scholarly journals Clinical Significance of Measurements in Adult Acquired Flatfoot Deformity using Weight Bearing CT: A Matched Case-Control Study

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0033
Author(s):  
Francois Lintz ◽  
Alessio Bernasconi ◽  
Matthieu Lalevée ◽  
Céline Fernando ◽  
Alexej Barg ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Case Control Study ◽  
Weight Bearing ◽  
Roc Curves ◽  
Case Control ◽  
Foot And Ankle ◽  
Adult Acquired Flatfoot Deformity ◽  
Diagnostic Power ◽  
2D And 3D ◽  
Control Study

Category: Hindfoot; Other Introduction/Purpose: Adult Acquired Flatfoot Deformity (AAFD) results in progressive foot collapse through peritalar subluxation. Numerous radiographic and Weight Bearing CT (WBCT) measurements have been described in the literature aiming to gauge the severity of the multiple components of the deformity. However, the real diagnostic power of each measurement is currently unknown. Moreover, novel measurements have recently been described such as 3D biometrics and multidimensional measurements. The objective of this case-control study was to individually assess the diagnostic accuracy of known 2D and 3D WBCT measurements and to compare it with a novel multidimensional measurement. We hypothesized that the latter would demonstrate superior diagnostic power than isolated 2D and 3D measurements. Methods: Retrospective case-control study, including 19 AAFD feet and 19 controls that were matched for age, gender and BMI (9 male, 10 female, mean age 54.4 years in both groups). All patients had standing WBCT imaging as baseline assessment of their foot pathology. 2D measurements assessed included: axial and sagittal talus-first metatarsal angles (TM1A), talonavicular coverage angle (TNCA), forefoot arch angle (FFAA) and middle facet incongruence angle (MF°) and uncoverage percentage (MF%). The 3D Foot and Ankle Offset (FAO) was calculated using semi-automatic software. A novel multiplanar biometric measurement (AAFD- MD) was calculated using a multidimensional mathematical algorithm that pooled multiplanar 2D measurements. Intra and interobserver reliabilities were assessed. Comparisons between variables were done using Student-t test or Wilcoxon rank-sum test. Receiver Operating Characteristic (ROC) curves were calculated to determine diagnostic accuracy, sensitivity and specificity of each measurement. Results: AUC for ROC curves were 1. for MF%, 0.96 for FAO, 0.94 for MF° and 0.92 for AAFD-MD. For MF%, a threshold value equal of greater than 28.1% was found to be diagnostic of AAFD with a sensitivity of 100% and specificity of 100%. FFAA were decreased in AAFD: 6.3° versus 15.2° in controls (p<0.001). Axial and sagittal TM1A were respectively 17.6° and 20.8° in AAFD, while in controls: 7.5° (p<0.001) and 6.3° (p< 0.001). The TNCA was increased in AAFD: 27.9° versus 15.6° in controls (p<0.001). In AAFD, MF° and MF% were respectively 13° and 49.4% compared with 5.3° and 10.6% in controls (p<0.001 for both). The FAO was 7.5% in AAFD and 1.1% in controls (p<0.001). Conclusion: The observed results did not confirm our hypothesis. The multidimensional measurement was not as accurate a diagnostic tool as Middle Facet uncoverage percentage which expresses the amount of subluxation of the MF. In that respect, this could mean that congruency of the middle facet could be the last frontier between asymptomatic Pes Planovalgus and symptomatic AAFD, leading to progressive foot collapse, secondarily affecting the FAO. These results also give insight into the meaning of the FAO, which appears here to be a more general assessment of the Foot and Ankle Complex alignment, rather than a marker for a specific pathology.

scholarly journals Evaluation of a Weightbearing CT Artificial Intelligence-based Automatic Measurement for Hallux Valgus: A Case-Control Study

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0003
Author(s):  
Jonathan Day ◽  
Francois Lintz ◽  
Martinus Richter ◽  
Céline Fernando ◽  
Scott J. Ellis ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Hallux Valgus ◽  
Case Control Study ◽  
Weight Bearing ◽  
Intraclass Correlation ◽  
Automatic Measurement ◽  
Case Control ◽  
Foot And Ankle ◽  
Beta Version ◽  
Control Study

Category: Bunion; Other Introduction/Purpose: Cone Beam Weight Bearing CT (WBCT) is gaining traction, particularly in the foot and ankle, due to the ability to perform natural stance weight bearing 3D scans. However, the resulting wealth of 3D data renders daily clinical use time consuming. Therefore, reliable automatic measurements are indispensable in order to make best use of the technology. The aim of this study was to evaluate a beta-version WBCT artificial intelligence (AI) automatic measurement system for the M1-M2 intermetatarsal angle (IMA), which is applicable in the absence of metallic hardware in the foot and ankle. We hypothesized that automatic measurements would correlate well with human measurements, and that software reproducibility would be better and close to perfect compared to manual measurements. Methods: In this retrospective case-control study, 90 feet were included from patients who underwent WBCT scans during routine follow up: 44 feet (90.9% female, mean age 54 years) with symptomatic hallux valgus (HV), 46 controls (76.1% female, mean age 49 years). Patients were excluded if they had history of surgery or trauma involving the first or second metatarsals, hallux rigidus, or presence of metal in their foot/ankle. IMA was measured manually on Digitally Reconstructed Radiographs (DRR IMA) and automatically with AI software producing auto 2D (ground plane projection) and 3D (multiplanar) measurements. Each IMA DRR was measured by two independent raters twice to calculate intraclass correlation coefficients (ICCs). To assess intra- software reliability, AI software measurements were made twice on each dataset. Manual and automatic measurements were compared between HV and control groups. Failures of the AI software to produce a measurement were recorded. Results: Mean values for controls were 8.6° +-1.8° (range, 5°-14°) for the manually measured DRR IMA, 9.3° +-2.8° (range, 3°- 17°) for auto 2D, and 9.2° +-2.6° (range, 3°-16°) for auto 3D IMA measurements. Compared to controls, HV patients demonstrated significantly increased IMA (p<0.0001): 14.2° +-2.7° (range, 8°-21°) for the manually measured DRR IMA, 15.4°+- 4.4° (range, 8°-26°) for auto 2D, and 15.1° +-4.1° (range 8°-28°) for auto 3D IMA measurements. There were strong correlations (r=0.75 and r=0.80) between manual and auto 2D and 3D measurements. Intraobserver and interobserver ICCs for DRR IMA were 0.96 and 0.90, respectively, and the intra-software ICCs for the AI were near 1.0 for both auto 2D and auto 3D IMA. The AI software failed in 32.3% cases. Conclusion: Our results demonstrated strong correlation between a WBCT Artificial Intelligence based automatic measurement for IMA with human measurements, with the ability to distinguish HV from control with close to 100% repeatability. However, the number of failures was still high due to the early stage beta-version of the algorithm tested. While these early results are promising, further developments are warranted in order to improve usability of this tool in daily practice, especially in the presence of metal hardware. [Figure: see text]

scholarly journals Diagnostic accuracy and validity of three manual examination tests to identify alar ligament lesions: results of a blinded case-control study

2018 ◽  
Vol 27 (2) ◽  
pp. 83-91 ◽  
Author(s):  
Piekartz Harry Von ◽  
Rakan Maloul ◽  
Marisa Hoffmann ◽  
Toby Hall ◽  
Med Martin Ruch ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Case Control Study ◽  
Case Control ◽  
Alar Ligament ◽  
Manual Examination ◽  
Control Study

scholarly journals Accuracy of a Self-monitoring Test for Identification and Monitoring of Age-related Macular Degeneration: A Diagnostic Case-control Study

2018 ◽  
Vol 12 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Martin K. Schmid ◽  
Livia Faes ◽  
Lucas M. Bachmann ◽  
Michael A. Thiel
Keyword(s):  
Diagnostic Accuracy ◽  
Case Control Study ◽  
Case Control ◽  
Age Related Macular Degeneration ◽  
Index Test ◽  
Vernier Acuity ◽  
Self Monitoring ◽  
Age Related ◽  
Control Study ◽  
Wet Amd

Objective: To evaluate diagnostic accuracy of a new self-monitoring device using a Vernier hyperacuity alignment task. Method: A total of 11 wet Age-Related Macular Degeneration (AMD) patients and 9 controls contributing 37 eyes were consecutively enrolled into this prospective diagnostic case-control study at the retina centre of the Cantonal Hospital Lucerne, Switzerland. Vernier acuity testing (index test) and Optical Coherence Tomography (OCT, reference test) were performed in all participants. OCT scans were evaluated and graded by a retinal specialist masked to diagnosis and index test results. Candidate parameters of the index test to be used as the diagnostic statistic were identified using a bootstrap procedure. Ten parameters remaining were further assessed in univariate analyses. The overall Standard Deviation (SD) of absolute distances across all four axes of the Vernier acuity test provided the highest area under the Receiver Operating Characteristics (ROC) curve and was therefore selected. Results: Mean age of patients with wet AMD was 81.2 years (SD 4.99), mean numbers of letters were 67.4 (SD 14.1). The proportion of women was similar in both groups (controls: 88%, wet AMD: 72%). The area under the ROC curve was 0.87 (95% confidence interval CI: 0.75- 0.99) indicating excellent discrimination. Best accuracy was reached at a cut-off value of 0.64 with a sensitivity of 75% and a specificity of 94%. Conclusion: This diagnostic case-control study of a new screening device for AMD shows acceptable diagnostic accuracy. The promising preliminary data of this study call for further upstream evaluations in reasonably sized clinical studies.

scholarly journals New parathyroid function index for the differentiation of primary and secondary hyperparathyroidism: a case-control study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yanhong Guo ◽  
Qin Wang ◽  
Chunyan Lu ◽  
Pianpian Fan ◽  
Jing Li ◽  
...  
Keyword(s):  
Vitamin D ◽  
Secondary Hyperparathyroidism ◽  
Vitamin D Deficiency ◽  
Likelihood Ratio ◽  
Case Control Study ◽  
Case Control ◽  
Function Index ◽  
Parathyroid Function ◽  
Diagnostic Power ◽  
Control Study

Abstract Background Patients with primary hyperparathyroidism (PHPT) may be asymptomatic, and some may present with normocalcemic PHPT (NPHPT). Patients with vitamin D deficiency may also be asymptomatic, with normal calcium and elevated PTH concentrations. These latter patients are usually diagnosed with vitamin D deficiency-induced secondary hyperparathyroidism (VD-SHPT). Therefore, it is very difficult to distinguish PHPT and NPHPT from VD-SHPT based on calcium or PTH concentrations in clinical settings. In this case-control study, we aimed to verify the diagnostic power of a new parathyroid function index (PFindex = Ca*PTH/P). Methods This study enrolled 128 patients with surgically and pathologically confirmed PHPT, including 36 with NPHPT, at a hospital in West China between January 2009 and September 2017. Thirty-seven patients with VD-SHPT and 45 healthy controls were selected from the population of a cross-sectional epidemiological study as the SHPT and healthy groups, respectively. We used the PFindex to describe the characteristics of PHPT, NPHPT, and VD-SHPT.. Differences between the four groups were compared, and a receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic power of PFindex. Results The PHPT group had the highest PFindex (454 ± 430), compared to the other three groups (NPHPT: 101 ± 111; SHPT: 21.7 ± 6.38; healthy: 12.2 ± 2.98, all p < 0.001). A PFindex cut-off value of 34 yielded sensitivity and specificity rates of 96.9 and 97.6% and of 94.4 and 94.6% for the diagnoses of PHPT and NPHPT, respectively. The use of a PFindex > 34 to differentiate NPHPT from VD-SHPT yielded the highest positive likelihood ratio and lowest negative likelihood ratio. Conclusion The PFindex provided excellent diagnostic power for the differentiation of NPHPT from VD-SHPT. This simple tool may be useful for guiding timely decision-making processes regarding the initiation of vitamin D treatment or surgery for PHPT.

scholarly journals Maximizing efficiency and diagnostic accuracy triage of acute stroke patients: A case-control study

2016 ◽  
Vol 22 (3) ◽  
pp. 304-309 ◽  
Author(s):  
Scott L Zuckerman ◽  
Ahilan Sivaganesan ◽  
Chi Zhang ◽  
Michael C Dewan ◽  
Peter J Morone ◽  
...  
Keyword(s):  
Case Control Study ◽  
Roc Curves ◽  
Case Control ◽  
National Institutes Of Health ◽  
Vessel Occlusion ◽  
Sum Score ◽  
Comprehensive Stroke Center ◽  
Stroke Center ◽  
High Degree ◽  
Control Study

Background Recent data have demonstrated that mechanical thrombectomy (MT) is beneficial for patients presenting within zero to six hours of symptom onset after stroke. However, transferring all patients with possible strokes for endovascular therapy and MT would be inefficient and costly. We conducted a case-control study to identify a subset of the National Institutes of Health Stroke Scale (NIHSS) to identify patients with large-vessel occlusion (LVO) to a high degree of specificity, in order to select those patients for whom transfer is most appropriate. Methods Acute code stroke alerts presenting to a comprehensive stroke center from 2012 to 2013 (779) and corresponding NIHSS were collected. All patients had vascular imaging and 125 demonstrated LVO (cases) and were compared to 272 small-vessel strokes and stroke mimics (controls). Demographics of both groups and modified receiver operating characteristic (ROC) curves were generated for each combination of three NIHSS items to optimize specificity of LVO for those who would benefit from MT. Results The average NIHSS of cases was higher than controls (12.5 vs. 6.5, p < 0.0001). The subset of three NIHSS items with the largest modified AUC (optimized for specificity) was maximum “Arm,” “Sensory,” and “Extinction.” Using a cutoff of seven out of a total 10 possible points, the sum score for these items has 90.2% specificity and 16.0% sensitivity for LVO. Conclusion We present a validated three-question subset of the NIHSS for those who would benefit from MT with a high degree of specificity.

Risk Factors Associated With Nonunion After Elective Foot and Ankle Reconstruction: A Case-Control Study

2017 ◽  
Vol 56 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Kyle R. Moore ◽  
Michael A. Howell ◽  
Karl R. Saltrick ◽  
Alan R. Catanzariti
Keyword(s):  
Risk Factors ◽  
Case Control Study ◽  
Case Control ◽  
Foot And Ankle ◽  
Factors Associated ◽  
Control Study
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