Pelvic obliquity as a compensatory mechanism leading to lower energy recovery: Characterization among the types of prostheses in subjects with transfemoral amputation

BackgroundSubjects with transfemoral amputation (TFA) show an asymmetric gait pattern associated with a decreased ability to recover mechanical energy and an increased metabolic cost of walking.Research questionThis study aimed to identify the spatio-temporal and kinematic gait variables correlated with mechanical energy values in subjects with TFA and to observe the ability of the identified parameters to discriminate between TFA and controls according to the type of prosthesis.MethodsThe gait of 40 subjects with TFA was evaluated with a motion 3-D optoelectronic system. Nine subjects wore a mechanical prosthesis (TFAm), seventeen a C-Leg prosthesis (TFAc), and fourteen a Genium prosthesis (TFAg). Spatio-temporal and pelvic kinematic parameters were measured. Energy recovery was measured relative to the whole-body center of mass (CoM) kinematics as the fraction of mechanical energy recovered during each walking step (R-step). Correlation tests and multiple linear regression analyses were used to evaluate the correlation and association between kinematic and energy variables, respectively. Receiver operating characteristics curves were plotted to assess the ability of the correlated parameter to distinguish subjects with TFA from controls, and optimal cutoff point values were calculated according to the type of prosthesis.ResultsAmong the spatio-temporal and kinematic parameters correlated to R-step, only pelvic obliquity of the prosthetic side was significantly associated with R-step. It showed an excellent ability to discriminate between TFA and controls. Furthermore, pelvic obliquity showed an excellent discriminative ability in identifying TFAm and TFAc and a good discriminative ability in identifying TFAg from controls.SignificancePelvic obliquity plays an important role in energy recovery during gait for subjects using prosthetics. This information might be exploited to monitor the adaptation of subjects with TFA to prosthetic devices, to lower the energetic cost of walking potentially, and to reduce the long-term risks of secondary physical complications in prosthetic users.     

The 2018 International Consensus Meeting Minor Criteria for Chronic Hip and Knee Periprosthetic Joint Infection: Validation From a Single Center

BackgroundRecently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center.MethodsWe retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed.ResultsA total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98).ConclusionThe modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.     

Le travail de l’exil à l’adolescence. Dispositif d’étayage groupal et de médiation par la bande dessinée

ObjectiveThe exile is particularly traumatic for adolescents who, in the host country, live the post-migration experience in uncertainty. In order to enhance the continuous sense of being and the imaginary of a group of young unaccompanied minors, and to promote the narrative of their exile, we have set up a group mediated by comics. We strive to understand how and by which processes a comic mediation group could enable the support of the continuous sense of being as well as the imagination in a group of unaccompanied minors.MethodSix (n = 6) adolescents aged 15 to 17 were invited to design a group comic strip. Participants were invited to create a comic in group. The study was divided in three specific times: (1) the first was to invent a story, (2) the second was to do a storyboard and (3) the third and last one consisted in the creation of a comic. The group proceeded in X session and each session ended with a speaking time. We chose to create a comic as a medium because of its formal qualities: the specificity and complexity of its codes seemed appropriate to work on the time and space. Therefore, the breaks and discontinuities as essential parts of the comic structure allowed the participants to work out their temporal and special experiences of exile. As working in group enables to enhance the creative processes, we have designed and set up a comic mediation group.ResultsWe observed that the creation of the comic facilitates the updating of break and loss experiences, because of its formal structure. This sometimes made the group envelope porous and fragile, and damaged the group associative chain. The mediation group allowed participants to express and transform their primary affects through images and words, which led them to go from a fixed time to a historicized time. The comic became an object that represents the individual psychic reality work, the group work but also refers to the common societal reality that concerns those adolescents. Through the comic, they question the adults, the institutions and the environments that are supposed to protect them. The structure of the comic and the group setting helped participants to restore a sense of security. Moreover, the secure and containing space created by the setting allowed the group to enhance its imagination.DiscussionThe setting permitted participants to be in an active position, which supported them in the process of identity reconstruction. They used comics to transform and make sense of a painful part of their story in order to appropriate it. It is necessary to keep doing research on this subject to improve the support given for this young people. Moreover, it is essential to offer them places where they can be accompanied in the crossing of their exile experience.