SAM

Validation of hip joint center localization methods during gait analysis using 3D EOS imaging in typically developing and cerebral palsy children

ASSI, Ayman — Fri, 01 Jan 2016 00:00:00 GMT

Validation of hip joint center localization methods during gait analysis using 3D EOS imaging in typically developing and cerebral palsy children ASSI, Ayman; SAURET, Christophe; MASSAAD, Abir; BAKOUNY, Ziad; SKALLI, Wafa; GHANEM, Ismat; PILLET, Helene Localization of the hip joint center (HJC) is essential in computation of gait data. EOS low dose biplanar X-rays have been shown to be a good reference in evaluating various methods of HJC localization in adults. The aim is to evaluate predictive and functional techniques for HJC localization in typically developing (TD) and cerebral palsy (CP) children, using EOS as an image based reference. Eleven TD and 17 CP children underwent 3D gait analysis. Six HJC localization methods were evaluated in each group bilaterally: 3 predictive (Plug in Gait, Bell and Harrington) and 3 functional methods based on the star arc technique (symmetrical center of rotation estimate, center transformation technique and geometrical sphere fitting). All children then underwent EOS low dose biplanar radiographs. Pelvis, lower limbs and their corresponding external markers were reconstructed in 3D. The center of the femoral head was considered as the reference (HJCEOS). Euclidean distances between HJCs estimated by each of the 6 methods and the HJCEOS were calculated; distances were shown to be lower in predictive compared to functional methods (p < 0.0001). Contrarily to findings in adults, functional methods were shown to be less accurate than predictive methods in TD and CP children, which could be mainly due to the shorter thigh segment in children. Harrington method was shown to be the most accurate in the prediction of HJC (mean error ≈ 18 mm, SD = 9 mm) and quasi-equivalent to the Bell method. The bias for each method was quantified, allowing its correction for an improved HJC estimation.

Three-dimensional evaluation of skeletal deformities of the pelvis and lower limbs in ambulant children with cerebral palsy

MASSAAD, Abir — Fri, 01 Jan 2016 00:00:00 GMT

Three-dimensional evaluation of skeletal deformities of the pelvis and lower limbs in ambulant children with cerebral palsy MASSAAD, Abir; ASSI, Ayman; BAKOUNY, Ziad; SAURET, Christophe; KHALIL, Nour; SKALLI, Wafa; GHANEM, Ismat Skeletal abnormalities, affecting posture and walking pattern, increase with motor impairment in children with cerebral palsy (CP). However, it is not known whether these skeletal malalignments occur in children with slight motor impairment. Our aim was to evaluate skeletal malalignment at the level of the pelvis and lower limbs in ambulant children with CP, with slight motor impairment, using a low dose biplanar X-ray technique. Twenty-seven children with spastic CP (mean age: 10.9 ± 4 years, 7 Hemiplegia, 20 Diplegia, GMFCS levels I:17, II:10), with no previous treatments at the hips and knees, underwent EOS® biplanar X-rays. A control group consisting of 22 typically developing children was also included. Three-dimensional reconstructions of the pelvis and lower limbs were performed in order to calculate 11 radiological parameters related to the pelvis, acetabulum and lower limbs. Pelvic incidence and sacral slope were significantly increased in children with CP compared to TD children (48° ± 7° vs. 43° ± 8°, 42° ± 7° vs. 38° ± 5°, respectively, p = 0.003). Acetabular parameters did not significantly differ between the two groups. Femoral anteversion and neck shaft angle were significantly increased in children with CP (25° ± 12° vs. 14° ± 7°, p < 0.001; 134° ± 5° vs. 131° ± 5°, p = 0.005 respectively). No difference was found for tibial torsion. This study showed that even slightly impaired children with CP have an anteverted and abducted femur and present positional and morphological changes of the pelvis in the sagittal plane. The orientation of the acetabulum in 3D seems to not be affected when children with CP present slight motor impairment.

Variation of the sagittal vertical axis during walking and its determinants

ASSI, Ayman — Mon, 01 Jan 2018 00:00:00 GMT

Variation of the sagittal vertical axis during walking and its determinants ASSI, Ayman; BAKOUNY, Ziad; BIZDIKIAN, Aren Joe; OTAYEK, Joeffroy; YARED, Fares; LAFAGE, Virginie; KHALIL, Nour; MASSAAD, Abir; GHANEM, Ismat; SKALLI, Wafa Patients with adult spinal deformities (ASD) are known to have altered postural alignment aﬀecting their quality of life and activities of daily living, especially gait. The Sagittal Vertical Axis (SVA), a postural parameter calculated as the distance between the posterior corner of the sacrum and the C7-plumbline on full-body sagittal radiographs [1], has been shown to be highly altered in ASD. Even though this parameter is positional and could vary during gait, no studies have investigated its variation during walking even in asymptomatic subjects.

Alterations of treatment-naïve pelvis and thigh muscle morphology in children with cerebral palsy

MASSAAD, Abir — Tue, 01 Jan 2019 00:00:00 GMT

Alterations of treatment-naïve pelvis and thigh muscle morphology in children with cerebral palsy MASSAAD, Abir; ASSI, Ayman; BAKOUNY, Ziad; BIZDIKIAN, Aren Joe; SKALLI, Wafa; GHANEM, Ismat Lower limb (LL) muscle morphology and growth are altered in children with cerebral palsy (CP). Muscle alterations differ with age and with severity of motor impairment, classified according to the gross motor classification system (GMFCS). Muscle alterations differ also with orthopedic intervention, frequently performed at the level of the shank muscles since an early age, such as the gastrocnemius. The aim was to investigate the alterations of treatment-naïve pelvis and thigh muscle lengths and volumes in children with GMFCS levels I and II, of varying ages. 17 children with CP (GMFCS I: N = 9, II: N = 8, age: 11.7 ± 4 years), age-matched to 17 typically developing (TD) children, underwent MRI of the LL. Three-dimensional reconstructions of the muscles were performed bilaterally. Muscle volumes and lengths were calculated in 3D and compared between groups. Linear regression between muscle volumes and age were computed. Adductor-brevis and gracilis lengths, as well as rectus-femoris volume, were decreased in GMFCS I compared to TD (p < 0.05). Almost all the reconstructed muscle volumes and lengths were found to be altered in GMFCS II compared to TD and GMFCS I. All muscle volumes showed significant increase with age in TD and GMFCS I (R2 range: 0.3–0.9, p < 0.05). Rectus-femoris, hamstrings and adductor-longus showed reduced increase in the muscle volume with age in GMFCS II when compared to TD and GMFCS I. Alterations of treatment-naïve pelvis and thigh muscle volumes and lengths, as well as muscle growth, seem to increase with the severity of motor impairment in ambulant children with CP.

Influence of Spino-Pelvic and Postural Alignment Parameters on Gait Kinematics

OTAYEK, Joeffroy — Wed, 01 Jan 2020 00:00:00 GMT

Influence of Spino-Pelvic and Postural Alignment Parameters on Gait Kinematics OTAYEK, Joeffroy; BIZDIKIAN, Aren Joe; YARED, Fares; SAAD, Eddy; BAKOUNY, Ziad; MASSAAD, Abir; GHANIMEH, Joe; LABAKI, Chris; SKALLI, Wafa; ISMAT, Ghanem; KREICHATI, Gaby; ASSI, Ayman Introduction: Postural alignment is altered with spine deformities that might occur with age. Alteration of spino-pelvic and postural alignment parameters are known to affect daily life activities such as gait. It is still unknown how spino-pelvic and postural alignment parameters are related to gait kinematics. Research question: To assess the relationships between spino-pelvic/postural alignment parameters and gait kinematics in asymptomatic adults. Methods: 134 asymptomatic subjects (aged 18-59 years) underwent 3D gait analysis, from which kinematics of the pelvis and lower limbs were extracted in the 3 planes. Subjects then underwent full-body biplanar X-rays, from which skeletal 3D reconstructions and spino-pelvic and postural alignment parameters were obtained such as sagittal vertical axis (SVA), center of auditory meatus to hip axis plumbline (CAM-HA), thoracic kyphosis (TK) and radiologic pelvic tilt (rPT). In order to assess the influence of spino-pelvic and postural alignment parameters on gait kinematics a univariate followed by a multivariate analysis were performed. Results: SVA was related to knee flexion during loading response (β = 0.268); CAM-HA to ROM pelvic obliquity (β = -0.19); rPT to mean pelvic tilt (β = -0.185) and ROM pelvic obliquity (β = -0.297); TK to ROM hip flexion/extension in stance (β = -0.17), mean foot progression in stance (β = -0.329), walking speed (β = -0.19), foot off (β = 0.223) and step length (β = -0.181). Significance: This study showed that increasing SVA, CAM-HA, TK and rPT, which is known to occur in adults with spinal deformities, could alter gait kinematics. Increases in these parameters, even in asymptomatic subjects, were related to a retroverted pelvis during gait, a reduced pelvic obliquity and hip flexion/extension mobility, an increased knee flexion during loading response as well as an increase in external foot progression angle. This was associated with a decrease in the walking pace: reduced speed, step length and longer stance phase.

How do skeletal and postural parameters contribute to maintain balance during walking?

MEKHAEL, Mario — Wed, 01 Jan 2020 00:00:00 GMT

How do skeletal and postural parameters contribute to maintain balance during walking? MEKHAEL, Mario; LABAKI, Chris; BIZDIKIAN, Aren Joe; BAKOUNY, Ziad; OTAYEK, Joeffroy; YARED, Fares; MASSAAD, Abir; SKALLI, Wafa; GHANEM, Ismat; ASSI, Ayman Introduction: Maintaining balance during gait allows subjects to minimize energy expenditure and avoid falls. Gait balance can be measured by assessing the relationship between the center of mass (COM) and center of pressure (COP) during gait. Demographics, skeletal and postural parameters are known to influence gait balance. Purpose: What are the determinants of dynamic balance during gait in asymptomatic adults among skeletal and demographic parameters? Methods: 115 adults underwent 3D gait analysis and full-body biplanar X-rays. Angles between the COM-COP line and the vertical were calculated in frontal and sagittal planes during gait: maxima, minima, and ROM were evaluated. Full-body 3D reconstructions were obtained; skeletal and postural parameters of the spine (lumbar lordosis, thoracic kyphosis, sagittal vertical axis SVA), pelvis (pelvic tilt and incidence, acetabular orientation in the 3 planes) and lower limbs (neck shaft angle femoral and tibial torsions) were calculated. A univariate followed by a multivariate analysis were computed between the COM-COP parameters and skeletal and demographic parameters. Results: The univariate analysis showed that in the frontal plane, maximum (4.6°) of the COMCOP angle was significantly correlated with weight (r =0.53), age (r =0.28), height (r = 0.35), SVA (r = 0.23), T1T12 (r = 0.24) and pelvic width (r = 0.25).In the sagittal plane, maximum COM-COP (19.7 ± 2.8°) angle was significantly correlated to acetabular tilt (r = 0.25) and acetabular anteversion (r =0.21). The multivariate analysis showed that, in the frontal plane, an increase in the maximum of the COM-COP angle was determined by a decreasing height (β = −0.28), an increasing weight (β = 0.48), being a male (β = −0.42), and an increasing posterior acetabular coverage (β = 0.22). In the sagittal plane, an increasing maximum COMCOP angle was determined by a decreasing height (β = −0.38) and an increasing SVA (β = 0.19). Conclusion: Frontal imbalance appeared to be mainly correlated to demographic parameters. Sagittal imbalance was found to be correlated with weight, height, acetabular parameters and SVA. These results suggest that in addition to demographic parameters, acetabular parameters and SVA are important determinants of balance during gait.

A new approach in the clinical decision-making for cerebral palsy using three-dimensional subject-specific musculoskeletal reconstructions.

MASSAAD, Abir — Fri, 01 Jan 2016 00:00:00 GMT

A new approach in the clinical decision-making for cerebral palsy using three-dimensional subject-specific musculoskeletal reconstructions. MASSAAD, Abir; ASSI, Ayman; BAKOUNY, Ziad; SKALLI, Wafa; GHANEM, Ismat Cerebral palsy (CP) is a neurological disorder which can cause muscular spasticity. Children with this condition suffer from a combination of gait deviations, skeletal deformities and muscular abnormalities. Precise evaluation of each of these three components is crucial for management planning in children with CP. The aim of this study is to review the latest innovative methods used for three-dimensional (3D) gait analysis and musculoskeletal modeling in children with cerebral palsy. 3D gait analysis is a quantitative objective method based on the use of infrared cameras. It allows the evaluation of dynamic joint angles, forces and moments applied on joints and is usually coupled with dynamic electromyography. Skeletal evaluation is usually based on two-dimensional X-rays and physical examination in clinical practice. However, a novel method based on stereoradiographic 3D reconstruction of biplanar low dose X-rays allows a more thorough evaluation of skeletal deformities, and in particular torsional anomalies. Muscular evaluation of children with CP is most commonly based on magnetic resonance imaging, whereby delimitation of lower limb muscles on axial slices allows 3D reconstruction of these muscles. Novel innovative techniques allow similar reconstructions by extrapolation, thus limiting the necessary quantity of axial slices that need to be manually delimitated.

Three dimensional kinematics of upper limb anatomical movements in asymptomatic adults: Dominant vs.non-dominant

ASSI, Ayman — Fri, 01 Jan 2016 00:00:00 GMT

Three dimensional kinematics of upper limb anatomical movements in asymptomatic adults: Dominant vs.non-dominant ASSI, Ayman; BAKOUNY, Ziad; KARAM, Mohammad; MASSAAD, Abir; SKALLI, Wafa; GHANEM, Ismat The effect of dominance on upper limb (UL) kinematics has only been studied on scapular movements. Moreover, when an anatomical UL movement is performed in a specific plane, secondary movements in the remaining planes involuntarily occur. These secondary movements have not been previously evaluated. The aim of this study was to compare the kinematics of primary and secondary angles of dominant and non-dominant UL during anatomical movements in asymptomatic adults. 25 asymptomatic adults performed 6 anatomical movements bilaterally: shoulder flexion-extension, abduction-adduction, horizontal abduction-adduction, internal-external rotation, elbow flexion-extension and wrist pronation-supination. Kinematics of the dominant and non-dominant UL were compared by their ranges of motion (ROM) and their angular waveforms (Coefficient of Multiple Correlations, CMC). The comparison between dominant and non-dominant UL kinematics showed different strategies of movement, most notably during elbow flexion-extension (CMC = 0.29): the dominant UL exhibited more pronation at maximal elbow flexion. Significant secondary angles were found on most of the UL anatomical movements; e.g. a secondary ROM of shoulder (humero-thoracic) external-internal rotation (69° ± 16°) was found when the subject intended to perform maximal shoulder abduction-adduction (119° ± 21°). Bias of dominance should be considered when comparing pathological limb to the controlateral one. Normative values of primary and secondary angles during anatomical movements could be used as a reference for future studies on UL of subjects with neurological or orthopedic pathologies.

Global Sagittal Angle and T9-tilt seem to be the most clinically and functionally relevant global alignment parameters in patients with Adult Spinal Deformity

NASSIM, Nabil — Mon, 01 Apr 2024 00:00:00 GMT

Global Sagittal Angle and T9-tilt seem to be the most clinically and functionally relevant global alignment parameters in patients with Adult Spinal Deformity NASSIM, Nabil; MEKHAEL, Elio; RACHKIDI, Rami El; SAADE, Maria; AYOUB, Elma; RTEIL, Ali; JABER, Elena; CHAAYA, Celine; REHAYEM, Rami; ABI NAHED, Julien; KARAM, Mohamad; GHANEM, Ismat; MASSAAD, Abir; ASSI, Ayman Introduction Radiographic analysis is necessary for the assessment and the surgical planning in adults with spinal deformity (ASD). Restoration of global alignment is key to improving patient's quality of life. However, the large number of existing global alignment parameters can be confusing for surgeons. Research question To determine the most clinically and functionally relevant global alignment parameters in ASD. Material and methods ASD and controls underwent full body biplanar X-ray to calculate global alignment parameters: odontoid to hip axis angle (OD-HA), global sagittal angle (GSA), global tilt (GT), SVA, center of auditory meatus to hip axis (CAM-HA), SSA, T1-tilt and T9-tilt. All subjects filled HRQoL questionnaires: ODI, SF-36, VAS for pain and BDI (Beck's Depression Inventory). 3D gait analysis was performed to calculate kinematic and spatio-temporal parameters. A machine learning model predicted gait parameters and HRQoL scores from global alignment parameters. Results 124 primary ASD and 47 controls were enrolled. T9 tilt predicted the most BDI (31%), hip flexion/extension during gait (36%), and double support time (39%). GSA predicted the most ODI (26%), thorax flexion/extension during gait (33%), and cadence (36%). Discussion and conclusion Among all global alignment parameters, GSA, evaluating both trunk shift and knee flexion, and T9 tilt, evaluating the shift of the center of mass, were the best predictors for most of HRQoL scores and gait kinematics. Therefore, we recommend using GSA and T9 tilt in clinical practice when evaluating ASD because they represent the most quality of life and functional kinematic of these patients.

Kinematic limitations during stair ascent and descent in patients with adult spinal deformity

FAKHOURY, Marc — Sun, 01 Dec 2024 00:00:00 GMT

Kinematic limitations during stair ascent and descent in patients with adult spinal deformity FAKHOURY, Marc; RACHKIDI, Rami; SEMAAN, Karl; ABI KARAM, Krystel; SAADÉ, Maria; AYOUB, Elma; CHAAYA, Celine; RTEIL, Ali; JABER, Elena; MEKHAEL, Elio; NASSIM, Nabil; KARAM, Mohamad; ABINAHED, Julien; GHANEM, Ismat; MASSAAD, Abir; ASSI, Ayman Background: Adults with spinal deformity (ASD) are known to have spinal malalignment, which can impact their quality of life and their autonomy in daily life activities. Among these tasks, ascending and descending stairs is a common activity of daily life that might be affected. Research question: What are the main kinematic alterations in ASD during stair ascent and descent? Methods: 112 primary ASD patients and 34 controls filled HRQoL questionnaires and underwent biplanar X-from which spino-pelvic radiographic parameters were calculated. Patients were divided into 3 groups: 44 with sagittal malalignment (ASD-Sag: PT > 25°, SVA>5 cm or PI-LL>10°), 42 with isolated thoracic hyperkyphosis (ASD-HyperTK: TK > 60°), 26 with isolated frontal spine deformity (ASD-Front: Cobb>20°). All participants underwent 3D motion analysis of the whole body while ascending and descending a stair step from which kinematic waveforms were extracted. Results: During stair ascent, ASD-Sag exhibited an increased thorax flexion (20 vs 5°), a decreased lumbar lordosis L1L3-L3L5 (7 vs 14°), and an increased ROM of lumbo-pelvic joint (15 vs 10°, all p < 0.05), compared to controls. Similar compensations were shown while descending the stairstep. ASD-HyperTK had similar kinematic limitations as ASD-Sag but to a lesser extent. ASD-Front had normal kinematic patterns. PCS-SF36 correlated to thorax flexion (r = -0.45) and ODI was correlated to pelvic tilt ROM (r = 0.46). Discussion and conclusion: ASD subjects with sagittal malalignment tend to ascend and descend stairs with increased thorax flexion, making them more prone to falls. Compensation mechanisms occur at the head and lumbo-pelvic levels to maintain balance and avoid falling forward.