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Background Scoliosis curves present transverse plane deviations due to vertebral rotation. The Schroth method supports thoracic derotation by training patients to exert “derotational” breathing based on assumed enhanced ventilation in areas called “humps” in scoliosis and a patient’s ability to voluntarily direct ventilation in less ventilated areas called “flats.” Objective To assess the asymmetric ventilation distribution and the ability of patients to direct their ventilation to perform derotational breathing. Methods Twelve girls with adolescent idiopathic scoliosis and 12 healthy girls performed 3 × 3 min of rest, maximal, and derotational breathing. Electrical impedance tomography was used to record locoregional lung ventilation distribution (LLVD) within 4 thoracic regions of interest: anterior right (ROI 1), anterior left (ROI 2), posterior right (ROI 3), and posterior left (ROI 4) quadrants. Humps and flats were the sums of ROI ‘2 + 3’ and ROI ‘1 + 4,’ respectively. Results Overall, no difference in LLVD was observed in the flats and humps between groups. At rest, the LLVD in the humps was more elevated than that in the flats (51.5 ± 8.1% versus 43.6 ± 7.9%; p = .021) when considering both groups. Maximal and derotational breathing led to a more homogeneous LLVD between the humps and flats. Conclusion The postulated derotational breathing effect was not confirmed.

Open tibia fractures (OTF) can cause significant morbidity. These injuries justify early antibiotic therapy, adequate debridement, stable osteosynthesis, and early coverage of the fracture. The mostly poor infrastructural conditions concerning the provision of health services in developing countries (DCs) likely render adequate treatment of problematic fractures practically impossible. The hygienic conditions required for surgical treatment involving techniques of internal osteosynthesis may be insufficient; for cost reasons, the necessary devices including image intensifier and implants may be lacking in places where such treatment could indeed be offered. Thus, casting with plaster of Paris (POP) is still the commonly used restraint method due to its availability and low-cost. However, this method may cause many complications. In this context, the external fixator (EF) is still the implant of choice, which is also suitable for precarious areas. The EF has proven its usefulness in the treatment of open fractures. This alternative could be employed to circumvent the difficulties of implementing a classic osteosynthesis. There are many sophisticated external fixators on the market, but they are too expensive, which limits their usefulness in our country. This doctoral thesis investigated the locally-developed external fixator (LDEF) manufactured from available and easily accessible materials for treating shaft fractures of long bones, including the tibia. The first part of this thesis investigated the treatment of open fractures in DCs in sub-Saharan Africa. A prospective clinical study on the management of OTF in a reference health facility in Ivory Coast was carried out, as was a systematic review of literature concerning the treatment of OTF. This was meant to establish an inventory concerning the treatment of open tibia fractures. The second part of this thesis investigated the design and biomechanical aspects of different LDEFs. Design of the LDEF was made from, (MED - Sciences médicales) -- UCL, 2021

INTRODUCTION: Accuracy of thyroid cartilage fenestration during Montgomery thyroplasty (MTIS) is considered a key success factor. The primary aim of the study was to retrospectively evaluate the accuracy of fenestration. Furthermore, recent publications indicate a possible discrepancy in MTIS voice outcomes related to gender. The secondary aim of the study was to investigate whether the fenestration accuracy could explain this discrepancy. MATERIAL AND METHOD: Study was performed by virtually drawing the fenestration on a 3D CT scan as proposed by the MTIS's instructions for use (the "expected window" (EW)), and comparing it to the actually realized fenestration (the "realized window "(RW)). Four position variables, (a) surface overlap (%), (b) the distances between RW and EW centers (mm), (c) the angle between RW and EW (°), and (d) the orientation of RW's center, were studied and compared to MPT (seconds) and VHI-30 scores outcomes. A descriptive statistical analysis and comparison between males and females were performed using a Mann-Whitney U test. Linear regression and multivariate analysis were also performed. RESULTS: The median overlapping surface was 58.8 % [34.6; 75.4]. The median radius was 3.2 mm [1.7; 4.1]. The median angle was 16° [6.8; 21.2]. Results show no significant differences of overlapping surface percentage, distance, or angle by gender. Data show no correlation between voice outcome and percentage overlap, distance, or angle. However, data show better outcomes when fenestration was located in the infero-anterior orientation. All patients of this orientation were males. CONCLUSIONS: Data provided by this study advocate a maximal infero-anterior positioning of the window during MTIS. This position is more difficult to obtain in female patients.

Purpose: Robotic-assisted therapy has been shown to be effective for post-stroke rehabilitation. However, clinicians seem to be reluctant to use it in clinical practice. This qualitative study aims to examine the reasons underlying the lack of rehabilitation robot (RR) use in the clinical practice among therapists. Methods: Eight French-speaking therapists, which participate in a clinical study, underwent a semi-structured interview. Questions where defined from the Unified theory of Acceptance and Use of Technology. Interviews were transcribed, summarized and a transversal analysis was finally performed. Results: Seven themes were highlighted: effort expectancy, performance expectancy, social influence, self-efficacy, relationship, experience and cost. Some therapists found that RR did not provide a functional training and had a perception of ineffectiveness. However, almost all therapists mentioned that RR was complementary to conventional therapy, provided a high number of movement repetitions and was effective for some responders. Most of the therapists found that the installation time was an additional energy cost. All therapists were positively influenced by their head of department to use the RR, but a small number of them were negatively influenced by their team. Finally, all therapists received a training session before using the RR and found it essential. Conclusion: This study showed that it is difficult to change routine in clinic and add information towards robotic acceptance in clinical context. The communication between clinicians and researchers is crucial and could help to further develop and improve certain aspect of the RR.

PURPOSE To assess radiological and gait biomechanical changes before, at one and 10 years after surgery in AIS patients. METHODS This clinical prospective study included fifteen adult women (mean[SD] age: 26 Goldberg et al. (2008) [1] years) diagnosed with thoraco-lumbar/lumbar AIS and operated 10 years ago. Clinical, radiological and gait variables, including kinematics, electromyography (EMG), mechanics and energetics were compared between presurgery (S0), 1 year (S1) and 10 years (S2) postsurgery period using a one way repeated measure ANOVA. RESULTS The Cobb angle of the scoliosis curve was reduced by 55% at 1 year postsugery but only by 37% at 10 years postsurgery suggesting a loss of 32% over time. Frontal plumb line C7-S1 distance was significantly improved by surgery (−44%) and remained stable at 10 years postsurgery. Lower limb kinematics was not affected by the surgery at long term. Excessive bilateral activation of lombo-pelvic muscles, observed before surgery, decreased significantly at S1 and S2 period. Mechanical energy increased significantly between S0, S1 and S2 session, without any change for the energetic variables. CONCLUSIONS Between 1 and 10 years post-surgery, thoraco-lumbar/lumbar AIS women showed a few decompensation of the curve without any change of the improved frontal body balance. Lower limbs and pelvic motion, during gait, was not affected by the surgery. But presurgical excessive EMG activity of the lumbo-pelvic muscle and reduced mechanical energy produced to walk get similar normal patterns. Only the oxygen consumption remained excessive probably due to physical deconditioning or postural instability.

OBJECTIVES: To measure passive musculoarticular ankle stiffness (PMAAS) and its intra- and interday reliability in adult control subjects without ankle disorders. We also sought to quantify PMAAS in children, adolescents and young adults with haemophilia (CAAwH) taking into account the accurate tibiotalar and subtalar joints structural status obtained by magnetic resonance imaging (MRI). METHODS: We included 23 CAAwH and 23 typically developing boys (TDB) matched by age, weight and height, along with 25 healthy volunteers for reliability assessment. All CAAwH underwent bilateral ankle MRI, with anatomical status assessed using the International Prophylaxis Study Group MRI scale. All CAAwH underwent PMAAS testing for both sides randomly vs the dominant side (DS) in TDBs. For assessing viscous stiffness (VS) and elastic stiffness (ES), eight different oscillation frequencies were randomly repeated three times for each subject. RESULTS: Good-to-excellent intra- and interday reliability was observed for ES and VS variables. No relevant differences were observed between the ankle viscoelastic properties in CAAwH without joint damage and matched TDBs, whereas the study revealed significantly increased ES in the affected ankles of CAAwH with severe unilateral joint involvement compared to the non-affected joint. CONCLUSION: This study confirmed increased ES in the severely affected ankles of CAAwH compared to non-affected sides. No differences in the ankle viscoelastic properties of CAAwH with or without joint damage were observed, however, compared to matched TDB.

This PhD thesis aims to study the clinical and experimental use of a new intraoperative cone beam computed tomography (CBCT) imaging system for pedicle screw insertion in spine surgery. In spine surgery, some pathologies such as vertebral fracture or deformities require surgical stabilization in order to prevent, for example, spinal cord damages or spine malalignment. To reach the bone fusion required for spine stabilization, titanium instrumentation is used to connect vertebrae. Pedicle screw is the most widely used implant to obtain a solid anchorage in a given vertebra. The screw-rods construct allows spine stabilization and later definitive segmental fusion. Pedicle screws require accurate placement in the pedicle center to ensure the best anchorage and avoid pedicle cortical effractions. Indeed, misplacement can lead to instability of the construct and delayed fusion, or to potentially dramatic complications such as spinal cord, nerve and vascular lesions. Assistive technologies have been developed to control pedicle screw insertion during surgery and improve the accuracy of pedicle screw placement. The Artis zeego II is a new intraoperative CBCT robotic system allowing two-dimensional (2D) and three-dimensional (3D) fluoroscopy acquisitions. The purpose of this device is to assist the pedicle screw insertion and to assess screw placement intraoperatively. This thesis firstly aims to assess the clinical use of the Artis zeego II in terms of accuracy and safety of use for pedicle screw insertion. The second aim, consists proposing a new standardized and quantitative approach based on the intraoperative 3D CBCT images to objectively assess screw placement., (MED - Sciences médicales) -- UCL, 2018

PURPOSE: The goals of this paper are to assess the ionizing radiation exposure to the patients during thoracic and lumbar spinal fusion using a new intraoperative 3D imaging system and to evaluate the factors that could explain the variability in the observed doses. METHOD: We retrospectively reviewed 97 patients who underwent posterior instrumented thoracic and/or lumbar spinal fusion from December 2013 to November 2014. Primary data were the total dose area product (total DAP, Gy cm2) and total skin dose (total SD, mGy). Influence of different variables (patient characteristics, surgical technique, and intraoperative imaging system parameters) that could influence patients' exposure was analyzed. RESULTS: Radiation dose imparted to patients depended on four parameters including acquisition protocol, surgical technique, patient's BMI and operative time. Minimally invasive surgery (MIS) resulted in twofold higher dose for patients, compared to open surgery. The use of low dose acquisition protocols reduced patient exposure by a factor three. CONCLUSION: Patient exposure was highly variable. Four parameters were found to explain about 68% of its variance when using a multi-axis robotic C-arm system. MIS technique (with navigation or not) as well as the acquisition protocol dramatically increases the radiation dose for patients. These results show the necessity to develop specific strategies adapted to patients and surgical procedures.

Surgical accuracy is multifactorial. Therefore, it is crucial to consider all influencing factors when investigating the accuracy of a surgical procedure, such as the surgeon's experience, the assistive technologies that may be used by the surgeon, and the patient factors associated with the specific anatomical site. For in vitro preclinical investigations, accuracy should be linked to the concepts of trueness (e.g., distance from the surgical target) and precision (e.g., variability in relation to the surgical target) to gather preclinical, quantitative, objective data on the accuracy of completed surgical procedures that have been performed with assistive technologies. The clinical relevance of improvements in accuracy that have been observed experimentally may be evaluated by analyzing the impact on the risk of failure and by taking into account the level of tolerance in relation to the surgical target (e.g., the extent of the safety zone). The International Organization for Standardization (ISO) methodology enables preclinical testing of new assistive technologies to quantify improvements in accuracy and assess the benefits in terms of reducing the risk of failure and achieving surgical targets with tighter tolerances before the testing of clinical outcomes.

Spine surgery planning involves many decisions for which the surgeon has not enough information, and for which biomechanical models might be helpful. Research studies show a high variability in decision making in the planning of scoliosis surgery by experienced groups of surgeons. That variability is problematic because it may cause complications for the patient, such as revision surgery or an increased limitation in spine mobility. Therefore, a biomechanical model for spine surgery planning may be useful in providing the surgeon the information needed to propose the best treatment. In this context, intervertebral efforts represent an essential input in assisting diagnosis and subsequently guiding the surgical planning of scoliosis. The long-term motivation of this thesis consists in assisting surgeons in obtaining quantitative - kinematic and dynamical - information that will allow them to improve the surgical planning of scoliosis, by specifying the set of vertebrae to be fused, while preserving the spinal mobility. In regards to this final motivation, the thesis seeks to develop a clinical protocol based on experimental data and on a multibody model of the upper body, to quantify the intervertebral efforts for idiopathic scoliotic adolescents in standing up position (statics) and during moderate gait (dynamics). The estimation of intervertebral efforts is based upon four interwoven topics: patient physiology, spine geometry, spine and pelvis kinematics, as well as muscular forces. In line with this, if this work’s final objective is to be met, three targeted contributions must be achieved: -The elaboration of a clinical protocol focusing on assessment of the scoliotic patient’s parameters: necessary anthropomorphic data, spine shape and kinematics, and muscle force calibration; -The development of a physiologically-based multibody model of the upper body, able to predict the spine’s kinematics and dynamics during gait; -In terms of internal efforts, using the mul, (FSA - Sciences de l'ingénieur) -- UCL, 2017

Avec l’essor des nouvelles technologies numériques, les chirurgiens sont amenés à travailler étroitement avec les ingénieurs pour répondre à leurs besoins cliniques en constante évolution. Cette étude de cas pilote caractérise les représentations de professeurs chirurgiens et ingénieurs sur leur pratique de supervision et d’évaluation de mémoires de fin d’études dans le domaine de la chirurgie orthopédique assistée par ordinateur, et une situation de coopération potentielle entre les étudiants ingénieurs et les résidents orthopédiques durant la réalisation d’un projet de recherche commun. L’étude s’appuie sur des entretiens semi-structurés menés avec quatre professeurs chirurgiens et trois professeurs ingénieurs. Les données collectées sur les pratiques actuelles de supervision et d’évaluation de mémoires et sur la situation de coopération potentielle entre mémorants chirurgiens et ingénieurs ont été recueillies selon un modèle de recherche collaborative. Les participants identifient des freins à une formation efficace à la recherche en chirurgie orthopédique assistée par ordinateur : l’absence de plus-value scientifique et/ou chirurgicale, la difficulté d’offrir aux mémorants l’accompagnement rapproché nécessaire, et la tendance inutile à former une simple relation client-producteur entre chirurgiens et ingénieurs. Les participants identifient des conditions à satisfaire avant de démarrer un projet de recherche commun entre étudiants ingénieurs et résidents orthopédiques : atteindre un consensus sur les objectifs de recherche et formation, assurer une interdépendance positive entre mémorants, garantir l’engagement des superviseurs, et démontrer scientifiquement les bénéfices potentiels d’une coopération entre mémorants chirurgiens et ingénieurs durant la réalisation de leur mémoire. Les résultats constituent en soi une évaluation du dispositif mis en place et sont à exploiter pour initier une démarche de recherche-action collaborative et développer des premiers cri

PURPOSE: The goals of this study were to assess the accuracy of pedicle screw insertion using an intraoperative cone beam computed tomography (CBCT) system, and to analyze the factors potentially influencing this accuracy. METHODS: Six hundred and ninety-five pedicle screws were inserted in 118 patients between October 2013 and March 2016. Screw insertion was performed using 2D-fluoroscopy or CBCT-based navigation. Accuracy was assessed in terms of breach and reposition. All the intraoperative CBCT scans, done after screw insertion, were reviewed to assess the accuracy of screw placement using two established classification systems: Gertzbein and Heary. Generalized linear mixed models were used to model the odds (95% CI) for a screw to lead to a breach according to the independent variables. RESULTS: The breach rate was 11.7% using the Gertzbein classification and 15.4% using the Heary classification. Seventeen screws (2.4%) were repositioned intraoperatively. The only factor affecting statistically the odds to have a breach was the indication of surgery. The patients with non-degenerative disease had a significantly higher risk of breach than those with degenerative disease. CONCLUSION: Use of intraoperative CBCT as 2D-fluoroscopy or coupled with a navigation system for pedicle screw insertion is accurate in terms of breach occurrence and reposition. However, these rates depend on the classification or grading system used. Use of a navigation system does not decrease the risk of breach significantly. And the risk of breach is higher in non-degenerative conditions (trauma, scoliosis, infection, and malignancy disease) than in degenerative diseases.

PURPOSE: The goal of this study was to compare the accuracy of a novel intraoperative cone beam computed tomography (CBCT) imaging technique with that of conventional computed tomography (CT) scans for assessment of pedicle screw placement and breach detection. METHODS: Three hundred and forty-eight pedicle screws were inserted in 58 patients between October 2013 and March 2016. All patients had an intraoperative CBCT scan and a conventional CT scan to verify the placement of the screws. The CBCT and CT images were reviewed by two surgeons to assess the accuracy of screw placement and detect pedicle breaches using two established classification systems. Agreement on screw placement between intraoperative CBCT and postoperative CT was assessed using Kappa and Gwet's coefficients. Using CT scanning as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the ability of CBCT imaging to accurately evaluate screw placement. RESULTS: The Kappa coefficient was 0.78 using the Gertzbein classification and 0.80 using the Heary classification, indicating a substantial agreement between the intraoperative CBCT and postoperative CT images. Gwet's coefficient was 0.94 for both classifications, indicating almost perfect agreement. The sensitivity, specificity, positive predictive value and negative predictive value of the CBCT images were 77, 98, 86, and 96%, respectively, for the Gertzbein classification and 79, 98, 88, and 96%, respectively, for the Heary classification. CONCLUSIONS: Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws. This technique may make postoperative CT imaging unnecessary.