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 degrees, SVA>5 cm or PI-LL>10 degrees), 42 with isolated thoracic hyperkyphosis (ASD-HyperTK: TK > 60 degrees), 26 with isolated frontal spine deformity (ASD-Front: Cobb>20 degrees). 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 degrees), a decreased lumbar lordosis L1L3-L3L5 (7 vs 14 degrees), and an increased ROM of lumbo-pelvic joint (15 vs 10 degrees, 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.

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.

IntroductionRadiographic 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 questionTo determine the most clinically and functionally relevant global alignment parameters in ASD.Material and methodsASD 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.Results124 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 conclusionAmong 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.

To investigate kinematic adaptations from self-selected to fast speed walking in ASD patients. 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. 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). 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.

Immune checkpoint inhibitors (ICIs) have emerged as an integral component of the management of various cancers and have contributed to significant improvements in overall survival. Most available ICIs target anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4), and anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD1/PDL1). Gastrointestinal immune-related adverse events remain a common complication of ICIs. The predominant manifestations include diarrhea and colitis, which often manifest concurrently as immune-mediated diarrhea and colitis (IMDC). Risk factors for developing these side effects include baseline gut microbiota, preexisting autoimmune disorders, such as inflammatory bowel disease, and type of neoplasm. The hallmark symptom of colitis is diarrhea which may be accompanied by mucus or blood in stools. Patients may also experience abdominal pain, fever, vomiting, and nausea. If not treated rapidly, ICI-induced colitis can lead to serious life-threatening complications. Current management is based on corticosteroids as first-line, and immunosuppressants like infliximab or vedolizumab for refractory cases. Microbiota transplantation and specific cytokines and lymphocyte replication inhibitors are being investigated. Optimal patient care requires maintaining a balance between treatment toxicity and efficacy, hence the aim of this review is to enhance readers’ comprehension of the gastrointestinal adverse events associated with ICIs, particularly IMDC. In addition to identifying the risk factors, we discuss the incidence, clinical presentation, workup, and management options of IMDC.

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.

Introduction:Adult spinal deformity (ASD) is classically evaluated by health-related quality of life (HRQoL) questionnaires and static radiographic spino-pelvic and global alignment parameters. Recently, 3D movement analysis (3DMA) was used for functional assessment of ASD to objectively quantify patient's independence during daily life activities. The aim of this study was to determine the role of both static and functional assessments in the prediction of HRQoL outcomes using machine learning methods. Methods:ASD patients and controls underwent full-body biplanar low-dose x-rays with 3D reconstruction of skeletal segment as well as 3DMA of gait and filled HRQoL questionnaires: SF-36 physical and mental components (PCS&MCS), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), and visual analog scale (VAS) for pain. A random forest machine learning (ML) model was used to predict HRQoL outcomes based on three simulations: (1) radiographic, (2) kinematic, (3) both radiographic and kinematic parameters. Accuracy of prediction and RMSE of the model were evaluated using 10-fold cross validation in each simulation and compared between simulations. The model was also used to investigate the possibility of predicting HRQoL outcomes in ASD after treatment. Results:In total, 173 primary ASD and 57 controls were enrolled; 30 ASD were followed-up after surgical or medical treatment. The first ML simulation had a median accuracy of 83.4%. The second simulation had a median accuracy of 84.7%. The third simulation had a median accuracy of 87%. Simulations 2 and 3 had comparable accuracies of prediction for all HRQoL outcomes and higher predictions compared to Simulation 1 (i.e., accuracy for PCS = 85 ± 5 vs. 88.4 ± 4 and 89.7% ± 4%, for MCS = 83.7 ± 8.3 vs. 86.3 ± 5.6 and 87.7% ± 6.8% for simulations 1, 2 and 3 resp., p < 0.05). Similar results were reported when the 3 simulations were tested on ASD after treatment. Discussion:This study showed that kinematic parameters can better predict HRQoL outcomes than stand-alone classical radiographic parameters, not only for physical but also for mental scores. Moreover, 3DMA was shown to be a good predictive of HRQoL outcomes for ASD follow-up after medical or surgical treatment. Thus, the assessment of ASD patients should no longer rely on radiographs alone but on movement analysis as well.

Patients with adult spinal deformity (ASD) are known to compensate by retroverting their pelvis and flexing their knees in order to maintain postural stability [1]. Increased pelvic retroversion in patients with ASD is associated with alteration of acetabular orientation both in standing and during walking, increasing the risk of hip osteoarthritis usually treated by total hip replacement [2,3]. A safe zone is targeted during cup positioning where acetabular orientation is calculated relatively to the invariant morphological Lewinnek plane, unruled by the patient's position. Changes in hip positioning encountered in daily life activities were associated with higher rates of prosthesis instability in ASD patients. To evaluate the mismatch between Lewinnek and positional acetabular measurements in variable patient's postures. 121 primary ASD and 32 controls (age and sex matched: 54 years, 73% F) underwent biplanar X-rays in both standing and sitting positions. 3D acetabular parameters (anteversion, abduction, anterior coverage, posterior coverage) were calculated in both the Lewinnek and radiological positional planes (frontal, sagittal and horizontal). The mismatch between Lewinnek and positional acetabular measurements (Δ=Lewinnek-Positional) was evaluated. Radiographic pelvic tilt (PT) adjusted to pelvic incidence (PI) was calculated (adj.PT=0.37*PI-7°). Patients having a high adjusted PT (>2 SD in controls) were grouped as ASD-HighPT, otherwise as ASD-NormPT. 42 ASD had a high PT and 79 a normal PT. Although all 3 groups had similar PI (average: 52°), ASD-HighPT had a decreased lumbar lordosis (L1S1=33°, PT=31°) and decompensated sagittal malalignment (SVA=76 mm). In standing position, ASD-HighPT showed an increased planes mismatch of their acetabular parameters (Δanteversion=-12 vs 2°, Δabduction=-8 vs 0°, ∆anterior coverage=13 vs 0°, Δposterior coverage=-8 vs -1°, all p<0.001), compared to other groups. In the sitting position, ASD-HighPT showed an increased planes mismatch of their acetabular parameters (Δanteversion=-16 vs -10°, Δabduction=-12 vs -8°, ∆anterior coverage=16 vs 11°, Δposterior coverage=-12 vs -8°, all p<0.001), but to a lesser extent than the standing position. PT was strongly correlated to Δanteversion (r=-0.74) and Δanterior coverage (r=0.67, Fig. 1) in the standing position, and moderately correlated in the sitting position (r=-0.40 & 0.28 resp., all p<0.001). This study showed that the Lewinnek plane is not representative of the positional acetabular orientation in the presence of sagittal malalignment. This emphasizes the importance to consider the variation of the acetabular orientation between different postures. It is then necessary to determine a patient-specific functional safe zone in the preoperative planning of total hip replacement to avoid cup instability. Fig. 1: Correlation between pelvic tilt and planes mismatch of acetabular orientation.Download : Download high-res image (91KB)Download : Download full-size image

The ultimate goal when treating patients with Adult Spinal Deformity (ASD) is to enhance their quality of life. Classical evaluation is based on static radiographs in order to assess spinal malalignment and associated compensatory mechanisms [1]. However, static radiographs do not reflect the patient's main complaints encountered in their daily life. Recent 3D movement analysis studies performed during daily life activities in ASD allowed for the calculation of several kinematic parameters of the whole-body joints and segments [2,3]. It is still unknown if there are specific kinematic strategies that ASD patients adopt during daily life activities. What are the kinematic strategies adopted by ASD during daily life activities? 115 primary ASD (with sagittal and/or frontal malalignment) and 36 controls underwent biplanar Xrays for the calculation of static spinopelvic and global alignment parameters. They all underwent 3D movement analysis of the following tasks: walking (t1), sit-to-stand on a chair (t2), and stair ascent/descend (t3), from which joint and segment kinematics were calculated: head (ODHA angle between center of the head, center of the hips and the vertical), neck, thorax, spinal segments, pelvis, hips, knees, ankles, feet [4,5]. In order to identify relevant patterns of kinematic strategies adopted during each task, an artificial intelligence approach was used: kinematic variables were first reduced using a principal component analysis, then a k-means hierarchical classification was applied by simulating 2 to 6 kinematic patterns while taking into account their clinical significance. Similar kinematic strategies were found to be developed by ASD patients during the 3 movements (Fig. 1). Pattern-1 patients had a forward head (N=25%, 19%, 30% during t1, t2, t3 resp.; dynamic-ODHA=18°) with normal pelvic kinematics. Pattern-2 patients had a retroverted pelvis (N=12%, 7%, 10% resp.; dynamic pelvic-retroversion=-2°). Pattern-3 patients had a forward head with retroverted pelvis (N=7%, 6%, 10% resp.; dynamic-ODHA=17°; dynamic pelvic-retroversion=-2°). Pattern-4 patients had normal kinematics (N=56%, 68%, 50% resp.; Fig. 1). ASD with a sagittal malalignment profile (having the following static radiographic parameters: SVA=68 mm, PT=34°, PI-LL=25°) exhibited mostly a Pattern-3 kinematic strategy. It was worthy to note that only 13% of the patients adopted the same kinematic pattern in all 3 tasks: no association between kinematic strategies adopted by patients and performed movements was found (Chi2-test: p=0.9). In this movement analysis-based study performed on 3 daily life activities, 4 patterns of kinematic strategies were identified in ASD patients. While head and pelvis are known to be key elements in static balance, they were shown to be the most discriminant segments in defining kinematic strategies developed by ASD patients during daily life movements. Future studies will investigate the post-surgical effect of spino-pelvic fixation on kinematic strategies adopted by patients. Fig. 1 Kinematic strategies adopted by Adult Spinal Deformity patients during daily life activities.Download : Download high-res image (133KB)Download : Download full-size image

Patients with Adult spinal Deformity (ASD) are known to have a deteriorated quality of life (QOL). Severe spinal deformity can develop into postural malalignment caused by a forward shift of the trunk and head. Recent studies have shown that sagittal malalignment in patients with ASD can affect joints and segments' kinematics during daily life activities [1,2]. On the other hand, ASD patients are known to present with muscular degeneration [3]. However, it is still unknown how trunk muscle's weakness can affect ASD postural alignment in static position and during daily life activities. To investigate the relationship between muscle forces, radiographic parameters, joint kinematics during daily activities, and QOL scores in ASD. 25 ASD & 19 controls underwent biplanar radiographs in both standing and sitting positions with the calculation of 3D classic spinopelvic and postural alignment parameters (i.e: SVA plumbline between C7 and posterior corner of the sacrum; ODHA angle between line joining odontoid process and middle of hip axis with the vertical). Movement analysis was performed during walking, sit-to-stand, and stair ascent-descent with the calculation of 3D joint and segment kinematics. Participants filled out QOL questionnaires (SF-36 with both physical and mental components, Oswestry Disability Index ODI). The strength of the following muscle groups was measured using a hand-held dynamometer: trunk extensors, flexors, and right & left lateral flexors. ASD were divided into 2 groups based on the age-normalized strength of trunk extensors compared to controls: ASD-normal extensors and ASD-weak extensors (having strength

To evaluate the global alignment of non-operated subjects with adolescent idiopathic scoliosis. 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. 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. 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.