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.

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.

Global postural malalignment in adolescent idiopathic scoliosis: The axial deformity is the main driver

KARAM, Mohamad — Sat, 01 Jan 2022 00:00:00 GMT

Global postural malalignment in adolescent idiopathic scoliosis: The axial deformity is the main driver KARAM, Mohamad; GHANEM, Ismat; VERGARI, Claudio; KHALIL, Nour; SAADE, Maria; CHAAYA, Céline; RTEIL, Ali; AYOUB, Elma; SAAD, Eddy; KHARRAT, Khalil; SKALLI, Wafa; ASSI, Ayman Purpose: To evaluate the global alignment of non-operated subjects with adolescent idiopathic scoliosis. Method: A total of 254 subjects with AIS and 64 controls underwent low dose biplanar X-rays and had their spine, pelvis, and rib cage reconstructed in 3D. Global alignment was measured in the sagittal and frontal planes by calculating the OD-HA angle (between C2 dens to hip axis with the vertical). Subjects with AIS were classified as malaligned if the OD-HA was > 95th percentile relative to controls. Results: The sagittal OD-HA in AIS remained within the normal ranges. In the frontal plane, 182 AIS were normally aligned (Group 1, OD-HA = 0.9°) but 72 were malaligned (Group 2, OD-HA = 2.9°). Group 2 had a more severe spinal deformity in the frontal and horizontal planes compared to Group 1 (Cobb: 42 ± 16° vs. 30 ± 18°; apical vertebral rotation AVR: 19 ± 10° vs. 12 ± 7°, all p < 0.05). Group 2 subjects were mainly classified as Lenke 5 or 6. 19/72 malaligned subjects had a mild deformity (Cobb < 30°) but a progressive scoliosis (severity index ≥ 0.6). The frontal OD-HA angle was found to be mainly determined (adjusted-R2 = 0.22) by the apical vertebral rotation and secondarily by the Lenke type. Conclusions: This study showed that frontal malalignment is more common in distal major structural scoliosis and its main driver is the apical vertebral rotation. This highlights the importance of monitoring the axial plane deformity in order to avoid worsening of the frontal global alignment.

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.