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Surgical cutting guides are increasingly used for maxillofacial reconstruction. They are usually provided by laboratories. In recent years, surgical teams have published studies on the possibility of manufacturing their own cutting guides thanks to 3D printers. The object of this study is to analyze the impact of the sterilization on the surface of those personalized models and to assess the effectiveness of sterilization. Using the data from high-resolution CT scan of patient, 3D models were generated through computerized assisted design and fabricated with a 3D printer using Acrylonitrile Butadiene Styrene (ABS). For the sterilization, a Sterrad method was used. In order to evaluate the effectiveness of sterilization, 3D models were artificially contaminated with several bacterial reference strains, sterilized and finally cultured. The surfaces and mechanical modifications were analyzed before and after sterilization with infrared spectrometry, surface contact angle, extensometer, scanning electron microscopy and atomic force microscopy. Ten models of different shapes and 24 samples were fabricated, sterilized and analyzed. The 3D models were designed in 48 h, printed in an average of 122 min and underwent a 47 min cycle of sterilization. All experimentally contaminated 3D models were negative in culture, with at least, a six log reduction of the initial inoculum. The hydrophobicity and roughness of the surface suffered few changes. The reproducibility of this procedure was proved by identical results in the three sterilization rounds. Using Sterrad process for the sterilization of ABS printed material doesn’t represent a bacterial risk for the patient. It is a feasible and safe innovative reconstructive method that can save time particularly for oncological cases.

The primary stability of the acetabular cup (AC) implant is an important determinant for the long term success of cementless hip surgery. However, it remains difficult to assess the AC implant stability due to the complex nature of the bone-implant interface. A compromise should be found when inserting the AC implant in order to obtain a sufficient implant stability without risking bone fracture. The aim of this study is to evaluate the potential of impact signals analyses to assess the primary stability of AC implants inserted in cadaveric specimens. AC implants with various sizes were inserted in 12 cadaveric hips following the same protocol as the one employed in the clinic, leading to 86 different configurations. A hammer instrumented with a piezoelectric force sensor was then used to measure the variation of the force as a function of time produced during the impact between the hammer and the ancillary. Then, an indicator I was determined for each impact based on the impact momentum. For each configuration, twelve impacts were realized with the hammer, the value of the maximum amplitude being comprised between 2500 and 4500 N, which allows to determine an averaged value IM of the indicator for each configuration. The pull-out force F was measured using a tangential pull-out biomechanical test. A significant correlation (R2 = 0.69) was found between IM and F when pooling all data, which indicates that information related to the AC implant biomechanical stability can be retrieved from the analysis of impact signals obtained in cadavers. These results open new paths in the development of a medical device that could be used in the future in the operative room to help orthopedic surgeons adapt the surgical protocol in a patient specific manner.

Dental implants are widely used in the clinic. However, there remain risks of failure, which depend on the implant stability. The aim of this paper is to compare two methods based on resonance frequency analysis (RFA) and on quantitative ultrasound (QUS) and that aim at assessing implant stability. Eighty-one identical dental implants were inserted in the iliac crests of 11 sheep. The QUS and RFA measurements were realized after different healing times (0, 5, 7, and 15 weeks). The results obtained with the QUS (respectively RFA) method were significantly different when comparing two consecutive healing time for 97% (respectively, 18%) of the implants. The error made on the estimation of the healing time when analyzing the results obtained with the QUS technique was around 10 times lower than that made when using the RFA technique. The results corresponding to the dependence of the ISQ versus healing time were significantly different when comparing two directions of RFA measurement. The results show that the QUS method allows a more accurate determination of the evolution of dental implant stability when compared to the RFA method. This study paves the way towards the development of a medical device, thus providing a decision support system to dental surgeons.

BackgroundCompared to other life-threatening infection survivors, long-term health-related quality of life (QOL) of patients surviving necrotizing soft-tissue infections (NSTI) and its determinants are little known.In this monocentric prospective cohort including NSTI survivors admitted between 2014 and 2017, QOL was assessed during a phone interview using the 36-Item Short-Form Health Survey (SF-36), the Hospital Anxiety and Depression (HAD), the activity of daily living (ADL), instrumental ADL (IADL) scales and the Impact of Event Scale-Revised (IES-R). The primary outcome measure was the SF-36 physical component summary (PCS). NSTI patients were compared according to intensive care unit (ICU) admission status. ICU survivors were matched on SAPS II with non-NSTI related septic shock survivors.ResultsForty-nine NSTI survivors were phone-interviewed and included in the study. Median PCS was decreased compared to the reference population [− 0.97 (− 2.27; − 0.08) SD]. Previous cardiac disease was the only variable associated with PCS alteration [multivariate regression coefficient: − 8.86 (− 17.64; − 0.07), p  =  0.048]. Of NSTI survivors, 15.2% had a HAD-D score  ≥  5 and 61.2% an IES-R score  ≥  33. ICU admission was not associated with lower PCS [35.21 (25.49–46.54) versus (vs) 41.82 (24.12–51.01), p  =  0.516], but with higher IES-R score [14 (7.5–34) vs 7 (3–18), p  =  0.035] and a higher proportion of HAD-D score  ≥  5 (28.6 vs 4.0%, p  =  0.036). Compared to non-NSTI septic shock-matched controls, NSTI patients had similar PCS [33.81 (24.58; − 44.39) vs 44.87 (26.71; − 56.01), p  =  0.706] but higher HAD-D [3.5 (1–7) vs 3 (1.5–6), p  =  0.048] and IES-R scores [18 (8–35) vs 8 (3–19), p  =  0.049].ConclusionsLong-term QOL in NSTI survivors is severely impaired, similarly to that of non-NSTI septic shock patients for physical compartments, but with more frequent depressive and/or post-traumatic stress disorders. Only ICU admission and previous cardiac disease were predictive of QOL impairment.

BackgroundThe objective of breast reconstruction (BR) is to erase the after-effects of total mastectomy by allowing patients to restore their breast shape. The aim of our study was to investigate the body map integration of different types of BR using functional magnetic resonance (fMRI).Patients and MethodsWe prospectively enrolled all women undergoing BR for breast cancer to the Remasco study (NCT02553967). Participants were categorized into four groups according to the standard of care they required: immediate BR (IBR), delayed BR (DBR), flap (autologous), or implant BR. Each patient performed sensorimotor tasks during the fMRI acquisition.ResultsData of 38 patients were analyzed. We identified the cingulate region as the area of interest in the brain. In the case of DBR, the brain area activated during palpation of the total mastectomy scar (before BR) was different from the brain area activated during palpation of the reconstructed breast (Brodmann areas 31 versus 32). Palpation of the native breast and reconstructed breast activated the same Brodmann area 32. Comparing the brain activation signal during palpation of the native breast and the reconstructed breast did not reveal any significant difference in the overall population (P = 0.41) or in the groups: autologous (P = 0.32), implant (P = 0.10), IBR (P = 0.72), or DBR (P = 0.10).ConclusionsThis experimental study allowed us to describe and understand the brain plasticity processes that accompany BR. The results suggest that the reconstructed breast is integrated into the body schema, regardless of the type of BR or the timing.

Dental implant stability, which is an important parameter for the surgical outcome, can now be assessed using quantitative ultrasound. However, the acoustical propagation in dental implants remains poorly understood. The objective of this numerical study was to understand the propagation phenomena of ultrasonic waves in cylindrically shaped prototype dental implants and to investigate the sensitivity of the ultrasonic response to the surrounding bone quantity and quality. The 10-MHz ultrasonic response of the implant was calculated using an axisymetric 3D finite element model, which was validated by comparison with results obtained experimentally and using a 2D finite difference numerical model. The results show that the implant ultrasonic response changes significantly when a liquid layer is located at the implant interface compared to the case of an interface fully bounded with bone tissue. A dedicated model based on experimental measurements was developed in order to account for the evolution of the bone biomechanical properties at the implant interface. The effect of a gradient of material properties on the implant ultrasonic response is determined. Based on the reproducibility of the measurement, the results indicate that the device should be sensitive to the effects of a healing duration of less than one week. In all cases, the amplitude of the implant response is shown to decrease when the dental implant primary and secondary stability increase, which is consistent with the experimental results. This study paves the way for the development of a quantitative ultrasound method to evaluate dental implant stability.

BackgroundNecrotizing skin and soft tissue infections (NSTIs) require both prompt medical and surgical treatment. The coordination of multiple urgent interventions by care bundles has improved outcome in other settings. This study aimed to assess the impact of a multidisciplinary care bundle on management and outcome of patients with NSTIs.MethodsPatients with NSTIs admitted between 2006 and 2017 were compared according to admission before or after bundle implementation (2012–2013). This bundle consisted mainly in (1) the creation of a multidisciplinary task force; (2) management guidelines on empirical antibiotics, intensive care unit admission criteria, a triage algorithm to accelerate operating room access; and (3) an active communication policy. Patient recruitment and management were compared between pre- and post-implementation periods. Main outcome was day 60-censored hospital survival.ResultsOverall, 224 patients were admitted: 60 before, 35 during, and 129 after bundle implementation. Admission after implementation was associated with increased yearly admissions (10 [8–13] vs 30 [24–43] patients/year, p = 0.014) and decreased mortality (30 vs 15%, HR = 0.49 [0.26–0.92]; p = 0.026) but was no longer a protective factor for mortality after adjustment on confounding factors (adjusted HR = 0.90 [0.43–1.88], p = 0.780). There was no significant difference regarding time to surgery (0 [0–1] vs 0 [0–1] days, p = 0.192) or rate of antibiotic treatment within 24 h (98% vs 99%, p > 0.99).ConclusionsImplementation of a multidisciplinary care bundle for NSTIs was feasible, but in a retrospective study from an already experienced center was not associated with significantly increased survival after adjustment.

The incidence of necrotising soft-tissue infections has increased during recent decades such that most physicians might see at least one case of these potentially life-threatening infections in their career. Despite advances in care, necrotising soft-tissue infections are still associated with high morbidity and mortality, underlining a need for continued education of the medical community. In particular, failure to suspect necrotising soft-tissue infections, fuelled by poor awareness of the disease, promotes delays to first surgical debridement, amplifying disease severity and adverse outcomes. This Review will focus on practical approaches to management of necrotising soft-tissue infections including prompt recognition, initiation of specific management, exploratory surgery, and aftercare. Increased alertness and awareness for these infections should improve time to diagnosis and early referral to specialised centres, with improvement in the prognosis of necrotising soft-tissue infections.

Press-fit surgical procedures aim at providing primary stability to acetabular cup (AC) implants. Impact analysis constitutes a powerful approach to retrieve the AC implant insertion properties. The aim of this numerical study was to investigate the dynamic interaction occurring between the hammer, the ancillary and bone tissue during the impact and to assess the potential of impact analysis to retrieve AC implant insertion conditions. A dynamic two-dimensional axisymmetric model was developed to simulate the impaction of the AC implant into bone tissue assuming friction at the bone–implant interface and large deformations. Different values of interference fit (from 0.5 to 2 mm) and impact velocities (from 1 to 2 m.s −1 ) were considered. For each configuration, the variation of the force applied between the hammer and the ancillary was analyzed and an indicator I was determined based on the impact momentum of the signal. The simulated results are compared to the experiments. The value of the polar gap decreases with the impact velocity and increases with the interference fit. The bone–implant contact area was significantly correlated with the resonance frequency ( R 2  = 0.94) and the indicator ( R 2  = 0.95). The results show the potential of impact analyses to retrieve the bone–implant contact properties.