Reliability of Three-Dimensional Spinal Modeling of Patients With Idiopathic Scoliosis Using EOS System

Reliability of the Biomechanical Assessment of the Sagittal Lumbar Spine and Pelvis on Radiographs Used in Clinical Practice: A Systematic Review of the Literature

Background: Biomechanical analysis of the sagittal alignment of the lumbar spine and pelvis on radiographs is common in clinical practices including chiropractic, physical therapy, scoliosis-related thoraco-lumbo-sacral orthosis (TLSO) management, orthopedics, and neurosurgery. Of specific interest is the assessment of pelvic morphology and the relationship between angle of pelvic incidence, sacral slope, and lumbar lordosis to pain, disability, and clinical treatment of spine conditions. The current state of the literature on the reliability of common methods quantifying these parameters on radiographs is limited. Methods: The objective of this systematic review is to identify and review the available studies on the reliability of different methods of biomechanical analysis of sagittal lumbo-pelvic parameters used in clinical practice. Our review followed the recommendations of the preferred reporting items for systematic reviews and meta-analyses (PRISMA). The design of this systematic review was registered with PROSPERO (CRD42023379873). Results: The search strategy yielded a total of 2387 articles. A total of 1539 articles were screened after deduplication and exclusion by automation tools, leaving 473 full-text articles that were retrieved. After exclusion, 64 articles met the inclusion criteria. The preponderance of the evidence showed good to excellent reliability for biomechanical assessment of sagittal lumbo-pelvic spine alignment. Conclusions: The results of this systematic review of the literature show that sagittal radiographic analysis of spinal biomechanics and alignment of the human lumbo-pelvic spine is a reliable tool for aiding diagnosis and management in clinical settings.

Correlation of transverse rotation of the spine using surface topography and 3D reconstructive radiography in children with idiopathic scoliosis

PURPOSE

The relationship between axial surface rotation (ASR) measured by surface topography (ST) and axial vertebral rotation (AVR) measured by radiography in the transverse plane is not well defined. This study aimed to: (1) quantify ASR and AVR patterns and their magnitudes from T1 to L5; (2) determine the correlation or agreement between the ASR and AVR; and (3) investigate the relationship between axial rotation differences (ASR-AVR) and major Cobb angle.

METHODS

This is a retrospective study evaluating patients (age 8-18) with IS or spinal asymmetry with both radiographic and ST measurements. Demographics, descriptive analysis, and correlations and agreements between ASR and AVR were evaluated. A piecewise linear regression model was further created to relate rotational differences to Cobb angle.

RESULTS

Fifty-two subjects met inclusion criteria. Mean age was 14.1 ± 1.7 and 39 (75%) were female. Looking at patterns, AVR had maximal rotation at T8, while ASR had maximal rotation at T11 (r = 0.35, P = .006). Cobb angle was 24.1° ± 13.3° with AVR of - 1° ± 4.6° and scoliotic angle was 20.9° ± 11.5° with ASR of - 2.3° ± 6.6°. (ASR-AVR) vs Cobb angle was found to be very weakly correlated with a curve of less than 38.8° (r = 0.15, P = .001).

CONCLUSION

Our preliminary findings support that ASR measured by ST has a weak correlation with estimation of AVR by 3D radiographic reconstruction. This correlation may further help us to understand the application of transverse rotation in some clinical scenarios such as specific casting manipulation, padding mechanism in brace, and surgical correction of rib deformity.

3D Back Contour Metrics in Predicting Idiopathic Scoliosis Progression: Retrospective Cohort Analysis, Case Series Report and Proof of Concept

Adolescent Idiopathic Scoliosis is a 3D spinal deformity commonly characterized by serial radiographs. Patients with AIS may have increased average radiation exposure compared to unaffected patients and thus may be implicated with a modest increase in cancer risk. To minimize lifetime radiation exposure, alternative imaging modalities such as surface topography are being explored. Surface topography (ST) uses a camera to map anatomic landmarks of the spine and contours of the back to create software-generated spine models. ST has previously shown good correlation to radiographic measures. In this study, we sought to use ST in the creation of a risk stratification model. A total of 38 patients met the inclusion criteria for curve progression prediction. Scoliotic curves were classified as progressing, stabilized, or improving, and a predictive model was created using the proportional odds logistic modeling. The results showed that surface topography was able to moderately appraise scoliosis curvatures when compared to radiographs. The predictive model, using demographic and surface topography measurements, was able to account for 86.9% of the variability in the future Cobb angle. Additionally, attempts at classification of curve progression, stabilization, or improvement were accurately predicted 27/38 times, 71%. These results provide a basis for the creation of a clinical tool in the tracking and prediction of scoliosis progression in order to reduce the number of X-rays required.

Influence of kinematics of the lumbopelvic complex in hip arthroplasty dislocation: from assessment to recommendations

INTRODUCTION

In total hip arthroplasty (THA), misplacement of the implant can provide instability. Adequate orientation of the acetabular cup is a challenge due to variations in inter-individual anatomy and kinematics of the pelvis in everyday life. The aim of this study was to characterize the kinematic factors influencing the risk of dislocation in order to give recommendations for optimal placement of the cup. We hypothesized that the lack of pelvic adaptation would influence the risk of prosthetic instability and motivate adapted.

MATERIALS AND METHODS

Eighty patients with primary unilateral THA were included in a matched case-control study. Seventy-four patients were divided into two groups: group 1 (G1) consisting of patients with postoperative THA dislocation (37 patients) and group 2 (G2), without episodes of dislocation within two years postoperatively (37 patients). In both groups, spino-pelvic parameters and cup orientation were measured in standing and sitting positions with EOS^® X-ray imaging and compared to each other between 12 and 24 months post-operatively.

RESULTS

No significant difference between the two groups was found for static parameters. In a sitting position, a lack of pelvic retroversion with a significant lower variation in sacral slope was observed in group 1 (8.0° ± 9.3 for G1 versus 14.7° ± 6.2 for G2, p < 0.01). Twenty-two (59%) patients with THA instability had sacral slope variations of less than 10° versus eight (21% of patients) with stable THA (p < 0.01). Cup orientation in the Lewinnek safe zone was not significantly different (59% vs 67%, p = 0.62), and the spino-pelvic parameters and cup orientation measured did not change between the standing and sitting positions. However, only 14 (37%) cups in G1 were in the functional safe zone versus 24 (67%) in G2 (p = 0.03).

CONCLUSION

Static parameters of the sagittal spinopelvic balance have a low predictive value for prosthetic instability. Dynamic analysis is essential. Kinematic parameters must be taken into account in determining the ideal position of the cup or stem. Stiffness with locked standing or sitting pelvis must be integrated in order to determine a personalized safe zone.

LEVEL OF EVIDENCE

Level III (matched case-control study).

A fresh look at spinal alignment and deformities: Automated analysis of a large database of 9832 biplanar radiographs

We developed and used a deep learning tool to process biplanar radiographs of 9,832 non-surgical patients suffering from spinal deformities, with the aim of reporting the statistical distribution of radiological parameters describing the spinal shape and the correlations and interdependencies between them. An existing tool able to automatically perform a three-dimensional reconstruction of the thoracolumbar spine has been improved and used to analyze a large set of biplanar radiographs of the trunk. For all patients, the following parameters were calculated: spinopelvic parameters; lumbar lordosis; mismatch between pelvic incidence and lumbar lordosis; thoracic kyphosis; maximal coronal Cobb angle; sagittal vertical axis; T1-pelvic angle; maximal vertebral rotation in the transverse plane. The radiological parameters describing the sagittal alignment were found to be highly interrelated with each other, as well as dependent on age, while sex had relatively minor but statistically significant importance. Lumbar lordosis was associated with thoracic kyphosis, pelvic incidence and sagittal vertical axis. The pelvic incidence-lumbar lordosis mismatch was found to be dependent on the pelvic incidence and on age. Scoliosis had a distinct association with the sagittal alignment in adolescent and adult subjects. The deep learning-based tool allowed for the analysis of a large imaging database which would not be reasonably feasible if performed by human operators. The large set of results will be valuable to trigger new research questions in the field of spinal deformities, as well as to challenge the current knowledge.

Three-Dimensional Assessment of Vertebral Derotation in Adolescent Idiopathic Scoliosis: Review of a Surgical Technique and Its Success in Achieving Derotation in the Instrumented and Uninstrumented Spine

BACKGROUND

Three-dimensional (3D) imaging represents a novel way to assess surgical derotation maneuvers in adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To assess the following in patients with AIS undergoing derotation surgery with Lenke type 1/2 curves using 3D imaging: (1) the primary outcome of thoracic apical vertebral rotation (T-AVR) and (2) secondary outcomes of thoracic kyphosis (TK), lumbar AVR (L-AVR), and rotation of each thoracic/lumbar vertebrae.

METHODS

A retrospective, pilot study of type 1/2 AIS patients from 2017 to 2018 was performed. All patients received posterior pedicle screw/rod constructs with consistent direct vertebral derotational maneuvers and received full length SterEOS imaging with 3D reconstruction. The primary outcome of interest was T-AVR. Secondary outcomes included TK, L-AVR, and rotation at each thoracic/lumbar vertebrae.

RESULTS

Fifteen patients (mean age 15.7 ± 1.2 years, 67.0% female) were studied. The mean preoperative/postoperative Cobb angle of the major curve was 51.8° ± 14.9° (range 39.8-62.0) and 11.0° ± 5.1° (range 3.7-20.7). Mean level fused was 10.5 ± 1.2. The primary outcome of T-AVR showed significant improvement (13.8° ± 12.5° vs 9.2° ± 8.6°, P = .015) after surgery, along with secondary outcome of TK (T1-12/T4-12, P = .008/.027). Significant spontaneous rotational improvement was seen in L-AVR (P = .016). Significant improvement was also seen in 11 of 17 (64.7%) individual vertebrae (T3-8/T11-L3) (P < .05).

CONCLUSION

In Lenke Type 1/2 AIS patients undergoing surgical derotation and fusion, 3D imaging techniques captured improvements in rotation. Significant postoperative improvement was seen in T-AVR, TK, L-AVR, and rotation of the individual vertebrae T3-8/T11-L3. These pilot results warrant the study of 3D imaging in all patients with AIS and other scoliosis populations.

Radiophobia Overreaction: College of Chiropractors of British Columbia Revoke Full X-Ray Rights Based on Flawed Study and Radiation Fear-Mongering

Fears over radiation have created irrational pressures to dissuade radiography use within chiropractic. Recently, the regulatory body for chiropractors practicing in British Columbia, Canada, the College of Chiropractors of British Columbia (CCBC), contracted Pierre Côté to review the clinical use of X-rays within the chiropractic profession. A "rapid review" was performed and published quickly and included only 9 papers, the most recent dating from 2005; they concluded, "Given the inherent risks of radiation, we recommend that chiropractors do not use radiographs for the routine and repeat evaluation of the structure and function of the spine." The CCBC then launched an immediate review of the use of X-rays by chiropractors in their jurisdiction. Member and public opinion were gathered but not presented to their members. On February 4, 2021, the College announced amendments to their Professional Conduct Handbook that revoked X-ray rights for routine/repeat assessment and management of patients with spine disorders. Here, we highlight current and historical evidence that substantiates that X-rays are not a public health threat. We also point out critical and insurmountable flaws in the single paper used to support irrational and unscientific policy that discriminates against chiropractors who practice certain forms of evidence-based X-ray-guided methods.

Don't forget the pelvis: accounting for pelvic rotation in the preoperative assessment of adolescent idiopathic scoliosis

Background

Accurate radiographic assessment of adolescent idiopathic scoliosis (AIS) is crucial to achieving surgical correction, yet pelvic rotation may alter measurements. In Lenke Type 1/2 AIS patients, we conducted a pilot study to assess how pelvic rotation (i.e., the patient's position in the X-ray scanner) affected sagittal, coronal, and rotational measurements.

Methods

A retrospective, pilot study of Type 1/2 AIS patients was undertaken. Demographics and three-dimensional (3D) SterEOS imaging were obtained. Measurements were compared between two scenarios: (I) radio plane-patient's natural position in the scanner; and (II) patient plane-patient's position after correcting to the transverse plane. Sagittal, coronal, and rotational measurements were compared, including: thoracic kyphosis (TK), lumbar lordosis (LL), main thoracic (MT) and thoracolumbar/lumbar (TL-L) Cobb, and apical vertebral rotation (AVR) in the proximal thoracic (PT), MT, and TL/L regions.

Results

Of 15 patients, average age was 15.7 years and 67% were female. Average baseline pelvic obliquity was 4.0 mm and pelvis rotation was 5.1°. Significant differences were seen between the radio vs. patient plane, respectively, in the following three measurements: TK, LL, and AVR: (I) TK (T1-12: 36.5° vs. 32.8°, P=0.003; T4-12: 28.4° vs. 22.7°, P<0.001); (II) LL (L1-5: 46.6° vs. 42.8°, P=0.002; L1-S1: 58.2° vs. 55.1°, P=0.003); (III) AVR (PT-AVR: 4.0° vs. 8.2°, P=0.003; MT-AVR: -14.8° vs. -10.5°, P=0.004; TL/L-AVR: (4.5° vs. 8.7°, P=0.003). No significant differences were seen in coronal cobb angles.

Conclusions

After accounting for pelvic rotation, sagittal and rotational measurements were significantly altered. These results have implications for measurement accuracy, surgical decision-making, and postoperative monitoring.

Radiation exposure during the treatment of spinal deformities

AIMS

To benchmark the radiation dose to patients during the course of treatment for a spinal deformity.

METHODS

Our radiation dose database identified 25,745 exposures of 6,017 children (under 18 years of age) and adults treated for a spinal deformity between 1 January 2008 and 31 December 2016. Patients were divided into surgical (974 patients) and non-surgical (5,043 patients) cohorts. We documented the number and doses of ionizing radiation imaging events (radiographs, CT scans, or intraoperative fluoroscopy) for each patient. All the doses for plain radiographs, CT scans, and intraoperative fluoroscopy were combined into a single effective dose by a medical physicist (milliSivert (mSv)).

RESULTS

There were more ionizing radiation-based imaging events and higher radiation dose exposures in the surgical group than in the non-surgical group (p < 0.001). The difference in effective dose for children between the surgical and non-surgical groups was statistically significant, the surgical group being significantly higher (p < 0.001). This led to a higher estimated risk of cancer induction for the surgical group (1:222 surgical vs 1:1,418 non-surgical). However, the dose difference for adults was not statistically different between the surgical and non-surgical groups. In all cases the effective dose received by all cohorts was significantly higher than that from exposure to natural background radiation.

CONCLUSION

The treatment of spinal deformity is radiation-heavy. The dose exposure is several times higher when surgical treatment is undertaken. Clinicians should be aware of this and review their practices in order to reduce the radiation dose where possible. Cite this article: Bone Joint J 2021;103-B(4):1-7.

Accuracy of EOS Imaging Technology in Comparison to Computed Tomography in the Assessment of Vertebral Rotational Orientation in Instrumented Spines in Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective radiographic reliability study.

OBJECTIVE

The aim of this study was to assess the validity of EOS 3D imaging technology in the determination of vertebral rotations in the spine of patients with previous instrumentation.

SUMMARY OF BACKGROUND DATA

There is a lack of evidence on the accuracy of vertebral rotational measurement using EOS 3D morphological analysis in the instrumented spine.

METHODS

A retrospective review of 31 patients with adolescent idiopathic scoliosis (AIS) who underwent instrumented fusion and postoperative computed tomography (CT) scans of the spine was performed. Vertebral rotations of the apex vertebra, the uppermost (UIV) and lowermost (LIV) instrumented vertebra, the noninstrumented vertebra one level cranial to the UIV (UIV + 1) and one level caudal to LIV (LIV + 1) were determined using EOS 3D reconstruction. The vertebral rotation was also measured using reformatted CT axial images. Relative vertebral rotational difference (VRD) were calculated for UIV to apex, UIV + 1 to apex, LIV to apex, LIV + 1 to apex, UIV to LIV and UIV + 1 to LIV + 1. Paired t tests were used to compare the VRD measured using the two different imagining modalities. For values where P > 0.05, the Bland-Altman plot was used to assess the agreement between the measures. Interclass correlation (ICC) was used to determine interobserver and intraobserver reliabilities of EOS and CT measurements.

RESULTS

EOS analysis of relative VRD was found to be significantly different from that of CT for UIV to apex (P = 0.006) and UIV + 1 to apex (P = 0.003). No significant differences were found for LIV to apex (P = 0.06), LIV + 1 to apex (P = 0.06), UIV to LIV (P = 0.59) and UIV + 1 to LIV + 1 (P = 0.64). However, Bland-Altman plots showed that agreement was poor, and variance was beyond acceptable. ICC showed good interobserver and good to very good intraobserver reliability for EOS.

CONCLUSION

EOS 3D morphological analysis of VRD in the instrumented levels of the spine demonstrated significant difference and unacceptable variance in comparison to CT measurement.Level of Evidence: 4.

Associations between three-dimensional measurements of the spinal deformity and preoperative SRS-22 scores in patients undergoing surgery for major thoracic adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective study.

OBJECTIVE

To analyze the relationships between three-dimensional (3D) measurements of spinal deformity and Scoliosis Research Society-22 (SRS-22) scores in preoperative patients with major thoracic adolescent idiopathic scoliosis (AIS). Previous studies reported 2D measurements were not or only weakly correlated with preoperative SRS-22 scores. However, 2D measures do not always accurately represent the 3D deformity.

METHODS

A multicenter prospective registry of surgically treated AIS patients was reviewed for patients with right major thoracic AIS (Lenke type 1-4) who underwent biplanar radiography and completed the SRS-22 questionnaire preoperatively. For the 3D measurements, two reference frames were utilized: global (gravity/patient-based) and local (vertebra/disc-based). To obtain regional measurements, the individual segments in the appropriate reference plane were summed between the levels of interest. Patients were divided into two groups for each SRS-22 domain according to their scores: low (< 4) and high (≥ 4) score groups. Group differences and correlations with SRS-22 scores were analyzed with p < 0.01 as the threshold for significance.

RESULTS

There were 405 eligible patients (mean age, 14.4 years). The mean 3D thoracic curve was 59° (45°-115°). The only significant group difference of 3D measurements occurred in the local lumbar lordosis (LL) with a small mean difference (- 3.4°, p = 0.008) in the mental health domain. In the correlation analyses, global and local thoracic kyphosis (TK) and TK/LL ratio demonstrated significant, but weak, correlations with function and total scores (|r|< 0.2, p < 0.01).

CONCLUSION

3D measurements of scoliosis severity have only weak associations with preoperative SRS-22 scores, which might indicate a limit to the discriminative capacity of the SRS-22 within surgical range major thoracic AIS curves. Interestingly, the sagittal plane was the principle 3D plane in which significant correlations existed.

LEVEL OF EVIDENCE

II, prognostic.

Current concepts in the diagnosis and management of adolescent idiopathic scoliosis

BACKGROUND

Adolescent Idiopathic Scoliosis (AIS) is a complex 3D structural disorder of the spine that has a significant impact on a person's physical and emotionalstatus. Thus, efforts have been made to identify the cause of the curvature and improve management outcomes.

AIM

This comprehensive review looks at the relevant literature surrounding the possible aetio-pathogenesis of AIS, its clinical features, investigations, surgicalmanagement options, and reported surgical outcomes in anterior spinal fusion, posterior spinal fusion or combined approach in the treatment of AIS.

The accuracy of Cobb angle measurement on CT scan projection radiograph images

INTRODUCTION

Adolescent idiopathic scoliosis (AIS) is a spinal deformity that can affect young children. It requires frequent exposure to X-rays to monitor the deformity, which can lead to the development of radiation-induced cancer later in life. The aim of this study is to test the accuracy of using scan projection radiography (SPR) in computed tomography (CT) scans for AIS assessment. This scanning mode delivers low radiation compared with conventional radiography.

METHOD

A bespoke phantom with a 14° scoliotic spine was scanned in CT SPR mode using 18 imaging acquisitions. These images were visually evaluated against set criteria to determine their suitability for Cobb angle measurements Those deemed of insufficient quality were excluded from the study (n = 8, excluded). Cobb angle measurements were then performed on the remaining images (n = 10, included) by 13 observers.

RESULTS

On average, the difference between the measured Cobb angle and the known angle was -2.75° (SD 1.46°). The agreement between the observers was good (p = 0.861, 95% CI 0.70-0.95) and comparable to similar studies on other imaging modalities which are used for Cobb angle estimation.

CONCLUSION

CT SPR images can be used for AIS assessment with the 5° margin of error that is clinically acceptable.

IMPLICATIONS FOR PRACTICE

The outcome is promising for patients and health providers because it provides an opportunity to reduce patient dose, achieve clinically acceptable Cobb angle measurements whilst using existing (CT) technology that is available in most hospital.