SAM

Combined 3D analysis of lower-limb morphology and function in children with idiopathic equinovarus clubfoot: A preliminary study

RAMPAL, Virginie — Wed, 01 Jan 2020 00:00:00 GMT

Combined 3D analysis of lower-limb morphology and function in children with idiopathic equinovarus clubfoot: A preliminary study RAMPAL, Virginie; BONNET-LEBRUN, Aurore; FONESCA, Mickael; DESAILLY, Eric; WICART, Philippe; SKALLI, Wafa; ROHAN, Pierre-Yves; PILLET, Helene Introduction In children treated for idiopathic equinovarus clubfoot (EVCF), the relation between morphologic defects on clinical examination and standard X-ray on the one hand and functional abnormalities on the other is difficult to objectify. The aim of the present study was to demonstrate the feasibility of combined 3D analysis of the foot and lower limb based on biplanar EOS radiographs and gait analysis. The study hypothesis was that this provides better understanding of abnormalities in form and function. Methods Ten children with unilateral EVCF and “very good” clinical results were included. They underwent gait analysis on the Rizzoli Institute multisegment foot model. Kinematic data were collected for the hip, knee, ankle and foot (hindfoot/midfoot, midfoot/forefoot and hindfoot/forefoot). Biplanar EOS radiographs were taken to determine anatomic landmarks and radiological parameters. Results Complete acquisition time was around 2 hours per patient. No significant differences were found between EVCF and healthy feet except for calcaneal incidence, tibiocalcaneal angle and hindfoot/midfoot and hindfoot/forefoot inversion. Discussion The feasibility of the combined analysis was confirmed. There were no differences in range of motion, moment or power between EVCF and healthy feet in this series of patients with very good results. The functional results are related to radiological results within the normal range. The protocol provided anatomic and kinematic reference data. A larger-scale study could more objectively assess the contribution of EOS radiography using optoelectronic markers. Level of evidence II, low-power prospective study.

Mechanical Work and Metabolic Cost of Walking with Knee-Foot Prostheses: A Study with a Prosthesis Simulator

BONNET-LEBRUN, Aurore — Sun, 01 Dec 2024 00:00:00 GMT

Mechanical Work and Metabolic Cost of Walking with Knee-Foot Prostheses: A Study with a Prosthesis Simulator BONNET-LEBRUN, Aurore; SEDRAN, Lucas; HEIDSIECK, Cécile; THOMAS-POHL, Marie; PILLET, Helene; BONNET, Xavier Background At equivalent speeds, above-knee amputee subjects have a higher metabolic cost than non-amputees. Following amputation, the ankle propulsion is reduced, and using other joints to compensate is mechanically less efficient. Objective This study investigated the link between mechanical work and metabolic cost in abled-bodied subjects using a prosthesis simulator, and the influence of foot energy restitution by comparing a foot with restitution to one without. Method Six volunteers fitted with an orthosis immobilising their ankle and knee, enabling the use of a prosthesis, carried out a gait analysis and an analysis of metabolic cost. The total lower limb mechanical work and works at the hip, knee and ankle were computed. Results With an almost twofold increase, metabolic cost and hip work were significantly higher in both configurations with prosthesis than without (p < 0.001 for both variables in both configurations), while total lower limb mechanical work showed no significant difference between configurations. No significant difference was observed between the two prosthetic feet in terms of metabolic cost nor mechanical work performed by the subject. Discussion Total lower limb mechanical work alone cannot explain the extra metabolic cost in subjects fitted with a knee-foot prosthesis simulator; internal inefficiencies exist. We also found that metabolic cost and hip work increase and decrease simultaneously, thus studying hip muscles work could be interesting. With no significant difference between the two feet, optimising ankle propulsion seems to be ineffective in improving metabolic cost. These findings should be evaluated in a sample of above-knee amputee subjects. AFAAPE (DGA RAPID 19290 6115 AAFAPE)

Assessment of a novel deep learning-based marker-less motion capture system for gait study

VAFADAR, Saman — Sun, 01 May 2022 00:00:00 GMT

Assessment of a novel deep learning-based marker-less motion capture system for gait study VAFADAR, Saman; SKALLI, Wafa; BONNET-LEBRUN, Aurore; ASSI, Ayman; GAJNY, Laurent Background. Marker-less systems based on digital video cameras and deep learning for gait analysis could have a deep impact in clinical routine. A recently developed system has shown promising results in terms of joint center position but has not been yet evaluated in terms of gait outcomes. Research question. How does this novel marker-less system compare to a marker-based reference system in terms of clinically relevant gait parameters? Methods. The deep learning method behind the developed marker-less system was trained on a dedicated dataset consisting of forty-one asymptomatic and pathological subjects each performing ten walking trials. The system could estimate the three-dimensional position of seventeen joint centers or keypoints (e.g., neck, shoulders, hip, knee, and ankles). We evaluated the marker-less system against a marker-based system in terms of differences in joint position (Euclidean distance), detection of gait events (e.g., heel strike and toe-off), spatiotemporal parameters (e.g., step length, time), kinematic parameters (e.g., hip and knee extension-flexion), and inter-trial reliability for kinematic parameters. Results. The marker-less system was able to estimate the three-dimensional position of joint centers with a mean difference of 13.1 mm (SD = 10.2 mm). 99% of the estimated gait events were estimated within 10 milliseconds of the corresponding reference values. Estimated spatiotemporal parameters showed zero bias. The mean and standard deviation of the differences of the estimated kinematic parameters varied by parameter (for example, the mean and standard deviation for knee extension flexion angle were -3.0° and 2.7°). Inter-trial reliability of the measured parameters was similar to that of the marker-based references. Significance. The developed marker-less system can measure the spatiotemporal parameters within the range of the minimum detectable changes obtained using the marker-based reference system. Moreover, except for hip extension flexion, the system showed promising results in terms of several kinematic parameters.

Quantitative analysis of lower limb and pelvic deformities in children with X-linked hypophosphatemic rickets

BONNET-LEBRUN, Aurore — Wed, 01 Dec 2021 00:00:00 GMT

Quantitative analysis of lower limb and pelvic deformities in children with X-linked hypophosphatemic rickets BONNET-LEBRUN, Aurore; LINGLART, Agnès; DE TIENDA, Marine; OUCHRIF, Younes; BERKENOU, Jugurtha; ASSI, Ayman; WICART, Philippe; SKALLI, Wafa Introduction X-linked hypophosphatemia (XLH) rickets mainly causes leg deformities in children that can get worse as they grow. We hypothesized that quantifying the bone parameters will help to document and monitor these deformities in children with XLH. Methods Thirty-five growing children affected by XLH were included in this cross-sectional study. Biplanar radiographs were taken with an EOS system allowing 3D reconstructions of the pelvis and legs. Sixteen geometric parameters were calculated for the legs and pelvis. A control group of 40 age-matched patients was used to define the reference values for these geometric parameters. Results For the legs, significant differences (p < 0.05) appeared between the XLH patients and the control group in the neck-shaft angle, femur/tibia length ratio and HKS. Among the 70 legs in the XLH group, 23 were in genu varum, 25 were in genu valgum and 22 were straight. There were significant differences between the genu varum and genu valgum subgroups in the femoral mechanical angle and the HKS. A strong correlation was found between the femoral mechanical angle and tibiofemoral angle (r² = 0.73) and between the femoral mechanical angle and HKS (r²=0.69) The sacral slope and acetabular anteversion were significant different from the reference values. Discussion Quantitative radiological parameters derived from 3D reconstructions show that the deformities in XLH patients are 1) mainly in but not limited to the femoral shaft; 2) highly variable from one person to another. Some of these radiological parameters may be useful for the diagnosis and monitoring of XLH patients.

A novel dataset and deep learning-based approach for marker-less motion capture during gait

VAFADAR, Saman — Fri, 01 Jan 2021 00:00:00 GMT

A novel dataset and deep learning-based approach for marker-less motion capture during gait VAFADAR, Saman; SKALLI, Wafa; BONNET-LEBRUN, Aurore; KHALIFÉ, Marc; RENAUDIN, Mathis; HAMZA, Amine; GAJNY, Laurent Background: The deep learning-based human pose estimation methods, which can estimate joint centers position, have achieved promising results on the publicly available human pose datasets (e.g., Human3.6 M). However, these datasets may be less efficient for gait study, particularly for clinical applications, because of the limited number of subjects, their homogeneity (all asymptomatic adults), and the errors introduced by marker placement on subjects’ regular clothing. Research question: How a new human pose dataset, adapted for gait study, could contribute to the advancement and evaluation of marker-less motion capture systems? Methods: A marker-less system, based on deep learning-based pose estimation methods, was proposed. A new dataset (ENSAM dataset) was collected. Twenty-two asymptomatic adults, one adult with scoliosis, one adult with spondylolisthesis, and seven children with bone disease performed ten walking trials, while being recorded both by the proposed marker-less system and a reference system – combining a marker-based motion capture system and a medical imaging system (EOS). The dataset was split into training and test sets. The pose estimation method, already trained on the Human3.6 M dataset, was evaluated on the ENSAM test set, then reevaluated after further training on the ENSAM training set. The joints coordinates were evaluated, using Bland-Altman bias and 95 % confidence interval, and joint position error (the Euclidean distance between the estimated joint centers and the corresponding reference values). Results: The Bland-Altman 95 % confidence intervals were substantially improved after finetuning the pose estimation method on the ENSAM training set (e.g., from 106.9 mm to 17.4 mm for the hip joint). With the new dataset and approach, the mean joint position error varied from 6.2 mm for ankles to 21.1 mm for shoulders. Significance: The proposed marker-less system achieved promising results in terms of joint position errors. Future studies are necessary to assess the system in terms of gait parameters.

Fast quasi-automated 3D reconstruction of lower limbs from low dose biplanar radiographs using statistical shape models and contour matching

GIRINON, François — Tue, 01 Mar 2022 00:00:00 GMT

Fast quasi-automated 3D reconstruction of lower limbs from low dose biplanar radiographs using statistical shape models and contour matching GIRINON, François; BAYOUD, Wael; LAHKAR, Bhrigu; BONNET-LEBRUN, Aurore; LAZENNEC, Jean-Yves; SKALLI, Wafa; ROUCH, Philippe; GAJNY, Laurent Three-dimensional bone reconstructions from medical imaging are essential for biomechanical modelling and are growing tools in clinics. Several methods of lower limbs reconstruction from biplanar radiographs have been proposed in the literature but with significant operator dependence. A novel reconstruction method based on reduced manual annotation, statistical shape models and fully automatic adjustments was proposed in this study. While significantly reducing operator intervention, the proposed method demonstrated similar or better precision than previous approaches on clinical parameters. Meanwhile, shape accuracy was improved to around 1mm. By quasi-automating the 3D reconstruction without loss of accuracy and precision, the proposed approach is a considerable step towards extensive use of 3D personalized models in clinical routine and large cohort biomechanical studies.

Combined gait analysis and radiologic examination in children with X-linked hypophosphatemia

BONNET-LEBRUN, Aurore — Sat, 01 Apr 2023 00:00:00 GMT

Combined gait analysis and radiologic examination in children with X-linked hypophosphatemia BONNET-LEBRUN, Aurore; LINGLART, Agnès; DE TIENDA, Marine; NGUYEN KHAC, Virginie; OUCHRIF, Younes; BERKENOU, Jugurtha; PILLET, Helene; ASSI, Ayman; WICART, Philippe; SKALLI, Wafa Background: X-linked hypophosphataemia causes bone deformities and gait abnormalities that tend to worsen with age in the absence of appropriate treatment. However, doctors do not currently use quantitative tools to characterize these symptoms and their possible interactions. Methods: Radiographs and 3D gait data from 43 non-surgical growing children with X-linked hypophosphataemia were acquired prospectively. Data from age-matched typically developing children were used to form the reference group. Subgroups based on radiological parameters were compared with each other and with the reference population. Linear correlations between radiographic parameters and gait variables were examined. Finding: X-linked hypophosphatemic patients differed from the control group in pelvic tilt, ankle plantarflexion, knee flexion moment and power. High correlations with tibiofemoral angle were found for trunk lean, knee and hip adduction, and knee abduction moment. The Gait Deviation Index was below 80 for 88% of the patients with a high tibiofemoral angle (varus). Compared to other subgroups, varus patients had augmented trunk lean (+3°) and knee adduction (+10°) and decreased hip adduction (-5°) and ankle plantarflexion (-6°). Femoral torsion was associated with alterations in rotation at the knee, and hip. Interpretation: Gait abnormalities induced in X-linked hypophosphataemia have been described in a large cohort of children. Links between gait alterations and lower limb deformities were found, with varus deformities standing out. Since bony deformities appear when X-linked hypophosphatemic children start walking and have been found to alter gait patterns, we suggest that combining radiology with gait analysis may improve the clinical management of X-linked hypophosphataemia. Autre financement : Kyowa Kirin Pharma

MRI quantitative muscle characterization in children with X-linked hypophosphatemia

DE TIENDA, Marine — Wed, 01 May 2024 00:00:00 GMT

MRI quantitative muscle characterization in children with X-linked hypophosphatemia DE TIENDA, Marine; BONNET-LEBRUN, Aurore; MANNES, Inès; NGUYEN KHAC, Virginie; OUCHRIF, Younes; ASSI, Ayman; MASSAAD, Abir; LINGLART, Agnès; ADAMSBAUM, Catherine; SKALLI, Wafa; WICART, Philippe Introduction Children with X Linked Hypophosphatemia (XLH) suffer from carential ricket, bone deformities and lameness. No previous study demonstrated a morphological distinction in muscles in these patients. The aim of this prospective study was to characterize, using Magnetic Resonance Imaging (MRI), the muscle morphology of pelvis, thigh and leg in children with XLH and to compare it with typically developed (TD) children. Hypothesis We hypothesized that lower limbs muscles in children with XLH are different from TD children and could explain limp walking. Material and methods Three-dimensional reconstructions of the muscles were performed in 11 patients with XLH and 15 TD children. Muscle lengths, sections and volumes were calculated and normalized with height and weight. Mean age was 10. Results Lengths were all smaller in children with XLH except for the Medius/minimus gluteus muscles (p = 0.64). The difference seemed higher in muscles with a long tendinous part as semitendinosus (0.139 vs 0,164; p < 0.01). All volumes were significantly inferior in children with XLH. This preliminary study showed significant differences in muscle structures between patients with XLH and TD children. Discussion Medius/minimus gluteus seemed to be particularly developed in children with XLH. Nevertheless it is not possible to conclude if it is related to XLH or a consequence of bone deformities.

Thigh and paraspinal muscles change after fusionless bipolar fixation for early onset scoliosis in type 2 spinal muscular atrophy

GAUME, Mathilde — Fri, 01 Nov 2024 00:00:00 GMT

Thigh and paraspinal muscles change after fusionless bipolar fixation for early onset scoliosis in type 2 spinal muscular atrophy GAUME, Mathilde; VERGARI, Claudio; CREZE, Maud; BONNET-LEBRUN, Aurore; MUTH-SENG, Christophe; QUIJANO-ROY, Susana; MILADI, Lotfi; SKALLI, Wafa; CARLIER, Robert-Yves Background Spinal muscular atrophy is a severe, progressive autosomal recessive neuromuscular disorder associated with neuromuscular scoliosis. When bracing is not sufficient to control the deformity, early spinal surgery is required. To the best of our knowledge, no work in the literature have assessed modifications in spinal and thigh muscles of subjects with type 2 spinal muscular atrophy (SMA2) following spinal surgery. Objective This study aimed to better understand modifications in the spinal and thigh muscles of subjects with SMA2 and early onset scoliosis, before and after minimally invasive fusionless surgery. Methods and settings 20 SMA2 patients with confirmed scoliosis on bi-planar low-dose X-ray were included: 10 preoperative and 10 postoperative patients with a minimal follow-up of 5 years after surgery. The surgery consisted of a bilateral sliding rod construct extended from T1 to the sacrum, through a minimally invasive approach. All subjects had fat/water separation muscle magnetic resonance imaging from the spine to the thigh. The percentage of fat degeneration was compared before and after surgery. A quality-of-life survey was performed. Results Fat infiltration was diffuse and symmetric in both groups of patients, and on average six times more compared to control subjects previously published at thigh level. Adductors, sartorius, and gracilis were less affected with respectively, 51%, 56%, and 57% of fat fraction before surgery. Comparing the preoperative and postoperative groups, fat infiltration was higher in sartorius and multifidus after surgery (p < 0.05). No significant difference was found for the other muscles studied. These results did not affect quality of life. Conclusion This is the first study to compare fat infiltration of spinal and thigh muscles of SMA2 patients before and after minimally invasive surgery. Our results demonstrate that muscles were globally preserved apart from multifidus and sartorius which were more affected.