Interobserver Interobserver Intraclass Correlation Coefficients Research Articles

Reliability of Vertebral Pelvic Angles in Assessment of Spinal Alignment.

Reliability analysis. Vertebral pelvic angles (VPA) are gaining popularity given their ability to describe the shape of the spine. Understanding the reliability and minimal detectable change (MDC) is necessary to determine how these measurement tools should be used in the manual assessment of spine radiographs. Our aim is to assess intra- and interobserver intraclass correlation coefficients (ICC) and the MDC in the use of VPA for assessing alignment in adult spinal deformity (ASD). Three independent examiners blindly measured T1, T4, T9, L1, and L4PA twice in ASD patients with a 4-week window after the initial measurements. Patients who had undergone hip or shoulder arthroplasty, fused or transitional vertebrae, or whose hip joints were not visible on radiographs were excluded. Power analysis calculated a minimum sample size of 19. Both intra- and interobserver ICC and MDC, which denotes the smallest detectable change in a true value with 95% confidence, were calculated. Out of the 193 patients, 39 were ultimately included in the study, and 390 measurements were performed by 3 raters. Intraobserver ICC values ranged from .90 to .99. The interobserver ICC was .97, .97, .96, .95, and .92, and the MDC was 5.3°, 5.1°, 4.8°, 4.9°, and 4.1° for T1, T4, T9, L1, and L4PA, respectively. All VPAs showed excellent intra- and interobserver reliability, however, the MDC is relatively high compared to typical ranges for VPA values. Therefore, surgeons must be aware that substantial alignment changes may not be detected by a single VPA.

Preoperative planning using computed tomography in tibial plateau levelling osteotomy: A comparison with conventional radiography.

BackgroundTibial plateau levelling osteotomy (TPLO) is currently one of the most common surgical procedures for the correction of the stifle joint with a ruptured cranial cruciate ligament. TPLO is based on the preoperative tibial plateau angle (TPA); therefore, it is essential to optimise the consistency and repeatability of TPA measurements.ObjectivesThis study aims to compare computed tomography (CT) with conventional radiography in the preoperative planning of TPLO.MethodsThis prospective study included six dogs (12 hindlimbs) and 13 canine cadaveric hindlimbs. In the six beagle dogs, TPAs were measured by three radiologists using digital radiographic and CT images to evaluate the intra‐ and inter‐observer agreement. To evaluate the intra‐observer agreement of the TPA before and after surgery, and the intended angle of the postoperative TPA according to the preoperative planning method, 13 cadaveric hindlimbs were evaluated thrice at random by a single radiologist.ResultsThe intra‐ and inter‐observer intraclass correlation coefficients (ICCs) of the CT method were higher than those of the radiographic method in normal beagle dogs. The intra‐observer ICC of the CT method before and after TPLO was generally higher than that of the radiographic method in the cadaver. However, no significant difference was noted in the evaluation of the intended postoperative TPA according to the preoperative planning method.ConclusionsThe intra‐ and inter‐observer ICCs allowed for easy identification of landmarks required to consistently determine the TPA in the preoperative planning of TPLO based on CT images.

Healing pattern classification for thoracolumbar burst fractures after posterior short-segment fixation

BackgroundThoracolumbar burst fractures can be treated with posterior short-segment fixation. However, no classification can help to estimate whether the healed vertebral body will have sufficient stability after implant removal. We aimed to develop a Healing Pattern Classification (HPC) to evaluate the stability of the healed vertebra based on cavity size and location.MethodsFifty-two thoracolumbar burst fracture patients treated with posterior short-segmental fixation without fusion and followed up for an average of 3.2 years were retrospectively studied. The HPC was divided into 4 types: type I - no cavity; type II - a small cavity with or without the violation of one endplate; type III - a large cavity with or without the violation of one endplate; and type IV - a burst cavity with the violation of both endplates or the lateral cortical shell. The intraobserver and interobserver intraclass correlation coefficients (ICCs) of the HPC were assessed. The demographic characteristics and clinical outcomes of the cohort were compared between the stable group (types I and II) and the unstable group (types III and IV). Logistic regression was conducted to evaluate risk factors for unstable healing.ResultsThe intraobserver and interobserver ICCs of the HPC were 0.86 (95% CI = 0.74–0.90) and 0.77 (95% CI = 0.59–0.86), respectively. While the unstable healing group (types III and IV) accounted for 59.6% of the patients, most of these patients were asymptomatic. The preoperative Load Sharing Classification (LSC) comminution score may predict the occurrence of unstable healing (OR = 8.4, 95% CI = 2.4–29.7).ConclusionsA reliable classification for assessing the stability of a healed vertebra was developed. With type I and II healing, the vertebra is considered stable, and the implant can be removed. With type III healing, the vertebra may have healing potential, but the implant should not be removed unless type II healing is achieved. With type IV healing, the vertebra is considered extremely unstable, and instrumentation should be maintained. Assessing the LSC comminution score preoperatively may help to predict unstable healing after surgery.

Anatomical sacral slope, a new pelvic parameter, is associated with lumbar lordosis and pelvic incidence in healthy Japanese women: A retrospective cross-sectional study.

Anatomical sacral slope (a-SS), a pelvic anatomical parameter that does not require the center of the femoral head, strongly correlates with pelvic incidence (PI) during three-dimensional measurements in normal subjects. Sagittal alignment of spinal and pelvic parameters is typically evaluated using two-dimensional radiographs; however, the relationship between a-SS and PI has not been evaluated using radiographs. This study aimed to evaluate the correlation between a-SS and other spinal and pelvic parameters using radiographs. We evaluated 144 healthy women. Using sagittal radiographs, we measured lumbar lordosis (LL), thoracic kyphosis, PI, SS, pelvic tilt, and a-SS, which were defined as the angle between the superior end plate of S1 and a line perpendicular to the anterior pelvic plane. Pearson coefficients were used to determine correlations, and intraobserver and interobserver intraclass correlation coefficients (ICCs) were used for validation. There was a strong correlation between PI and a-SS (r = 0.756). Moreover, correlations between a-SS and LL and between PI and LL were similar (r = 0.661 and r = 0.554, respectively). The intraobserver ICCs were 0.884 for a-SS and 0.840 for PI. The interobserver ICCs were 0.856 for a-SS and 0.653 for PI. a-SS was strongly correlated with PI. The correlation between a-SS and LL was equivalent to the correlation between PI and LL. Moreover, the ICC for a-SS was larger than that of PI. This study suggests that a-SS is a useful new pelvic anatomical parameter that can be used instead of PI.

Navigation-assisted suture anchor insertion for arthroscopic rotator cuff repair

BackgroundSuture anchor placement for subscapularis repair is challenging. Determining the exact location and optimum angle relative to the subscapularis tendon direction is difficult because of the mismatch between a distorted arthroscopic view and the actual anatomy of the footprint. This study aimed to compare the reliability and reproducibility of the navigation-assisted anchoring technique with conventional arthroscopic anchor fixation.MethodsArthroscopic shoulder models were tested by five surgeons. The conventional and navigation-assisted methods of suture anchoring in the subscapularis footprint on the humeral head were tested by each surgeon seven times. Angular results and anchor locations were measured and compared using the Wilcoxon signed rank test. Interobserver intraclass correlation coefficients (ICCs) were analyzed among the surgeons.ResultsThe mean angular errors of the targeted anchor fixation guide without and with navigation were 17° and 2° (p < 0.05), respectively, and the translational errors were 15 and 3 mm (p < 0.05), respectively. All participants showed a narrow range of anchor fixation angular and translational errors from the original target. Among the surgeons, the interobserver reliabilities of angular errors for ICCs of the navigation-assisted and conventional methods were 0.897 and 0.586, respectively, and the interobserver ICC reliabilities for translational error were 0.938 and 0.619, respectively.ConclusionsThe navigation system may help surgeons be more aware of the surrounding anatomy and location, providing better guidance for anchor orientation, including footprint location and anchor angle.

Digital Measurements With Hallux Valgus Before and After Modified Long Oblique Osteotomy

Radiographic measurements of the hallux valgus (HV) angle (HVA) and the first intermetatarsal angle (IMA1-2) are important for assessing the severity of HV. The purpose of the present study was to digitally investigate the intraobserver and interobserver reliability of various methods for measuring HVA and IMA1-2, as well as each axis composing them, such as axes of the first proximal phalanx (PP1), the first metatarsal (MT1), and the second metatarsal (MT2) in patients with a metatarsal shaft osteotomy-modified long oblique osteotomy. Three orthopedic surgeons measured the HVA, IMA1-2, and the angles between axes of PP1, MT1, and MT2, and the digitally-set reference line (α, β, and γ, respectively) using 6 different methods for 39 patients with a minimum of 1 year of follow-up after operative treatment. The intraobserver and interobserver intraclass correlation coefficients (ICC) and agreements were calculated. Significant differences were observed within the methods with regard to preoperative HVA, IMA1-2, α, and β, and postoperative IMA1-2 and β. Intraobserver and interobserver ICC were high or very high in most methods. For HVA and IMA1-2, the method connecting the center of the head through the center of the base showed the highest agreement. For α, β, and γ, this method showed the highest agreement, more than 80% intraobserver and interobserver agreement and a discrepancy of <2°. A digital method connecting the center of the head through the center of the base was regarded as the least variable for the HV evaluation and the assessment of the radiographic results in a metatarsal shaft osteotomy-modified long oblique osteotomy.

Are pancreatic IPMN volumes measured on MRI images more reproducible than diameters? An assessment in a large single-institution cohort.

To assess reproducibility of volume and diameter measurement of intraductal papillary mucinous neoplasms (IPMNs) on MRI images. Three readers measured the diameters and volumes of 164 IPMNs on axial T2-weighted images and coronal thin-slice navigator heavily T2-weighted images using manual and semiautomatic techniques. Interobserver reproducibility and variability were assessed. Interobserver intraclass correlation coefficients (ICCs) for the largest diameter measured using manual and semiautomatic techniques were 0.979 and 0.909 in the axial plane, and 0.969 and 0.961 in the coronal plane, respectively. Interobserver ICCs for the volume measurements were 0.973 and 0.970 in axial and coronal planes, respectively. The highest intraobserver reproducibility was noted for coronal manual measurements (ICC 0.981) followed by axial manual measurements (ICC 0.969). For the diameter measurements, Bland-Altman analysis revealed the lowest interobserver variability for manual axial measurements with an average range of 95% limits of agreement (LOA) of 0.68 cm. Axial and coronal volume measurements showed similar 95% LOA ranges (8.9 cm3 and 9.4 cm3, respectively). Volume and diameter measurements on axial and coronal images show good interobserver and intraobserver reproducibility. The single largest diameter measured manually on axial images showed the highest reproducibility and lowest variability. The 95% LOA may help define reproducible size changes in these lesions using measurements from different readers. • MRI measurements by different radiologists can be used for IPMN follow-up. • Both diameter and volume measurements demonstrate excellent interobserver and intraobserver reproducibility. • Manual axial measurements show the highest interobserver reproducibility in determining size. • Axial and coronal volume measurements show similar limits of agreement. • Manual axial measurements show the lowest variability in agreement range.

A comparison of semi-automated volumetric vs linear measurement of small vestibular schwannomas

ObjectiveAccurate and precise measurement of vestibular schwannoma (VS) size is key to clinical management decisions. Linear measurements are used in routine clinical practice but are prone to measurement error. This study aims to compare a semi-automated volume segmentation tool against standard linear method for measuring small VS. This study also examines whether oblique tumour orientation can contribute to linear measurement error.Study designExperimental comparison of observer agreement using two measurement techniques.SettingTertiary skull base unit.ParticipantsTwenty-four patients with unilateral sporadic small (< 15 mm maximum intracranial dimension) VS imaged with 1 mm-thickness T1-weighted Gadolinium enhanced MRI.Main outcome measures(1) Intra and inter-observer intraclass correlation coefficients (ICC), repeatability coefficients (RC), and relative smallest detectable difference (%SDD). (2) Mean change in maximum linear dimension following reformatting to correct for oblique orientation of VS.ResultsIntra-observer ICC was higher for semi-automated volumetric when compared with linear measurements, 0.998 (95% CI 0.994–0.999) vs 0.936 (95% CI 0.856–0.972), p < 0.0001. Inter-observer ICC was also higher for volumetric vs linear measurements, 0.989 (95% CI 0.975–0.995) vs 0.946 (95% CI 0.880–0.976), p = 0.0045. The intra-observer %SDD was similar for volumetric and linear measurements, 9.9% vs 11.8%. However, the inter-observer %SDD was greater for volumetric than linear measurements, 20.1% vs 10.6%. Following oblique reformatting to correct tumour angulation, the mean increase in size was 1.14 mm (p = 0.04).ConclusionSemi-automated volumetric measurements are more repeatable than linear measurements when measuring small VS and should be considered for use in clinical practice. Oblique orientation of VS may contribute to linear measurement error.

Transcultural adaptation and validation of the Mexican version of the kidney disease questionnaire KDQOL-SF36 version 1.3.

To translate the Kidney Disease Quality of Life Short Form 36 (KDQOL-SF36) v1.3 questionnaire into the Spanish language, adapt it culturally, and validate it in the Mexican population. The translation and transcultural adaptation were performed according to the recommendations of RAND Health (translation/pilot test/back-translation). We used coefficient alpha to determine the internal consistency, intra- and interobserver intraclass correlation coefficients (ICCs) to determine the test-retest reliability, and Pearson correlation coefficients to confirm the construct validity. The questionnaires were applied to 194 Mexican on haemodialysis. In total, 37.6% lived in the northern region of Mexico, 28.9% lived in the southern region, and 33.5% lived in the central region. The average age was 54±16years, and 54.6% were male. The intra- and interobserver ICCs were ≥0.7 for most dimensions evaluated (range 0.5-0.9). The internal consistency was acceptable, with coefficient alpha values ≥0.7 for 12 of the 18 dimensions (range 0.4-0.9). The construct validity was acceptable, especially in the generic component SF36, with correlation coefficients >0.5 for most dimensions. Psychometric testing indicated that the Mexican version of the KDQOL-SF36 provided valid and reliable scores that were similar to the results obtained with the original English version.

Feasibility and reproducibility of ShearWave(TM) elastography of fetal baboon organs.

The purpose of this study was to assess the feasibility and reproducibility of transabdominal ShearWave(TM) elastography of fetal organs in pregnant baboons. Fetal ultrasounds of all pregnant baboons in a single primate research center were performed prospectively during 9 months. The visualization of fetal targeted organs (liver, proximal and distal lungs, brain white matter and periventricular gray matter) was initially performed using 2D ultrasound, and then elastography mode was activated. For each organ, three measurements were carried out by two operators. Intra-observer and inter-observer intra-class correlation coefficients (ICC) were calculated. During the study period (03/2013-12/2013), 21 pregnant baboons (21 fetuses) were included. One to three ultrasound scans were performed for each fetus. The measurements were feasible by the two operators in all cases. The intra-observer and inter-observer ICC were 0.654, 95% CI (0.606 to 0.699) and 0.645, 95% CI (0.553 to 0.721) respectively. Transabdominal ShearWave(TM) Elastography of fetal organs can be achieved in pregnant baboons. The intra-observer and inter-observer reproducibility is correct but vary according to the targeted organs.

SAT0250 Validation of a New Scoring Method for the Evaluation of Fat Lesions in the Spine of Patients with Axial Spondyloarthritis: The Canada-Denmark Fat Spondyloarthritis Spine Score (FASSS)

BackgroundFat lesions (FL) have been shown to follow resolution of inflammation in the spine of patients with axial spondyloarthritis (SpA) (1), and to predict development of new syndesmophytes (2). Thus,...

Cervical blood perfusion assessed using power Doppler‐derived estimation of fractional moving blood volume: a reproducibility study

To evaluate the reproducibility of estimation of power Doppler-derived fractional moving blood volume (FMBV) in the uterine cervix of women with uncomplicated pregnancies. Two experienced operators evaluated 30 uncomplicated singleton pregnancies at 20-24 weeks of gestation. The PDU box was positioned in a mid-sagittal view of the cervix, including the internal os and external os, in the same plane as that in which cervical length is measured. Two consecutive examinations were performed by each operator, in each of which the cervical length was measured and five consecutive good-quality images with PDU information were obtained. The region of interest (ROI) (cervix) was delineated offline and FMBV, which expresses the percentage of blood occupying the ROI, was calculated with purpose-designed software. Intra- and interobserver intraclass correlation coefficients (ICCs) and mean differences with 95% limits of agreement (LOA) were calculated. The median gestational age at examination was 22 + 0 weeks. Measurements (median ± SD) obtained for cervical length and FMBV were as follows: Operator A: 37 ± 7.4 mm and 8.11 ± 2.9%; Operator B: 37.5 ± 9.3 mm and 7.9 ± 3.3%, respectively. The intra- and interobserver ICCs for FMBV were 0.88 (95% CI, 0.75-0.94) and 0.82 (95% CI, 0.64-0.94), respectively. There was a mean difference in FMBV measurement between operators of - 0.2 ± 1.75% (95% LOA, - 3.7 to 3.2%). Reproducible assessment of cervical blood perfusion through estimation of FMBV can be achieved while cervical length is being measured.

Comparison between constrained and non-constrained Cobb techniques for the assessment of thoracic kyphosis and lumbar lordosis

Sagittal curvatures of the spine can be assessed using the constrained or non-constrained Cobb techniques. However, there is no study that specifically compares these two techniques. The objective of this study is to assess the reproducibility and clinical relevance of the non-constrained Cobb technique (non-constrained limit vertebrae) compared to the constrained Cobb technique (constrained limit vertebrae). Standing sagittal radiographs of the spine of ten adolescents with idiopathic scoliosis, ten adolescents with spondylolisthesis and ten normal adolescents were selected. Thoracic kyphosis (TK) and lumbar lordosis (LL) were measured twice by three observers using both constrained and non-constrained Cobb techniques. Pearson's correlation coefficients, as well as intra- and inter-observer intra-class correlation coefficients (ICC) were calculated. Inter-observer ICCs were similar for TK and LL with both techniques, ranging from 0.84 to 0.89. Intra-observer ICCs for both techniques were between 0.74 and 0.92 for TK, while they were between 0.87 and 0.97 for LL. The two techniques were highly correlated for the measurement of the TK (r = 0.96) and LL (r = 0.94). Computer-assisted assessment of the sagittal profile using the non-constrained Cobb technique provides excellent reproducibility. As opposed to the constrained Cobb technique, the non-constrained Cobb technique takes into account the variability in the level of transition between the TK and LL. However, adequate use of this technique requires accurate identification of the limit vertebrae in the thoracolumbar spine. Consequently, a computer-assisted technique is recommended when using the non-constrained Cobb technique.

Computerized Assessment of Sagittal Curvatures of the Spine

The tangent circles technique has been proposed as an alternative to the Cobb angle technique to assess sagittal curves of the spine. However, it has never been compared directly to the Cobb technique. This study compares the reproducibility and clinical relevance of the maximum Cobb angle and tangent circles techniques. Standing sagittal radiographs of the spine of 10 adolescents with idiopathic scoliosis, 10 adolescents with spondylolisthesis, and 10 healthy adolescents were used. Thoracic kyphosis (TK) and lumbar lordosis (LL) were measured by 3 observers using the maximum Cobb angle and the tangent circles techniques. Intra- and interobserver intraclass correlation coefficients (ICCs) were calculated. Intra- and interobserver ICCs for TK were 0.88 and 0.85, respectively, for the maximum Cobb angle technique, and 0.94 and 0.83, respectively, for the tangent circles technique. Intra- and interobserver ICCs for LL were 0.97 and 0.77, respectively, for the maximum Cobb angle technique, and 0.88 and 0.94, respectively, for the tangent circles technique. The 2 techniques were highly correlated for the measurement of the TK (r=0.93) and LL (r=0.88). Both techniques provide excellent intra- and interobserver reproducibility. Tangent circles technique may be a good alternative to the Cobb angle technique because it allows the evaluation of the global geometry of sagittal spinal curves, especially when there is limited visibility of bony structures on radiographs.