SAM

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.

Weak trunk extensors in adult spinal deformity patients are related to sagittal malalignment and kinematic limitations

SAADÉ, Maria — Wed, 01 Jan 2025 00:00:00 GMT

Weak trunk extensors in adult spinal deformity patients are related to sagittal malalignment and kinematic limitations SAADÉ, Maria; RACHKIDI, Rami; RTEIL, Ali; AYOUB, Elma; JABER, Elena; CHAAYA, Celine; NASSIM, Nabil; MEKHAEL, Elio; REHAYEM, Rami; NAHED, Julien Abi; RAMADAN, Bilal; KARAM, Mohamad; GHANEM, Ismat; MASSAAD, Abir; ASSI, Ayman Background: Adult spinal deformity (ASD) is associated with muscles' degeneration that affects postural control and outcomes of an eventual corrective surgery. Evaluation of ASD is usually based on static radiographs and more recently on functional assessment. However, there has been limited exploration of muscle strength weakness in ASD. The aim was to investigate the relationship between trunk muscles' strength in ASD and its relationship with radiographic and kinematic alterations and quality-of-life decline. Methods: 28 ASD and 18 asymptomatic subjects underwent biplanar radiographs with 3D calculation of spino-pelvic and global postural parameters. 3D movement analysis of gait, sitting to standing and stair ascent, was studied allowing the calculation of head, trunk and lower limbs 3D kinematics. Participants filled out health related quality of life questionnaires. A single operator measured 4 times the strength of the trunk muscles, using a hand-held dynamometer, to assess measurements' reliability. ASD population was divided into two groups based on the strength of trunk extensors: ASD-weak extensors (N = 11 patients having trunk extensors strength0.94). On standing radiographs, the ASD-weak extensors group showed an increased positive sagittal malalignment compared to the other groups (SVA=61 mm vs ASD-normal extensors: 18 mm, controls: -4 mm, p < 0.001). This sagittal malalignment remained during movement (kinematic-SVA=223 mm vs ASD-normal extensors:178 mm, controls:138 mm, p < 0.001). Muscle strength weakness was correlated to the decline of quality-of-life scores (PCS-SF36: r = 0.48, VAS for pain: ρ=-0.39). Conclusions: This study showed that weak trunk extensors are associated with sagittal malalignment in static position, kinematic limitations during daily life activities and reduced quality of life scores. Future studies will investigate the effect of muscle strengthening on both static and dynamic alignment in ASD and their quality of life.

Alteration of the sitting and standing movement in adult spinal deformity

SAAD, Eddy — Sat, 01 Jan 2022 00:00:00 GMT

Alteration of the sitting and standing movement in adult spinal deformity SAAD, Eddy; SEMAAN, Karl; KAWKABANI, Georges; MASSAAD, Abir; SALIBY, Renée Maria; MEKHAEL, Mario; FAKHOURY, Marc; KARAM, Krystel Abi; JABER, Elena; GHANEM, Ismat; LAFAGE, Virginie; SKALLI, Wafa; RACHKIDI, Rami; ASSI, Ayman Adults with spinal deformity (ASD) are known to have spinal malalignment affecting their quality of life and daily life activities. While walking kinematics were shown to be altered in ASD, other functional activities are yet to be evaluated such as sitting and standing, which are essential for patients’ autonomy and quality of life perception. In this cross-sectional study, 93 ASD subjects (50 ± 20 years; 71 F) age and sex matched to 31 controls (45 ± 15 years; 18 F) underwent biplanar radiographic imaging with subsequent calculation of standing radiographic spinopelvic parameters. All subjects filled HRQOL questionnaires such as SF36 and ODI. ASD were further divided into 34 ASD-sag (with PT > 25° and/or SVA >5 cm and/or PI-LL >10°), 32 ASD-hyperTK (with only TK >60°), and 27 ASD-front (with only frontal malalignment: Cobb >20°). All subjects underwent 3D motion analysis during the sit-to-stand and stand-to-sit movements. The range of motion (ROM) and mean values of pelvis, lower limbs, thorax, head, and spinal segments were calculated on the kinematic waveforms. Kinematics were compared between groups and correlations to radiographic and HRQOL scores were computed. During sit-to-stand and stand-to-sit movements, ASD-sag had decreased pelvic anteversion (12.2 vs 15.2°), hip flexion (53.0 vs 62.2°), sagittal mobility in knees (87.1 vs 93.9°), and lumbar mobility (L1L3-L3L5: −9.1 vs −6.8°, all p < 0.05) compared with controls. ASD-hyperTK showed increased dynamic lordosis (L1L3–L3L5: −9.1 vs −6.8°), segmental thoracic kyphosis (T2T10–T10L1: 32.0 vs 17.2°, C7T2–T2T10: 30.4 vs 17.7°), and thoracolumbar extension (T10L1–L1L3: −12.4 vs −5.5°, all p < 0.05) compared with controls. They also had increased mobility at the thoracolumbar and upper-thoracic spine. Both ASD-sag and ASD-hyperTK maintained a flexed trunk, an extended head along with an increased trunk and head sagittal ROM. Kinematic alterations were correlated to radiographic parameters and HRQOL scores. Even after controlling for demographic factors, dynamic trunk flexion was determined by TK and PI-LL mismatch (adj. R² = 0.44). Lumbar sagittal ROM was determined by PI-LL mismatch (adj. R² = 0.13). In conclusion, the type of spinal deformity in ASD seems to determine the strategy used for sitting and standing. Future studies should evaluate whether surgical correction of the deformity could restore sitting and standing kinematics and ultimately improve quality of life.

Kinematic adaptations from self-selected to fast speed walking in patients with adult spinal deformity

ABI KARAM, Krystel — Mon, 01 Jan 2024 00:00:00 GMT

Kinematic adaptations from self-selected to fast speed walking in patients with adult spinal deformity ABI KARAM, Krystel; EL RACHKIDI, Rami; SEMAAN, Karl; SAAD, Eddy; FAKHOURY, Marc; SAADE, Maria; AYOUB, Elma; RTEIL, Ali; JABER, Elena; MEKHAEL, Elio; NASSIM, Nabil; MASSAAD, Abir; GHANEM, Ismat; ASSI, Ayman Purpose To investigate kinematic adaptations from self-selected to fast speed walking in ASD patients. Methods 115 primary ASD and 66 controls underwent biplanar radiographic X-rays and 3D gait analysis to calculate trunk, segmental spine and lower limb kinematics during self-selected and fast speed walking. Kinematic adaptation was calculated as the difference (Δ) between fast and self-selected speed walking. ASD with 7 or more limited kinematic adaptation parameters were classified as ASD-limited-KA, while those with less than 7 limited kinematic adaptation parameters were classified as ASD-mild-KA. Results 25 patients were classified as ASD-limited-KA and 90 as ASD-mild-KA. ASD-limited-KA patients walked with a lesser increase of pelvic rotation (Δ = 1.7 vs 5.5°), sagittal hip movement (Δ = 3.1 vs 7.4°) and shoulder–pelvis axial rotation (Δ = 3.4 vs 6.4°) compared to controls (all p < 0.05). ASD-limited-KA had an increased SVA (60.6 vs − 5.7 mm), PT (23.7 vs 11.9°), PI–LL (9.7 vs − 11.7°), knee flexion (9.2 vs − 0.4°) and a decreased LL (44.0 vs 61.4°) compared to controls (all p < 0.05). Kinematic and radiographic alterations were less pronounced in ASD-mild-KA. The limited increase of walking speed was correlated to the deteriorated physical component summary score of SF-36 (r = 0.37). Discussion Kinematic limitations during adaptation from self-selected to fast speed walking highlight an alteration of a daily life activity in ASD patients. ASD with limited kinematic adaptations showed more severe sagittal malalignment with an increased SVA, PT, PI–LL, and knee flexion, a decreased LL and the most deteriorated quality of life. This highlights the importance of 3D movement analysis in the evaluation of ASD.

Toward understanding the underlying mechanisms of pelvic tilt reserve in adult spinal deformity: the role of the 3D hip orientation

MEKHAEL, Mario — Fri, 01 Jan 2021 00:00:00 GMT

Toward understanding the underlying mechanisms of pelvic tilt reserve in adult spinal deformity: the role of the 3D hip orientation MEKHAEL, Mario; KAWKABANI, Georges; SALIBY, Renée Maria; SKALLI, Wafa; SAAD, Eddy; JABER, Elena; RACHKIDI, Rami; KHARRAT, Khalil; KREICHATI, Gaby; GHANEM, Ismat; LAFAGE, Virginie; ASSI, Ayman Purpose: To explore 3D hip orientation in standing position in subjects with adult spinal deformity (ASD) presenting with different levels of compensatory mechanisms. Methods: Subjects with ASD (n = 159) and controls (n = 68) underwent full-body biplanar X-rays with the calculation of 3D spinopelvic, postural and hip parameters. ASD subjects were grouped as ASD with knee flexion (ASD-KF) if they compensated by flexing their knees (knee flexion ≥ 5°), and ASD with knee extension (ASD-KE) otherwise (knee flexion < 5°). Spinopelvic, postural and hip parameters were compared between the three groups. Univariate and multivariate analyses were then computed between spinopelvic and hip parameters. Results: ASD-KF had higher SVA (67 ± 66 mm vs. 2 ± 33 mm and 11 ± 21 mm), PT (27 ± 14° vs. 18 ± 9° and 11 ± 7°) and PI-LL mismatch (20 ± 26° vs − 1 ± 18° and − 13 ± 10°) when compared to ASD-KE and controls (all p < 0.05). ASD-KF also had a more tilted (34 ± 11° vs. 28 ± 9° and 26 ± 7°), anteverted (24 ± 6° vs. 20 ± 5° and 18 ± 4°) and abducted (59 ± 6° vs. 57 ± 4° and 56 ± 4°) acetabulum, with a higher posterior coverage (100 ± 6° vs. 97 ± 7° for ASD-KE) when compared to ASD-KE and controls (all p < 0.05). The main determinants of acetabular tilt, acetabular abduction and anterior acetabular coverage were PT, SVA and LL (adjusted R² [0.12; 0.5]). Conclusions: ASD subjects compensating with knee flexion have altered hip orientation, characterized by increased posterior coverage (acetabular anteversion, tilt and posterior coverage) and decreased anterior coverage which can together lead to posterior femoro-acetabular impingement, thus limiting pelvic retroversion. This underlying mechanism could be potentially involved in the hip-spine syndrome.

Alterations of gait kinematics depend on the deformity type in the setting of adult spinal deformity

SEMAAN, Karl — Mon, 01 Aug 2022 00:00:00 GMT

Alterations of gait kinematics depend on the deformity type in the setting of adult spinal deformity SEMAAN, Karl; RACHKIDI, Rami; SAAD, Eddy; MASSAAD, Abir; KAWKABANI, Georges; SALIBY, Renée Maria; MEKHAEL, Mario; ABI KARAM, Krystel; FAKHOURY, Marc; JABER, Elena; GHANEM, Ismat; SKALLI, Wafa; LAFAGE, Virginie; ASSI, Ayman Purpose : To evaluate 3D kinematic alterations during gait in Adult Spinal Deformity (ASD) subjects with different deformity presentations. Methods : One hundred nineteen primary ASD (51 ± 19y, 90F), age and sex-matched to 60 controls, underwent 3D gait analysis with subsequent calculation of 3D lower limb, trunk and segmental spine kinematics as well as the gait deviation index (GDI). ASD were classified into three groups: 51 with sagittal malalignment (ASD-Sag: SVA > 50 mm, PT > 25°, and/or PI-LL > 10°), 28 with only frontal deformity (ASD-Front: Cobb > 20°) and 40 with only hyperkyphosis (ASD-HyperTK: TK > 60°). Kinematics were compared between groups. Results ASD-Sag had a decreased pelvic mobility compared to controls with a decreased ROM of hips (38 vs. 45°) and knees (51 vs. 61°). Furthermore, ASD-Sag exhibited a decreased walking speed (0.8 vs. 1.2 m/s) and GDI (80 vs. 95, all p < 0.05) making them more prone to falls. ASD-HyperTK showed similar patterns but in a less pronounced way. ASD-Front had normal walking patterns. GDI, knee flex/extension and walking speed were significantly associated with SVA and PT (r = 0.30–0.65). Conclusion Sagittal spinal malalignment seems to be the driver of gait alterations in ASD. Patients with higher GT, SVA, PT or PI-LL tended to walk slower, with shorter steps in order to maintain stability with a limited flexibility in the pelvis, hips and knees. These changes were found to a lesser extent in ASD with only hyperkyphosis but not in those with only frontal deformity. 3D gait analysis is an objective tool to evaluate functionality in ASD patients depending on their type of spinal deformity.

Head and pelvis are the key segments recruited by adult spinal deformity patients during daily life activities

AYOUB, Elma — Sun, 01 Sep 2024 00:00:00 GMT

Head and pelvis are the key segments recruited by adult spinal deformity patients during daily life activities AYOUB, Elma; RTEIL, Ali; CHAAYA, Celine; RACHKIDI, Rami; SAADE, Maria; JABER, Elena; MEKHAEL, Elio; NASSIM, Nabil; REHAYEM, Rami; KARAM, Mohammad; BIZDIKIAN, Aren Joe; GHANEM, Ismat; SKALLI, Wafa; MASSAAD, Abir; ASSI, Ayman Functional assessment is a key element in evaluating adult spinal deformity (ASD) patients. The multitude of 3D kinematic parameters provided by movement analysis can be confusing for spine surgeons. The aim was to investigate movement patterns of ASD based on key kinematic parameters. 115 primary ASD and 36 controls underwent biplanar radiographs and 3D movement analysis during walking, sit-to-stand and stair ascent to calculate joint and segment kinematics. Principal component analysis was applied to identify the most relevant kinematic parameters that define movement strategies adopted by ASD. Pelvis and head relative to pelvis kinematics were the most relevant parameters. ASD patients adopted four different movement strategies. Class 1: normative head and pelvis kinematics. Class 2: persistent pelvic backward tilt. Class 3: persistent forward shift of the head. Class 4: both pelvic backward tilt and forward shift of the head. Patients in class 3 and 4 presented sagittal malalignment on static radiographs with increased pelvic tilt, pelvic incidence-lumbar lordosis mismatch and sagittal vertical axis. Surprisingly, patients in class 3 had normal pelvic kinematics during movement, showing the importance of functional evaluation. In addition to being key segments in maintaining static global posture, head and pelvis were found to define movement patterns.