Diagnostic accuracy of measurements in progressive collapsing foot deformity using weight bearing computed tomography: A matched case-control study. Issue 7 (October 2022)

• Record Type: Journal Article
• Authors: Lintz, François; Bernasconi, Alessio; Li, Shuyuan; Lalevée, Matthieu; Fernando, Céline; Barg, Alexej; Dibbern, Kevin; de Cesar Netto, Cesar
• Is Part Of: Foot and ankle surgery. Volume 28:Issue 7(2022)
• Page Start: 912
• Page End: 918
• Publication Date: 2022-10
• Subjects: Weight bearing computed tomography -- PedCAT -- TALAS -- Foot ankle offset -- Middle facet -- Progressive collapsing foot deformity -- PCFD; Foot -- Surgery -- Periodicals; Ankle -- Surgery -- Periodicals; Ankle -- surgery -- Periodicals; Foot -- surgery -- Periodicals; Ankle -- Surgery; Foot -- Surgery; Periodicals; Electronic journals; 617.58
• DOI: 10.1016/j.fas.2021.12.012
• Languages: English
• ISSNs: 1268-7731

Abstract

Highlights: The study aimed to investigate diagnostic accuracy of known 2D and 3D measurements for PCFD in WBCT. Middle Facet Uncoverage percentage and Foot Ankle Offset were the 2 most accurate diagnostic measurements The combination of MF%> 28.7 and FAO> 4.6% yielded 100% sensitivity and 100% specificity for symptomatic PCFD. Abstract: Background: We aimed to investigate the diagnostic accuracy of known two-dimensional (2D) and three-dimensional (3D) measurements for Progressive Collapsing Foot Deformity (PCFD) in weight-bearing computed tomography (WBCT). We hypothesized that 3D biometrics would have better specificity and sensitivity for PCFD diagnosis than 2D measurements. Methods: This was a retrospective case-control study, including 28 PCFD feet and 28 controls matched for age, sex and Body Mass Index. Two-dimensional measurements included: axial and sagittal talus-first metatarsal angles (TM1A and TM1S), talonavicular coverage angle (TNCA), forefoot arch angle (FFAA), middle facet incongruence angle (MF°) and uncoverage percentage (MF%). The 3D Foot Ankle Offset (FAO) was obtained using dedicated semi-automatic software. Intra and interobserver reliabilities were assessed. Receiver Operating Characteristic (ROC) curves were calculated to determine diagnostic accuracy (Area Under the Curve (AUC)), sensitivity and specificity. Results: In PCFD, mean MF% and MF° were respectively 47.2% ± 15.4 and 13.3° ± 5.3 compared with 13.5% ± 8.7 and 5.6° ± 2.9 in controls (p < 0.001). The FAO was 8.1% ± 3.8 in PCFD and 1.4% ± 1.7 in controls (p < 0.001). AUCs were 0.99 (95%CI, 0.98–1) for MF%, 0.96 (95%CI, 0.9–1) for FAO, 0.90 (95%CI, 0.81–0.98) for MF°. For MF%, a threshold value equal or greater than 28.7% had a sensitivity of 100% and specificity of 92.8%. Conversely, a FAO value equal or greater than 4.6% had a specificity of 100% and a sensitivity of 89.2%. All other 2D measurements were significantly different in PCFD and controls (p < 0.001). Conclusions: MF% and FAO were both accurate measurements for PCFD. MF% demonstrated slightly better specificity. FAO better sensitivity. A combination of threshold values of 28.7% for MF% and 4.6% for FAO yielded 100% sensitivity and specificity.