Load-Bearing Radioulnar Distances to Evaluate an Unstable Distal Radioulnar Joint in Patients With Triangular Fibrocartilage Complex Tears

Aiping Yu; Xuanyu Zhao; Huali Zhao; Jianfeng Luo; Huawei Yin; Wendong Xu

doi:10.1016/j.jhsa.2022.01.008

Load-Bearing Radioulnar Distances to Evaluate an Unstable Distal Radioulnar Joint in Patients With Triangular Fibrocartilage Complex Tears

J Hand Surg Am. 2022 May;47(5):437-443. doi: 10.1016/j.jhsa.2022.01.008. Epub 2022 Mar 2.

Authors

Aiping Yu¹, Xuanyu Zhao², Huali Zhao², Jianfeng Luo³, Huawei Yin⁴, Wendong Xu¹

Affiliations

¹ Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China; Department of Hand and Upper Extremity Surgery, Jing'an District Center Hospital, Shanghai, China.
² Department of Hand and Upper Extremity Surgery, Jing'an District Center Hospital, Shanghai, China.
³ Department of Biostatistics, School of Public Health, Fudan University, Shanghai, China; NHC Key Laboratory of Health Technology Assessment, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety of Ministry of Education, Fudan University, Shanghai, China.
⁴ Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China. Electronic address: yinhuawei1983@126.com.

PMID: 35248425
DOI: 10.1016/j.jhsa.2022.01.008

Abstract

Purpose: Tears of the proximal component of the triangular fibrocartilage complex (pc-TFCC) lead to instability in the distal radioulnar joint. The aim of this study was to measure the load-bearing radioulnar distances (RaUls) and to evaluate its diagnostic suitability in patients with pc-TFCC tears.

Methods: We retrospectively assessed and compared the lateral wrist radiographs of 61 adult patients with arthroscopically confirmed tears of pc-TFCC with those of a control group of 64 healthy participants. The RaUl was measured on lateral radiographs, and the difference in RaUl (D-value) between load-bearing and nonloading conditions was calculated in the 2 groups. Receiver operator characteristic curves were plotted to determine the diagnostic accuracy and optimal cutoff-score of load-bearing RaUl and RaUl D-value. The diagnostic performance was verified in a validation sample of patients (30 wrists) with pc-TFCC tears and a control group of healthy individuals (30 wrists).

Results: In the training sample, load-bearing RaUls of the affected wrists were higher than the same side of the controls (12.0 mm vs 7.1 mm). The TFCC-injury group showed a significantly higher RaUl D-value than the control group (8.5 mm vs 3.4 mm). Using a receiver operator characteristic curve, the cutoff value of load-bearing RaUl was 10 mm (sensitivity = 97.6%, specificity = 85.7%) and that of RaUl D-value was 6.5 mm (sensitivity = 90.2%, specificity = 78.5%). The areas under the curve of load-bearing RaUl and RaUl D-value were 0.96 and 0.88, respectively. In the test sample, the sensitivity, specificity, and accuracy of RaUl were 0.93, 0.70, and 0.82 and those of RaUl D-value were 0.77, 0.83, and 0.80 respectively.

Conclusions: Load-bearing RaUl measurement is a simple method to diagnose an unstable distal radioulnar joint in patients with TFCC injury. The load bearing RaUl of >10 mm or RaUl D-value of >6.5 mm can be used to differentiate TFCC injuries and showed acceptable accuracy.

Type of study/level of evidence: Diagnostic II.

Keywords: Distal radioulnar joint; load; radioulnar distance; stability; triangular fibrocartilage complex.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Arthroscopy / methods
Humans
Retrospective Studies
Triangular Fibrocartilage* / diagnostic imaging
Triangular Fibrocartilage* / injuries
Weight-Bearing
Wrist Injuries* / diagnostic imaging
Wrist Injuries* / surgery
Wrist Joint / diagnostic imaging