Placement of ilio-sacral screws in fusionless technique for pediatric neuromuscular scoliosis utilizing planning software, in conjunction with intraoperative navigation, results in a safer optimal screw: a CT-based study.

PURPOSE: The insertion of ilio-sacral (IS) screws for distal anchoring in the instrumentation of pediatric neuromuscular scoliosis (NS) presents a significant challenge, often leading to elevated rates of complications. Utilizing computed tomography (CT) navigation and preoperative planning technology is proposed as a potential solution to mitigate these challenges. This study aims to assess the precision of IS screw placement through CT-graphic measurements, both with and without preoperative planning, followed by navigated IS screw insertion, in pediatric neuromuscular scoliosis. METHODS: Thirty-two treated patients were grouped based on surgical procedure: planned (P): 19 patients (n = 38 screws) and non-planned (NP): 13 patients (n = 26 screws). All screw placements (P and NP) took place under CT navigation. IS screw trajectories of P-group were drawn preoperatively on CT images with the cranial trajectory planning program and fused with the intraoperative CT images. There are several important anatomical structures that should be avoided when placing the IS screw (L5 root, spinal canal, L5S1 facet, SI joint, neurovascular structures anteriorly to the sacrum, S1 root in the S1 foramen and the intestines). Each trajectory was evaluated based on seven radiographical parameters whom we have enlisted partially based on the essentials of a good trajectory described by Miladi et al. (1: Ilium; 2: SI joint; 3: Promontorium; 4: Sacral plate; 5: Anterior sacral cortex; 6: S1 foramen; 7: Spinal canal). An independent sample T test was executed to compare both groups. RESULTS: The trajectories in the P group showed a significantly (P < 0.05) higher overall similarity and optimality (12.1 ± 2.1 vs 9.1 ± 2.2 points) compared to the non-planned trajectory. CONCLUSIONS: Preoperative planning and navigated placement of IS screws on fusion images with intraoperative CT, results in a better trajectory of the ilio-sacral screws.

Qualitative study exploring the views of patients and healthcare providers on current rehabilitation practices after lumbar fusion surgery.

OBJECTIVES: To explore the views of patients and healthcare providers on current rehabilitation after lumbar fusion surgery (LFS) to fuel the development of a novel rehabilitation care pathway. DESIGN: A cross-sectional, qualitative study with an interpretive descriptive design. SETTING: Academic and non-academic hospital setting in Belgium. PARTICIPANTS: 31 caregivers from (non)-academic settings and 5 patients with LFS were purposefully sampled and in-depth interviewed. RESULTS: Out of the data of all interviews, participants reported opinions on 23 thematic clusters that were expressed in a time-contingent manner from the preoperative, perioperative to postoperative phase. Afterwards, themes were mapped to the Consolidated Framework for Implementation Research, with a larger role for concepts related to the innovation, inner and individual domain. As an overarching theme, the importance of an 'individualised, patient-centred rehabilitation built on a strong therapeutic alliance with an accessible interprofessional team' was stressed for patients undergoing LFS. Specifically, participants stated that a biopsychosocial approach to rehabilitation should start in the preoperative phase and immediately be continued postoperatively. No consensus was observed for movement restrictions postoperatively. Uniform communication between the involved caregivers was considered essential for optimal therapeutic alliance and clinical outcome. The precise role and competence of each member of the interprofessional team needs, therefore, to be clearly defined, respected and discussed. An accessible case manager to guide the patient trajectory and tackle problems could further support this. Interestingly, only patients, psychologists and physiotherapists addressed return to work as an important outcome after LFS. CONCLUSIONS: This qualitative study identified key experiences and points to consider in the current and future rehabilitation pathway for LFS. Future research should incorporate these findings to build a novel rehabilitation pathway for LFS and evaluate its feasibility and cost-effectiveness. TRIAL REGISTRATION NUMBER: This study was registered at clinicaltrials.gov (NCT03427294).

Three- instead of two-dimensional evaluation of key parameters alters the choice of the lowest instrumented vertebra in Lenke 1 and 2 AIS patients.

PURPOSE: Treatment of AIS, a three-dimensional spinal (3D) deformity, is guided by a two-dimensional (2D) evaluation. Novel 3D approaches that address the 2D limitations have not been adopted in AIS care due to their lengthy and complex 3D reconstruction procedures. This study aims to introduce a simple 3D method that translates the 2D key parameters (Stable vertebra (SV), Lenke lumbar modifier, Neutral vertebra (NV)) into 3D and to quantitively compare these 3D corrected parameters to the 2D assessment. METHODS: The key parameters of 79 surgically treated Lenke 1 and 2 patients were measured in 2D by two experienced spine surgeons. Next, these key parameters were measured in 3D by indicating relevant landmarks on biplanar radiographs and using the 'true' 3D CSVL which was perpendicular to the pelvic plane. Differences between the 2D and 3D analysis were examined. RESULTS: A 2D-3D mismatch was identified in 33/79 patients (41.8%) for at least one of the key parameters. More specifically, a 2D-3D mismatch was identified in 35.4% of patients for the Sag SV, 22.5% of patients for the SV and 17.7% of patients for the lumbar modifier. No differences in L4 tilt and NV rotation were found. CONCLUSION: The findings highlight that a 3D evaluation alters the choice of the LIV in Lenke 1 and 2 AIS patients. Although, the true impact of this more precise 3D measurement on preventing poor radiographic outcome needs further investigation, the results are a first step toward establishing a basis for 3D assessments in daily practice.

Partial Femoral Diaphysectomy With Vastus Lateralis Interposition in a Paraplegic Patient With Severely Debilitating Hip Ankylosis: Low Risks and High Gains?

We present the case of a 56-year-old male unable to sit because of an ankylosed right hip. This ankylosis originated from combined neurogenic heterotopic ossifications (NHO) and traumatic heterotopic ossifications (THO) as a result of a road traffic accident. Because of multiple ossifications, the proximity of neurovascular structures, and chronic pressure ulcers, a resection was deemed unsafe. We opted for a new articulation distal to the ossifications in unstained tissue. A partial femoral diaphysectomy was performed just distal of the lesser trochanter. and the vastus lateralis was rotated in the new articulation. Postoperatively, the patient was able to sit as his hip could flex again. A partial femoral diaphysectomy with vastus lateralis interposition flap appears to be a valid option in paraplegic patients with extensive heterotopic ossifications (HO) in close proximity to neurovascular structures with a low risk of complications and high gain in hip mobility.

Best practice rehabilitation pathway for the management of single and double-level lumbar fusion surgery: a modified Delphi Study.

BACKGROUND: There is limited evidence to guide the rehabilitation of patients following single or double-level lumbar fusion surgery (LFS). This is reflected in extensive variability in current rehabilitation regimes and subsequent low clinical success rates, which urges a call for a consensus rehabilitation pathway. AIM: To establish consensus on the optimal pre-, peri- and postoperative rehabilitation of LFS. DESIGN: A modified Delphi Study. SETTING: Belgium and the Netherlands. POPULATION: A multidisciplinary panel of 31 experts in the field of LFS and rehabilitation participated. Nine patients validated the consensus pathway. METHODS: A three-round online Delphi questionnaire was followed by an in-person consensus meeting. In each round, experts could suggest new statements, and received group summary statistics and feedback for reconsidered statements. Consensus threshold was set at ≥75% agreement. The resulting rehabilitation pathway was validated by patients through an online questionnaire and subsequent in-person focus group. RESULTS: A total of 31 experts participated in the first online round, with 27 (87%) completing all online rounds, and 17 (55%) attending the in-person consensus meeting. Consensus was reached on 122 statements relating to pre-, peri- and postoperative rehabilitation of LFS, and validated by patients. Key components of the rehabilitation pathway included prehabilitation, education, physiotherapy in every phase, early postoperative mobilization, and little movement restrictions. Patients emphasized the need for support during the return-to-work process. CONCLUSIONS: This process resulted in 122 expert-consensus statements on best practice rehabilitation for managing LFS, validated by patients. CLINICAL REHABILITATION IMPACT: The proposed rehabilitation pathway can serve as guidance to support clinicians, reduce practice variability, and subsequently improve clinical outcomes after LFS.

Applying the ICF model in adult spinal deformity: disability in terms of participation should be incorporated in the care pathway.

PURPOSE: To investigate the participation restriction of adult spinal deformity (ASD) patients, and its relation with the impairments in body structure and function, and activity limitation, as this important information regarding the individual's perspective on the social impact of the disease on their life is presently not captured. METHODS: Forty-three ASD patients participated in the study and completed the impact on participation and autonomy (IPA) questionnaire to assess the level of participation. Activity limitations and impairments were measured with the Balance Evaluation Systems Test (BESTest) and Scoliosis Research Society-22r (SRS-22). Also, age, body height, body weight, BMI, Mini-mental state examination and Cumulative Illness Rating Scale were assessed. A univariate linear regression analysis was conducted to investigate the relationship between the IPA and the independent variables, whereas a multivariate analysis identified the significant predictive variables for the IPA questionnaire. RESULTS: The univariate analysis identified performance on the BESTest and SRS-22 as significantly (p < 0.001) related to the IPA questionnaire. The multiple regression analysis revealed that the performance on BESTest (p = 0.073) and SRS-22 (p < 0.001) independently predicted the IPA questionnaire, explaining 73.5% of its variance. CONCLUSION: To fully understand the impact of ASD on the individual's functioning, disability and health-status, it is suggested that questionnaires on participation to society should be considered, together with clinical postural tests (e.g. the BESTest) and questionnaires related to HRQOL (e.g. the SRS-22), in the ASD care path. This additional information should allow the surgeon to make a more informed selection of surgical patients.

Rehabilitation to improve outcomes of lumbar fusion surgery: a systematic review with meta-analysis.

PURPOSE: To evaluate the effectiveness of rehabilitation strategies on disability, pain, pain-related fear, and return-to-work in patients undergoing lumbar fusion surgery for degenerative conditions or adult isthmic spondylolisthesis. METHODS: Six electronic databases were systematically searched for randomized controlled trials (RCTs) evaluating the effect of rehabilitation (unimodal or multimodal). The estimated effect size was calculated for interventions with homogeneous content using a random-effects model. Certainty of evidence was assessed by GRADE. RESULTS: In total, 18 RCTs, including 1402 unique patients, compared specific rehabilitation to other rehabilitation strategies or usual care. Most described indications were degenerative disc disease and spondylolisthesis. All rehabilitation interventions were delivered in the postoperative period, and six of them also included a preoperative component. Intervention dose and intensity varied between studies (ranging from one session to daily sessions for one month). Usual care consisted mostly of information and postoperative mobilization. At short term, low quality of evidence shows that exercise therapy was more effective for reducing disability and pain than usual care (standardized mean difference [95% CI]: -0.41 [-0.71; -0.10] and -0.36 [-0.65; -0.08], four and five studies, respectively). Multimodal rehabilitation consisted mostly of exercise therapy combined with cognitive behavioral training, and was more effective in reducing disability and pain-related fear than exercise therapy alone (-0.31 [-0.49; -0.13] and -0.64 [-1.11; -0.17], six and four studies, respectively). Effects disappeared beyond one year. Rehabilitation showed a positive tendency towards a higher return-to-work rate (pooled relative risk [95% CI]: 1.30 [0.99; 1.69], four studies). CONCLUSION: There is low-quality evidence showing that both exercise therapy and multimodal rehabilitation are effective for improving outcomes up to six months after lumbar fusion, with multimodal rehabilitation providing additional benefits over exercise alone in reducing disability and pain-related fear. Additional high-quality studies are needed to demonstrate the effectiveness of rehabilitation strategies in the long term and for work-related outcomes.

Variability drivers of treatment costs in hospitals: A systematic review.

OBJECTIVES: Studies on variability drivers of treatment costs in hospitals can provide the necessary information for policymakers and healthcare providers seeking to redesign reimbursement schemes and improve the outcomes-over-cost ratio, respectively. This systematic literature review, focusing on the hospital perspective, provides an overview of studies focusing on variability in treatment cost, an outline of their study characteristics and cost drivers, and suggestions on future research methodology. METHODS: We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Handbook for Systematic Reviews of Interventions. We searched PubMED/MEDLINE, Web of Science, EMBASE, Scopus, CINAHL, Science direct, OvidSP and Cochrane library. Two investigators extracted and appraised data for citation until October 2020. RESULTS: 90 eligible articles were included. Patient, treatment and disease characteristics and, to a lesser extent, outcome and institutional characteristics were identified as significant variables explaining cost variability. In one-third of the studies, the costing method was classified as unclear due to the limited explanation provided by the authors. CONCLUSION: Various patient, treatment and disease characteristics were identified to explain hospital cost variability. The limited transparency on how hospital costs are defined is a remarkable observation for studies wherein cost variability is the main focus. Recommendations relating to variables, costs, and statistical methods to consider when designing and conducting cost variability studies were provided.

The Function Assessment Scale for Spinal Deformity: Validity and Reliability of a New Clinical Scale.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The aim of this study was to develop and validate the Function Assessment scale for Spinal Deformity (FASD). SUMMARY OF BACKGROUND DATA: Spinal malalignment impacts daily functioning. Standard evaluation of adult spinal deformity (ASD) is based on static radiography and patient-reported scores, which fail to assess functional impairments. A clinical scale, quantifying function and balance of patients with ASD, could increase our insights on the impact of ASD on functioning. METHODS: To develop the FASD, 70 ASD patients and 20 controls were measured to identify the most discriminating items of the Balance Evaluation Systems Test and Trunk Control Measurement Scale. Discussions between experts on the clinical relevance of selected items led to further item reduction. The FASD's discriminative ability was established between 43 patients and 19 controls, as well as between three deformity subgroups. For its responsiveness to treatment, 10 patients were reevaluated 6 months postoperatively. Concurrent validity was assessed through correlation analysis with radiographic parameters (pelvic tilt; sagittal vertical axis [SVA]; pelvic incidence minus lumbar lordosis [PI-LL]; coronal vertical axis) and patient-reported scores [Oswestry Disability Index]; Scoliosis Research Society outcome questionnaire; Falls Efficacy Scale-International). Test-retest and interrater reliability were tested on two groups of ten patients using intraclass correlation coefficients (ICC). RESULTS: Patients with ASD, mainly with sagittal malalignment, scored worse compared to controls on FASD (P < 0.001) and its subscales. No significant improvement was observed 6 months postoperatively (P = 0.758). FASD correlated significantly to all patient-reported scores and to SVA and PI-LL. Reliability between sessions (ICC = 0.97) and raters (ICC = 0.93) was excellent. Subscales also showed good to excellent reliability, except FASD 1 on "spinal mobility and balance" between sessions (ICC = 0.71). CONCLUSION: FASD proved to be a valid and reliable clinical scale for evaluation of functional impairments in ASD. Objective information on function and balance might ultimately guide physiotherapeutic treatment toward improved functioning.Level of Evidence: 2.

Spinopelvic movement strategies during sit-to-stand and stand-to-sit in adult spinal deformity.

BACKGROUND: Research interest on the impact of adult spinal deformity (ASD) on spinopelvic and whole body motion has increased over the past years. Studies focusing on overground walking, showed that patients with ASD indeed present with functional impairments. Functional tasks challenging the spinopelvic complex, such as sit-to-stand-to-sit, might identify clinically relevant biomechanical parameters and could further increase our insights on how ASD impacts functioning and disability. RESEARCH QUESTION: Do patients with ASD use different spinopelvic strategies during sit-to-stand (STSt) and stand-to-sit (StTS) compared to healthy controls? METHODS: In this prospective study, marker-based motion analysis and a subject-specific polynomial fit were used to assess spinopelvic kinematics (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), trunk, pelvis) during STSt/StTS in 42 patients with ASD and 18 control subjects. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Continuous kinematic and kinetic data were analyzed through statistical parametric mapping. RESULTS: Patients with ASD showed decreased LL and increased trunk flexion and SVA during STSt/StTS compared to controls. These differences were mainly observed in sagittal deformity patients (ASD 1 and 2). In contrast, coronal patients (ASD 3) did not differ from controls. Dynamic LL and SVA significantly correlated with radiographic LL and SVA, however these relations decreased during the middle third of the motion cycle. SIGNIFICANCE: Patients with ASD use aberrant spinopelvic strategies during STSt/StTS compared to healthy controls. Only partial correlation to static radiographic parameters suggests other mechanisms need to be identified in addition to spinal malalignment. These might include impaired neuromuscular control or muscle weakness. Further research on movement patterns during functional tasks might ultimately result in treatment strategies that aim to augment activity participation by targeting improvements in movement function.

Applying a knowledge translation framework for triaging low back pain and radicular pain at an emergency department: an iterative process within an uncontrolled before-and-after design.

BACKGROUND: Diagnostic imaging for low back pain (LBP) without any indication of a serious underlying cause does not improve patient outcomes. However, there is still overuse of imaging, especially at emergency departments (EDs). Although evidence-based guidelines for LBP and radicular pain management exist, a protocol for use at the ED in the Belgian University Hospitals Leuven was not available, resulting in high practice variation. The present paper aims to describe the process from protocol development to the iterative implementation approach and explore how it has influenced practice. METHODS: In accordance with a modified 'knowledge-to-action' framework, five steps took place within the iterative bottom-up implementation process: (1) identification of the situation that requires the implementation of evidence based recommendations, (2) context analysis, (3) development of an implementation plan, (4) evaluation and (5) sustainability of the implemented practice recommendations. Two potential barriers were identified: the high turnover of attending specialists at the ED and patients' and general practicioners' expectations that might overrule the protocol. These were tackled by educational sessions for staff, patient brochures, an information campaign and symposium for general practitioners. RESULTS: The rate of imaging of the lumbar spine decreased from over 25% of patients to 15.0%-16.4% for CT scans and 19.0%-21.8% for X-rays after implementation, but started to fluctuate again after 3 years. After introducing a compulsory e-learning before rotation and catchy posters in the ED staff rooms, rates decreased to 14.0%-14.6% for CT scan use and 12.7-13.5% for X-ray use. CONCLUSIONS: Implementation of a new protocol in a tertiary hospital ED with high turn over of rotating trainees is a challenge and requires ongoing efforts to ensure sustainability. Rates of imaging represent an indirect though useful indicator. We have demonstrated that it is possible to implement a protocol that includes demedicalisation in an ED environment and to observe changes in indicator results.

Subject-Specific Spino-Pelvic Models Reliably Measure Spinal Kinematics During Seated Forward Bending in Adult Spinal Deformity.

Image-based subject-specific models and simulations are recently being introduced to complement current state-of-the-art mostly static insights of the adult spinal deformity (ASD) pathology and improve the often poor surgical outcomes. Although the accuracy of a recently developed subject-specific modeling and simulation framework has already been quantified, its reliability to perform marker-driven kinematic analyses has not yet been investigated. The aim of this work was to evaluate the reliability of this subject-specific framework to measure spine kinematics in ASD patients, in terms of 1) the overall test-retest repeatability; 2) the inter-operator agreement of spine kinematic estimates; and, 3) the uncertainty of those spine kinematics to operator-dependent parameters of the framework. To evaluate the overall repeatability 1], four ASD subjects and one control subject participated in a test-retest study with a 2-week interval. At both time instances, subject-specific spino-pelvic models were created by one operator to simulate a recorded forward trunk flexion motion. Next, to evaluate inter-operator agreement 2], three trained operators each created a model for three ASD subjects to simulate the same forward trunk flexion motion. Intraclass correlation coefficients (ICC's) of the range of motion (ROM) of conventional spino-pelvic parameters [lumbar lordosis (LL), sagittal vertical axis (SVA), thoracic kyphosis (TK), pelvic tilt (PT), T1-and T9-spino-pelvic inclination (T1/T9-SPI)] were used to evaluate kinematic reliability 1] and inter-operator agreement 2]. Lastly, a Monte-Carlo probabilistic simulation was used to evaluate the uncertainty of the intervertebral joint kinematics to operator variability in the framework, for three ASD subjects 3]. LL, SVA, and T1/T9-SPI had an excellent test-retest reliability for the ROM, while TK and PT did not. Inter-operator agreement was excellent, with ICC values higher than test-retest reliability. These results indicate that operator-induced uncertainty has a limited impact on kinematic simulations of spine flexion, while test-retest reliability has a much higher variability. The definition of the intervertebral joints in the framework was identified as the most sensitive operator-dependent parameter. Nevertheless, intervertebral joint estimations had small mean 90% confidence intervals (1.04°-1.75°). This work will contribute to understanding the limitations of kinematic simulations in ASD patients, thus leading to a better evaluation of future hypotheses.

Spinal Palpation Error and Its Impact on Skin Marker-Based Spinal Alignment Measurement in Adult Spinal Deformity.

Spinal alignment measurement in spinal deformity research has recently shifted from using mainly two-dimensional static radiography toward skin marker-based motion capture approaches, allowing three-dimensional (3D) assessments during dynamic conditions. The validity and accuracy of such skin marker-based methods is highly depending on correct marker placement. In this study we quantified, for the first time, the 3D spinal palpation error in adult spinal deformity (ASD) and compared it to the error in healthy spines. Secondly, the impact of incorrect marker placement on the accuracy of marker-based spinal alignment measurement was investigated. 3D, mediolateral and inferosuperior palpation errors for thoracolumbar and lumbar vertebral levels were measured on biplanar images by extracting 3D positions of skin-mounted markers and their corresponding anatomical landmarks in 20 ASD and 10 healthy control subjects. Relationships were investigated between palpation error and radiographic spinal alignment (lordosis and scoliosis), as well as body morphology [BMI and soft tissue (ST) thickness]. Marker-based spinal alignment was measured using a previously validated method, in which a polynomial is fit through the marker positions of a motion trial and which allows for radiograph-based marker position correction. To assess the impact of palpation error on spinal alignment measurement, the agreement was investigated between lordosis and scoliosis measured by a polynomial fit through, respectively, (1) the uncorrected marker positions, (2) the palpation error-corrected (optimal) marker positions, and (3) the anatomically corrected marker positions (toward the vertebral body), and their radiographic equivalents expressed as Cobb angles (ground truth), using Spearman correlations and root mean square errors (RMSE). The results of this study showed that, although overall accuracy of spinal level identification was similar across groups, mediolateral palpation was less accurate in the ASD group (ASDmean: 6.8 mm; Controlmean: 2.5 mm; p = 0.002). Significant correlations with palpation error indicated that determining factors for marker misplacement were spinal malalignment, in particular scoliotic deformity (r = 0.77; p < 0.001), in the ASD group and body morphology [i.e., increased BMI (r s = 0.78; p = 0.008) and ST thickness (r s = 0.66; p = 0.038)] in healthy spines. Improved spinal alignment measurements after palpation error correction, shows the need for radiograph-based marker correction methods, and therefore, should be considered when interpreting spinal kinematics.

A Dynamic Optimization Approach for Solving Spine Kinematics While Calibrating Subject-Specific Mechanical Properties.

This study aims to propose a new optimization framework for solving spine kinematics based on skin-mounted markers and estimate subject-specific mechanical properties of the intervertebral joints. The approach enforces dynamic consistency in the entire skeletal system over the entire time-trajectory while personalizing spinal stiffness. 3D reflective markers mounted on ten vertebrae during spine motions were measured in ten healthy volunteers. Biplanar X-rays were taken during neutral stance of the subjects wearing the markers. Calculated spine kinematics were compared to those calculated using inverse kinematics (IK) and IK with imposed generic kinematic constraints. Calculated spine kinematics compared well with standing X-rays, with average root mean square differences of the vertebral body center positions below 10.1 mm and below [Formula: see text] for joint orientation angles. For flexion/extension and lateral bending, the lumbar rotation distribution patterns, as well as the ranges of rotations matched in vivo literature data. The approach outperforms state-of-art IK and IK with constraints methods. Calculated ratios reflect reduced spinal stiffness in low-resistance zone and increased stiffness in high-resistance zone. The patterns of calibrated stiffness were consistent with previously reported experimentally determined patterns. This approach will further our insight into spinal mechanics by increasing the physiological representativeness of spinal motion simulations.

Dynamic sagittal alignment and compensation strategies in adult spinal deformity during walking.

BACKGROUND CONTEXT: Radiographic evaluation in adult spinal deformity (ASD) offers no information on spinopelvic alignment and compensation during dynamic conditions. Motion analysis offers the potential to bridge the gap between static radiographic and dynamic alignment measurement, increasing our understanding on how ASD impacts function. PURPOSE: This study aimed to explore the changes in sagittal alignment and compensation strategies in ASD between upright standing and walking, compared to control subjects and within different sagittal alignment groups. Ten patients were measured pre- and six months postoperatively to explore the impact of surgical alignment correction on gait. STUDY DESIGN: Prospective study. SAMPLE SIZE: Full protocol: 58 ASD and 20 controls; Spinal kinematic analysis: 43 ASD and 18 controls; Postoperative analysis: 10 ASD. OUTCOME MEASURES: Standing and walking sagittal spinopelvic (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvis), and lower limb kinematics, spinopelvic changes between standing and walking (∆ ie, difference between mean dynamic and static angle), lower limb kinetics, spatiotemporal parameters, balance (BESTest), patient-reported outcome scores (SRS-22r, ODI, and FES-I) and radiographic parameters. METHODS: Motion analysis was used to assess the standing and walking spinopelvic and lower limb kinematics, as well as the lower limb kinetics during walking. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Ten patients were reassessed 6 months after spinal corrective surgery. Continuous kinematic and kinetic data were analyzed through statistical parametric mapping. RESULTS: All patient groups walked with increased forward trunk tilt (∆SVA=41.43 mm, p<.001) in combination with anterior pelvic tilt (∆Pelvis=2.58°, p<.001) compared to standing, as was also observed in controls (∆SVA=37.86 mm, p<.001; ∆Pelvis=1.62°, p=.012). Patients walked with increased SVA, in combination with decreased LL and alterations in lower limb kinematics during terminal stance and initial swing, as well as altered spatiotemporal parameters. Subgroup analysis could link these alterations in gait to sagittal spinopelvic malalignment (ASD 1 and 2). After surgical correction, lower limb kinematics and spatiotemporal parameters during gait were not significantly improved. CONCLUSIONS: To compensate for increased trunk tilt and pelvic anteversion during walking, patients with sagittal malalignment show altered lower limb gait patterns, which have previously been associated with increased risk of falling and secondary lower limb pathology. Since surgical correction of the deformity did not lead to gait improvements, further research on the underlying mechanisms is necessary to improve our understanding of how ASD impacts function.

Returning to Elective Orthopedic Surgery During the COVID-19 Pandemic: A Multidisciplinary and Pragmatic Strategy for Initial Patient Selection.

OBJECTIVE: The aim of the study was to design an objective, transparent, pragmatic, and flexible workflow to assist with patient selection during the initial phase of return to elective orthopedic surgery during the COVID-19 pandemic with the main purpose of enhancing patient safety. METHODS: A multidisciplinary working group was formed consisting of representatives for orthopedics, epidemiology, ethics, infectious diseases, cardiovascular diseases, and intensive care medicine. Preparation for upcoming meetings consisted of reading up on literature and testing of proposed methodologies on our own waiting lists. RESULTS: A workflow based on 3 domains, that is, required resources, patient fitness, and time sensitivity of the procedure, was considered most useful. All domains function as standalones, in a specific order, and no sum score is used. The domain of required resources demands input from the surgical team, results in a categorical (yes or no) outcome, and generates a list of potential patients who can be scheduled for surgery under these particular circumstances. The (weighted) items for the domain of patient fitness are the same for every patient, are scored on a numerical scale, but are likely to change during the pandemic as more data become available. Time sensitivity of the procedure is again scored on a numerical scale and becomes increasingly important when returning to elective surgery proves to be acceptably safe. After patient selection, an augmented informed consent, screening, and testing according to local guidelines will take place. CONCLUSIONS: A workflow is proposed for patient selection aiming for the safest possible return to elective orthopedic surgery during the COVID-19 pandemic.

Development and validation of a modeling workflow for the generation of image-based, subject-specific thoracolumbar models of spinal deformity.

Quantitative dynamic evaluation of spino-pelvic motion in subjects with spinal deformity using optical motion analysis is currently lacking. The aim of this study was to develop and validate subject-specific, thoracolumbar spine multi-body skeletal models for evaluating spino-pelvic kinematics in a spinal deformity population. A new workflow for creating subject-specific spino-pelvic models in a weight-bearing position through computed tomography (CT) and biplanar radiography is described. As part of a two-step validation process the creation of such a model was first validated against a ground truth CT reconstruction of a plastinated cadaver. Secondly, biplanar radiographic images of one healthy and 12 adult spinal deformity subjects were obtained in two standing positions: upright and bent. Two subject-specific models for each of these subjects were then created to represent both standing positions. The result of inverse kinematics solutions, simulating the specific bending motion using the upright models, are compared with the models created in bent position, quantifying the marker-based spino-pelvic tracking accuracy. The workflow created spinal deformity models with mean accuracies between 0.71-1.95 mm and 1.25-2.27° for vertebral positions and orientations, respectively. In addition, the mean marker-based spino-pelvic tracking accuracies were between 0.9-1.8 mm and 2.9-5.6° for vertebral positions and rotations, respectively. This study presented the first validated biplanar radiography-based method to generate subject-specific spino-pelvic, rigid body models that allows the inclusion of subject-specific bone geometries, the personalization of the 3D weight-bearing spinal alignment with accuracy comparable to clinically used software for 3D reconstruction, and the localization of external markers in spinal deformity subjects. This work will allow new concepts of dynamic functionality evaluation of patients with spinal deformity.

Variability in Hospital Costs of Adult Spinal Deformity Care.

STUDY DESIGN: Retrospective, single-center analysis. OBJECTIVE: To calculate the total clinical hospital cost of the Adult Spinal Deformity (ASD) care trajectory, to explain cost variability by patient and surgery characteristics, and to identify areas of process improvement opportunities. SUMMARY OF BACKGROUND DATA: ASD is associated with a high financial and clinical burden on society. ASD care thus requires improved insights in costs and its drivers as a critical step toward the improvement of value, i.e., the ratio between delivered health outcome and associated costs. METHODS: Patient characteristics and surgical variables were collected following ethical approval in a cohort of 139 ASD patients, treated between December, 2014 and January, 2018. Clinical hospital costs were calculated, including all care activities, from initial consultation to 1 year after initial surgery (excl. overhead) in a university hospital setting. Multiple linear regression analysis was performed to analyze the impact of patient and surgical characteristics on clinical costs. RESULTS: 75.5% of the total clinical hospital cost (&OV0556;27,865) was incurred during initial surgery with costs related to the operating theatre (80.3%), nursing units (11.9%), and intensive care (2.9%) being the largest contributors. 57.5% of the variation in total cost could be explained in order of importance by surgical invasiveness, age, coronary disease, single or multiple-staged surgery, and mobility status. Revision surgery, unplanned surgery due to complications, was found to increase average costs by 87.6% compared with elective surgeries (&OV0556; 44,907 (± &OV0556; 23,429) vs. &OV0556; 23,944 (± &OV0556; 7302)). CONCLUSION: This study identified opportunities for process improvement by calculating the total clinical hospital costs. In addition, it identified patient and treatment characteristics that predict 57.5% of cost variation, which could be taken into account when developing a payment system. Future research should include outcome data to assess variation in value. LEVEL OF EVIDENCE: 4.

A subject-specific method to measure dynamic spinal alignment in adult spinal deformity.

BACKGROUND CONTEXT: Two-dimensional static radiography currently forms the golden standard in spinal alignment measurement in adult spinal deformity (ASD). However, these static measurements offer no information on dynamic spinal behavior. To fully understand the functionality and compensation strategies of ASD patients, tools to assess dynamic spinal alignment are needed. PURPOSE: Therefore, the aim of this study was to introduce, validate and assess the reliability of a new kinematic model to measure dynamic spinal parameters in ASD based on a polynomial function, taking into account the subject-specific anatomy. STUDY DESIGN: Validation and reliability study OUTCOME MEASURES: Radiographic parameters, spinal kinematics and range of motion (ROM), Scoliosis Research Society Outcome Questionnaire (SRS-22), Core Outcome Measures Index (COMI). METHODS: Spinal alignment of 23 ASD patients and 18 controls was measured using both x-rays and motion capture. Marker positions were corrected to the underlying anatomy and a polynomial function was fitted through these corrected marker positions. By comparing the polynomial method to x-ray measurements concurrent validity was assessed. Test-retest, inter- and intrarater reliability during standing and sit-to-stand (STS) were assessed on a subsample of eight ASD patients and eight controls. RESULTS: The results showed good to excellent correlations (r>0.75) between almost all x-ray and anatomy-corrected polynomial parameters. Anatomy correction consistently led to better correlations than no correction. Intraclass correlation coefficients for the polynomial method were good to excellent (>0.75) between sessions and between and within raters and comparable or even better than radiographic measurements. Also, during STS reliability was excellent. Fair to moderate correlations were found between spinal ROM during STS and quality of life, measured with SRS-22 and COMI. CONCLUSIONS: The results of this study indicate the polynomial method, with subject-specific anatomy correction, can measure spinal alignment in a valid and reliable way using motion capture in both healthy and deformed spines. This method makes it possible to extend evaluation in ASD from mainly static, by means of x-ray measurements, to dynamic and functional assessments. CLINICAL SIGNIFICANCE: Eventually, this newly obtained dynamic spinal alignment information might lead to new insights in clinical decision-making and new treatment strategies, based and oriented on dynamic parameters and functionality.