Which radiographic plane should be used to quantify the distal tibia angle on weightbearing CT images?

Jules Rasschaert; Pedro Drummond; Cédric Bonte; Wolfram Grün; Enrico Pozzessere; François Lintz; Cesar de Cesar Netto; Arne Burssens

doi:10.1016/j.fas.2026.04.007

Which radiographic plane should be used to quantify the distal tibia angle on weightbearing CT images?

Foot Ankle Surg. 2026 Apr 21:S1268-7731(26)00104-9. doi: 10.1016/j.fas.2026.04.007. Online ahead of print.

Authors

Jules Rasschaert¹, Pedro Drummond², Cédric Bonte³, Wolfram Grün⁴, Enrico Pozzessere⁵, François Lintz⁶, Cesar de Cesar Netto⁵, Arne Burssens⁷

Affiliations

¹ Ghent University Hospital, Faculty of Medicine and Healthcare Sciences, Corneel Heymanslaan 10, Ghent, OVL 9000, Belgium.
² Hospital Madre Teresa, Department of Orthopaedics and Traumatology, Av. Raja Gabáglia, 1002, Gutierrez, Belo Horizonte 1093, Brazil.
³ Ghent University Hospital, Corneel Heymanslaan 10, Ghent, OVL 9000, Belgium.
⁴ 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.
⁵ Department of Orthopaedics, Duke University Hospital, 2301 Erwin Rd, Durham, NC 27710, United States.
⁶ Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA; Ramsay Healthcare Clinique de l'Union, Department of Orthopaedic Surgery, Foot and Ankle Division, Saint-Jean, Toulouse, France.
⁷ Department of Orthopaedics, Ghent University Hospital, Corneel Heymanslaan 10, Ghent , OVL 9000, Belgium. Electronic address: arne.burssens@uzgent.be.

PMID: 42091367
DOI: 10.1016/j.fas.2026.04.007

Abstract

Background: Precise quantification of distal tibial alignment is essential for planning corrective osteotomies and ankle joint replacement surgery. The lateral distal tibial angle (LDTA) is the principal radiographic parameter used for this purpose. While LDTA is increasingly measured on weightbearing cone-beam CT (WBCT) using two-dimensional coronal slices, the optimal measurement plane remains unclear.

Methods: In this retrospective comparative study, full-leg WBCT scans of patients scheduled for supramalleolar osteotomy (n = 20; mean age 47 ± 12.8 years) were analyzed. LDTA was measured on three coronal planes of the distal tibial plafond (anterior edge, mid-dome, posterior edge) and compared with semi-automated three-dimensional (3D) tibial alignment measurements as the reference standard.

Results: Mid-dome LDTA showed no significant difference from the 3D reference (p > 0.05) and demonstrated excellent agreement. Anterior measurements significantly overestimated LDTA, while posterior measurements underestimated it (both p < 0.05), with only fair agreement.

Conclusion: LDTA should be measured at the mid-dome of the distal tibial plafond on WBCT to ensure accurate and reproducible alignment assessment.

Level of evidence: Level III - Retrospective Comparative Study.

Keywords: 3D measurement; Corrective ankle surgery; Distal tibia angle; Weightbearing CT.