial femoral condyle flaps in hindfoot and ankle defects: a report of two cases[END_REF][START_REF] Haddock | Vascular bone transfer options in the foot and ankle: a retrospective review and update on strategies[END_REF][START_REF] Haddock | Applications of the medial femoral condyle free flap for foot and ankle reconstruction[END_REF].

En cas de PDS ≥3,5cm, un transfert vascularisé est préconisé. En effet, le risque de résorption osseuse lors de transfert vascularisé est moins important que pour une greffe conventionnelle, permettant ainsi une meilleure cicatrisation [START_REF] Goldberg | Biology of vascularized bone grafts[END_REF][START_REF] Arata | Revascularized segmental diaphyseal bone transfers in the canine. An analysis of viability[END_REF][START_REF] Cutting | Comparison of residual osseous mass between vascularized and nonvascularized onlay bone transfers[END_REF]. Les transferts osseux vascularisés pour reconstruire le pied sont majoritairement libre mais peuvent aussi être pédiculés. Les transfert pédiculé des 2 ème et 4 ème métatarsiens sont possibles pour reconstruire les 1 er et 5 ème rayons du pied (Fig. 1 et 2A-E). Ce transfert est possible grâce sa vascularisation constituée d'une artère nourricière diaphysaire et de 2 réseaux vasculaires métaphyso-épiphysaires aux 2 extrémités de l'os. Dans les autres cas, le transfert de fibula vascularisé libre associant une palette cutanée est à privilégier. Pour la reconstruction de grandes PDS osseuses, le prélèvement de fibula reste le choix thérapeutique le moins pourvoyeur de morbidité sur le site donneur.

Comme site donneur au membre supérieur, seront envisagés des lambeaux composites sur le tronc vasculaire subscapulaire, permettant de prélever de la scapula ou de la côte [START_REF] Kang | Reconstruction of the Lower Extremity Using Free Flaps[END_REF], ou encore un lambeau antébrachial composite sur l'artère radiale associant du radius mais sacrifiant un axe vasculaire [START_REF] Yazar | One-stage reconstruction of composite bone and soft-tissue defects in traumatic lower extremities[END_REF][START_REF] Chicarilli | Complete plantar foot coverage with the free neurosensory radial forearm flap[END_REF][START_REF] Weinzweig | Foot and ankle reconstruction using the radial forearm flap: a review of 25 cases[END_REF]. Les indications de reconstruction nerveuse seront dictées par la taille du défect nerveux ainsi que les autres PDS tissulaires associées. Les petites PDS nerveuses pourront être suturées d'emblée si l'anastomose peut être réalisée sans tension, en particulier sur des sections franches du nerf. Si non, l'utilisation d'une chambre de repousse nerveuse peut être la solution pour les PDS < 3cm [START_REF] Wangensteen | Collagen tube conduits in peripheral nerve repair: a retrospective analysis[END_REF][START_REF] Navissano | Neurotube for facial nerve repair[END_REF]. Une greffe nerveuse est envisageable pour les PDS nerveuse < 6cm (Fig. 3), au delà les chances de succès sont <50% [START_REF] Kim | Management and outcomes in 318 operative common peroneal nerve lesions at the Louisiana State University Health Sciences Center[END_REF]. L'essentiel est de rétablir une sensibilité plantaire pour redonner une sensibilité de protection et une proprioception à l'appui. Ainsi, la zone plantaire et proximale du pied est à privilégier dans la reconstruction. Sur le plan fonctionnelle après reconstruction, il est décrit que plus le pied récupère une sensibilité normale plus le patient a tendance à l'appui [START_REF] Nurse | The effect of changes in foot sensation on plantar pressure and muscle activity[END_REF].

Concernant la sensibilité dorsale ou latérale du pied, la reconstruction d'une PDS nerveuse nous apparaît moins intéressante considérant la balance bénéfice risque du site donneur.

Il sera toujours élégant d'envisager une ré innervation par un lambeau composite embarquant un contingent nerveux sensitif, en cas de couverture cutanée associée, bien que ce paradigme de reconstruction reste sujet à débat pour la région plantaire [START_REF] Ducic | Innervated free flaps for foot reconstruction: a review[END_REF][START_REF] Kuran | Comparison between sensitive and nonsensitive free flaps in reconstruction of the heel and plantar area[END_REF]. Pour ce choix thérapeutique, il est indiquer d'infiltrer à la lidocaïne les nerfs des sites donneur et receveur avant les prélèvement et transfert. Cela permettrait de meilleurs résultats fonctionnelles par une meilleure intégration corticale du nouveau schéma nerveux [START_REF] Santanelli | Free flap reconstruction of the sole of the foot with or without sensory nerve coaptation[END_REF]. La localisation et la taille de la PDS vont orienter sur le choix du lambeau (Fig. 4).

Au talon, il est préférable de proposer un lambeau plantaire interne axé sur l'artère plantaire médiale [START_REF] Shaw | Anatomic basis of plantar flap design: clinical applications[END_REF], dont la surface peut atteindre 90 cm2 [START_REF] Miyamoto | Current concepts of instep island flap[END_REF]. L'indication nous semble optimale lorsque les PDS sont comprises entre 6 et 12 cm de grand axe (Fig. 5). L'intérêt de ce lambeau réside dans la similarité des propriétés de texture et résistance aux contraintes avec la peau du talon [START_REF] Shanahan | Medial plantar sensory flap for coverage of heel defects[END_REF], mais également par le caractère sensible de ce lambeau [START_REF] Shanahan | Medial plantar sensory flap for coverage of heel defects[END_REF][START_REF] Wan | Quality of innervation in sensate medial plantar flaps for heel reconstruction[END_REF][START_REF] Oh | Weight-bearing plantar reconstruction using versatile medial plantar sensate flap[END_REF][START_REF] Trevatt | Long-term sensation in the medial plantar flap: a two-centre study[END_REF][START_REF] Lykoudis | Free sensate medial plantar flap for contralateral plantar forefoot reconstruction with flap reinnervation using end-to-side neurorrhaphy: a case report and literature review[END_REF][START_REF] Scheufler | Instep free flap for plantar soft tissue reconstruction: indications and options[END_REF]. Cette réflexion est également transposable pour les couvertures des PDS plantaires de l'avant pied [START_REF] Harrison | The instep island flap to resurface plantar defects[END_REF]. Le transfert de ce lambeau pour les zones porteuses du pied a l'avantage de limiter les sensations de « marcher sur de la ouate » et de « savonnage » à la marche par rapport à d'autres lambeaux.

Lorsque nous sommes en présence de petites et moyennes PDS < 5cm et de localisation latérale sur le talon, il est possible de transférer un lambeau pédiculé par les branches cutanées de l'artère calcanéenne latérale [START_REF] Grabb | The lateral calcaneal artery skin flap (the lateral calcaneal artery, lesser saphenous vein, and sural nerve skin flap)[END_REF][START_REF] Demirseren | Reappraisal of island modifications of lateral calcaneal artery skin flap[END_REF]. Pour le talon, le lambeau fascio-neuro-cutané sural « a contrario » pourra également être envisagé [START_REF] De Soras | Neurocutaneous flap of the external saphenous nerve. A safe, easy and fast procedure for covering loss of substances of the ankle. A propos of 5 cases[END_REF][START_REF] Hasegawa | The distally based superficial sural artery flap[END_REF][START_REF] Masquelet | Skin island flaps supplied by the vascular axis of the sensitive superficial nerves: anatomic study and clinical experience in the leg[END_REF][START_REF] Donski | Distally based fasciocutaneous flap from the sural region. A preliminary report[END_REF]. Il présente comme inconvénients l'insensibilité du lambeau, une adhérence moindre au talon et un risque d'engorgement veineux en post opératoire. Pour les PDS plus étendues, l'utilisation d'un lambeau libre sera nécessaire.

Les lambeaux fasciocutanés libres seront priorisés, avec comme alternative les lambeaux musculaires libres. La consolation avec les lambeaux musculaires pour la couverture plantaire est qu'ils ont un effet de savonnage moins prononcés que les lambeaux fasciocutanés par adhérences post opératoire (Fig. 6).

Pour les PDS en régions plantaires antérieure et moyenne, un lambeau d'avancement basé sur l'artère plantaire médiale permettra de couvrir la zone porteuse médiale de l'avant pied (1 er et 2 ème métatarsiens) [START_REF] Pallua | Forefoot reconstruction by reversed island flaps in diabetic patients[END_REF][START_REF] Sato | Ostectomy and Medial Plantar Artery Flap Reconstruction for Charcot Foot Ulceration Involving the Midfoot[END_REF]. Pour les PDS étendues plantaires de l'avant pied ou latérales, le transfert libre d'un lambeau fasciocutané est indiqué. Pour les même raisons évoquées que pour la région talonnière, le transfert d'un lambeau plantaire interne semble le plus adapté [START_REF] Mourougayan | Medial plantar artery (instep flap) flap[END_REF]. Il s'agira donc d'un lambeau libre de plantaire interne prélevé au membre controlatéral.

La couverture cutanée du dos du pied pourra être réalisée par un lambeau supra malléolaire latéral pédiculé par l'artère perforante issue de l'anastomose entre l'artère fibulaire, l'artère tibiale antérieure et le réseau anastomotique péri articulaire de la cheville [START_REF] Voche | The lateral supramalleolar flap: experience with 41 flaps[END_REF][START_REF] Lee | Distally based lateral supramalleolar adipofascial flap for reconstruction of the dorsum of the foot and ankle[END_REF][START_REF] Masquelet | The lateral supramalleolar flap[END_REF][START_REF] Valenti | Technical refinement of the lateral supramalleolar flap[END_REF]. Grâce au cercle anastomotique artériel péri articulaire de la cheville et du dos du pied, le pédicule à contrario peut être prolongé par une dissection jusqu'au sinus du tarse permettant la couverture du dos du pied pouvant aller jusqu'à P1 de l'hallux. Ce lambeau peut être utile pour les PDS ≤ 8cm de grand axe. Cette zone peut également être couverte par un lambeau plantaire interne, vascularisé de manière antérograde ou rétrograde (Fig. 7 et 2F-I). La forme rétrograde est possible par le réseau perforant entre la vascularisation dorsale et plantaire du pied, distribué par les arcades vasculaires du pied. Les inconvénients de ces lambeaux rétrograde ou « a contrario » résident dans leur retour veineux moins efficace présentant un risque pour la vitalité du lambeau. Il faudra également se soucier du potentiel effet de masse de ces lambeaux pédiculés pour le dos du pied susceptible de gêner le chaussage et nécessite parfois une reprise chirurgicale pour modelage du lambeau. Pour cette raison, de surcroît pour le dos du pied, l'indication d'un lambeau libre devra être discutée quelque soit la taille de la PDS et toujours en fonction du terrain physique, mental du patient. Un lambeau libre fin peut apporter un meilleur résultat esthétique et fonctionnel qu'un lambeau pédiculé, avec moins de trouble de cicatrisation [START_REF] Pollak | Short-term wound complications after application of flaps for coverage of traumatic soft-tissue defects about the tibia. The Lower Extremity Assessment Project (LEAP) Study Group[END_REF]. Pour les pertes de substance >8cm, la reconstruction nécessitera le transfert d'un lambeau libre. Les lambeaux fasciocutanés minces seront priorisés.

Les pertes de substances de petites tailles <3cm de large qu'elles soient plantaires ou dorsales pourront être couvertes par des lambeaux perforants libres de l'artère surale médiale, dont les perforantes musculo-cutanées sont situées au niveau du tiers proximal médial de la jambe [START_REF] Hallock | Medial sural artery perforator free flap: legitimate use as a solution for the ipsilateral distal lower extremity defect[END_REF][START_REF] Wang | Reconstruction of distal limb defects with the free medial sural artery perforator flap[END_REF]. L'alternative au lambeau libre est la mobilisation de lambeaux musculaires intrinsèques du pied. Le choix du muscle dépendra de la localisation de la PDS, en raison du faible arc de rotation. Certains auteurs évoquent des séquelles fonctionnelle sur la stabilité de l'appui suite au transfert de ces lambeaux musculaires [START_REF] Furukawa | Long-term complications of reconstruction of the heel using a digitorum brevis muscle flap[END_REF].

Parmi les lambeaux locaux, des lambeaux vascularisés par des branches distales de l'artère tibiale postérieure sont exploitables pour la couverture du pied mais pour uniquement dans sa portion proximale (Fig. 8). il est également possible de mobiliser des lambeaux perforants dépendants de l'artère dorsale du pied qui proposent des artères perforantes cutanées à la jonction tarso-métatarsienne et à l'extrémité distale de la première commissure intermétatarsienne. Au niveau plantaire, des artères perforantes sont également exploitables issues de l'artère plantaire latérale entre le muscle court fléchisseur des orteils et l'abducteur du V ème orteil et les perforantes issues de l'artère plantaire médiale par sa branche superficielle [START_REF] Jakubietz | The 180-degree perforator-based propeller flap for soft tissue coverage of the distal, lower extremity: a new method to achieve reliable coverage of the distal lower extremity with a local, fasciocutaneous perforator flap[END_REF][START_REF] Boucher | Atlas of skin perforator arteries of trunk and limbs -guide in the realization of perforator flaps[END_REF].

De manière générale, le choix des lambeaux libres fasciocutanés ou fasciocutanés perforants doivent répondre aux exigences de la couverture du pied, impliquant un faible encombrement et une résistance aux contraintes. Ainsi les lambeaux basés sur les perforantes cutanées des artères antérolatérale de cuisse (ALT) [START_REF] Song | The free thigh flap: a new free flap concept based on the septocutaneous artery[END_REF][START_REF] Wei | Have we found an ideal soft-tissue flap? An experience with 672 anterolateral thigh flaps[END_REF][START_REF] Fodor | Simultaneous Extended ALT Flaps for Foot Salvage After Severe Frostbite[END_REF][START_REF] Olivan | Chimerical anterolateral thigh flap for plantar reconstruction[END_REF][START_REF] Sekido | Change of weight-bearing pattern before and after plantar reconstruction with free anterolateral thigh flap[END_REF], circonflexes iliaques [START_REF] Peek | Functional total and subtotal heel reconstruction with free composite osteofasciocutaneous groin flaps of the deep circumflex iliac vessels[END_REF][START_REF] Koshima | Superficial circumflex iliac artery perforator flap for reconstruction of limb defects[END_REF][START_REF] Hong | Modified superficial circumflex iliac artery perforator flap and supermicrosurgery technique for lower extremity reconstruction: a new approach for moderate-sized defects[END_REF][START_REF] Kim | Reconstruction of Moderate-Sized Distal Limb Defects using a Superthin Superficial Circumflex Iliac Artery Perforator Flap[END_REF] et subscapulaire restent nos premiers choix pour le pied (Fig. 1 et 9A-E). Le prélèvement du lambeau ALT sera effectué en supra fascial, améliorant la finesse du lambeau (4 à 6mm) sans augmenter le risque de nécrose tissulaire [START_REF] Crowe | Strategies for Reconstruction of the Plantar Surface of the Foot: A Systematic Review of the Literature[END_REF].

Pour les PDS exclusivement cutanées et sous réserve d'une bonne vitalité du plan tissulaire sous jacent, une greffe de peau ½ épaisse sera envisageable. L'adjonction d'un substitut dermique pour améliorer la trophicité et la résistance de la couverture pourra être discutée.

Dans le cas où le membre traumatisé ne peut pas être utilisé pour transposer ou accueillir un lambeau, le membre controlatéral pourra toujours être utilisé. Un lambeau basé sur les perforantes médiales de l'artère tibiale postérieure du membre sain pourra être mobilisé sous forme « cross » pour couvrir le membre lésé. Cette méthode a l'inconfort majeur de devoir fixer jointement les 2 membres inférieurs le temps de l'autonomisation du lambeau. Sur le même raisonnement, si l'état vasculaire du membre lésé est incompatible à l'accueil d'un lambeau libre, les anastomoses de ce dernier pourront s'effectuer sur les vaisseaux du membre controlatéral le temps de son autonomisation avec les mêmes inconvénients de posture que pour le lambeau pédiculé « cross » [START_REF] Chen | Cross-leg free flaps for difficult cases of leg defects: indications, pitfalls, and long-term results[END_REF].

Mesures post opératoires

Une reconstruction cutanée ou composite du pied impose une décharge d'appui en post opératoire.

La verticalisation progressive dépendra de la localisation des tissus reconstruits et de la technique utilisée. Pour la peau des régions non portantes, une verticalisation sans appui pourra être envisagée dès 15 jours, permettant la rééducation. En cas d'une reconstruction par un lambeau libre sans reconstruction osseuse, il est préférable d'attendre 4 semaines avant tout appui [START_REF] Xipoleas | A survey of microvascular protocols for lower extremity free tissue transfer II: postoperative care[END_REF][START_REF] Rohde | A recommended protocol for the immediate postoperative care of lower extremity free-flap reconstructions[END_REF].

En cas de reconstruction de structures nerveuses et tendineuses associées, nous préconisons d'attendre 6 semaines avant d'autoriser l'appui, même protégé. Les mobilisations passives peuvent être envisagées dès 3 semaines pour les reconstructions des parties molles.

Pour les reconstructions osseuses, l'appui sera repris à plus de 3 mois. Il devra être précédé d'examens radiographiques ou scanner à la recherche de signes en faveur d'une ébauche de consolidation osseuse. Selon la littérature, une consolidation osseuse est acquise en moyenne entre 6 à 8 mois. Certaine équipes préconisent le maintien d'une attelle de marche pour une durée totale de 2 ans post opératoire [START_REF] Yazar | One-stage reconstruction of composite bone and soft-tissue defects in traumatic lower extremities[END_REF].

Le temps de la décharge impliquera une immobilisation du pied et de la cheville par une attelle limitant une posture vicieuse associée à une anticoagulation préventive et des aides à la mobilisation corporelle. Pour préparer l'organisme à l'hyper catabolisme de la cicatrisation et de la lutte contre l'infection, le patient devra être sensibilisé aux bonnes pratiques nutritionnelles [START_REF] Patel | The Role of Nutrition in the Management of Lower Extremity Wounds[END_REF]. Toutes imprégnation nicotinique est à proscrire autour du geste opératoire et le temps d'obtenir une cicatrisation totale [START_REF] Schmitz | Effect of smoking on tibial shaft fracture healing[END_REF].

Conclusion

  Ces patients doivent impérativement bénéficier d'un bilan de leur état général en vue d'une prise en charge globale. Ils doivent bénéficier au minimum d'une imagerie des axes vasculaires afférents et efférents. Ces examens auront de plus un intérêt dans la planification opératoire pour les reconstructions plus sophistiquées qu'une greffe de peau. Sur un mauvais flux vasculaire du membre inférieur, la revascularisation par les chirurgiens vasculaires sera préalable à toute reconstruction du pied. L'état général du patient et l'état locorégional du membre lésé peuvent aboutir à contre indiquer certaines techniques de reconstruction. Enfin, il est indispensable de coupler les réflexions techniques aux niveaux de compliance, d'acceptation et d'exigence du patient.

  Reconstruction tendineuse La reconstruction des PDS tendineuses concerne d'avantage les tendons des muscles extrinsèques du pied. Leur réparation aura l'intérêt de rétablir leur fonction de mobilisation active mais également de limiter des déviations posturales des orteils. Pour cela, des greffes tendineuses sont envisageables pour les PDS de petites tailles. Les transferts tendineux du muscle court extenseur des orteils est une possibilité thérapeutique pour les PDS tendineuses du dos du pied. Le transfert d'un lambeau composite cutanéo-musculotendineux réinnervé est toujours envisageable mais reste rarement compatible avec la volonté d'un lambeau fin pour la reconstruction du pied. Reconstruction nerveuse L'innervation du pied est mixte et dépend des branches supra fasciales des nerfs fibulaires superficiel et profond, suraux, saphène et les nerfs plantaires. Le nerf fibulaire profond propose une branche musculaire pour le muscle court extenseur des orteils au dos du pied, les autres muscles intrinsèques du pied étant innervés par les nerfs plantaires.

  Reconstruction cutanée L'objectif de la couverture cutanée est de rétablir une barrière de protection pour les structures anatomiques sous jacente : osseuses, tendineuses vasculaires et nerveuses avec comme mire le chaussage et la marche. La couverture doit donc être fine et résistante aux frictions et compressions. Il est préférable de procéder à une couverture cutanée synchrone à la reconstruction des autres PDS pour limiter le temps de le reconstruction et proposer une rééducation précoce. La taille et l'épaisseur du lambeau devront être adaptées au pied. Il devra être fin pour la face dorsal et matelassé pour la face plantaire. Il faudra limiter les aspérités, les incongruences et l'effet de masse pour éviter les ulcérations à répétition. Pour la couverture cutanée, les lambeaux fascio-cutanés sont à privilégier. En plus de l'épaisseur qui est adaptée à la reconstruction du pied, ce type de lambeau permet un modelage plus simple et la possibilité d'une mobilisation pour toute chirurgie secondaire. De plus, le fascia va constituer une lame de glissement sur les structures sous-jacentes (tendons, nerfs) modérant les adhérences. Cette propriété est d'avantage recherchée au dos du pied. Il sera préférable d'éviter, dans la mesure du possible, les lambeaux musculaires associés à une greffe de peau car ils génèrent souvent un effet de masse et limitent la mobilisation secondaire et le modelage en raison d'absence d'autonomisation de ces lambeaux musculaires par les berges. Il y a donc un risque constant sur la vitalité du lambeau en cas de mobilisation secondaire.

  Les couvertures des PDS du pied représentent un pan difficile de la reconstruction du membre inférieur en raison du segment terminal du pied. Les techniques chirurgicales pour cette reconstruction sont nombreuses et impliquent une maîtrise étendue de l'arsenal thérapeutique pour proposer la solution la plus adaptée à la localisation et l'étendue de la PDS tout en limitant les séquelles du site donneur. La directive de reconstruction consistera à évaluer l'étendue et la sévérité du traumatisme en vue d'un parage exhaustif pour permettre une stabilisation osseuse précoce suivie d'une couverture cutanée fine et résistante. Le choix thérapeutique sera dicté par les objectifs fonctionnels de la reconstruction du pied : un appui, une marche et un chaussage indolores. Pour mener à bien cette mission, une collaboration pluridisciplinaire est incontournable, notamment avec le chirurgien orthopédiste sur les PDS osseuses et les médecins pour l'encadrement de l'état général du patient et des traitement adjuvants. Enfin, toute décision thérapeutique devra impliquer le patient dans la discussion en considérant son terrain, sa compliance et ses exigences face au protocole de reconstruction.

Figure 4 :

 4 Figure 4: Decision-making algorithm for cutaneous coverage according to size and location of loss of substance

Figure 1 :Figure 2 :

 12 Figure 1 : Amputation des 3 derniers rayons du pied avec une perte de substance composite. Reconstruction de l'arche du pied avec le transfert vascularisé du 2 ème métatarsien selon la technique de chiroplastie et interposition de ses phalanges pour élargir l'arche et rééquilibrer l'appui. Traitement de la perte de substance cutanée par un lambeau antéro latéral de cuisse libre (A à F)

Figure 3 :Figure 4

 34 Figure 3 : Traumatisme du pied avec perte de substances vasculaire, nerveuses et exposition osseuse malléolaire médiale et calcanéenne traité par un pontage veineux de l'artère tibiale postérieure, greffes nerveuses et couverture par un lambeau libre de muscle gracile (A à D)

Figure 5 :Figure 6 :Figure 7 :Figure 8 :Figure 9 :

 56789 Figure 5 : Couverture de l'os calcanéum avec un lambeau plantaire médial sensible (A à C)