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 (rs = 0.78; p = 0.008) and ST thickness (rs = 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

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 &lt; 0.001), in the ASD group and body morphology [i.e., increased BMI (rs = 0.78; p = 0.008) and ST thickness (rs = 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

Variability in hospital costs of adult spinal deformity care

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 (€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 (€ 44,907 (± € 23,429) vs. € 23,944 (± € 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.The KU Leuven grant (C24/17/095) funds were received in support of this work

The appropriate management of persisting pain after spine surgery: a European panel study with recommendations based on the RAND/UCLA method

Purpose: Management of patients with persisting pain after spine surgery (PPSS) shows significant variability, and there is limited evidence from clinical studies to support treatment choice in daily practice. This study aimed to develop patient-specific recommendations on the management of PPSS. Methods: Using the RAND/UCLA appropriateness method (RUAM), an international panel of 6 neurosurgeons, 6 pain specialists, and 6 orthopaedic surgeons assessed the appropriateness of 4 treatment options (conservative, minimally invasive, neurostimulation, and re-operation) for 210 clinical scenarios. These scenarios were unique combinations of patient characteristics considered relevant to treatment choice. Appropriateness had to be expressed on a 9-point scale (1 = extremely inappropriate, 9 = extremely appropriate). A treatment was considered appropriate if the median score was ≥ 7 in the absence of disagreement (≥ 1/3 of ratings in each of the opposite sections 1–3 and 7–9). Results: Appropriateness outcomes showed clear and specific patterns. In 48% of the scenarios, exclusively one of the 4 treatments was appropriate. Conservative treatment was usually considered appropriate for patients without clear anatomic abnormalities and for those with new pain differing from the original symptoms. Neurostimulation was considered appropriate in the case of (predominant) neuropathic leg pain in the absence of conditions that may require surgical intervention. Re-operation could be considered for patients with recurrent disc, spinal/foraminal stenosis, or spinal instability. Conclusions: Using the RUAM, an international multidisciplinary panel established criteria for appropriate treatment choice in patients with PPSS. These may be helpful to educate physicians and to improve consistency and quality of care. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material. [Figure not available: see fulltext.

Subaxial Rotational Vertebral Artery Syndrome: Resection of the Uncinate Process and Anterior Fusion Can Be Sufficient! Case Report and Review of the Literature

STUDY DESIGN: A case report on rotational vertebral artery syndrome (RVAS) and surgical treatment. OBJECTIVE: To illustrate a safe treatment option of RVAS with diminished risk of iatrogenic damage to the vertebral artery. SUMMARY OF BACKGROUND DATA: RVAS is an uncommon cause of symptomatic transient vertebrobasilar insufficiency induced by physiological head rotation with temporary significant external compression of the dominant subaxial vertebral artery. Previous reports state that the treatment of choice consists of decompression of the vessel with resection of the anterior rim of the transverse process and any fibrotic sheet or intertransverse muscle, if necessary, combined with an anterior cervical discectomy and fusion (ACDF) with uncus resection. METHODS: This is a case report on RVAS and its surgical treatment. The diagnosis of RVAS due to an osteophyte of the uncinate process at level C5/C6 was confirmed using computed tomographic angiography. We performed a classic ACDF using the contralateral approach with complete resection of the uncovertebral joint at the pathologic site. RESULTS: In our case, the symptoms of transient vertebrobasilar insufficiency induced by head rotation completely resolved postoperatively, and computed tomographic angiography images at 3 months postoperatively showed good bony ingrowth and restoration of vertebral artery patency during extreme rotation. CONCLUSIONS: Classic ACDF with complete resection of the uncovertebral joint is a safe treatment option for RVAS in the subaxial cervical spine. Fusion at the pathologic level will eliminate rotation and prevent further formation of osteophytes at the operated level. Unroofing of the vertebral artery seems not always necessary, diminishing the surgical risk.status: publishe

Case report of a guide wire loss and migration after central venous access

We report a case of guide wire loss and migration after central venous access for spinal deformity surgery. Guide wire migration was noticed on a follow-up full spine x-ray 69 days postoperatively. Percutaneous retrieval was successfully performed using endovascular techniques. With this case report, we want to highlight the fact that one could miss other pathologies visible on these full spine x-rays when concentrating only on the measurement of spinopelvic parameters.status: publishe

Excruciating Low Back Pain After Strenuous Exertion: Beware of Lumbar Paraspinal Compartment Syndrome

Low back pain is extremely common and usually a minor self-limiting condition. Rarely, however, it is a harbinger of serious medical illness. Paraspinal compartment syndrome is a rare condition, but its timely recognition is important to allow adequate treatment.publisher: Elsevier articletitle: Excruciating Low Back Pain After Strenuous Exertion: Beware of Lumbar Paraspinal Compartment Syndrome journaltitle: The Journal of Emergency Medicine articlelink: http://dx.doi.org/10.1016/j.jemermed.2015.06.056 content_type: article copyright: Copyright © 2015 Elsevier Inc. All rights reserved.status: publishe

Reliability of the balance evaluation systems test and trunk control measurement scale in adult spinal deformity

OBJECTIVE: To test the reliability of the Balance Evaluation Systems Test (BESTest) and Trunk Control Measurement Scale (TCMS) between sessions and raters in the adult spinal deformity (ASD) population. SUMMARY OF BACKGROUND DATA: Up to now evaluation in ASD was mainly based on static radiographic parameters. Recently literature showed that dynamic balance was a better predictor of health-related quality of life than radiographic parameters, stressing the importance of balance assessment. However, to the best of our knowledge, reliability of balance assessment tools has not yet been investigated in the ASD population. METHODS: Twenty ASD patients participated in this study. Ten patients were included in the test-retest study, including repeated measurements. Ten patients were measured once, simultaneously but independently by three raters. Each participant performed two balance scales, namely the BESTest and the TCMS. Statistical analysis consisted of intra class correlations (ICC) on scale- and subscale level, and kappa scores on item-level. Cronbach's alpha on total scores, standard errors of measurement (SEM), smallest detectable differences and percentages of agreement were also calculated. Bland-altman plots were created to investigate systematic bias. RESULTS: ICC scores between sessions and raters for TCMS (0.76 and 0.88) and BESTest (0.90 and 0.94) total scores were good to excellent. SEM's between sessions and raters were also low for total scores on TCMS (1.66 and 2.35) and BESTest (2.99 and 2.32). However, on subscale- and item-level reliability decreased and ceiling effects were observed. No systematic bias was observed between sessions and raters. CONCLUSION: BESTest and TCMS showed to be reliable tools to measure balance in ASD on scale-level. However, on subscale- and item-level reliability decreased and ceiling effects were observed. Therefore, the question arises if there is need for an ASD-specific balance scale.status: publishe

Reliability of the balance evaluation systems test and trunk control measurement scale in adult spinal deformity.

ObjectiveTo test the reliability of the Balance Evaluation Systems Test (BESTest) and Trunk Control Measurement Scale (TCMS) between sessions and raters in the adult spinal deformity (ASD) population.Summary of background dataUp to now evaluation in ASD was mainly based on static radiographic parameters. Recently literature showed that dynamic balance was a better predictor of health-related quality of life than radiographic parameters, stressing the importance of balance assessment. However, to the best of our knowledge, reliability of balance assessment tools has not yet been investigated in the ASD population.MethodsTwenty ASD patients participated in this study. Ten patients were included in the test-retest study, including repeated measurements. Ten patients were measured once, simultaneously but independently by three raters. Each participant performed two balance scales, namely the BESTest and the TCMS. Statistical analysis consisted of intra class correlations (ICC) on scale- and subscale level, and kappa scores on item-level. Cronbach's alpha on total scores, standard errors of measurement (SEM), smallest detectable differences and percentages of agreement were also calculated. Bland-altman plots were created to investigate systematic bias.ResultsICC scores between sessions and raters for TCMS (0.76 and 0.88) and BESTest (0.90 and 0.94) total scores were good to excellent. SEM's between sessions and raters were also low for total scores on TCMS (1.66 and 2.35) and BESTest (2.99 and 2.32). However, on subscale- and item-level reliability decreased and ceiling effects were observed. No systematic bias was observed between sessions and raters.ConclusionBESTest and TCMS showed to be reliable tools to measure balance in ASD on scale-level. However, on subscale- and item-level reliability decreased and ceiling effects were observed. Therefore, the question arises if there is need for an ASD-specific balance scale

Personalized musculoskeletal modeling of spinal deformities based on stereoradiographic images for biomechanical analysis of motion

1. INTRODUCTION Adult Spinal Deformity (ASD) is present in 68% of the population older than 60 years [1]. Surgical treatment aims at stabilizing the deformed spine which, apart from preventing curve progression, also aims at achieving a balanced spinal posture and reducing back pain. Although, surgery is associated with more positive outcome compared to non-surgical treatment, up to 70% of ASD patients suffer from post-operative complications [2]. This high complication rate is expected to be closely linked to a conceptual lacuna in the clinical evaluation process, and specifically in the lack of knowledge about how ASD impacts the locomotor system [3]. Since most pain and complaints for ASD patients arise during dynamic activities of daily living, the use of static medical image-based assessment approaches alone fails to describe the functional ability during these activities. Therefore the insights into the impact of the deformity itself as well as its treatment are severely limited. Musculoskeletal modeling and simulation has clear potential to fill this knowledge gap. Through these techniques, the functional ability of spine patients can be assessed in terms of muscle and contact forces during motion. Unfortunately however, applying multi-body simulation in ASD is currently not possible, as most available musculoskeletal models (MSMs) do not allow to include the effect of spinal deformities on musculoskeletal geometry. Therefore, the aim of this research project is to develop a software platform for radiograph-based subject-specific modeling of the spine. 2. MATERIALS AND METHODS Using the state-of-the-art generic model of Bruno et al. [4] as a basis, the modeling platform allows for custom-made, manual routines to adjust the size and pose of the included bone models, based on biplanar x-ray images (fig. 1), acquired using the EOS Imaging system (EOS Imaging, France), which is considered as ground truth. The modeling platform further allows the identification of reflective markers and the definition of their position relative to the underlying bony segments and has fully functional import and export links to the OpenSim simulation platform (SimTK, Stanford, fig. 2). Following ethical approval and informed consent We applied the workflow to a subject with ASD (49y, male, 71kg), obtaining a subjectspecific model. Furthermore we applied the standard approach of marker-based scaling of the generic model (fig. 3). This subject underwent 3D motion analysis using a motion capture system (Vicon Nexus, Oxford, UK). Next, both models were compared statically and dynamically through MSM simulations. 3. RESULTS AND DISCUSSION Using the developed modeling platform, the need for subject-specific MSMs is confirmed as the currently available generic musculoskeletal model failed to accurately represent spinal deformity using the standard approach of marker-based scaling (fig. 3 vs. fig. 4). Furthermore, the potential of image-based marker personalization was demonstrated as a means of correcting palpation errors. Finally, the estimated vertebral compressive loading and muscle activations using dynamic simulations of spine motion were found to be very sensitive to the vertebral alignment in the MSM used.status: publishe