System Maintenance Notice

Please note that maintenance work is scheduled between 4 AM and 5 AM - CET. During this time, you may experience reduced performance. Thanks for your patience.

Publications

Journal Article Epublish 1 citation

PubMed: 41783721 DOI: 10.1177/24730114261422230

Automated vs Manual Measurement of Middle Facet Subluxation in Progressive Collapsing Foot Deformity Using Weightbearing CT.

Foot Ankle Orthop 11(1):24730114261422230

Authors: Wolfram Grün, Francois Lintz, Emily J Luo, Carla Carfi, Enrico Pozzessere, Antoine Acker, Pierre-Henri Vermorel, Cesar de Cesar Netto

Affiliations

  • Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA.
  • Department of Orthopaedic Surgery, Østfold Hospital Trust, Grålum, Norway.
  • Division of Orthopaedic Surgery, Oslo University Hospital, Oslo, Norway.
  • Ramsay Healthcare Clinique de l'Union, Saint-Jean, Toulouse, France.
  • Ankle and Foot Unit, Humanitas San Pio X Hospital, Milan, Italy.
  • Department of Biomedical Sciences, Humanitas University, Milan, Italy.
  • Centre of Foot and Ankle Surgery, Clinique La Colline, Geneva, Switzerland.
  • Inter-university Laboratory of Human Movement Science, University Lyon-University Jean-Monnet Saint-Étienne, Saint-Etienne, France.
  • Department of Orthopaedic Surgery, University Hospital Centre of Saint-Étienne, Saint-Étienne, France.

Abstract

BACKGROUND

Peritalar subluxation (PTS) is a key driver of symptomatic progression in progressive collapsing foot deformity (PCFD). Middle facet subluxation (MFS) is an established weightbearing computed tomography (WBCT) parameter to quantify PTS, but manual measurement is time consuming and dependent on rotation and slice selection. Automated WBCT-based tools may streamline measurement and improve reproducibility.

METHODS

Retrospective, institutional review board-approved study including 66 PCFD patients and 25 normally aligned controls. Manual MFS (mMFS) was measured by 2 fellowship-trained surgeons, repeated for intra- and interrater reliability. Automated MFS (aMFS) was calculated using a developer-level version of BoneLogic (Disior). Agreement was assessed using paired tests, correlations, intraclass correlation coefficients (ICCs), and Bland-Altman analysis.

RESULTS

In PCFD, no significant difference was found between mMFS and aMFS (36.4% ± 15.2% vs 37.4% ± 20.7%, P = .83). Controls showed lower automated values (18.6% ± 8.4% vs 11.9% ± 10.7%, P < .01). Across all cases, manual interrater ICC was 0.80, manual-automated ICC 0.76, and manual intrarater ICC 0.72. Agreement was moderate-to-good in PCFD but weaker in controls. Correlation between mMFS and aMFS was strong overall and moderate in PCFD. Bland-Altman analysis demonstrated minimal bias in PCFD (0.99%), within the a priori 1% acceptability threshold, whereas bias exceeded this threshold in controls (6.66%).

CONCLUSION

This study evaluates agreement between manual and a predominantly automated WBCT-based MFS measurement. Automated MFS showed moderate to good agreement and interchangeability with manual methods in PCFD, whereas agreement was limited in controls. These findings support the potential clinical and research utility of automated MFS in PCFD class D assessment, following external validation.

LEVEL OF EVIDENCE

Level III, diagnostic study.

MeSH

Congenital Abnormalities, Research Design, Bias, Foot, Foot Deformities