3D Biometrics for Hindfoot Alignment Using Weightbearing Computed Tomography

2019 ◽  
Vol 40 (6) ◽  
pp. 720-726 ◽  
Author(s):  
Jian Zhong Zhang ◽  
François Lintz ◽  
Alessio Bernasconi ◽  
Shu Zhang ◽  

Background: Weightbearing computed tomography (WBCT) is a useful tool for the assessment of hindfoot alignment (HA). Foot ankle offset (FAO) is a recently introduced parameter, determined from WBCT images using semiautomatic software. The aim of this study was to determine the clinical relevance and reproducibility of FAO for the evaluation of HA. Methods: A prospective comparative study was performed on consecutive patients requiring bilateral WBCT between September 2017 and April 2018. Based on the clinical assessment of HA, patients were divided into 3 groups: (1) normal alignment group (G1), (2) valgus (G2), and (3) varus (G3). FAO and long axial view (HACT) were measured on WBCT images, and the groups were compared. The reproducibility of FAO and HACT was determined through intraclass correlation coefficients (ICCs). Regression analysis was performed to investigate the correlation between the 2 methods. Overall, 249 feet (126 patients) were included (G1 = 115, G2 = 78, and G3 = 56 feet). Results: The mean values for FAO and HACT were 1.2% ± 2.8% and 3.9 ± 3.1, respectively, in G1; 8.1% ± 3.7% and 9.7 ± 4.9 in G2; and −6.6% ± 4.8% and −8.2 ± 6.6 in G3. Intra- and interobserver reliability was 0.987 and 0.988 for FAO and 0.949 and 0.949 for HACT, respectively. There was a good linear correlation between HACT and FAO ( R2 = 0.744), with a regression slope of 1.064. Conclusions: WBCT was a useful method for the characterization of HA. FAO was reproducible and correlated well with physical examination. Level of Evidence: Level II, prospective comparative study.

2019 ◽  
Vol 41 (2) ◽  
pp. 154-159 ◽  
Author(s):  
Matthew S. Conti ◽  
Aoife MacMahon ◽  
Scott J. Ellis ◽  
Elizabeth A. Cody

Background: Despite the importance of shoe wear to patients with hallux valgus (HV), few studies have investigated changes in foot width following surgery in this population. The purpose of our study was to determine if the modified Lapidus procedure would effectively decrease foot width in patients with HV. Methods: Thirty-one feet (19 left, 12 right) in 30 patients (29 females, 1 male) who underwent a modified Lapidus procedure in combination with a modified McBride and Akin osteotomy for treatment of HV were included in the study. All patients had preoperative and at least 5-month postoperative imaging, consisting of both weightbearing radiographs and computed tomography (WBCT) scans, which were used to measure bony and soft tissue foot widths pre- and postoperatively by 2 independent observers. Results: Intraclass correlation coefficients (ICCs) demonstrated high interobserver reliability (all ICCs >0.90). Bony foot width decreased significantly, by a mean of 8.9 mm (9.1%) on radiographs and 7.9 mm (8.4%) on WBCT scans ( P < .001). The soft tissue foot width also decreased significantly, by a mean of 6.9 mm (6.3%) on radiographs and 6.7 mm (6.4%) on WBCT scans ( P < .001). Changes in the hallux valgus angle and intermetatarsal angle correlated with changes in bony foot width on WBCTs (both r > 0.4, P < .02). Conclusions: The modified Lapidus procedure in combination with a modified McBride and Akin osteotomy resulted in statistically significant changes in both bony and soft tissue foot width. Patients should be counseled that foot width decreases, on average, by 0.5 to 1 cm. Level of Evidence: Level III, comparative series.


2021 ◽  
pp. 107110072110141
Author(s):  
Christopher B. Arena ◽  
Yantarat Sripanich ◽  
Richard Leake ◽  
Charles L. Saltzman ◽  
Alexej Barg

Background: Hindfoot alignment view (HAV) radiographs are widely utilized for 2-dimensional (2D) radiographic assessment of hindfoot alignment; however, the development of weightbearing computed tomography (WBCT) may provide more accurate methods of quantifying 3-dimensional (3D) hindfoot alignment. The aim of this study was to compare the 2D calcaneal moment arm measurements on HAV radiographs with WBCT. Methods: This retrospective cohort study included 375 consecutive patients with both HAV radiographs and WBCT imaging. Measurement of the 2D hindfoot alignment moment arm was compared between both imaging modalities. The potential confounding influence of valgus/varus/neutral alignment, presence of hardware, and motion artifact were further analyzed. Results: The intraclass correlation coefficients (ICCs) of interobserver and intraobserver reliability for measurements with both imaging modalities were excellent. Both modalities were highly correlated (Spearman coefficient, 0.930; P < .001). HAV radiographs exhibited a mean calcaneal moment arm difference of 3.9 mm in the varus direction compared with WBCT (95% CI, –4.9 to 12.8). The difference of hindfoot alignment between both modalities was comparable in subgroups with neutral/valgus/varus alignment, presence of hardware, and motion artifact. Conclusion: Both HAV radiographs and WBCT are highly reliable and highly correlated imaging methods for assessing hindfoot alignment. Measurements were not influenced by severe malalignment, the presence of hardware, or motion artifact on WBCT. On average, HAV radiographs overestimated 3.9 mm of varus alignment as compared with WBCT. Level of Evidence: Level III, retrospective comparative study.


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0010
Author(s):  
Alessio Bernasconi ◽  
Lucy Cooper ◽  
Shirley Lyle ◽  
Shelain Patel ◽  
Nicholas Cullen ◽  
...  

Category: Basic Sciences/Biologics, Hindfoot Introduction/Purpose: Pes cavovarus is a three-dimensional complex foot deformity variably involving a varus hindfoot, high longitudinal arch and forefoot adduction. Two-dimensional radiographs may be flawed by rotational bias and operator-related bias, while standard computed tomography (CT) cannot be perfomed in loading conditions. Three-dimensional (3D) cone beam weightbearing computed tomography (WBCT) may overcome these drawbacks, obtaining physiological weightbearing images with low-dose radiation. New 3D semiautomatic tools have been proposed to measure hindfoot alignment, but reliability in pes cavovarus has never been tested. The aim of this study was to assess intra and interobserver reliability of 3D biometrics on WBCT imaging in pes cavovarus. Our hypothesis was that foot and ankle offset, calcaneal offset and hindfoot angle were reliable measures regardless of type and severity of deformity. Methods: Cone beam WBCT anonymised datasets from 34 pes cavovarus (PC) (17 neurological, 17 non-neurological) and 17 normal feet were retrospectively reviewed. All WBCTs were performed during routine investigation. Inclusion criteria consisted of no previous ipsilateral foot/ankle surgery and ability to heel weightbear. Three foot and ankle surgeons (blinded to patient diagnosis) independently measured the following variables on 51 feet: foot and ankle offset (FAO), calcaneal offset (CO) and hindfoot angle (HA) using dedicated software. Each observer repeated all measurements two-weeks apart. The Shapiro–Wilk test was used to assess normality of data distribution. The Pearson or Spearman correlation test and Intraclass Correlation Coefficients (ICCs) and were used to assess intra and interobserver reliability, respectively. Subgroup analysis was performed to assess whether clinical diagnosis (neurological PC, non-neurological PC, normal controls) or severity of varus deformity (4 groups based on FAOs 25th, 50th and 75th centiles) could affect reliability of FAO measurements. Results: Intra and interobserver reliability for FAO (r= 0.98; ICC: 0.98), CO (r=0.94; ICC 0.89) and HA measurements (r=0.93; ICC:0.89) were excellent. Subgroup analysis showed that FAOs intra and interobserver reliability remained excellent in neurological PC (r= 0.96; ICC: 0.97), non-neurological PC (r=0.95; ICC: 0.96) and normal feet (r=-0.97; ICC: 0.94). Also, intraobserver (r=0.95, r=0.76, r=0.82 and r=0.92 for FAO >0%, from -7% to 0%, from -13% to -7%, and <-13%, respectively) and interobserver reliability for FAO measurements (ICC: 0.78, ICC: 0.76, ICC: 0.85 and ICC: 0.92) scored excellent regardless of the deformity. Conclusion: This study confirms that three-dimensional semiautomatic tools used on weightbearing CT datasets have excellent intra and interobserver reliability in the assessment of hindfoot alignment in pes cavovarus. The nature and severity of the deformity does not affect the reliability of the measurements. This infers that these 3D biometric tools on WBCT images can be reliably used in severe neurological cavovarus feet to evaluate and monitor cavovarus deformity and assess response to intervention.


1991 ◽  
Vol 34 (5) ◽  
pp. 989-999 ◽  
Author(s):  
Stephanie Shaw ◽  
Truman E. Coggins

This study examines whether observers reliably categorize selected speech production behaviors in hearing-impaired children. A group of experienced speech-language pathologists was trained to score the elicited imitations of 5 profoundly and 5 severely hearing-impaired subjects using the Phonetic Level Evaluation (Ling, 1976). Interrater reliability was calculated using intraclass correlation coefficients. Overall, the magnitude of the coefficients was found to be considerably below what would be accepted in published behavioral research. Failure to obtain acceptably high levels of reliability suggests that the Phonetic Level Evaluation may not yet be an accurate and objective speech assessment measure for hearing-impaired children.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Minjeong Kim ◽  
Ja Young Oh ◽  
Seon Ha Bae ◽  
Seung Hyeun Lee ◽  
Won Jun Lee ◽  
...  

AbstractWe evaluated the reliability and validity of the 5-scale grading system to interpret the point-of-care immunoassay for tear matrix metalloproteinase (MMP)-9. Six observers graded red bands of photographs of the readout window in MMP-9 immunoassay kit (InflammaDry) two times with 2-week interval based on the 5-scale grading system (i.e. grade 0–4). Interobserver and intraobserver reliability were evaluated using intraclass correlation coefficients. The interobserver agreements were analyzed according to the severity of tear MMP-9 expression. To validate the system, a concentration calibration curve was made using MMP-9 solutions with reference concentrations, then the distribution of MMP-9 concentrations was analyzed according to the 5-scale grading system. Both intraobserver and interobserver reliability was excellent. The readout grades were significantly correlated with the quantified colorimetric densities. The interobserver variance of readout grades had no correlation with the severity of the measured densities. The band density continued to increase up to a maximal concentration (i.e. 5000 ng/mL) according to the calibration curve. The difference of grades reflected the change of MMP-9 concentrations sensitively, especially between grade 2 and 4. Together, our data indicate that the subjective 5-scale grading system in the point-of-care MMP-9 immunoassay is an easy and reliable method with acceptable accuracy.


Author(s):  
Ian S. MacLean ◽  
Taylor M. Southworth ◽  
Ian J. Dempsey ◽  
Neal B. Naveen ◽  
Hailey P. Huddleston ◽  
...  

AbstractThe tibial tubercle–trochlear groove (TT-TG) distance is currently utilized to evaluate knee alignment in patients with patellar instability. Sagittal plane pathology measured by the sagittal tibial tubercle–trochlear groove (sTT-TG) distance has been described in instability but may also be important to consider in patients with cartilage injury. This study aims to (1) describe interobserver reliability of the sTT-TG distance and (2) characterize the change in the sTT-TG distance with respect to changing knee flexion angles. In this cadaveric study, six nonpaired cadaveric knees underwent magnetic resonance imaging (MRI) studies at each of the following degrees of knee flexion: −5, 0, 5, 10, 15, and 20. The sTT-TG distance was measured on the axial T2 sequence. Four reviewers measured this distance for each cadaver at each flexion angle. Intraclass correlation coefficients were calculated to determine interobserver reliability and reproducibility of the sTT-TG measurement. Analysis of variance (ANOVA) tests and Friedman's tests with a Bonferroni's correction were performed for each cadaver to compare sTT-TG distances at each flexion angle. Significance was defined as p < 0.05. There was excellent interobserver reliability of the sTT-TG distance with all intraclass correlation coefficients >0.9. The tibial tubercle progressively becomes more posterior in relation to the trochlear groove (more negative sTT-TG distance) with increasing knee flexion. The sTT-TG distance is a measurement that is reliable between attending surgeons and across training levels. The sTT-TG distance is affected by small changes in knee flexion angle. Awareness of knee flexion angle on MRI is important when this measurement is utilized by surgeons.


2010 ◽  
Vol 80 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Yi Liu ◽  
Raphael Olszewski ◽  
Emanuel Stefan Alexandroni ◽  
Reyes Enciso ◽  
Tianmin Xu ◽  
...  

Abstract Objective: To determine the accuracy of volumetric analysis of teeth in vivo using cone-beam computed tomography (CBCT). Materials and Methods: The physical volume (Vw) of 24 bicuspids extracted for orthodontic purposes (16 were imaged with the I-CAT and 8 with the CB MercuRay) were determined using the water displacement technique. Corresponding pretreatment CBCT image data were uploaded into Amira 4.0 for segmentation and radiographic volume (Va). All measurements were performed twice by two observers. The statistical difference between Vw and Va was assessed using a paired t-test. The intraobserver and interobserver reliability were determined by calculating Pearson correlation coefficients and intraclass correlation coefficients. Results: The overall mean Vw of teeth specimens was 0.553 ± 0.082 cm3, while the overall mean Va was 0.548 ± 0.079 cm3 (0.529 ± 0.078 cm3 for observer 1 and 0.567 ± 0.085 cm3 for observer 2). There were statistically significant differences between Va and Vw (P &lt; .05). Between observer 1 and observer 2, Va measurements were statistically significantly different (P &lt; .05). The interobserver and intraobserver correlation coefficient for Vw was high. Lastly, surface smoothing reduced the volume by 3% to 12%. Conclusions: In vivo determination of tooth volumes from CBCT data is feasible. The measurements slightly deviate from the physical volumes within −4% to 7%. Smoothing operations reduce volume measurements. Currently, no requirements for accuracy of volumetric determinations of tooth volume have been established.


Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Zeki Dostbil ◽  
Yusuf Dag ◽  
Ozlem Cetinkaya ◽  
Mehmet Akdag ◽  
Bekir Tasdemir

Objectives.The measurement of mucociliary transport velocity by rhinoscintigraphy with Tc-99m-macroaggregated albumin (99mTc-MAA) is reliable measure of mucociliary clearance. The aim of this study is to assess the intratest, interobserver, and intraobserver reproducibility of nasal mucociliary transport rate (NMTR) measurement.Materials and Methods.Twenty-two subjects were evaluated to determine intratest reproducibility and a group of 35 subjects was examined to determine inter- and intraobserver reproducibility. Rhinoscintigraphy with99mTc-MAA was used to measure NMTR in all study subjects. Paired NMTR measurements were compared using a range of statistical methodologies. Intraclass correlation coefficients (ICC) and repeatability coefficients and Bland-Altman plots were applied to assess the degree of intratest, interobserver, and intraobserver variation.Results.Statistical analysis of test and retest experiments demonstrated the statistical equivalence of intratest NMTR measurements, interobserver NMTR measurements, and intraobserver NMTR measurements. The intratest ICC, interobserver ICC, and intraobserver ICC were 0.96, 0.83, and 0.91, respectively, indicating that intratest and intraobserver reproducibility are excellent and interobserver reproducibility is good.Conclusions.Rhinoscintigraphy using99mTc-MAA results in highly reproducible measurement of NMTR. The use of radionuclide imaging in measuring NMTR results in excellent intratest and intraobserver reproducibility and good interobserver reliability.


2020 ◽  
pp. 193229682097465
Author(s):  
Joel Willem Johan Lasschuit ◽  
Jill Featherston ◽  
Katherine Thuy Trang Tonks

Background: In an era of increasing technology and telehealth utilization, three-dimensional (3D) wound cameras promise reliable, rapid, and touch-free ulceration measurements. However, reliability data for commercially available devices in the diabetes foot service setting is lacking. We aimed to evaluate the reliability of diabetes-related foot ulceration measurement using a 3D wound camera in comparison to the routinely used ruler and probe. Method: Participants were prospectively recruited from a tertiary interdisciplinary diabetes foot service. Ulcerations were measured at each visit by two blinded observers, first by ruler and probe, and then using a 3D wound camera twice. Reliability was evaluated using intraclass correlation coefficients (ICC). Measurement methods were compared by Pearson correlation. Results: Sixty-three ulcerations affecting 38 participants were measured over 122 visits. Interobserver reliability of ruler measurement was excellent for estimated area (ICC 0.98, 95% CI 0.97-0.98) and depth (ICC 0.93, 95% CI 0.90-0.95). Intraobserver and interobserver reliability of the 3D wound camera area was excellent (ICC 0.96, 95%CI 0.95-0.97 and 0.97 95% CI 0.96-0.98, respectively). Depth was unrecordable in over half of 3D wound camera measurements, and reliability was inferior to probe measurement. Area correlation between methods was good ( R = 0.88 and 0.94 per observer); however, depth correlation was poor ( R = 0.49 and 0.65). Conclusions: 3D wound cameras offer practical advantages over ruler-based measurement. In diabetes-related foot ulceration, the reliability and comparability of area measurement was excellent across both methods, although depth was more reliably obtained by the probe. These limitations, together with cost, are important considerations if implementing this technology in diabetes foot care.


2000 ◽  
Vol 122 (2) ◽  
pp. 212-215 ◽  
Author(s):  
Fatma Tulin Kayhan ◽  
David Zurakowski ◽  
Steven D. Rauch

The Toronto Facial Grading System (TFGS) is an observer scale for rating facial nerve dysfunction. The TFGS scores aspects of resting symmetry, symmetry of voluntary movement, and synkinesis for each division of the face (subscores) and then provides calculated total scores and an overall composite score of facial function. The developers of the scale have validated its sensitivity for identifying small changes in facial dysfunction and the independence of the different components measured. Herein we report our results in a study of interob-server reliability using the TFGS. Twenty-five patients from the Massachusetts Eye and Ear Infirmary Facial Nerve Center with varying degrees of facial paresis, paralysis, and synkinesis were videotaped, and the video recordings were scored by 5 independent observers using the TFGS. Intraclass correlation coefficients (κ) and 95% confidence intervals were calculated for subscores and for each total and composite score. Intraclass correlation coefficients ranged from 0.59 to 0.85, all considered substantial to near-perfect agreement between observers. We believe the TFGS is superior to other scales by virtue of its sensitivity, comprehensiveness, ease of use, and interobserver reliability. The TFGS presently appears to be the best option in those situations in which accurate and precise documentation of facial function is required.


Sign in / Sign up

Export Citation Format

Share Document