Letter to the editor - The impact of surgeons’ visual angle misperception on acetabular cup positioning accuracy: a retrospective multicenter cohort study

Sep 29, 2026

Uploaded by Mabel

Correspondence addressing the human-factors mechanism of surgeons’ visual angle misperception and its potential to shift acetabular cup orientation during total hip arthroplasty. The letter evaluates how visual tasks, benchtop measurements, and multicenter cohorts reveal that experience can narrow variability without eliminating systematic bias. It recommends improved harmonization of angle definitions and coordinate systems, clearer radiographic versus anatomical conversion rules, stronger agreement reporting for orientation estimation, and mixed-effects modeling to separate viewpoint effects while handling cluster imbalance.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Letter to the editor

Human-factors mechanism and transparency

Measurement alignment and definition harmonization

Orientation estimation and agreement metrics

Bench-to-bedside inference and modeling

Clinical translation and reporting recommendations

Correspondence Letter to the editor: The impact of surgeons’ visual angle misperception on acetabular cup positioning accuracy: a retrospective multicenter cohort study Yi Zhang, MDa , Xiguang Zhang, MDa , Qiaoning Yue, PhDa,b ,* We commend Hu et al for spotlighting a human-factors mechanism – surgeons’ visual angle misperception – that may systematically shift acetabular cup orientation during total hip arthroplasty[1] . By integrating a visual task, a benchtop platform, and a multicenter cohort, the authors show that experience narrows variability without abolishing bias. For transparency, this correspondence was prepared in line with the TITAN guideline on artificial intelligence-assisted writing, with human oversight throughout; no generative content beyond language assistance was introduced[2] . From a measurement standpoint, aligning intraoperative targets and postoperative readouts within a common reference frame would enhance clarity. Radiographic, operative, and anatomic definitions are not interchangeable; without explicit conversion rules (e.g., anatomical positioning protocol [APP]/ functional orientation), method variance can masquerade as perceptual error[3,4] . Providing a compact schematic that maps definitions, coordinate systems, and operative-to-radiographic transformations would substantially improve interpretability. Regarding orientation estimation, EBRA’s strength lies in migration/wear tracking, and its accuracy for absolute anteversion/inclination depends on pelvic pose, beam geometry, and rim visualization. Adding inter-reader agreement (intraclass correlation coefficient with 95% confidence intervals) and Bland–Altman plots versus a computed tomography-based or validated geometric method would quantify systematic offsets and limits of agreement beyond mean comparisons[5,6]. Specifying minimal acceptable limits for agreement would further support auditability. For bench-to-bedside inference, vantage- and approachdependent asymmetry is plausible (right-handed surgeons, posterolateral approach, lateral decubitus) . Re-estimating key effects with a mixed-effects specification that nests hips within aDepartment of Orthopedics, The People’s Hospital of Yuxi City, The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan, China and bDepartment of Graduate School, Kunming Medical University, Kunming, Yunnan, China Sponsorships or competing interests that maybe relevant to content are disclosed atthe end of this article. *Corresponding author. Address: Department of Orthopedics, The People’s Hospital of Yuxi City, The Sixth Affiliated Hospital of Kunming Medical University, 21 Nie’er Road, Hongta District, Yuxi 653100, Yunnan, China. Tel.: +86 18487075935. [E-mail: gwkyqn@163.com](E-mail: gwkyqn@163.com) (Q. Yue). Copyright © 2025 The Author(s). Published by Wolters Kluwer Health, Inc. This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Annals of Medicine & Surgery (2026) 88:1160–1161 Received 22 October 2025; Accepted 31 October 2025 Published online 24 November 2025 [http://dx.doi.org/10.1097/MS9.0000000000004318](http://dx.doi.org/10.1097/MS9.0000000000004318) surgeons and centers – with side and approach as fixed effects – would separate viewpoint effects from misperception while addressing cluster imbalance. This modeling step would also clarify whether the observed bias persists after adjusting for case-mix and exposure. In terms of clinical translation, reliance on legacy “safe zones”risks oversimplification. Dislocations can occur within classical zones, and functional posture plus hip–spine coupling modulate effective cup orientation[7–9] . Sensitivity analyses under a functional safe-zone framework and, where outcomes are available, expression of angular deviations as absolute risk d

FAQs

What core concern does the correspondence raise about surgeons’ visual angle misperception?

It suggests that visual angle misperception may systematically shift acetabular cup orientation, and that experience may reduce variability while leaving a residual bias.

How does the letter recommend improving clarity of measurement and reporting?

It calls for harmonizing angle definitions, coordinate systems, and explicit operative-to-radiographic conversion rules, including mapping schematics that improve interpretability.

Which statistical and methodological enhancements does the letter propose?

It recommends adding inter-reader agreement metrics (with confidence intervals and Bland–Altman plots), specifying limits of agreement, and using mixed-effects modeling that accounts for side/approach and nested hips within centers.

Sep 29, 2026

Uploaded by Mabel